Ectopic pregnancies in caesarean section scars: 5 years experience

The aim of the study is to evaluate our 5 years experience in diagnosis and treatment of ectopic pregnancy developing in a Caesarean section scar.

The study included twenty-one women, diagnosed with a Caesarean scar ectopic pregnancy (CSEP) in the first trimester, which was confirmed by ultrasound and treated in our hospital during 5 years between 2012 and 2016. The clinical presentations, imaging findings, and treatment outcomes of all these pregnancies were recorded.

The main complaints of the patients were vaginal bleeding in 7 (33.3%) of cases and abdominal pain in association with vaginal bleeding in 4 (19.1%) of cases. However, the remaining 10 cases (47.6%) were asymptomatic. The number of previous Caesarean sections ranged from 1 to 4 with an average of 2.14, 24% (5/21) of our patients had only one prior Caesarean section, 43% (9/21) had 2 prior Caesarean sections, 28% (6/21) had 3 prior Caesarean sections and only 5%, (1/21) had 4 prior Caesarean sections. All our 21 cases underwent successful early first trimester diagnosis with trans-vaginal color Doppler ultrasonography. All our 21 cases showed empty uterus and empty cervical canal with visualization of gestational sac at the presumed site of the Caesarean scar; however, 13 cases showed thinned myometrium (<5 mm) between the gestational sac and bladder. The mean thickness of Caesarean section incision scar was 0.3 ± 0.15 cm. 7 cases (33.3%) showed no embryo in the gestational sac while 14 cases (66.7%) showed embryonic gestational sac, 9 cases from the 14 showed heart activity. MRI studies were done in 7 patients with Caesarean scar ectopic pregnancy to confirm the diagnosis and to follow up 2 complicated cases. In all 7 cases, the diagnosis of Caesarean scar ectopic pregnancy using MRI included empty uterine and cervical cavities, and a gestational sac seen embedded within the site of caesarean scar, with thin myometrium adjacent to the sac. No bulging of the sac through the myometrium or bladder invasion was detected. Termination of pregnancy was done by systemic methotrexate administration in 14 cases, and with trans-cervical aspiration of the gestational sac in 7 cases. Intra-operative bleeding occurred in all 7 cases treated with aspiration of the gestational sac, one of the 7 cases complicated with hysterectomy, while one patient complicated with uterine rupture and was treated conservatively. The cases treated with systemic methotrexate injection showed no complication. The Caesarean scar mass was followed with trans-vaginal ultrasound and regressed within 2 months to about 1 year post treatment.

Early imaging diagnosis and effective treatment of CSEP are critically important not only to improve outcomes, minimize maternal complications and the need for emergency extended surgery, but also to maintain treatment options, and potentially preserve future fertility.