An Amniotic Fluid Index ≤5 cm Within 7 Days of Delivery in the Third Trimester Is Not Associated with Decreasing Umbilical Arterial pH and Base Excess

Abstract

OBJECTIVE:To determine if an amniotic fluid index (AFI) r5.0 cm within 7 days of delivery in the third trimester is associated with decreasing umbilical arterial pH and base excess. STUDY DESIGN:Cases for this retrospective cohort study were all pregnancies Z26 weeks with intact membranes and an AFI r5.0 cm within 7 days of delivery between 11/99 and 7/02. Multiple gestations, aneuploid, and anomalous fetuses were excluded. Controls with an AFI >5.0 cm within 7 days of delivery were matched to each case within 1 week by gestational age. For a control group with a mean±SD umbilical arterial pH of 7.26±0.07 and a ¼ 0.05, a sample size of 100 would have a power of 99% to detect a difference with a study group whose mean was 7.20. Data were compared using paired Student's t-test, Mann-Whitney, Fisher's exact, w 2 and risk ratios with 95% confidence intervals. RESULTS:In all, 131 neonates with an AFI r5.0 cm were matched to 131 controls with an AFI >5 cm. There was no difference in gestational age (37.6±3.0, 37.7±3.0 weeks) or birth weight (2897±810, 2762±788 g). There was no difference in umbilical artery pH (7.25±0.07, 7.26±0.07) or base excess (À3.32±2.59, À2.83±2.45 mmol/l), even in small for gestational age (SGA) infants in both groups. There was no difference in the number of SGA neonates, 5-minute Apgar <7, respiratory distress syndrome, necrotizing enterocolitis, or neurologic morbidity. Linear regression showed no correlation between AFI and either umbilical arterial pH (r ¼ À0.00047, SE ¼ 0.001, p ¼ 0.63) or base excess (r ¼ À0.029, SE ¼ 0.037, p ¼ 0.428). CONCLUSION:An AFI r5.0 cm measured within 7 days of delivery in the third trimester is not associated with decreasing umbilical arterial pH and base excess.

Comparative Study of Maternal and Fetal Outcome between Low and Normal Amniotic Fluid Index

“…In the study by Tajinder et al the mean AFI in the study group (AFI=5) was 3.605 ± 1.1490 cm and in control group (AFI >5) was 12.001 ± 3.520 cm. In Driggers et al [9] the mean AFI in cases was 3.0 ± 1.5 cm and in controls was 10.7 ± 4.0 cm; which were similar to our study.…”

A Comparative Study of Perinatal Outcomes in Patients with Oligohydramnios (Low Amniotic Fluid Index)

“…The 5-min Apgar score was statistically insignificant between the groups (1 vs. 7 %). In similarity to this study, Driggers et al [12] observed that a 5-min Apgar score <7 in 3.8 % patients in an oligohydramnios group versus 4.6 % in a normal AFI group were not significant to each other. A study by Grubb et al [13] reported that the 1-min Apgar score <7 in 84 % patients with AFI ≤ 5 as compared to 14 % in the normal AFI group, which was statistically highly significant (p = 0.4140.…”

Relationship between Amniotic Fluid Index and Perinatal Outcome

“…A study by Driggers et al 13 reported at 5 min APGAR score of <7 in 3.8 % patients in an oligohydramnios group vs 4.6 % in a normal AFI group and concluded that there was no significnant difference. A study by Grubb et al 14 was found that 1 min APGAR score of <7 in 84% of patients with AFI of <5 as compared to 14 % in normal AFI groups which was highly significant (p=0.01). In the same study, 5 min score of <7 was seen in 13% patients with AFI of ≤ 5 cm vs 5% in normal AFI group.…”