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Maternal-Fetal and Women’s Imaging for Global Health Radiology

  • Diana DowdyEmail author
  • Toma Omofoye
Chapter

Abstract

The state of maternal-fetal and women’s health in low- and middle-income countries remains appalling despite growing global attention. Every year approximately 350,000 women in the world die while pregnant or giving birth, up to million newborns die within their first year of life, and there are 2.6 million stillbirths (Faveau V, Contributing Editor. The state of the world’s midwifery, 2011: delivering health, saving lives. United Nations Population Fund. http://www.unfpa.org/sowmy). Each day 3500 women experience birth complications and 900 are likely to die. Since the adoption of the Millennium Development goals (MDGs) by the United Nations in 2000, deployment of resources toward Goals 3 and 4 (reducing child mortality and improving maternal health) yielded little improvement by the end of the target deadline of 2015. A renewal effort known as the Sustainable Development Goals (SDGs) replaced and expanded the original eight MDGs to include 17 distinct targets. Developed by a group of 190 world leaders, these goals focus on ending extreme poverty, fighting inequality and injustice, and repairing global climate change.

Examination of the published epidemiologic data from around the world reveals unique characteristics and dissimilarities of countries with high maternal mortality. This chapter examines the scope of morbidity and mortality for women of reproductive age and their offspring, with special attention to conditions that can be diagnosed by ultrasound imaging. An overview is presented on the impact of regional, legal, and sociopolitical customs in target communities on practice of prenatal ultrasonography and how obstetric imaging may play a crucial role in reducing maternal and perinatal mortality. Published outcomes of projects using trained indigenous healthcare providers in the use of ultrasound are promising. With increasing availability of ultrasound technology, the replication of these prototype projects (coupled with other social and educational changes) could lead to improved maternal-fetal outcomes and achievement of Sustainable Development Goal 3 – “Ensure healthy lives and promote well-being for all at all ages” (United Nations 2017. Sustainable development goals, goal 3. Good health and well-being. www.un.ort/sustainabledevelopment/health/).

Keywords

Maternal/fetal health Maternal mortality Perinatal mortality Perinatal morbidity Fetal abnormalities Maternal complications Ultrasound – efficacy and utility Perinatal ultrasound Low- and middle-income countries Teleradiology Global healthcare/initiatives Sustainable development goals 

Introduction

The state of maternal-fetal and women’s health in low- and middle-income countries (LMICs) remains appalling despite growing global attention. Every year approximately 350,000 women in the world die while pregnant or giving birth, up to two million newborns die within their first year of life, and there are 2.6 million stillbirths [1]. Each day 3500 women experience birth complications and 900 are likely to die. Since the adoption of the Millennium Development goals (MDGs) by the United Nations in 2000, deployment of resources toward Goals 3 and 4 (reducing child mortality and improving maternal health) yielded little improvement by the end of the target deadline of 2015. A renewal effort known as the Sustainable Development Goals (SDGs) replaced and expanded the original eight MDGs to include 17 distinct targets. Developed by a group of 190 world leaders, these goals focus on ending extreme poverty, fighting inequality and injustice, and repairing global climate change.

Examination of the published epidemiologic data from around the world reveals unique characteristics and dissimilarities of countries with high maternal mortality. This chapter examines the scope of morbidity and mortality for women of reproductive age and their offspring, with special attention to conditions that can be diagnosed by ultrasound imaging. An overview is presented on the impact of regional, legal, and sociopolitical customs in target communities on practice of prenatal ultrasonography and how obstetric imaging may play a crucial role in reducing maternal and perinatal mortality. Published outcomes of projects using trained indigenous healthcare providers in the use of ultrasound are promising. With increasing availability of ultrasound technology, the replication of these prototype projects (coupled with other social and educational changes) could lead to improved maternal-fetal outcomes and achievement of Sustainable Development Goal 3 – “Ensure healthy lives and promote well-being for all at all ages.” [2]

The gap in healthcare outcomes between high-income countries (HICs) and low-income countries (LICs) is especially disparate in the field of maternal-fetal and women’s medicine. While global maternal mortality rates have declined since 1980, they remain unacceptably high in low- and middle-income countries (LMICs). Of the nearly 287,000 reported maternal deaths in 2010, 99% were preventable and occurred in LICs [3, 4]. Despite accounts from the United Nations reporting a drop in maternal mortality by 50–60% since 1990 in parts of Asia and northern Africa, the maternal mortality ratio (those who survive compared to those who die) remains 14 times higher in high-income countries. Despite upward trends of increased prenatal care, only half of women in LMICs receive the recommended amount of care [2].

Similarly, neonatal mortality rates (death within the first 4 weeks of life) were equally disproportionate, as an estimated 99% of the reported four million global neonatal deaths per year occurred in low-resource areas [5]. Of these deaths, prematurity, low birthweight, and asphyxiation account for 52% [6].

High maternal-fetal death rates not only impact the affected individual, but also affect the local community and nation. The World Health Organization (WHO) submits that maternal-fetal health tragedies contribute significantly to “poverty and [inhibit] affected individuals’ full participation in socio-economic development” [7]. The knowledge that most of these tragedies are considered preventable creates an incentive for further action.

This chapter reviews the epidemiological characteristics of disease in perinatal medicine as well as the impact of imaging, particularly ultrasound, on these disease processes. Unique sociopolitical and regulatory settings of different countries regarding maternal-fetal imaging are examined, as well as the variation in availability of resources affecting use of technology.

