Amniotic Fluid Index: Effect on labour and neonatal outcome

1. This study entitled, ‘Amniotic fluid index-Effect on Labour and Neonatal Outcome’ was done at Government Hospital for Women and Children, Egmore, Chennai between June 2006 to June2007. 2. This study was done with the aims and objectives of screening of antenatal patients at term for oligohydramnios or polyhydramnios and subjecting them to ultrasound examination to determine the amniotic fluid index by four-quadrant method and to study the effect of AFI on labour and neonatal outcome. 3. This was a descriptive follow-up study. 1500 antenatal patients were included in this study. They were categorized into 4 groups as AFI 25 cm. 4. All the studies done in this subject were extensively studied and analyzed and they were incorporated in the review of literature. 5. Measurement of outcomes included were incidence of non reactive NST, caesarean delivery for fetal distress, meconium staining, Apgar score <7 at 5 mts, birth weight < 2.5kg,IUGR, admission to NICU and neonatal death. 6. The various parameters, which were noted in our patients, were incorporated into proforma which is enclosed and which formed the basis of detailed discussion. 7. Incidence of caesarean section for fetal distress is highest in AFI <5 cm followed by AFI group 5-8 cm. 8. Neonatal morbidity and mortality is highest in AFI <5 cm followed by AFI group 5-8 cm. 9. Incidence of congenital malformations, which were diagnosed postnatally, was maximum in polyhydramnios group (AFI > 25cm). CONCLUSION: 1. This study suggests that AFI is a good predictor of neonatal morbidity and mortality as has been classically reported.The findings of this study are consistent with previous retrospective studies by Garmel et al who showed that there was significant increase in risk of caesarean delivery, fetal distress and low birth weight with oligohydramnios. 2. The AFI for detecting intrapartum oligohydramnios is a valuable screening test for subsequent fetal distress requiring caesareasn delivery. 3. There was an increased risk of nonreassuring fetal heart rate pattern during labour for oligohydramnios patients. 4. Significantly higher incidence of IUGR was found in women with low AFI as compared to women with normal AFI 5. Our data are consistent with reports of other investigations and suggest that the AFI of 5-8 cm should be an indication of twice weekly antepartum testing. 6. A border line AFI of 5-8 cm may be early marker of declining placental function and progressing fetal compromise and AFI measurements may provide an early dependent marker independent of weight and gestational age. 7. The possibility of fetal distress is much higher in the AFI group < 5 cm and 5-8 cm hence vigilance and early decision is important in these groups. Pregnancies with oligohydramnios and compromised fetuses are more likely to be terminated earlier than pregnancies with normal AFI and healthy appearing fetus. Any sign of deteriorating fetal condition may prompt immediate delivery. This selective censoring (or confounding by indication) may some extent have biased the time dependant outcomes (e.g. perinatal outcomes) towards better results in cases in oligohydramnios. 8. Neonatal morbidity and mortality is highest in AFI < 5 cm but there is significant neonatal morbidity and mortality in the AFI group of 5-8 cm and hence this group cannot be considered as normal even though the definition by Moore TR 1997 states that normal AFI is 5-25cm.