Introduction: Conjoined twins are an extremely rare occurrence registered in 1:50,000 to 1:100,000 live births. Due to the increased risk of perinatal morbidity and mortality it is crucial to do the prenatal evaluation and early diagnosis of conjoined twins by ultrasound scan in the first trimester. Early diagnosis in the first trimester gives the parents an option of safe termination of pregnancy.
Case report: A 27-year-old G2P1L1 female was referred to our department for routine first trimester antenatal ultrasound at 9 weeks 4 days according to last menstrual period (LMP). Ultrasound examination detected a monochorionic-monoamniotic twin pregnancy. The two fetuses were seen in a face-to-face fixed position with two separate fetal heads and chests seen. Two separate hearts were seen. The twins were found to be joined at the lower abdomen and pelvis. Based on ultrasound findings ischiopagus conjoined twins diagnosis was made. Parents were counseled and they opted for termination of pregnancy.
Conclusion: Conjoined twins are a very rare complication of monoamniotic-monochorionic pregnancies. Diagnosis on antenatal ultrasound can be made, if in a twin pregnancy, both fetuses persistently maintain a fixed position relative to each other. Early antenatal diagnosis by ultrasound gives the parents a chance to choose an option of safe termination.
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