Antenatal Doppler screening for fetuses at risk of adverse outcomes: a multicountry cohort study of the prevalence of abnormal resistance index in low-risk pregnant women

Abstract

Introduction Few interventions exist to address the high burden of stillbirths in apparently healthy pregnant women in low- and middle-income countries (LMICs). To establish whether a trial on the impact of routine Doppler screening in a low-risk obstetric population is warranted, we determined the prevalence of abnormal fetal umbilical artery resistance indices among low-risk pregnant women using a low-cost Doppler device in five LMICs. Methods We conducted a multicentre, prospective cohort study in Ghana, India, Kenya, Rwanda and South Africa. Trained nurses or midwives performed a single, continuous-wave Doppler screening using the Umbiflow device for low-risk pregnant women (according to local guidelines) between 28 and 34 weeks’ gestation. We assessed the prevalence of abnormal (raised) resistance index (RI), including absent end diastolic flow (AEDF), and compared pregnancy and health service utilisation outcomes between women with abnormal RI versus those with normal RI. Results Of 7151 women screened, 495 (6.9%) had an abnormal RI, including 14 (0.2%) with AEDF. Caesarean section (40.8% vs 28.1%), labour induction (20.5% vs 9.0%) and low birth weight (<2500 g) (15.0% vs 6.8%) were significantly more frequent among women with abnormal RI compared with women with normal RI. Abnormal RI was associated with lower birth weights across all weight centiles. Stillbirth and perinatal mortality rates were similar between women with normal and abnormal RI. Conclusion A single Doppler screening of low-risk pregnant women in LMICs using the Umbiflow device can detect a large number of fetuses at risk of growth restriction and consequent adverse perinatal outcomes. Many perinatal deaths could potentially be averted with appropriate intervention strategies. Trial registration number CTRI/2018/07/01486.

Stillbirths: contribution of preterm birth and size-for-gestational age for 119.6 million total births from nationwide records in 12 countries, 2000 to 2020

“…A recent multi-country study (Ghana, India, Kenya, Rwanda, and South Africa) found routine Doppler screening in a low-risk obstetric population an effective tool for reducing stillbirth rates. 26 In France, antenatal detection of fetal growth restriction (FGR ) was found to be protective against stillbirth, but despite detection of FGR, over 40% of stillbirths occurred among SGA babies. 27 There is a major focus on small size at birth, however increasing evidence indicates that large for gestational age, which may be associated with the maternal metabolic environment, is also associated with an increased risk of stillbirth.…”

Integrated growth assessment in the first 1000 d of life: an interdisciplinary conceptual framework

“…-Delphi Consensus Statement for FGR* includes absent end-diastolic flow (in isolation) and umbilical/uterine artery PI > 95th percentile, CPR < 5th percentile (in combination with other indicators) (43) -Umbiflow™: RI ≥ 75th percentile (Pattinson graphs) (48,100) Placental grading: appearance on ultrasound…”

Identifying the High-Risk Fetus in the Low-Risk Mother Using Fetal Doppler Screening

“…The Umbiflow International study, sponsored by the World Health Organization, conducted in 5 LMICs (Ghana, India, Kenya, Rwanda, and South Africa) reported an overall prevalence of 6.9% of abnormal UmA-RI among LRMs, with the highest prevalence recorded in Ghana. 30 A low-risk pregnancy was defined in all these studies as a pregnant woman attending nonspecialist antenatal care clinics and classified as "low risk" at the time of recruitment according to local clinical guidelines, based on their obstetric and clinical assessment. For South Africa, this is guided by the basic antenatal care plus (called "BANC-Plus") program, following the World Health Organization's recommendations for a positive pregnancy experience.…”

“… The Umbiflow International study, sponsored by the World Health Organization, conducted in 5 LMICs (Ghana, India, Kenya, Rwanda, and South Africa) reported an overall prevalence of 6.9% of abnormal UmA-RI among LRMs, with the highest prevalence recorded in Ghana. 30 …”

“…The Umbiflow International study found that fetuses with abnormal UmA-RI were significantly smaller at birth than their normal UmA-RI counterparts, across all birth weight centiles and after correction for sex and gestational age at birth, leading the research team to the conclusion that CWDU has the potential to diagnose FGR before birth. 30 After birth, FGR due to placental insufficiency can be assessed by studying the infant's body composition, in particular, the fat-free mass (FFM), which is a measure of muscle and bone mass. Unfortunately, this measure is not routinely available, but body composition can be measured in infants by air displacement plethysmography, dual-energy X-ray absorptiometry, or deuterium dilution.…”