Conservative Treatment of a Cesarean Scar Pregnancy Diagnosed and Treated via Transvaginal Ultrasonography

INTRODUCTION: Cesarean scar pregnancy is a form of ectopic implantation of the gestational sac where a pregnancy implants within the scar niche of a previous cesarean delivery. Prevalence is estimated to be between 1 in... [ view full abstract ]

INTRODUCTION: Cesarean scar pregnancy is a form of ectopic implantation of the gestational sac where a pregnancy implants within the scar niche of a previous cesarean delivery. Prevalence is estimated to be between 1 in 1800 to 1 in 2226 pregnancies and rates are increasing due to overall increase in the number of cesarean deliveries. Cesarean scar ectopic pregnancies cause a number of maternal morbidities and can be potentially fatal. Reported complications include placenta accreta/percreta, uterine rupture, hemorrhage and bladder injury. Hemorrhage is often so severe that it requires hysterectomy. Early diagnosis is the key to reducing maternal morbidity and mortality, as well as preservation of uterus for future fertility.
CASE REPORT: Our patient was a 26 year old obese G3P2002 with two prior uncomplicated cesarean deliveries. She presented to the emergency room complaining of vaginal bleeding and nausea for 5 days. Patient was hemodynamically stable and did not demonstrate any abdominal tenderness on exam. Quantitative β-hcg was 102,819 mIU/mL. The initial ultrasound in the emergency department did not diagnose the abnormal implantation. Our service was consulted because of her vaginal bleeding. Our subsequent transvaginal ultrasound demonstrated a live gestation measuring 7 weeks and 3 days. The pregnancy was noted to be abnormally located in the lower uterine segment with no overlying myometrium between the gestation and the bladder. Additionally there was increased color Doppler flow surrounding the gestation, vascularized lacunae within the placenta, and an outward bulging of anterior uterine contour. Surgical and medical management of this condition were discussed with the patient. Patient desired future fertility at the time of presentation to our facility.
She received methotrexate injection (50 mg) into the gestational sac via transvaginal ultrasound guidance with real-time confirmation of the injection into the placental bed (25mg) and gestational sac (25 mg). Despite the methotrexate therapy, fetal heart activity on ultrasound was seen at 24, 48, and 72 hours post injection which prompted the decision to administer transvaginal ultrasound guided intracardiac injection of potassium chloride on hospital day 3. She was discharged home shortly after this procedure. She returned the following day for quantitative β-hcg which trended down to 78,675 mIU/mL.
Unfortunately the patient did not continue to follow up as requested and relocated to live with family several hours away. She presented to an outside facility 15 days after initial treatment. At that time she was clinically stable but had complaints of worsening pelvic pain. Quantitative β-hcg at the outside facility was noted to be less than 1000. There was no fetus identifiable on ultrasound. The patient requested hysterectomy for definitive management of her pain symptoms.
The physician who performed the abdominal hysterectomy noted that there was a large clot in the lower-uterine segment at the time of hysterectomy. There was no identifiable fetus and the placental tissue easily peeled off the bladder with no injury and minimal bleeding
DISCUSSION: The optimal management and the clinical course following conservative management of cesarean scar ectopic pregnancy are limited to a few case series and case reports. Some case series report that it can take up to 9 weeks to clear β-hcg. Resolution of the gestation sac may take 5 months or more. Single local injection with methotrexate is reported to be successful in 73.9% of cases. However, meta-analyses of known case reports and series seem to indicate that patient’s with quantitative β-hcg greater than 100,000 mIU/mL are more likely to require surgical management. Although this patient did eventually require surgery for pain control as per maternal request, this case is not a failure of conservative management as her quantitative B-hcg dramatically decreased and the fetus was not identified at the time of surgery. Furthermore, the intraoperative management of the placental extraction from the bladder was rendered much less complicated by the pretreatment with Methotrexate and subsequent involution of the trophoblastic tissue.
CONCLUSION: This case demonstrates that conservative management is a reasonable option even in a rural setting, for those patients who desire future fertility even when presenting quantitative B-hcg exceeds 100,000 mIU/mL. It does however; highlight the importance of careful patient selection. Conservative management may not be appropriate in patients who are non-compliant or unreliable.