This study was a randomized control trial to see if we should continue to give women ultrasonographic exams in their third trimester if their pregnancies are deemed uncomplicated. These ultrasounds can be expensive, and this study was designed to see if they are beneficial at that point in the pregnancy. Specifically, they wanted to see if having a third trimester ultrasound in an uncomplicated pregnancy would have any effect on detection of “small for gestational age” (SGA) when the birth weight of the baby less than 10% for the baby’s gestational age.
From a study done in 2012, approximately 10% of babies were born with SGA, and these pregnancies did not improve with the routine prenatal care (bed rest, nutritional care, supplements). These pregnancies did improve when abnormal growth is discovered before birth so that it may be evaluated and techniques to improve growth could be implemented. The thinking is that these ultrasonographic exams can provide this information as to prevent the prevalence of SGA.
Of the women who were approached and gave consent, the detection of SGA was much higher (67%) when women had an ultrasonographic exam than the control (9%). The evidence is overwhelming that receiving an ultrasound–even in the third trimester of an uncomplicated pregnancy–can still be beneficial and worth the time and money. It was noted in the study that this may not be reflective of the entire population, as it had a small sample size. The women they studied were very easy to find and only came from three sites.
Hammad IA, Chauhan SP, Mlynarczyk M, et al. Uncomplicated pregnancies and ultrasounds for fetal growth restriction: a pilot randomized clinical trial. AJP Rep. 2016; 6(1):83-90.