Background and Epidemiology

In the year 2000, 193 nations and other international groups met at the Millennium Summit and established eight Millennium Development Goals (MDG) to improve socioeconomic conditions in LMICs. Of these, Goals 4 and 5 were specifically targeted to reduce childhood mortality by 67% and maternal mortality by 75% by 2015. The maternal mortality ratio (MMR) for any given country is the number of maternal deaths per 100,000 live births during a given timeframe. Although some reduction in maternal mortality was achieved, 15 years later, Goal 5 remained elusive, with persistently high MMR in LICs. This rate is nearly 15 times higher in LICs than HICs, with sub-Saharan Africa and Southeastern Asia accounting for 85% of the global burden [3, 4, 8] (Fig. 19.1). In some African countries the maternal mortality ratio is 620 per 100,000 live births compared to 14 per 100,000 live births in HICs. Fifty-eight LIC countries are identified as contributing to 91% of the global burden of maternal mortality, 80% of stillbirths, and 82% of the neonatal mortality [1]. There are also disparities between urban and rural regions, with rural areas demonstrating worse outcomes [6].
Fig. 19.1

Maternal mortality ratio worldwide in 2015. (Reprinted with permission from WHO Map: Maternal mortality ratio (per 100,000 live births), 2015, Health Stats and Info Systems, http://gamapserver.who.int/mapLibrary/Files/Maps/Global_mmr_2015.png)

Globally, over 70% of maternal deaths are due to the specific complications of pregnancy and childbirth of hemorrhage, infection, eclampsia, and obstructed labor. For perinatal mortality, the leading causes are infection, birth injuries, pre-term births, and birth defects [5, 9]. Because these deaths are largely preventable, numerous publications have discussed potential strategies for intervention: increasing access to emergency obstetric services, increasing availability of skilled healthcare providers, increasing access to antibiotic treatment, employing safe abortion practices, and promoting disease prevention through hygiene-focused health education [10, 11, 12].

WHO in 2016 [13] published its priorities for reducing maternal and perinatal mortality, and stated that “effective prevention and management of conditions in late pregnancy, childbirth and the early newborn period are likely to reduce the number of maternal deaths, antepartum and intrapartum stillbirths and early neonatal deaths significantly” This group outlined the importance of quality of care based on best practices for identifying “essential interventions” such as treatment of pre-eclampsia. However, admittedly this requires availability and appropriate use of infrastructure and resources, as well as knowledge and attitude of providers. Quality measures and benchmarking were identified by consensus among experts from many countries. Operational definitions developed from these include very specific quality measures. One such measure specific to ultrasound is Quality Statement 8.3 defining availability of supplies and equipment needed for routine care and management of complications. It specified that each health facility should have in place “a functioning diagnostic ultrasound machine and trained health staff who can conduct a basic obstetric ultrasound examination to determine the number of fetuses present, gestational age, prenatal diagnosis of fetal anomalies or early diagnosis of placental insufficiency” [13].

Maternal mortality can also extend to the infant in LICs. For example, in some sub-Saharan African cultures, it is culturally unacceptable to wet nurse an infant born to a woman who dies in childbirth, so if a baby is not accepted into an orphanage, the infant is abandoned to starve to death.

Women who are not childbearing but of reproductive age still have an alarming mortality rate in LICs. A recent study from a tertiary care center in Nigeria (2013–2015) reported that of the 340 deaths of women of reproductive age (out of 2606 female admissions), 77.9% were from nonpregnancy-related causes. Of those, the primary causes of death were infectious disease (46.8%) and disease of the circulatory system (24.5%), followed by female cancers (total 19.25%), trauma (6.8%), and others. Maternal deaths accounted for about a fourth of the deaths of women in this center. Of those maternal deaths, 41% were due to hypertensive disorders, 27% due to puerperal sepsis, 20% due to hemorrhage, and 8% due to obstructed labor. By mode of delivery, 48% were by cesarean section, 36% were by vaginal delivery, and 6.7% died undelivered. It was thought that many of these women presented late with complications, which increased their risk of death [14].

Similarly, perinatal and neonatal mortality rates remain unacceptably high in LICs, with most of these deaths occurring in five countries: India, Nigeria, China, Pakistan and Democratic Republic of Congo. Although global perinatal mortality rates have decreased by 28% between 1990 and 2009, this reduction was not sufficient to reach the target for MDG 4 by 2015 [15, 16].

Outcomes in Maternal Child Health are related to multiple factors, including healthcare delivery, socioeconomic, environmental, and cultural factors; therefore, no one technology or innovation can be expected to remedy all disparities. The utility of ultrasound imaging in the HICs has proven to be valuable in the early detection of common obstetric and gynecologic complications. Although research into its utility for use in LICs is not yet extensive, experience from HICs suggests that this technology may play a key role in early diagnosis and management of common maternal-fetal conditions. This review will address the potential value of ultrasound for the management of these conditions in LMICs.

Role of Ultrasound

Ultrasound (USD) is currently the most widely employed imaging modality for evaluating fetal well-being during pregnancy [17, 18, 19]. Its value for use in pregnancy has led most national and international organizations to recommend it as a standard exam for all pregnancies. The Federation of Gynecology and Obstetrics (FIGO) [20] has issued a recommendation that all pregnant women should be offered at least two ultrasounds in pregnancy.

Ultrasound has many advantages over other imaging modalities such as good image resolution, the ability of the operator to enhance images in real time, and immediate identification or diagnosis. The machines are portable and compact, allowing them to be used in most any location. They can also be programmed to be used for other clinical applications. Especially relevant for fetal imaging is that ultrasound does not use ionizing radiation for imaging acquisition.

