TITLE:
Factors Associated with Oligohydramnios and Related Neonatal Morbidity and Mortality: A Nested Case-Control Study in a Cohort
AUTHORS:
Mame Diarra Ndiaye, Mamour Gueye, Aissatou Mbodji, Aminata Niass, Abdoulaye Diakhate, Magatte Mbaye
KEYWORDS:
Oligohydramnios, Obstetric Complications, Perinatal Asphyxia, Obstetric Interventions
JOURNAL NAME:
Open Journal of Obstetrics and Gynecology,
Vol.14 No.11,
November
5,
2024
ABSTRACT: Objective: To study the factors associated with oligohydramnios and its related neonatal morbidity and mortality. Materials and Methods: This was a 10-year retrospective nested case-control study conducted at a level 2 maternity ward. Given that the prevalence of oligohydramnios ranges between 0.5% and 8%, the sample size of the cases was calculated using the following formula: n = (z/∆)2 × p(1 − p). We selected 20 controls for each case. Data were exported to Excel and analyzed using the Statistical Package for Social Sciences (SPSS) and R Studio 4.1.3 software. The maximal deepest pocket of amniotic fluid or the amniotic fluid index was used to establish the diagnosis. Qualitative variables were described as proportions relative to the total. Data were compared using the chi-square test when normality conditions were met or non-parametric tests otherwise. The significance threshold was set at 0.05. Results: Out of a cohort of 56,775 deliveries, we collected 145 cases of oligohydramnios and 2953 controls. The prevalence of preeclampsia was seven times higher in cases of oligohydramnios (OR = 7.7 [5.12; 11.7]). The prevalence of small-for-gestational-age (SGA) fetuses was four times higher in the case group (OR = 4.3 [3.04; 6.21]). Oligohydramnios were associated with an increased risk of labor artificial induction and cesarean sections respectively 4.51 ([2.95; 6.99]) and 3.41 ([3.03; 3.78]). Perinatal asphyxia was nearly three times more frequent in children born in the context of oligohydramnios (OR = 2.7 [1.38; 5.30]). Vaginal delivery and SGA were not associated with neonatal morbidity or mortality in cases of oligohydramnios. Conclusion: Oligohydramnios is associated with obstetric pathologies and increased neonatal morbidity and mortality. However, vaginal delivery and labor induction do not impact neonatal morbidity and mortality. The risk of perinatal asphyxia in oligohydramnios requires special monitoring in the delivery room. Further studies on the relationship between fetal heart patterns during and asphyxia in oligohydramnios will need to be conducted.