Ultrasonographic measurement of amniochorionic membrane in asymptomatic pregnant women is not a useful tool for preterm birth prediction.

Aim: The objective of this study was to determine the accuracy of ultrasonographic measurement of amniochorionic membrane thickness (AMT) in the prediction of preterm birth among an asymptomatic pregnant population.
Methods: One hundred and ninety consecutive singleton pregnant women presenting for prenatal care between May 2010 and August 2011 were recruited for the study. AMT of the patients was measured once between 18 and 22 weeks of gestation and then again between 28 and 32 weeks of gestation with transabdominal ultrasound. The results of measurements were recorded and compared with the perinatal outcome related to prematurity.
Results: Thirteen of the 190 births were preterm. The mean AMT of the pregnant women who delivered at term were 0.79 ± 0.23 mm in the second trimester and 0.88 ± 0.27 mm in the third trimester. The mean AMT of pregnant women who delivered preterm were 0.77 ± 0.27 mm in the second trimester and 0.91 ± 0.20 mm in the third trimester. There were no statistically significant differences between the second and third trimester AMT of the preterm delivery group and term delivery group (P = 0.542 and P = 0.448, respectively).
Conclusion: In this study, ultrasonographic measurement of fetal membranes was not found to be a useful marker for prediction of preterm birth. The findings of our study may help in understanding ultrasonographic changes in fetal membranes in normal pregnancies.
(© 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.)