Twin fetuses associated with double amniotic sacs diagnosed using transvaginal ultrasonography: A case report

Background: Conjoined twins are a rare twin malformation commonly presenting as single amniotic sac twinning, with double amniotic sac twinning being extremely rare and poorly reported. Most conjoined twins are females.

Case summary: A woman of childbearing age conceived naturally, and at 8 wk of gestation, transvaginal ultrasonography showed an embryo and cardiac tube pulsation in both amniotic sacs. On dynamic observation, the two embryos were connected in the lower abdomen, with restricted movement. A repeat transvaginal ultrasound at 11 wk showed that the intestinal tubes of both fetuses were connected in the lower abdomen. The pregnancy was terminated and labor was induced.

Conclusion: Transvaginal ultrasound may detect conjoined twin malformations in an early stage. Our case provides diagnostic insights for ultrasonographers and can help develop early therapeutic interventions.