Placental abruption in parents who were born small: registry‐based cohort study. (28th August 2017) - Rasmussen, S
Abstract : Objective: To assess whether parents who were born small for gestational age (below the 10th birthweight centile, SGA) have increased risk of severe or mild placental abruption. To assess whether a history of SGA in other family members modifies this intergenerational effect. Design: Prospective population‐based observational study. Setting: The Medical Birth Registry of Norway. Population: From 1967 to 2013, 785 333 mother–offspring pairs, 643 066 father–offspring pairs, 272 941 maternal tetrads (i.e. her offspring, sibling, and niece/nephew), and 265 505 paternal tetrads were identified. Methods: Cohort study based on linked data from the Medical Birth Registry of Norway. Main outcome measures: Relative risk (RR) of severe placental abruption (preterm birth, birthweight below the 10th centile, or perinatal death) and mild placental abruption (other cases) in families with SGA. Results: Mothers who were born SGA had increased risk of severe placental abruption (RR 1.5; 95% confidence interval, 95% CI 1.3–1.8), but not mild abruption. The paternal effects were weaker. The combined effect of SGA in the mother and her sibling on severe abruption was twofold (RR 2.4; 95% CI 1.7–3.3) compared with birthweight centiles ≥10 for both. Similarly, the effect of adding an SGA niece/nephew was twofold (RR 2.3; 95% CI 1.3–3.9), whereas the combined effect of SGA in the mother, her sibling and her niece/nephew was fourfold (RR 3.6; 95% CI 1.9–6.8). Conclusions: Women who were born SGA have an increased risk of severe placental abruption. The corresponding paternal effect was modest. A history of SGA in other family members increases the generational effect. Tweetable abstract: Women born small for gestational age have excess risk of placental abruption. Abstract : Tweetable abstract Women born small for gestational age have excess risk of placental abruption.