The Value of Routine Mid-Trimester Ultrasound in Low-Risk Pregnancies at Primary Care Level

ABSTRACT

This study investigated the effect of routine second-trimester ultrasound scanning on obstetric management and pregnancy outcomes. This was an open cluster; randomised; controlled trial. Clusters of women with low-risk pregnancies presenting in the second trimester were randomised to receive an ultrasound scan followed by usual antenatal care; or to an unscanned control group undergoing conventional antenatal care only. Out of the 962 women randomised; follow-up was successful for 804 (83.6); with 416 allocated to the ultrasound scan group and 388 controls. There were no significant differences between the ultrasound scan group and the control group in terms of prenatal hospitalisa- tion; mode of delivery; miscarriage; perinatal mortality rate and low birthweight rate. Ultrasound dating was associated with a lower rate of induction of labour for post-term pregnancy (1.4vs. 3.6; P=0.049). However; ultrasound scanning in low-risk pregnancies was not associated with improvements in pregnancy outcome: