Decreased placental thickness and impaired Doppler indices in idiopathic polyhydramnios: a prospective case–control study

Abstract

Objective: To evaluate placental thickness, Doppler velocimetry, biophysical profile and perinatal outcomes in pregnancies complicated by idiopathic polyhydramnios.Materials and methods: This prospective case–control study was conducted on 139 pregnant women, of these 70 patients with idiopathic polyhydramnios comprised the study group and 60 pregnant women comprised the control group. Risk factors recorded were; age, parity, body mass index (BMI), gestational weeks, amniotic fluid index (AFI), biophysical profiles (BPP), placental thickness, middle cerebral artery pulsatility index (MCA PI), umbilical artery Doppler velocimetry (Umb A S/D) values and perinatal outcomes.Results: Sixty-nine of the cases had mild-moderate (AFI: 250–450 mm) polyhydramnios (%98.5) and one of the cases had severe polyhydramnios (>450 mm) in study group. There was no statistically significant difference between the groups in terms of age, parity, BMI, gestational weeks, fetal birth weights and BPP (p > 0.05). Placental thickness, MCA PI and UA S/D values showed statistically significant difference between the groups (p < 0.05). The fetuses with lower placental thickness had lower scores of biophysical profile. There were negative correlations between placental thickness and AFI (r = −0.265), umbilical artery S/D and placental thickness (r = −0.212), MCA PI and AFI (r = −171, p = 0.44). However there was a positive correlation between AFI and umbilical artery Doppler values (r = 0.450).Conclusion: Idiopathic polyhydramnios is associated with decreased placental thickness, impaired uterine, umbilical and middle cerebral artery flow.