Adverse maternal and birth outcomes in women admitted to hospital for hyperemesis gravidarum: A population-based cohort study

Background: Evidence for risks of adverse maternal and birth outcomes in women with hyperemesis gravidarum (HG) is predominantly from small studies, unknown, or conflicting.Methods: A population-based cohort study using secondary health care records (Hospital Episode Statistics covering all of England from 1997 to 2012) was used to calculate odds ratios (OR) with 99% confidence intervals (CI) for the association between HG hospital admission and adverse outcomes, adjusting for maternal and pregnancy confounders.Results: Within 8 211 850 pregnancies ending in live births or stillbirths, women with HG had increased odds of anaemia (OR 1.28, 99% CI 1.23, 1.33), preeclampsia (OR 1.16, 99% CI 1.09, 1.22), eclampsia (OR 1.84, 99% CI 1.07, 3.18), venous thromboembolism antenatally (OR 1.94, 99% CI 1.57, 2.39 for deep vein thrombosis, and OR 2.54, 99% CI 1.89, 3.40 for pulmonary embolism) and post-partum. Odds of stillbirth (OR 0.77, 99% CI 0.66, 0.89) and post-term (OR 0.86, 99% CI 0.81, 0.92) delivery were decreased. Women were more likely to be induced (OR 1.20, 99% CI 1.16, 1.23), to deliver preterm (OR 1.11, 99% CI 1.05, 1.17), very preterm (OR 1.18, 99% CI 1.05, 1.32), or by caesarean section (OR 1.12, 99% CI 1.08, 1.16), to have low birthweight (OR 1.12, 99% CI 1.08, 1.17) or small for gestational age (OR 1.06, 99% CI 1.01, 1.11) babies and although absolute risks were small, their offspring were more likely to undergo resuscitation or neonatal intensive care.Conclusion: HG may have important antenatal and postnatal consequences that should be considered in communications between health care professionals and women to best manage HG and prevent progression during pregnancy