Transient Polyhydramnios during Pregnancy Complicated with Gestational Diabetes Mellitus: Case Report and Systematic Review.

Polyhydramnios is an obstetrical condition defined as a pathological increase in the amniotic fluid and is associated with a high risk of maternal-fetal complications. Common causes of polyhydramnios include fetal anatomical and genetic abnormalities, gestational diabetes mellitus, and fetal viral infections. We present the case of a 30-year-old Caucasian woman with transient polyhydramnios associated with gestational diabetes mellitus and obstetric complications. The diagnosis was based on the ultrasound assessment of amniotic fluid volume during a common examination at 26 weeks. Two weeks prior, the patient had been diagnosed with gestational diabetes mellitus. After 4 days, the patient was examined, and the amniotic fluid index returned to normal values. At 38 weeks, the patient presented to the emergency room due to lack of fetal active movement. Ultrasound revealed polyhydramnios, the patient was admitted for severe fetal bradycardia, and fetal extraction through emergency cesarian section was performed. Six weeks after birth, the patient underwent an oral glucose tolerance test with normal values, confirming gestational diabetes mellitus. We performed a systematic review of the literature on polyhydramnios, from January 2016 to April 2022, to analyze all recent published cases and identify the most common etiological causes and important aspects related to maternal-fetal outcomes.