While access to sonography may be limited in LMICs, the recent introduction of compact and affordable units may allow more widespread use of this technology [21]. These small units are not only portable, but they are sturdy; some offer unique features such as a rechargeable or solar battery, which are well-suited for areas with unreliable electricity. Many of the newer portable machines offer as standard the additional technology of color Doppler, improved image resolution, and DICOM (Digital Imaging and Communications in Medicine ) or image transfer capabilities. There is early evidence that compact machines provide enough information to determine appropriate triage for patients with obstetric emergencies [22].

The field of teleradiology is expanding globally. One innovation includes the Imaging the World initiative. This program allows transmission of images from a portable ultrasound via mobile phone. Pilot programs now exist in sub-Saharan Africa, India, and China [6]. Other telecommunications platforms are also in use wherever cell or satellite service is available.

The impact of imaging on maternal-fetal outcomes in LMICs remains an ongoing area of research. Studies consistently demonstrate evidence of improved maternal/fetal management with the use of ultrasound [6].

Causes of Maternal Mortality and Use of Ultrasound

By knowing the causes of morbidity and mortality, inference of potential roles of imaging can be made. The impact of obstetric ultrasound may be seen in conditions specific to the mother, fetus, and a few syndromes when fetal illness affects maternal health.

Maternal Hemorrhage

Hemorrhage is the leading cause of maternal mortality in both low- and middle-income countries worldwide [23]. The utility of ultrasound in detecting causes of hemorrhage cannot be overstated – it is most useful for detecting abnormal placentation, uterine abruption, abnormal implantation, failed pregnancy, and retained products of conception (POC).

Ectopic Pregnancy

An ectopic pregnancy is a complication of pregnancy in which the embryo implants outside the uterine cavity. With rare exceptions, ectopic pregnancies are not viable. Furthermore, they are dangerous for the mother, since internal hemorrhage is a life-threatening complication. Hemorrhage secondary to ruptured ectopic pregnancy is an important and preventable cause of early pregnancy-related deaths in both HICs and LICs. Clinical diagnosis of ectopic pregnancy can be difficult as the typical signs and symptoms of irregular vaginal bleeding (tender palpable adnexal mass, and abdominal or pelvic pain) may not always be present. In patients presenting with a positive pregnancy test and non-specific signs and symptoms, ultrasound can be very useful in confirming or excluding an ectopic pregnancy. Typical sonographic findings in ectopic pregnancy include: an adnexal mass containing a yolk sac or embryo, adnexal mass without an intrauterine gestational sac (Fig. 19.2), large amount of free cul-de-sac fluid, or presence of a normal gestational sac in an ectopic location such as the uterine cornua or cervix (Fig. 19.3). A right upper quadrant view looking for free fluid in Morison’s pouch (below the liver) can aid in the diagnosis [23]. Early diagnosis may potentially allow urgent surgical intervention, thereby averting serious complications including death upon rupture.
Fig. 19.2

(a) Sagittal midline view of the uterus on endovaginal ultrasound performed at 10 weeks of gestation by clinical dates. There is a thin endometrial stripe (arrowhead) in uterus without gestational sac. Note blood products in the lower uterine segment and cervix (curved arrow). (b) Sagittal imaging in the right adnexa in the same patient demonstrates a thickened, dilated fallopian tube (arrowhead). Arrow demonstrates a mass at the end of the fallopian tube, highly suspicious for a tubal ectopic pregnancy. (c) Sagittal Doppler imaging of the right adnexa in the same patient demonstrates further detail of the adnexal mass (white arrow) with peripheral blood flow (ring of fire). Note that this mass is separate from a normal ovary seen just inferior to it (yellow arrow). (Reprinted from Omonuwa et al. [24], Fig. 20.2, with permission from SpringerNature. Image courtesy Sujata Ghate, MD)

Fig. 19.3

Endovaginal ultrasound of another patient with positive beta-HCG. Transverse view of the superior uterus shows an eccentric implantation of the gestational sac in the uterine fundus with minimal myometrium surrounding it (wide arrow). The ovaries were normal (not shown). Findings are consistent with cornual ectopic pregnancy. (Reprinted from Omonuwa et al. [24], Fig. 20.3, with permission from SpringerNature. Image courtesy Sujata Ghate, MD)

While the incidence of ectopic pregnancy has increased in the United States, mortality from its complications has declined in recent years. Much of this decrease has been attributed to early detection by ultrasound imaging [25, 26]. Similarly, in LICs, where ultrasound has been utilized, diagnosis of ectopic pregnancy prior to rupture and subsequent intervention has resulted in the reduction of maternal morbidity and mortality [27, 28].

