A Case of Ultrasound Suspected Microcephaly With a Normal Head Circumference at Birth.

A 25-year-old first-time mother from Nepal had a well-progressing spontaneous pregnancy. However, from the 37th week, her baby's biparietal diameter (BPD) stopped growing at around 83 mm. At 40 weeks, measurements suggested possible microcephaly and fetal growth failure but no other abnormalities. No travel, infections, or cytomegalovirus were identified prenatally. By 41 weeks, the BPD and head circumference (HC) decreased further, while the estimated fetal birth weight (EFBW) slightly increased. The baby girl was born at 41 weeks and 1 day with a low birth weight but a normal head circumference. Postnatal checks showed no abnormalities, and she was discharged with normal growth at 10 days old.