Atypical hemolytic uremic syndrome and pregnancy outcomes: a cohort study

Abstract

Atypical Hemolytic Uremic syndrome (AHUS) is a rare microangiopathy. As a dearth of information was available on the effect of this condition on pregnancy, our study aimed to examine the association between maternal AHUS and obstetrical and neonatal outcomes. Using the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample from the US, a retrospective cohort study was conducted consisting of women who delivered between 1999-2015. ICD-9 code 283.11 was used to identify women with a diagnosis of AHUS. Multivariate logistic regression estimated the effect of AHUS on maternal and neonatal outcomes, while adjusting for maternal baseline variables. There were 13,792,429 women who delivered between 1999-2015, of which 115 had a diagnosis of AHUS (8/1,000,000). Women with AHUS, compared with those without this diagnosis, had greater prevalence of pre-existing diabetes, hypertension, and obesity. AHUS was associated with several adverse outcomes: maternal death, odds ratio 355.49, 95% CI 161.36-783.18, preeclampsia, 30.21, 20.61-44.27, eclampsia, 10.68, 1.49-76.68, placental abruptio, 16.77, 10.22-27.52, disseminated intravascular coagulation, 260.53, 134.30-505.40, venous thromboembolism, 18.82, 7.60-46.59, sepsis, 134.81, 48.73-372.96, myocardial infarction, 429.13, 102.99-1788.15, post-partum hemorrhage, 19.16, 13.09-28.04, requiring a blood transfusion, 121.43, 83.25-177.12, and cesarean delivery, 3.93, 2.63-5.86. Neonates born to women with AHUS were at increased risk for preterm birth, 3.89, 2.53-5.97, intrauterine growth restriction, 3.64, 1.83-7.25, and stillbirth, 13.66, 7.29-25.59. There was a greater risk of adverse maternal and neonatal outcomes, including maternal and fetal death, among AHUS-impacted pregnancies; hence, such pregnancies should be attentively monitored.