Amniotic fluid disorders and the effects on prenatal outcome: a retrospective cohort study.

BACKGROUND: The amniotic fluid is a protective liquid present in the amniotic sac. Two types of amniotic fluid disorders have been identified. First refers to polyhydramnios, which is an immoderate volume of amniotic fluid with an Amniotic Fluid Index (AFI) greater than 24 cm. Second includes oligohydramnios, which refers to decreased AFI i.e., less than 5 cm. This study aims to; a) identify the maternal risk factors associated with amniotic fluid disorders, b) assess the effect of amniotic fluid disorders on maternal and fetal outcome c) examine the mode of delivery in pregnancy complicated with amniotic fluid disorders.

METHODS: A comparative retrospective cohort study design is followed. Sample of 497 pregnant women who received care at King Abdullah bin Abdul-Aziz University Hospital (KAAUH) between January 2017 to October 2019 was included. Data were collected from electronic medical reports, and was analyzed using descriptive statistics. Association of qualitative variables was conducted by Chi-square test, where p-value < 0.05 was considered statistically significant.

RESULTS: Among the collected data, 2.8% of the cases had polyhydramnios and 11.7% patients had oligohydramnios. One case of still born was identified. A statically significant association was found between polyhydramnios and late term deliveries (P = 0.005) and cesarean section (CS) rates (P = 0.008). The rate of term deliveries was equal in normal AFI and oligohydramnios group (P = 0.005). Oligohydramnios was mostly associated with vaginal deliveries (P = 0.008). Oligohydramnios and polyhydramnios were found to be associated with diabetes mellitus patients (P = 0.005), and polyhydramnios with gestational diabetes patients (P = 0.052). Other maternal chronic diseases showed no effect on amniotic fluid index, although it might cause other risks on the fetus.

CONCLUSION: Diabetes mellitus and gestational diabetes are the most important maternal risk factors that can cause amniotic fluid disorders. Maternal and fetal outcome data showed that oligohydramnios associated with gestational age at term and low neonatal birth weight with high rates of vaginal deliveries, while polyhydramnios associated with gestational age at late term and high birth weight with higher rates of CS.