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 hospitalisation, 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 (1.4% vs. 3.6%; P=0.049). However, ultrasound scanning in low-risk pregnancies was not associated with improvements in pregnancy outcome. Opsomming Hierdie studie het die effek van roetine mid-trimester ultraklankskandering op swangerskapsorg en –uitkomste ondersoek. Dit was ’n oop tros, lukrake, beheerde proef. Groepe vroue met laerisikoswanger- skap in die midtrimester is lukraak toegewys vir ’n ultraklank-skandering, gevolg deur voorgeskrewe voorgeboor-tesorg, of vir ’n kontrolegroep wat voorgeboortesorg volgens nasionaal voorgeskrewe protokol sonder skandering ontvang het. Van die 962 vroue wat aan die steekproef deelgeneem het kon data vir 804 (83.6%) suksesvol opgevolg word, met 416 in die ultraklankgroep en 388 in die kontrolegroep. Geen beduidende verskille is tussen die twee groepe gevind ten opsigte van voorgeboorte-hospitalisasie, geboortemetode, miskraamstatistiek, perinatale komplikasies of laegeboortegewig nie. Ultraklankdatering van swangerskappe is met minder kraaminduksie (1.4% teen 3.6%; P=0.049) vir natrimesterswangerskap geassosieer. Roetine ultraklankskandering in laerisikoswangerskap het egter geen verbetering in swangerskapsuitkomste te weeg gebring nie.