Abnormalities of the Placenta and Cord

Implantation Abnormalities

Ultrasound evaluation of placental implantation can provide valuable information concerning maternal risk in pregnancy. The placenta normally attaches to an intact endometrial lining within the uterus. With scarring from previous Caesarian section, prior instrumentation, or trauma, the placenta may invade to (accreta), into (increta), or beyond (percreta) the myometrium. Mild degrees of invasion (accreta) may not produce clinical symptoms, but could result in marked intra- or post-partum hemorrhage with severe cases resulting in hysterectomy or maternal death. With prior knowledge of an implantation abnormality, strategies for delivery may be planned to avoid serious complications. Although MRI is most accurate at determining degree of invasion and detection of posterior placenta accreta, recent studies have shown that USD is also reliable, detecting 50–80% of placenta accrete [29]. Sonographic findings of loss of the retroplacental clear space and presence of multiple lacunar spaces within the placental body may be suggestive of an implantation abnormality (Fig. 19.4). For women who are at high risk for an implantation abnormality, USD may be an effective, low cost alternative to MRI, particularly in LMICs where access to MRI may be limited [30].
Fig. 19.4

A 32-year-old patient with history of prior Caesarian section, presented with hematuria. Color Doppler imaging demonstrates placenta (solid arrow) abutting the maternal bladder (dashed arrow) without intervening myometrium, suggesting invasion of the placenta to the level of the bladder wall. These findings are highly suggestive of placenta percreta. (Reprinted from Omonuwa et al. [24], Fig. 20.4, with permission from SpringerNature. Image courtesy Sujata Ghate, MD)

Previa

Clinical symptoms of painless vaginal bleeding can be attributed to a number of causes including uterine fibroids, cervical polyps, placenta previa, or vasa previa. Of these, both placenta previa and vasa previa may result in significant maternal or fetal blood loss during vaginal delivery. Placenta previa occurs when the placenta either extends to the margin of, partially covers, or completely covers the internal cervical os in the third trimester. With vasa previa, vessels from the fetal circulation may cross the internal cervical os (Fig. 19.5). During vaginal delivery, these vessels can tear and result in fetal blood loss. Vasa previa carries a fetal mortality risk of 33–100%. Early prenatal identification can lead to appropriate medical referral, preventing this outcome [30].
Fig. 19.5

A 25-year-old patient presented with painless vaginal bleeding. Color Doppler imaging of a gravid uterus at 20 weeks gestation demonstrates a posterior placenta (wide arrow) with velamentous insertion of the cord anteriorly (arrowhead). In addition, cord vessels (solid arrow) are seen crossing the internal cervical os (dashed arrow) consistent with vasa previa. (Reprinted from Omonuwa et al. [24], Fig. 20.5, with permission from SpringerNature. Image courtesy Sujata Ghate, MD)

Gestational Trophoblastic Disease (Molar Pregnancy)

Early identification of GTD by USD and subsequent early surgical intervention may reduce the risk of maternal morbidity from severe hemorrhage, preeclampsia, thyrotoxicosis, or cancer [31]. In locations where sophisticated lab analyses such as Beta HCGs are not available, ultrasound may be the only method of diagnosing this serious, potentially malignant condition (Fig. 19.6).
Fig. 19.6

(a) A 32-year-old patient with a positive beta-HCG presented with symptoms of hyperemesis. This is a thickened placenta with multiple cystic spaces (arrows). No fetal tissue or oligohydramnios are present. (b, c) Images of the ovaries in the same patient show multiple large cysts (arrows) consistent with theca luteal cysts. This constellation of findings is suspicious for a complete molar pregnancy. (Reprinted from Omonuwa et al. [24], Fig. 20.6, with permission from SpringerNature. Image courtesy Sujata Ghate, MD)

Abortion

The WHO estimates that approximately 13% of maternal deaths are linked to unsafe abortions, from procedures performed by unskilled practitioners with or without the use of sterile technique [32, 33]. Not every abortion is an elective termination of a live fetus; it can also include attempt to induce expulsion of a failed pregnancy, incomplete miscarriage, or fetal demise. The most common complications from these procedures are hemorrhage and infection (sepsis). In these situations, ultrasound may be helpful in determining the causes of hemorrhage such as retained products of conception (POC) or incomplete abortions. Findings suggestive of POC include gestational sac with or without an embryo, thickened or heterogeneous endometrial stripe with or without blood flow, or heterogeneous fluid collection within the endometrium. The use of ultrasound for definitive diagnosis may lead to earlier and more appropriate intervention for the condition. Timely detection and intervention are necessary as presence of POC can lead to sepsis, shock, hemorrhage, and maternal death [33, 34, 35].

In women who present with vaginal bleeding where a threatened spontaneous abortion is suspected, imaging may help differentiate nonviable from potentially viable pregnancies prior to surgical intervention. Ultrasound findings of irregular gestational sac without a yolk sac, absent cardiac activity, or too small gestational sac, can be diagnostic of a missed abortion or nonviable pregnancy (Fig. 19.7).
Fig. 19.7

Sagittal view of the uterus from endovaginal ultrasound performed for vaginal bleeding at 6 weeks and 5 days of gestation. Arrow denotes abnormally large, irregular gestational sac measuring 2.1 cm. No embryo or yolk sac is identified within the gestational sac. The findings are consistent with an anembryonic, nonviable pregnancy. (Reprinted from Omonuwa et al. [24], Fig. 20.7, with permission from SpringerNature. Image courtesy Sujata Ghate, MD)

Maternal Sepsis

Maternal sepsis, an uncommon but important complication of pregnancy, is responsible for 10–12% of maternal deaths in LICs [10, 29]. Clinical signs and symptoms of fever, chills, abdominal pain, or vaginal discharge in post-partum or post-cesarean section patients can indicate infection resulting from endometritis, chorioamnionitis, POC, or abscess [35]. Early diagnosis, broad-spectrum antibiotic therapy and treatment of the underlying cause of sepsis may prevent serious complications such as maternal death, secondary infertility, or long-term morbidity from chronic pelvic pain [36]. A diagnosis of sepsis is generally made based on clinical presentation of the patient. While USD may not be useful in diagnosis of sepsis, it may have value in detecting two important causes of sepsis: septic abortions or focal abscesses, both of which may require surgical intervention in addition to antibiotics for definitive treatment.

