Outcome of pregnancies subsequent to placental abruption: A risk assessment

Abstract

Objective. To assess the risk of small for gestational age (SGA), preterm birth, pregnancy induced hypertension (PIH), and perinatal death in the pregnancy immediate subsequent to a placental abruption (PA) in the same mother. Design. A cohort study based on the Medical Birth Registry of Norway. Results. Odds ratios of SGA in subsequent PA- and non-PA deliveries were 2.8 (absolute risk = 18.5%) and 2.0 (13.9%), respectively, compared with non-PA deliveries without a history of previous PA among siblings (7.5%) after exclusion of cases with SGA in the immediate previous birth. After exclusion of cases with spontaneous preterm birth in the immediate previous delivery, odds ratios of spontaneous preterm birth in subsequent PA- and non-PA deliveries were 17.0 (36.3%) and 2.1 (6.6%), compared with non-PA deliveries without a history of previous PA among siblings (3.2%). After exclusion of cases with PIH in the immediate previous pregnancy, odds ratios of PTH in subsequent PA- and non-PA pregnancies were 2.9 (6.3%,) and 1.6 (3.4%), compared with non-PA deliveries without a history of previous PA among siblings (2.3%). After adjustment for demographic variables and obstetrical complications, the increased risks persisted. Conclusion. A pregnancy following a PA must be considered a high risk pregnancy, not only in terms of excess risk of recurrence, but also due to excess risk of SGA, preterm birth, and PTH irrespective of recurrence of PA. Consequently, all pregnancies following a pregnancy with PA should be offered close antenatal surveillance and care.