Investigation of ultrasound screening efficiency for neural tube defects during pregnancy in rural areas of China

Objectives: To understand the uptake and efficacy of ultrasound screening for neural tube defects (NTDs) during pregnancy, and the outcomes when NTDs were detected in rural areas of China.

Study design: Prevalence study.

Methods: Four hundred and twenty-four women who delivered or gestated babies/fetuses with NTDs were selected at random in 20 counties of two provinces of China from March 2008 to January 2009. The uptake of ultrasound screening, NTD detection rate and termination of pregnancy (TOP) rate were calculated and analyzed. Generalized estimating equations were employed to control for potential confounding factors.

Results: The uptake of ultrasound screening was 98.8%. Among the study subjects, 361 (85.1%) NTDs were detected and 63 (14.9%) were not detected by prenatal ultrasound screening. The total detection rate was 43.3% (15.6%, 49.6% and 52.2% in the first, second and third trimesters, respectively; P < 0.05). Taking the possibility of NTD detection in the first trimester as 1.0, the possibilities in the second and third trimesters were 10.9 [95% confidence interval (CI) 6.5-18.3] and 25.2 (95% CI 13.3-47.6), respectively. The detection rate at the township health centres (THCs), family planning centres (FPCs), maternal and child care service centres (MCSCs) and hospitals was 24.5%, 29.1%, 53.6% and 78.1%, respectively (P < 0.05). Taking the possibility of NTD detection at THCs as 1.0, the possibilities at FPCs, MCSCs and hospitals were 0.9 (95% CI 0.5-1.6), 3.4 (95% CI 1.9-6.1) and 2.1 (95% CI 1.3-3.4), respectively. Three hundred and fifty-five (98.3%) of the 361 NTDs detected at prenatal ultrasound screening ended in TOP.

Conclusions: The uptake of ultrasound screening was satisfactory, but the NTD detection rate was low. Ultrasound screening did not play its full role in the secondary prevention of NTDs in the study areas. Medical institutions in rural areas in China need to improve their ultrasound screening skills in order to increase the efficacy of NTD control.