Causes of Maternal Morbidity and Use of Ultrasound

Obstetric Fistula

Ultrasound is likely to reduce the risk of obstetric fistula by identifying pregnancies that may result in obstructed labor and encouraging access to a birthing facility for delivery. It is estimated that two million women worldwide are living with an untreated obstetric fistula, contributing to a detrimental impact on quality of life. Gynecologic use of ultrasound is useful for detection of fistula and other consequences of birth trauma.

Gynecologic Infection and Disease

In addition to obstetric problems, bedside ultrasound can be used to evaluate gynecologic infections (tubo-ovarian abscess, complex adnexal masses, hydrosalpinx, and echogenic pelvic fluid). This has a high yield for diagnosis of gynecologic complications and potentially life-threatening infections for women [23]. It is useful for diagnosing disorders such as leiomyoma and uterine malformation, which can contribute to poor obstetric outcomes.

Causes of Perinatal Mortality

Fetal Growth Restriction

In women where menstrual history is unknown, such as with an unplanned pregnancy or failed contraception, first trimester crown rump length or second trimester biometry measurements provide an accurate and reliable estimate of gestational age as demonstrated by previous studies [37]. A precise estimation by sonography is necessary to avoid unnecessary pre- or post-date deliveries, which are important causes of perinatal mortality [38]. This accuracy decreases substantially by third trimester where measurements may have a much wider variation of normal. Accurate dating of a pregnancy theoretically allows early detection of fetal growth restriction (FGR), macrosomia, or post-date gestation; therefore, these measurements can potentially facilitate the timing and mode of delivery.

FGR, also known as IUGR (intrauterine growth restriction), is a complex condition, which may result in perinatal death from hypoxia, hypoglycemia, or meconium aspiration. There are two main types of FGR: asymmetric, from chronic fetal malnutrition, and symmetric, from diminished fetal supply later in the pregnancy. Asymmetric FGR is far more common and implicated in 90% of cases [39]. While FGR may be suspected clinically, sonography may be more accurate in predicting causes of and confirming presence of a compromised fetus [40]. Sonographic findings suggestive of symmetric growth restriction include low estimated fetal weight (<10th percentile for gestational age), decreased fetal abdominal circumference, or oligohydraminos. Ultrasound findings of fetal structural anomalies may be predictive of an abnormal karyotype, which may result in symmetric growth restriction, perinatal, or neonatal death. Other sonographic findings seen with both forms of growth restriction include abnormal umbilical artery cord Doppler ratios or waveforms, decreased fetal tone, movement or breathing. This diagnosis has implications for both maternal and fetal well-being. In the setting of preeclampsia/eclampsia, FGR is associated with severe placental disease and poor maternal and fetal outcome without appropriate treatment. Delivery is usually indicated in this context.

Pre- and Post-Term Pregnancy

Complications can occur from either pre- or post-term birth. Many women in LICs have irregular or unpredictable menstrual cycles due to malnutrition or peri-/post-lactation oligomenorrhea. Consequently, recall of last menstrual period is commonly inaccurate, giving an undetermined gestational age. One of the most important pieces of information that can be provided by an ultrasound is an estimated gestational age, and it is most accurate within the first trimester. Pre-term birth carries a risk of fetal lung immaturity and increased mortality due to respiratory distress of prematurity. Post-mature infants may succumb in-utero to placental deterioration.

Abnormal Lie and Malpresentation

Malpresentation can cause birth injury (maternal or fetal), umbilical cord compression, or prolapse during delivery, potentially resulting in perinatal death. Ultrasound can be used as an adjunct to physical examination to confirm the presence of malpresentation and potentially guide the maternal healthcare provider to determine appropriate delivery planning.

Causes Affecting Both Maternal and Fetal Health

Multiple Gestation Pregnancies

Twin pregnancies carry a higher maternal risk of pre-term delivery, postpartum hemorrhage, preeclampsia, and eclampsia [41]. Perinatal mortality is also approximately five times higher in twin pregnancies when compared with singletons [42]. While multiple gestations can be detected by careful physical examination and Doppler fetal heart rate monitors, the chorionicity and amnionicity can only be detected by careful ultrasound evaluation. This allows differentiating twin gestations with highest risk (monochorionic, monozygotic) from those at less risk. Monochorionic twin pregnancies have roughly 2.5-fold increase in perinatal morbidity and mortality compared with dichorionic twins [43].

In the first or early second trimester, dichorionic–diamniotic pregnancies can be identified by the presence of a thick, dividing membrane, separate placentas, discordant genders, or a “lambda” or “twin peak” sign [44, 45]. Monochorionic twins share placental vessels, which may lead to shunting of blood from one twin to the other. This twin–twin transfusion syndrome (TTS), a complication seen in up to a 30% of monochorionic gestations, is best identified by USD. TTS is a leading cause of fetal mortality. Early detection with careful follow-up and potential early delivery could lead to improved outcome [46].

