Abstract:
Objective: Stillbirths are a global challenge, especially in South Africa where we rank 50th of 54 upper middle income-countries in the world and 6th of 7 in Africa. The majority of antenatal stillbirths are categorised as unexplained or secondary to hypertensive disorders of pregnancy (HDP). Strategies to detect HDP are simple, namely measuring the blood pressure, but if not performed at the right time hypertension might not be detected and a stillbirth may result. Unexplained stillbirths are thought to be due to unrecognised placental insufficiency. No effective strategies to detect placental insufficiency are available in low- and middle-income countries. The objective of this thesis is to test strategies which if implemented would reduce these two major categories of stillbirth. The first strategy was to test whether increased antenatal contacts in the third trimester improved detection of HDP. The second strategy was to use an innovative approach viz. continuous wave Doppler ultrasound of the umbilical artery (CWDU-UmA) at a primary care level to detect placental insufficiency. (CWMU-UmA assesses the fetal blood flow to the placenta, and this has been shown to correlate very closely with placental function).
Method: There were two major studies, the first examined the effect of implementing the new World Health Organisation (WHO) recommendations which among other things entailed increasing the antenatal contacts in the third trimester. These recommendations were integrated into the national basic antenatal care (BANC) guideline and called BANC Plus. An observational study was performed in four sites throughout South Africa over 15 months. The impact of the implementation had on contacts, measuring the blood pressure and identifying HDP was assessed. The second major study was a cohort analytic study involving nine catchment areas across South Africa. CWDU-UmA was implemented at primary healthcare clinics in these catchment areas and the incidence of abnormal placental blood flow and the effect of detecting this on stillbirths in women classified as having low-risk pregnancies was assessed. The lessons learnt from implementing CWDU-UmA in the various sites were explored.
Results: Introduction of the BANC Plus guideline in the study sites significantly increased the antenatal contacts from an average of 4.7 to 5.9 over one year and women with HDP were identified significantly more frequently (12.0% to 19.5%). Screening with CWDU-UmA was performed using the UmbiflowTM device. Screening the low-risk pregnant populations demonstrated a high incidence of abnormal placental blood flow (13.0%) and absent end-diastolic flow (1.2%). The CWDU-UmA information together with an active standard management protocol demonstrated a significant reduction in the stillbirth rate (10.1/1000 vs 17.8/1000, RR 0.57, 95% CI 0.29–0.85) with no increase in the neonatal death rate.
Conclusion: The implementation of BANC Plus resulted in an increase in antenatal contacts and detection of HDP. The high prevalence of absent end-diastolic flow and the step-change reduction in stillbirths found in the second study warrants screening of low-risk pregnant women in South Africa. Integrating CWDU-UmA into BANC Plus at the 30 week visit is feasible and should result in a significant reduction in stillbirths.