Potential Risk Factors for Developing Cesarean Scar Pregnancy in Women With a History of Cesarean Section

Cesarean scar pregnancy (CSP) occurs in 0.2%-0.5% of women with a previous cesarean section globally. Multiple factors influence the development of CSP; however, to date, the critical factors contributing to the development of CSP have not been fully explored due to its relatively low incidence. Moreover, CSP can be clinically categorized into type 1 and type 2 CSP. In this retrospective study with a large sample size, we investigated potential risk factors that could contribute to CSP development.

Two hundred-one women diagnosed with CSP, either type 1 or type 2 CSP, and 1700 pregnant women with a history of cesarean section but without CSP diagnosis in subsequent pregnancy were included. Gravidity, previous live birth(s), consecutive cesarean section(s), surgical abortion(s), the interval between the pregnancies, and maternal age were compared between the 2 groups.

Gravidity, the number of previous live births, the number of previous consecutive cesarean sections, and the number of surgical abortions were significantly associated with CSP development in women with a past cesarean section. This association was regardless of the subtypes of CSP. Notably, the interval between 2 pregnancies was also significantly associated with CSP development, but this association was only seen in type 2 CSP. However, maternal age was not an independent risk factor for CSP development. Additionally, a higher incidence of CSP was observed in China compared to that reported in the literature.

In addition to a previous cesarean section, our study highlights at the number of surgical abortions also contributes to the development of CSP.