Abstract
OBJECTIVES: Hydrometrocolpos is a pelvic cystic mass representing the distension of the vagina and uterus due to obstructive congenital anomalies of the female causing accumulation of fluid secretions in the vagina and endometrial cavity. Prenatal diagnosis is uncommon and usually noticed during the adolescent period for failure to see menses with cyclic abdominal pain, abdominal mass, and local compressive symptoms. Late diagnosis after delivery of newborns with this condition results in poor outcomes from local compressive symptoms. CASE PRESENTATION: Here, we present a case diagnosed with congenital hydrometrocolpos at 39 weeks of gestation during routine third-trimester ultrasound scanning. The newborn was delivered vaginally and huge hydrometrocolpos secondary to imperforate hymen was diagnosed postnatally, and a hymenectomy was done and the newborn was discharged and improved from the hospital. CONCLUSIONS: Although congenital hydrometrocolpos occurs rarely, it is also better to suspect prenatally in a female fetus with a cystic pelvic mass. Antenatal ultrasound diagnosis of this condition will help to make decisions early and to prevent further complications which might occur both intrauterine and after birth.