A thirty-two-year-old gravida 1 para 0 was referred to High Risk Obstetrics with a diagnosis of dichorionic diamniotic twin gestation. She had been treated with clomiphene citrate to conceive following a history of unexplained infertility. An early ultrasound at six weeks gestation was reported as a dichorionic diamniotic twin gestation. This was based on a crown rump length (CRL) of 10.1 mm for fetus A and 16.8 mm for fetus B. Two separate and distinct fetal heartbeats were also reported. 
The patient wished to participate in Integrated Prenatal Screening, and she presented for a nuchal translucency at thirteen weeks and one day of gestation. This scan identified a triplet gestation complicated by a set of conjoined twins. One amniotic sac contained a single fetus (triplet A) with a CRL of 74 mm and a nuchal translucency of 1.5 mm. Within the second amniotic sac, triplets B and C, were joined through the thorax and abdomen, with four arms, four legs and a single heart centrally located between the two fetuses. The CRL for triplet B was 62.2 mm, and the nuchal translucency was measured at 3.9 mm. The CRL for triplet C was 62.5 mm, and a cystic hygroma was also seen. The nuchal translucency for Triplet C was 7.1 mm. Using 3D ultrasound and MRI, a diagnosis of thoracoomphalopagus was confirmed (see Figures 1-3).
The parents were counseled and options discussed included (1) continue the pregnancy understanding that the shared heart meant the conjoined twins could not be separated should they survive to delivery, (2) terminate the entire pregnancy or, (3) selective feticide of the conjoined twins. After further counseling and deliberation the parents chose the third option. This was carried out at 13 weeks and five of days gestation by intracardiac potassium chloride injection. A repeat scan was performed four days later again confirming a viable singleton gestation with fetal demise of conjoined twins. The patient went on to have another scan at 17 weeks and 6 days of gestation, which showed normal anatomy and interval growth of the remaining triplet. The nonviable conjoined twins were noted at the time of that scan. 
The pregnancy continued without complication, and a healthy male infant was delivered by low forceps for maternal exhaustion weighing 3590 grams at 40 of weeks gestation. Apgars were 7 and 9. The vestiges of the conjoined twins were not visible at the time of delivery. The mother and infant were discharged home on postpartum day four.