Fetoplacental Doppler, Amniotic Fluid, and Placental Maturity in Pregnancies at or Beyond 40 Weeks: A Hospital-Based Observational Study

Background: Pregnancies extending beyond 40 completed weeks are associated with progressive changes in placental function and fetal well-being.Assessment of fetoplacental Doppler parameters, amniotic fluid volume, and placental maturity may provide complementary information for antenatal surveillance.This study evaluated these parameters and their relationship with maternal and neonatal outcomes in pregnancies at or beyond 40 weeks.Methods: A hospital-based observational study was conducted among 139 women with singleton pregnancies at or beyond 40 completed weeks of gestation.Maternal and obstetric characteristics were recorded, and antenatal assessment included umbilical artery (UA) and middle cerebral artery (MCA) Doppler velocimetry, amniotic fluid index (AFI), and placental maturity according to Grannum grading.Labour characteristics, mode of delivery, maternal complications, and neonatal outcomes were documented.Participants were categorized according to gestational age as 40-40+6 weeks, 41-41+6 weeks, and ≥42 weeks.Results: Of the 139 participants, 110 (79.1%) were at 40-40+6 weeks, 25 (18.0%) at 41-41+6 weeks, and four (2.9%) at ≥42 weeks.Mean UA resistance increased with advancing gestation, with the UA resistance index (RI) increasing from 0.57 to 0.60 and 0.61 and the UA pulsatility index (PI) from 0.84 to 0.88 and 1.12 across the three gestational-age groups, respectively.The derived cerebroplacental ratio (CPR) declined from 1.90 to 1.70 and 1.16.Oligohydramnios (AFI <5 cm) was present in 21 (15.1%)women, while meconium-stained liquor occurred in 40 (28.8%).Labour was induced in 70 (50.4%)women, and lower segment caesarean section (LSCS) was performed in 49 (35.3%), with fetal distress being the leading indication.Eight neonates (5.7%) required neonatal intensive care unit (NICU) admission, and no perinatal mortality was recorded.Conclusion: Advancing gestational age beyond 40 weeks was accompanied by increasing umbilical artery Doppler resistance, declining derived CPR, reduced amniotic fluid, and progressive placental maturation.Integrated surveillance using Doppler assessment, AFI, and placental evaluation may assist in monitoring pregnancies extending beyond 40 weeks.The derived CPR findings should be interpreted cautiously because of limitations in directly recorded MCA PI measurements.