Different therapeutic options have been suggested in cases of ectopic pregnancies located in a Cesarean scar: hysterectomy, hysterotomy, conservative management with methotrexate or direct injection of methotrexate into the gestational sac. We present a case of the diagnosis of a viable pregnancy located in a Cesarean scar and treatment by direct potassium chloride (KCl) injection into the embryo. Follow-up was by serial monitoring of human chorionic gonadotropin (β-hCG) levels and ultrasound examination. After 12 weeks, β-hCG levels were below 2 mU/mL and only a small lesion was visible by ultrasound. Direct injection of KCl may be a new therapeutic option with minimal side effects for some types of ectopic pregnancies.
A 25-year-old woman, gravida 2 para 1, was referred to our unit because of suspected ectopic pregnancy (β-hCG level of 55 600 mU/mL and no intrauterine gestation visible). Delivery of her first pregnancy 11 months previously was by Cesarean section because of breech presentation. The patient had no pelvic pain or vaginal bleeding and she reported having amenorrhea for 8 weeks. Transvaginal ultrasound (TVS) examination revealed an empty uterine cavity. The gestational sac surrounded by myometrium was visualized in the anterior wall of the uterus at the cervicoisthmical region. A viable embryo with a crown–rump length of 12.0 mm (corresponding to 7 + 2 weeks' gestation) was detected (Figure 1). The diagnosis of an intact gestation in the uterine scar was made. Because the patient was asymptomatic, different management options were discussed: laparotomy or laparoscopy, methotrexate administration or transabdominal needle insertion and KCl injection into the embryo, according to the technique used to perform embryo reduction of multifetal pregnancies. The patient was informed that this management option had, to our knowledge, not been performed before and surgical intervention might be necessary. After informed consent was obtained, we inserted a 20-gauge needle under ultrasound guidance transabdominally directly into the embryo and injected 0.5 mL KCl. After the procedure, cardiac activity could no longer be detected. Expectant management included serial sonographic follow-up examination and measurement of β-hCG levels. β-hCG levels increased for 4 days after the procedure (up to 90 000 mU/mL) then slowly decreased. Twelve weeks after the procedure a small lesion was still visible by ultrasound but β-hCG levels were below 2 mU/mL. Six months after the procedure the patient became pregnant again, had an uneventful pregnancy, and was delivered by Cesarean section of a healthy baby at term.
An ectopic pregnancy in the scar of a former Cesarean pregnancy is a rare, but life-threatening, condition. Different therapeutic options have been discussed. It is generally believed that complete removal or destruction of the gestational mass by medical1 or surgical2 treatment is mandatory. It has been shown previously that direct local injection of methotrexate into the embryo or gestational sac under ultrasound guidance is a promising treatment for ectopic pregnancy3. In the present case we were able to show that after the death of the embryo the trophoblast also slowly disappeared. In the recently published paper by Haimov-Kochman and colleagues1, even a non-viable scar pregnancy with relatively low β-hCG levels was treated with systemic methotrexate. It could be speculated that in such cases the pregnancy would vanish even without treatment. Of course, follow-up ultrasound examination and monitoring of β-hCG levels should be performed to exclude potentially dangerous progression of trophoblastic growth.
In conclusion, an ectopic pregnancy located in the scar of a former Cesarean section can be visualized by TVS. Surgical or local methotrexate treatment have been shown to be safe methods for treating this condition and preserve fertility, but direct injection of KCl into the embryo could be a promising additional method that is minimally invasive and avoids the side effects of systemic medical therapy.
J. Hartung*, J. Meckies*, * Praxis für pränatale Medizin und Ultraschall, Schlossstrasse 88, 12163 Berlin, Germany