Successful treatment of a heterotopic cervical pregnancy and twin gestation by sonographically guided instillation of hyperosmolar glucose

Abstract

Heterotopic pregnancies (i.e. with combined intra- and extrauterine fetuses) are rare spontaneous occurrences, with an estimated rate of 1 in 30 000 pregnancies, although among patients who have undergone in vitro fertilization-embryo transfer therapy, the incidence is much higher, approaching 1% 1. We report a case of heterotopic cervical pregnancy and intrauterine twin gestation, with a surgical technique employed to selectively terminate the cervical pregnancy by sonographically guided instillation of hyperosmolar glucose. A 35-year-old Japanese woman, gravida 1, para 0, became pregnant after her fifth in vitro fertilization-embryo transfer. Three embryos were transferred to the low uterine cavity with the patient in the lithotomy position. Twenty four days after embryo transfer, vaginal ultrasonographic examination revealed two intrauterine gestational sacs and a low echogenic sac-like complex in the cervical canal. Power Doppler flow mapping revealed peritrophoblastic blood flow characteristic of early implantation, confirming a heterotopic cervical pregnancy and intrauterine gestation, but no yolk sac or embryonic heartbeat could be detected in the sac (Figure 1). After extensive counseling with the patient and husband, selective reduction of the heterotopic cervical pregnancy was performed at 6 weeks' gestation. The gestational sac was punctured with ultrasound guidance and aspirated. Then 4.5 ml of a 33% glucose solution was injected slowly, resulting in a hyperechogenic area in the region of the former gestational sac. The sac and blood flow around the sac had close to vanished after 4 days and did not reappear throughout gestation, with transvaginal ultrasonographic evaluation performed every 2 weeks. Maternal serum β-human chorionic gonadotropin (β-hCG) levels were measured every week until week 10 (Figure 2). The twin intrauterine pregnancy continued until 34 weeks when premature rupture of membranes and massive genital bleeding occurred. A healthy boy and girl weighing 2102 and 1760 g, respectively, were delivered by caesarean section. There was a considerable amount of postpartum vaginal bleeding (550 g) and ultrasonography showed a large hema-toma in the cervical canal. Conservative therapy with introduction of a gauze tamponade into the cervical canal for 24 hr was performed and the patient was discharged from the hospital without incidence. High serum β-hCG persisted for 5 weeks after the cesarean section (Figure 2). Transvaginal power Doppler flow mapping of the cervical pregnancy and two gestational sacs. Maternal serum β-human chorionic gonadotropin (β-hCG) levels after instillation of hyprerosmolar glucose and cesarean section. We document here the treatment of a heterotopic cervical pregnancy by sonographically guided instillation of hyperosmolar glucose and subsequent successful twin gestation. Methotrexate, administered either systemic or locally, has been established as a standard therapy for preservation of fertility in patients with early-stage cervical pregnancies. However, because of its toxicity to embryos, it is not applicable to heterotropic cervical pregnancies. KCl injections, cervical stay sutures, forceps evacuation, or resection by hysteroscopy have been employed previously 2 for selective resection. To our knowledge, this is the first case of heterotopic cervical and intrauterine pregnancy to be treated by sonographically guided local instillation of hyperos-molar glucose. However, intraamniotic instillation of hyperosmolar glucose in the treatment of tubal pregnancy with a simultaneous intrauterine pregnancy has been proved successful 3. While the efficacy of hyperosmolar glucose for ectopic pregnancy is still controversial, in cases with a β-hCG level of <2500 IU/l, the success rate is similar or superior to that with methotrexate 4. Unfortunately, determination of pre-operative β-hCG level is not valid with concomitant extra-and intrauterine pregnancies so that the procedure should be limited to patients in early stages of gestation. Furthermore, persistent β-hCG 5 weeks after cesarean section might result from surviving trivial villous tissue in the cervix causing massive bleeding, and thus we must bear this risk in mind even where these are no abnormal findings of ultrasonography in the cervical canal after instillation. In summary, from our present experience of treatment of a heterotopic cervical pregnancy and twin gestation by sonographically guided puncture and instillation of hyperosmolar glucose, we conclude that this transvaginal ultra-sonography-guided approach is a feasible option for maintaining intrauterine gestation at very early stages of heterotopic cervical pregnancy.