Cornual twin pregnancy following IVF/ICSI treatment.

Abstract

A 40-year-old nulliparous woman with no medical history attended our fertility center with the desire to become pregnant with sperm donation. Her ovarian reserve was moderately low (Anti-Müllerian hormone, 0.9 ng/mL; antral follicle count, 7) and she was advised to start in-vitro fertilization/intracytoplasmic sperm injection (ICSI) treatment. Two cleavage-stage embryos were transferred 3 days following oocyte retrieval. Twelve days later, serum beta-human chorionic gonadotropin (β-hCG) was positive. The first transvaginal ultrasound (TVS) scan at 7 weeks revealed an ectopic twin pregnancy, with one embryo in each cornu, both with cardiac activity. The gestational sacs (GS) were 11.6 mm and 18.5 mm in diameter (Figure 1). Following a second TVS examination, the patient was administered a first intramuscular injection of 75 mg methotrexate (MTX) at 8 weeks, however, a second dose was indicated, as there was no decrease in β-hCG after 7 days. One week later, TVS showed evolution and viability of the right pregnancy, so it was decided to perform a TVS-guided reduction of the pregnancy. The left cornual pregnancy without viability was injected with 100 mg/mL MTX, whereas the right cornual pregnancy received an intracardiac injection of 3 mEq potassium chloride (KCl) and 150 mg/1.5 mL of MTX intragestationally, using a Towako needle set (Cook Medical, Bloomington, IN, USA). TVS performed 1 week later showed an empty and collapsed sac in the right cornu (Figure 2). After 3 weeks, serum β-hCG was negative. A new treatment cycle with ICSI was started, which resulted in a biochemical pregnancy. In the next cycle, a thawed embryo was transferred and the patient had an ongoing eutopic pregnancy when she was last examined at 7 weeks' gestation. Cornual pregnancy occurs in 2–4% of all ectopic pregnancies, with a mortality rate of 2–3%1. Some studies report higher ectopic pregnancy rates after assisted reproductive technology (ART) cycles2, whereas others report similar ectopic implantation rates between spontaneous and assisted conception3. One factor contributing to ectopic pregnancy following ART cycles related to embryo implantation potential3. Another proposed factor is the influence of hormonal environment on the implantation site of the embryo transferred after ovarian stimulation in fresh-embryo transfer, with higher rates of ectopic pregnancy observed following fresh- compared with frozen-embryo transfer4. Cornual pregnancy diagnosis by TVS is suspected by findings such as an empty uterine cavity, an eccentrically located GS surrounded by a thin layer of myometrium measuring < 5 mm and the interstitial line sign5. Studies have demonstrated that three-dimensional imaging has increased sensitivity and specificity compared with two-dimensional sonography, allowing better evaluation of the interstitial regions of the uterus5. Early recognition and timely treatment of an interstitial pregnancy is imperative to avoid the high morbidity and mortality associated with this type of ectopic pregnancy1. Treatment modalities can be divided into surgical and conservative, the latter being the current preference in order to preserve fertility. Among them, systemic MTX therapy and ultrasound-guided injection of MTX or KCl into the GS are the alternatives. Local MTX administration allows ablation of the ectopic pregnancy and preservation of uterine integrity for subsequent pregnancies. In summary, ectopic cornual pregnancy should be suspected in patients who underwent ART when TVS examination shows suggestive signs. Prompt management is crucial and conservative methods should be the preferred choice for more optimal care.