To present a case of maternal morbidity encountered in a cervical heterotopic pregnancy after successful potassium chloride (KCl) injection for transvaginal multifetal pregnancy reduction. Case report. Tertiary referral care center. A woman with heterotopic twin gestation after IVF. Diagnosis of a viable cervical heterotopic pregnancy was made at 6 weeks by ultrasound. A transvaginal reduction by KCl injection of the cervical pregnancy was performed under sonographic guidance. Maternal morbidity and mortality. Although contents of the gestational sac within the cervix resolved, the trophoblastic tissue increased in both size and vascularity. The patient continued to have selflimited vaginal bleeding throughout the pregnancy. However, at 31 weeks, she had an acute hemorrhage, resulting in an emergency cesarean hysterectomy secondary to profuse bleeding from retained cervical trophoblastic tissue. Although KCl transvaginal multifetal pregnancy reduction might successfully terminate a cervical heterotopic pregnancy, the ongoing pregnancy might be complicated by persistence and even enlargement of remaining trophoblastic tissue, leading to obstetric hemorrhage. To present a case of maternal morbidity encountered in a cervical heterotopic pregnancy after successful potassium chloride (KCl) injection for transvaginal multifetal pregnancy reduction. Case report. Tertiary referral care center. A woman with heterotopic twin gestation after IVF. Diagnosis of a viable cervical heterotopic A transvaginal reduction by KCl injection of the cervical pregnancy was performed under sonographic guidance. Maternal morbidity and mortality. Although contents of the gestational sac within the cervix resolved, the trophoblastic tissue increased in both size and vascularity The patient continued to have self-limited vaginal bleeding throughout the pregnancy. However, at 31 weeks, she had an acute hemorrhage, resulting in an emergency cesarean hysterectomy secondary to profuse bleeding from retained cervical trophoblastic tissue. KCI transvaginal multifetal pregnancy reduction might successfully terminate a cervical heterotopic pregnancy, the ongoing pregnancy might be complicated by persistence and even enlargement of remaining trophoblastic tissue, leading to obstetric hemorrhage.