RESUMO
Uterine torsion is a rare obstetric complication with a non-specific presentation. We describe a patient with a bicornuate uterus and a pregnancy complicated by a markedly elevated second-trimester maternal serum alpha-fetoprotein (MSAFP), intermittent pelvic pain and fetal growth restriction. At 24 weeks gestational age, she presented to labour and delivery with an acute abdomen. A subsequent exploratory laparotomy revealed torsion and rupture of her right uterine horn. Uterine torsion can be difficult to diagnose because it is not associated with specific symptoms or characteristic imaging findings. In patients with a bicornuate uterus who present with abdominal pain, an elevated mid-trimester MSAFP may be a harbinger of placental ischaemia as a result of uterine torsion.