Risk factor profiles in in-vitro fertilization pregnancies that develop placenta accreta spectrum

Antenatal diagnosis of placenta accreta spectrum (PAS), allowing for advanced multidisciplinary planning, has been shown to reduce maternal morbidity. The strongest risk factors for PAS are prior cesarean delivery and a placenta previa. The objective of this study is to assess whether, among a cohort placenta accreta spectrum (PAS) patients, antenatal diagnosis of PAS was less likely in in-vitro fertilization (IVF) compared to non-IVF patients. This is an international multicenter retrospective study of patients with pathologically confirmed PAS (basal placenta myometrial fibers, accreta, increta, percreta) between 1998 – 2021. PAS patients were identified through a central international PAS database. Antenatal and pathologic criteria are specific to each institution. Pregnancies which resulted from IVF were compared to non-IVF pregnancies; singletons and multiple fetal gestations were included. Comparisons were made using a Chi-square or Fisher’s exact test for categorical variables and Wilcoxon rank-sum test for continuous variables. Of the 863 pregnancies included, 97 were in the IVF group and 766 were in the non-IVF group. The IVF group was less likely to have had a prior cesarean delivery (40% vs. 82%, p< 0.01) and less likely to have a placenta previa (36% vs. 59%, p< 0.01) compared to the non-IVF group. The IVF group was also less likely to have a prior cesarean delivery or placenta previa than the non-IVF group (50% vs. 86%, p< 0.01). Antenatal detection of PAS was less common in the IVF group compared to the non-IVF group (20% vs. 51%, p< 0.01, respectively). The IVF group had less severe pathological invasion compared to the non-IVF group (p< 0.01). (Table 1) Pregnant people with PAS who underwent IVF are less likely to have an antenatal diagnosis prior to delivery. This finding may be explained by the lower incidence of prior cesarean deliveries and/or placenta previa as well as less severe forms of PAS.