Placental thickness: A sonographic indicator of gestational age in normal singleton pregnancies in Nigerian women

Abstract

The study is aimed to investigate placental thickness as a parameter for estimating gestational age in normal singleton pregnancies in
Nigerian women. 730 Nigerian women with normal singleton pregnancies who were attending antenatal clinic at Federal Medical Centre, Makurdi, Nigeria were studied by transabdominal ultrasound between February, 2007 and January, 2008. Sonography was carried out using Sonoscape SSI 600
ultrasound machine with 3.5MHz transducer. Gestational age was  stimated by crown-rump length (CRL), biparietal diameter (BPD), femur length (FL) and abdominal circumference (AC) and the composite average recorded while placental thickness was measured at the point of insertion of the umbilical cord. Mean placental thickness with standard deviation was calculated for each gestational age. Correlation analysis was used to determine the relationship between placental thickness and gestational age while regression analysis yielded mathematical relationships between placental thickness and gestation age. The maximum mean placental thickness of 45.1 ± 6.4mm was recorded at 39 weeks gestation. There was a fairly linear increase in mean placental thickness with gestation age. There was significant and strong positive correlation between placental thickness and gestational age. Placental thickness appears promising as an accurate indicator of gestational age in singleton pregnancies in Nigerian women.