Placenta accreta and methotrexate treatment

Placenta accreta is a rare and potentially life-threatening complication during pregnancy and birth. The chorionic villi invade the myometrium. The condition may be caused by a poorly developed or partially absent decidua basalis. It is presented most often with a major postpartum hemorrhage or may be diagnosed during a cesarean section (CS). It may even occur during early pregnancy 1. This report presents a case of placenta accreta diagnosed during a CS and treated successfully with methotrexate (MTX) as adjuvant therapy with preservation of the uterus. A 30-year-old woman, gravida 2, para 1, was admitted to the obstetric department with premature rupture of membranes at 25 weeks of gestation. The patient had previously been operated on because of a congenital heart disease and she had a pacemaker, but she was taking no medication. She was treated with corticosteroids to accelerate the fetal lung maturation, and had atosiban (Tractocile) on two occasions for painful contractions. Prolongation of the pregnancy was successful until 30 weeks of gestation, when the patient went into labor with contractions. She had a breech presentation and a CS was performed. A female infant of birthweight 1380g and with Apgar scores 6 and 7 after 1 and 5 min, respectively, was delivered. The placenta was strongly attached to the posterior uterine wall. It was impossible to detect a zone between the uterine wall and parts of the placenta, which is consistent with the diagnosis of partial placenta accreta. Those parts that could be separated from the uterus had to be removed in pieces from the uterine wall. During the attempt to remove the placenta, there was slight bleeding, although not as much as could be feared by this diagnosis. When closing the uterotomy, there was still a considerable amount of placental tissue remaining attached to the myometrium, although there was adequate hemostasis. Further attempts to remove the remaining placental tissue were not undertaken to avoid inducing a severe bleed. On the second postoperative day an increase in C-reactive protein (CRP) to 186mg/L was noted, although the patient had been treated with antibiotics according to procedure. To prevent a serious infection with the considerable amount of placental tissue left in the uterus, we started treatment with intramuscular methotrexate (MTX) 1 mg/kg (73 mg). Ten hours later the remains of the placental tissue was disposed vaginally. The CRP concentration fell in the following days and the patient developed no clinical signs of infection. Vaginal ultrasound on day 8 postoperatively visualized an empty uterine cavity with no signs of remaining placental tissue. The patient was discharged on day 14 postoperatively in good health. MTX is a well-known cytotoxic agent used in treating tropho-blastic tumors and in selected cases of ectopic pregnancy. It reduces the placental vascularity and induces placental necrosis. Conservative treatment of pathological placentation with preservation of the uterus has been reported in the literature on several occasions in past years 2. MTX has been a part of this conservative treatment, although the experience is limited. The first report of MTX used in treating placenta accreta was presented by Arulkumaran et al. in 1986 3. Since then there have been reports of both successful 4 and unsuccessful 5 cases when the placenta has been left in situ in cases of pathological placentation. Previous reports of MTX treatment have been in cases of total placenta accreta left in situ. The patient in our case had partial placenta accreta with only the remains of the placenta left in the uterus. During the removal of the placenta there was only slight intraoperative bleeding, although the clinical diagnosis of partially placenta accreta was certain. Histopathological examination of the placenta did not confirm the diagnosis, although this is well known to be difficult when the tissue is extracted in pieces. In contrast to placenta increta and percreta, the diagnosis of placenta accreta does not rely solely on histopathological examination. The risk for development of infection was obvious as a considerable amount of placental tissue was left in situ when closing the uterotomy. MTX treatment was initiated to prevent infection and to preserve the uterus even though no clinical signs of infection were present. Whether the use of a cytotoxic agent such as MTX, with its possible side-effects, can be justified when only remnants of the placenta are left in situ is a question to be addressed regarding this case report. In our opinion and based on this case report, MTX as adjuvant therapy when a limited amount of placental tissue remains in the uterus after a CS is an option in selected cases in treating placenta accreta to avoid hysterectomy and prevent severe postpartum infection.