Background: Caesarean Scar Ectopic Pregnancy (CSP) is a rare and potentially life threatening form of ectopic pregnancies. Multiple treatment modalities were suggested, however, up to date there are no guidelines for management of CSP.
Aim: To describe the incidence, management, complications of treatment and define risk factors for conversion from medical to surgical treatment of CSP in a large tertiary center in Victoria, Australia.
Methods: A retrospective analysis of all CSP that occurred between 2008 and 2016 at The Royal Women’s Hospital, Melbourne, Australia was performed. The cohort was divided according to management; demographic, clinical and sonographic data were collected. Rates of conversion were compared between groups and risk factors necessitating conversion were sought.
Results: Forty-six cases of CSP were identified. Incidence of CSP has increased from 0.05% to 0.09% of all deliveries. A regression model for absolute numbers of CSP predicted an additional 0.47 CSP each year (p=0.03). The most common treatment modalities were systemic treatment with methotrexate (28.2%) and ultrasound-guided intra-sac injection of KCL with systemic treatment of methotrexate (58.7%). β-hCG levels (IU/L) at presentation were 42,189 and 19,729 for cases who were and were not converted, respectively (p=0.04). Only 6.3% of patients with β-hCG at presentation below 10,000 IU were converted from medical to surgical management. Mean Sac Diameter (MSD) of cases who were converted was 11.2 mm larger than in cases who were not converted (p<0.001). None of the patients with an MSD below 10mm or a trophoblastic mass below 20mm3 were converted to surgical management. There was no significant association between foetal cardiac activity and conversion from medical to surgical management.
Conclusions: CSP emerges as an important phenomenon in modern obstetrics and gynaecology and it appears that its frequency is on the rise. The preferred method of treatment is yet to be known, however, it is possible that a large MSD and trophoblastic mass, alongside markedly increased levels of β-hCG at presentation should prompt surgical treatment.