Short interval pregnancy is associated with pathology severity in placenta accreta spectrum (PAS)

Placenta accreta spectrum (PAS) is a continuum of invasive pathologies associated with significant maternal morbidity and mortality. Pregnancies with short intervals present additional complications which may result from suboptimal wound healing. The impact of short interval pregnancy on placental invasion is unknown our primary objective was to characterize the impact of short interval pregnancy in the subsequent invasive degree of PAS.

Here we present a retrospective case-control analysis of 133 patients with pathology-confirmed PAS who presented to our Placenta Accreta program and assessed for the impact of short interval pregnancy (<18 months) as an independent risk factor for the development of advanced pathology.

33.8% (45/133) of patients with PAS had pregnancies complicated by short intervals between gestations. Short interval pregnancies were significantly associated with placenta percreta/increta pathology (p = .006). Ordinal logistic regression showed an inversely proportional relationship between short-interval pregnancy and the degree of placental invasion (OR 2.91 [95% CI 1.02, 4.05]).

Short interval pregnancies are at increased risk for greater degrees of placenta invasion seen in placenta increta and percreta when compared to interpregnancy interval >18 months. This relationship is inversely proportional and consistent at shorter intervals. Thus, when counseling patients on their overall risk of placental invasive pathology, short interval pregnancy may be considered a significant risk factor.