Hydrops Fetalis

The classic definition of hydrops fetalis is the abnormal presence of fluid in two or more compartments [47]. The most common ultrasound findings include polyhydramnios, fetal pleural effusions, ascites, pericardial effusions, hepatosplenomegaly and skin edema (Fig. 19.8). Sources of hydrops fetalis may be broadly categorized into maternal (immune) or fetal (non-immune) causes. Rhesus isoimmunization is the primary immune-mediated source of hydrops. Non-immune factors contributing to hydrops include: fetal cardiac anomalies, arrhythmias, chest masses, peripheral shunts resulting from fetal or placental tumors, aneuploidy, infection, or TTS in multiple gestation pregnancies. The prognosis for the fetus can be variable depending on the cause. In cases where Rh-incompatibility is the underlying cause, early detection by ultrasound imaging is a critical first step, followed by close monitoring of the pregnancy and aggressive medical treatment. Early delivery can often result in a favorable prognosis.
Fig. 19.8

(a) Axial view of the fetal abdomen demonstrates fetal ascites (solid arrow) and skin thickening (dashed arrow). (b) Axial imaging of the fetal thorax in the same patient demonstrates a large pleural effusion (thick arrow) with associated mass effect on the fetal heart (dashed arrow). (Reprinted from Omonuwa et al. [24], Fig. 20.9, with permission from SpringerNature. Image courtesy Sujata Ghate, MD)

When maternal edema, preeclampsia, and proteinuria develop in association with hydrops fetalis, this condition is known as Mirror or Ballentyne syndrome . Studies have shown high rates of maternal morbidity and fetal intrauterine demise associated with this condition [47, 48, 49]. Early detection of fetal hydrops by sonography in conjunction with patient signs and symptoms may enable prompt surgical intervention or early delivery, potentially reducing maternal morbidity associated with this syndrome.

Overall Utility of Ultrasound

In reviewing literature from LICs, results conclude that most referrals for ultrasound of any kind are for OB/GYN (obstetric or gynecologic) reasons. One study in Liberia found 53% of patients coming for ultrasound required OB/GYN exams [50]. Similarly, in Cameroon 15% of referrals were obstetric and 32% gynecologic [51]; and in a Tanzanian refugee camp 24% were obstetric and 21.9% gynecologic [52]. The rate of obstetric exams was 30% obstetric in Rwanda and a majority in Botswana [53, 54]. These reports suggest that ultrasound is already being regularly used as an effective diagnostic tool.

Statistics for obstetrics and obstetric outcomes in LICs are generally unreliable, with only estimates available for most places. Up to 71% of births in sub-Saharan Africa are unregistered. Although ultrasound has been used in a number of these countries for some years, documentation on effectiveness or impact on outcomes has been made available only in recent years. Bussman performed 741 obstetric scans in Botswana, finding that the service was cost-effective, and improved patient management in 39% of cases [55]. The most common pathologies diagnosed were spontaneous abortion, fetal demise, low-lying placenta, and ectopic pregnancy. In Rwanda, obstetric scans were used primarily to determine fetal presentation, gestational age, and placental position [6]. These scans not only changed management in 43% of patients, but were considered affordable. In Liberia, a trial of 102 patients seen in a 5-week span, most were obstetric cases [6]. Pathologies most often seen were bleeding, fetal demise, gestational age determination, multiple gestation, and placenta previa, changing management in 62% of cases. In Northern Tanzania, a qualitative study reported that ultrasound helped delivery management, pre-procedural planning, and reduced pre- and post-term births [6]. Women also reported that knowing their estimated due date was helpful in planning a hospital delivery – highly significant since only 47% of Tanzanian deliveries occur in the hospital. A study in Malawi of 840 babies demonstrates the importance of diagnosing pre-term birth – in sub-Saharan Africa, a baby born at 32 weeks has a greatly diminished chance of survival, compared to one born in a HIC. Compared to babies born at term (confirmed by ultrasound), those diagnosed as pre-term were almost twice as likely to die in the first 2 years of life. Table 19.1 summarizes the above.
Table 19.1

Review of existing literature in support of ultrasound use in the LMICs and training guidelines currently in use [23, 55, 56]

Year

Country

Number

Findings – significance

1998

Egypt

828

FGR/IUGR major contributing factor perinatal mortality and morbidity

Mahran demonstrated 11.8% rate

Detection by fundal palpation is 34.7%

Detection by ultrasound 89.7%

1999

Cameroon

1119

78% of scans yielded abnormal findings – 68% judged to be useful for diagnosis

32% yielded diagnoses

2004

Ghana

 

Variety of settings

54% were abdominal and OB/GYN – 100% added to the clinical diagnosis

81% showed abnormal findings

40% influenced the outcome or treatment decision

2005

Malawi

512

OB scans prior to 24 weeks, providing EGA

20.3% delivered prematurely prior to 37 weeks. These infants were twice as likely to die as their full-term counterparts.

2008

Tanzania

542

Nurse-midwives trained in basic OB USD available to do scans 24 h per day; midwives had 100% agreement with sonographers in readings

542 suspected abnormal findings in 1 year; aided in dx of 39%

Changed management plans in 22%

Lessened workload of specialist

2010

Zambia

441

Rural area, 21 midwives,

6-month training program

Main abnormal findings

 Non-vertex presentation (61%)

 Multiple gestation (24%)

 Fetal demise (8%)

Prompted change in clinical decision-making in 17% of cases

2014

Kenya

271

5 midwives with extensive training

99.6% accuracy in interpreting scans done in remote areas

20 (7%) correctly labeled as high risk

25-minute turnaround time for transmission by cell phone to radiologist for interpretation

A review article by Harris and Marks summarizes anecdotal experience of ultrasound in limited resource settings [21]. The authors deployed donated units in Serbia, Vietnam, Nicaragua, Tanzania, Kenya, Mali, and Sierra Leone. The units had substantial impact on public healthcare, “particularly in maternal care.” In Nicaragua, physicians reported maternal mortality reduced from 12 deaths per year to 5 deaths year [6].

