Intrauterine Herpes Simplex Virus Infection: Insights Into a Silent Threat.

We report a rare case of congenital herpes simplex virus type 2 (HSV-2) infection in a neonate born to a mother with no clinical evidence of genital HSV infection either before or during pregnancy. Routine prenatal ultrasound assessments in the first two trimesters were unremarkable, and infectious disease screening results were negative. The pregnancy, however, was complicated by premature rupture of membranes (PROM) at 24 weeks of gestation. An ultrasound at that time revealed severe fetal malformations, including brain abnormalities and organomegaly. At 31 weeks, an emergency cesarean section was performed, delivering a female baby with profound physical abnormalities, including extensive skin erosions and severe neurological impairment. On the fourth day of life, grouped vesicles emerged, leading to the initiation of intravenous acyclovir therapy. Polymerase chain reaction testing of skin swabs confirmed HSV-2 infection. Despite antiviral treatment, the neonate's condition rapidly deteriorated, culminating in death on the fifth day of life. This case highlights the diagnostic challenges of intrauterine HSV infection in the absence of maternal symptoms. It emphasizes the importance of considering HSV infection in the differential diagnosis when PROM is accompanied by significant fetal malformations.