Causes, management and outcomes of polyhydramnios at a secondary level hospital in Cape Town, South Africa.

Introduction: Polyhydramnios is associated with both maternal and fetal adverse outcomes. Idiopathic polyhydramnios, regardless of its severity category, was considered not to be associated with an increase in adverse outcomes. In contrast, when conditions such as congenital and chromosomal abnormalities or diabetes mellitus are detected, neonatal and maternal adverse outcomes can be up to five times higher. We thus aimed to document the outcomes of patients with mild, moderate and severe polyhydramnios according to whether an underlying cause was found and which management protocol was followed.

Methodology: We conducted a retrospective cohort study of all patients with polyhydramnios on ultrasound examination at our secondary hospital between January 1, 2018 and December 31, 2020. Hospital folders were reviewed. We recorded demographic data, information on underlying causes, management and outcomes. We summarised categorical variables using count (percentage). We tested the association between categorical variables using the chi-square test. Statistical significance was set at p < 0.05.

Results: A total of 136 patients with polyhydramnios (80 mild, 42 moderate, and 14 severe) were included. Most cases of polyhydramnios were idiopathic regardless of category [81.2% (65/80), 78% (32/42) and 78% (11/14) in the mild, moderate and severe groups, respectively]. The likelihood of occurrence of the composite adverse outcome, was higher with increasing severity of polyhydramnios, with 6.75%. 19.05%, and 35.71% in the mild, moderate and severe groups, respectively, having the composite adverse outcome (p =  0.01). Elective delivery before 40 weeks' gestation for polyhydramnios in patients with idiopathic polyhydramnios was associated with a significant reduction in the occurrence of the composite adverse outcome compared to awaiting spontaneous labor (3.77% versus 15.79%, p =  0.036),.

Conclusions: Adverse outcomes were related to severity of the polyhydramnios and were significantly lower in the mild compared to the moderate and severe groups, with the rate of adverse outcome in the mild group comparable to that of the general population. Early delivery before 40 weeks gestation may be associated with benefit in moderate and severe groups of polyhydramnios.