In addition to detecting abnormalities for referral, ultrasound can reassure normalcy and reduce unnecessary intervention. A study in Cameroon showed that of 1119 scans, most were obstetric and gynecologic. Of these, 78% were normal. Geerts in South Africa scanned 3009 women in a low-resource setting, providing fetal anatomic scans. Results did not demonstrate improved outcomes, but it did significantly reduce the number of referrals to the regional medical center for increased surveillance. This was thought to be due to the accuracy of gestational age determination [57].

Safety and Efficacy of Obstetric Ultrasound

In consideration for widespread use of USD for standardized maternal and women’s ultrasound, demonstration of safety is paramount. The American Institute of Ultrasound in Medicine (AIUM), the WHO, International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), and other European Societies conclude that benefits of obstetric ultrasound outweigh the risks to the mother and fetus. In 2009, a meta-analysis of 61 publications conducted by the ISUOG-WHO found no association of ultrasound usage with adverse maternal or perinatal outcomes, presence of mental diseases in the child, impaired physical or neurological development, or decreased intellect. Although data from this study was mostly reassuring, there were limitations. The studies were observational, did not report on long-term bio-effects, and were mostly published before 1995 when the intensity of the ultrasound equipment was lower than in modern machines [58]. Nevertheless, the AIUM and other major international organizations consider ultrasound relatively safe during pregnancy.

To better regulate safety of obstetric ultrasound, the AIUM along with other international societies suggest the following general guidelines for clinical use [59, 60]:
  • Keep USD exposure as low as reasonably achievable (ALARA) by performing ultrasound only when clinically required and minimizing scan time.

  • Restrict use of color Doppler imaging in the first trimester as this technology may have potential to increase tissue temperatures.

  • Comply with output display standards.

  • Avoid non-medical use of ultrasound.

  • Avoid use of ultrasound contrast agents in obstetric patients as risks to the fetus are not well-studied.

Ethical, Legal, and Regulatory Concern

Implementation of diagnostic obstetric ultrasound in LICs may face unique ethical and legal challenges. By far the most disturbing negative outcome of widespread prenatal imaging is the emergence of sex-specific abortion. In many parts of the world, there remains a preference for sons over daughters, resulting in a gender imbalance in these societies. The sex ratio of a given country is the ratio of males to females at birth. Without outside influences, the average sex ratio at birth should be equal to 105 boys to 100 girls. Any deviation from this natural sex ratio constitutes a significant shift. In Asia, ratios of male to female births have been increasing since the 1980s, particularly in China where in 2009, there were 120 boys born for every 100 girls [61]. Prenatal imaging is partially implicated in this phenomenon [62].

Historically Chinese culture encouraged parents to continue having children until a satisfactory number of sons were born. Obviously, this carried some economic burden, and there may have been preferential allocation of resources to sons over daughters. In 1979, the One Child policy was enacted which placed a legal limit on the number of children, and therefore, sons, a family could have. The result was a dramatic increase in “son preference” as evidenced by a rise in prenatal sex selection by ultrasound, as well as female infanticide [61, 63]. The Chinese government has since responded to this imbalance by criminalizing non-medical determination of fetal gender and imposing substantial penalties for offenders; however, this practice persists. Reports have shown some of the consequences, including increasing crime rates and decreased marriage opportunities for males in China, in addition to the ethical repercussions on women’s welfare [64, 65].

Imbalanced sex ratios and sex-specific abortions are not isolated to China and have been reported in many parts of Asia and the world. In India, where there are 100 newborn boys for every 92.7 girls, abandonment of daughters, under-reporting of female births, and infanticide of newborn girls are serious issues [66, 67]. Although prenatal sex determination has been illegal in India since 1994, this law is difficult to enforce as it is nearly impossible to prevent unscrupulous sonographers from discretely alerting couples of fetal gender [68]. The Indian government is currently heading a strong initiative to limit sex-specific abortions in the 17 provinces with the most serious gender ratio imbalances. One state in India has recently started a policy of providing monetary compensation to parents giving birth to girls [69].

Illegal use of obstetric sonography in LICs may partially be due to the lack of government regulation and general oversight of these practices and practitioners. Many low-resource areas do not require formal training or licensure for sonographers, resulting in a few “entrepreneurs” who choose to perform scans for purely financial reasons while lacking the adequate technical skills. Furthermore, these practitioners may be more likely to break imaging-specific laws such as revelation of gender to expectant parents in regions of the world where this practice is illegal. Without appropriate healthcare infrastructure, it may be difficult to identify subpar or illegal practices [70, 71, 72, 73].

Detection or suspicion of fetal anomalies

Even in Western societies with state-of-the-art equipment and well-trained sonographers, definitive diagnosis of fetal abnormalities can still be difficult. In low-resource areas, where patient counseling and support is not as readily available, this uncertainty may be coupled with additional patient anxiety and insecurity. The choice of having a potentially disabled child versus enduring the stigma of abortion can be a difficult one for patients with limited resources as evidenced by one study in Vietnam [74]. While detection of fetal anomalies is an important role of screening obstetric ultrasound, appropriate support services should be available prior to implementation of such programs in LICs.

In LMICs, patient perception of obstetric USD may be influenced by education level, local culture, or religion. In a study that took place in Botswana, the act of “looking inside the womb” was perceived by some patients as invasive and inappropriate. For some women there is misconception that harm may come by looking at the unborn infant.

