Amniotic Fluid Index and Outcome in Prolonged Pregnancies

The aim of this study was to know the outcome of prolonged pregnancy with low amniotic fluid index (AFI 5 cm). This cross-sectional comparative study with 140 prolonged singleton pregnancies was conducted at the Obstetrics and Gynecology Department of Sylhet M. A. G. Osmani Medical College, Sylhet during the period from July 2009 to June 2011. Multiple pregnancies, foetal malpresentation, foetal abnormality, co-existing medical disorder like diabetes mellitus and hypertension were excluded from this study. Amniotic fluid index (AFI) was measured by ultrasonography. Those with AFI ≤5cm were taken as study group and with AFI >5cm were taken as control group. Maternal outcome was measured by mode of delivery, maternal injury and PPH; and the foetal outcome by the degree of neonatal asphyxia, perinatal death and normal baby. Mean age [23.7 (SD plus/minus 4.2) years vs. 23.8 (SD+ 3.8) years; p < 0 * 0.5 ] and mean gestational age (42.3 (SD plus/minus 0.4) weeks vs. 42.2 (SD plus/minus 0.4) weeks; p < 0.05 ] were similar in both low AFI group and normal AFI group. Low AFI was significantly associated with higher rate of LSCS (85.7%vs 28.6%; p<0.01) and maternal injury (50.0% vs 14.0%; p < 0.1 ]; and lower rate of normal vaginal delivery 7.1% vs 65.7%; p <= sigma*I ) . It was also associated with higher rate of birth asphyxia (67.1% vs. 41.4%; p < 0.05j low Apgar score (<7) at 1 min (82.9%vs48.6%; p < 0.05 ) and at 5 min (25.7% vs.10.05%; p <0.01) . Sensitivity and specificity of low AFI (>5mm) in detecting foetal adverse outcome were 63.0% vs. 5.0% respectively. Positive and negative predictive values were 82.9% and 51.4% respectively. The overall accuracy of the response was 67.1%. Low AFI was significantly associated with both maternal and foetal adverse outcome in prolonged pregnancy.