In some countries, like Tanzania, Botswana, Gambia, and Zimbabwe, the practice of witchcraft and spirits remains prevalent alongside the reliance of medicine. There exists a “medical pluralism” model of health where patients embrace both. Anecdotally, this author discovered a minor fetal anomaly while doing a third-trimester ultrasound in rural Tanzania. The woman was not advised of a minor detected fetal anomaly, lest the husband consider his wife to be cursed, causing him to abandon her. A similar fate might also happen to a woman told that she could not bear children.

For others, the ultrasound experience provided positive reassurance and the ability to plan ahead. Still others overestimated the technology; some even believing that ultrasound may help cure or treat fetal or maternal abnormalities. For the healthcare providers in this same study, the introduction of imaging sometimes replaced history-taking, critical thinking, and careful physical exams; all of these skills are essential for healthcare workers practicing in low-resource areas. These findings illustrate the need for specific guidelines on use of ultrasound and effective doctor–patient communication. Conversations about potential benefits and limitations may prevent the patient from having unrealistic or false expectations [75].

Sociopolitical Challenges

In formulating the MDGs, increasing the number of skilled birth attendants at delivery was identified by the WHO as a strategy for improving maternal-fetal health outcomes. The global shortage of trained health workers is estimated at more than four million [6]. Neonatal mortality and morbidity are inversely associated with coverage rates of skilled birth attendance – 60 million births occur annually outside of hospitals, 52 million without a birth attendant. One meta-analysis of three randomized trials showed no statistically significant reduction in maternal mortality when outcomes were compared with and without the use of trained attendants [76]. However, this might be mitigated by a definition of “skilled practitioner.” A midwife trained in the UK, for example, has significantly different skill level than a “trained birth attendant” in Indonesia, for example. In South Africa, where about 86% of births were attended by skilled practitioners, poor maternal outcomes persisted; this result is likely secondary to a wide discrepancy in expertise of these “skilled practitioners” [77, 78]. In contrast, one study in rural Bangladesh demonstrated that the MMR significantly decreased in villages where trained midwives participated in home-deliveries [79].

Countries that have achieved greater success in the reduction of maternal mortality have generally been the ones implementing a combination of strategies such as increasing availability of free antenatal care and preventive care, increasing patient education (family planning, birth spacing, hygiene, sexually transmitted diseases), and providing skilled attendants. This is the case in both Malaysia and Sri Lanka where MMR was substantially reduced over four decades by improving female education, increasing attendance of midwives at delivery, as well as providing access to healthcare resources in emergent situations [76, 80, 81, 82, 83, 84, 85, 86].

Ultrasound Training

Prior to implementing an ultrasound program in a population, a detailed analysis of the local environment is needed. A generic approach is not practical; a program must be tailored to the local setting in collaboration with local stakeholders. Specific to each population are unique factors of geography, disease prevalence, availability of providers, physical infrastructure (electricity, Internet and availability of tele-radiology, transportation, etc.), ability to purchase a machine and supplies, and access to repair technology. Practical and logistical considerations include referral pathways, access to advanced medical care for referrals, clinical guidelines, image reporting, record keeping, quality assurance, and availability of appropriate patient counseling and support. Ability to pay for services is of concern to many without means. Culture must be understood fully so that best decisions can be made about abnormalities. Even consideration of a provider’s gender must be considered. Availability of qualified providers for training is very important, as is the availability of training staff and access to educational media [6].

A cost–benefit analysis is reasonable for determining feasibility and depends on the ability of the planner to obtain resources either from government, NGOs, or charitable organizations to help with initial costs. This must be weighed against the burden/cost of the conditions that are likely to be avoided by use of ultrasound in that population. Initial outlay of cost is not the only consideration; determining sustainability is paramount to the success of a program. If the resources are lacking to continue ongoing training, quality assurance, equipment maintenance, and demonstration of effectiveness, the program is likely to be discontinued. If private entities assume ownership and make the service unaffordable to the poor, then the highest risk women remain underserved [6]. An entire chapter in this text is dedicated to ultrasound training and more information can be found there.

Conclusion

The state of maternal-fetal and women’s health in LMICs remains a challenge. The benefits of diagnostic ultrasound in HICs are well-known, and its role in reducing maternal mortality in low-resource areas is being increasingly supported. With the implementation of new strategies, there is a potential for prenatal imaging, specifically ultrasonography, to have a significant impact given its potential for quick and precise detection of potentially life-threatening conditions. However, obstetric ultrasound must be employed in such a way as to stay within regulatory guidelines and should not contribute to technology-based malpractice. Nor should it add to economic or technologic burden or treatment inequities. Ultimately, effective prenatal imaging requires basic healthcare and national infrastructure including electrical power, sustainable equipment maintenance, low cost, trained personnel, available skilled birth attendants, and referral centers, all necessary to improve health outcomes in a sustainable manner. Large-scale trials are greatly needed to continue to validate the efficacy of this tool in improving maternal and infant outcomes in LICs. This will support the allocation of resources toward expansion of the use of ultrasound in global women’s healthcare and solidify its contribution toward achieving the 2030 SDGs related to women’s and infant’s healthcare.

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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Midwifery and WHNP Programs, VUSON, Women’s Point of Care, Ultrasound with InnovatED UltrasoundNashvilleUSA
  2. 2.Vanderbilt University School of Nursing, American Registry of Diagnostic SonographersNashvilleUSA
  3. 3.Department of Diagnostic Radiology, Breast Imaging SectionUniversity of Texas MD Anderson Cancer CenterSpringUSA

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