Abstract
Study question
Does primary hyperaldosteronism(PA) confer an independent risk for adverse pregnancy or neonatal outcomes, based on analysis of the Healthcare-Cost and Utilization Project-Nationwide Inpatient Sample(HCUP-NIS) database?
Summary answer
After controlling for all significant confounders, women with PA are at increased risk for gestational hypertension, eclampsia, and operative vaginal delivery, but unexpectedly not preeclampsia
What is known already
PA is extremely rare in pregnancy, and our current knowledge regarding PA during pregnancy is derived only from case reports and series. No pregnancy control studies exist in the literature for this endocrinopathy. PA is characterized by autonomous aldosterone and suppressed rennin production from the adrenals. Caused by adenomas or hyperplasia, it presents with hypertension and hypokalaemia.
Study design, size, duration
This is a retrospective population-based cohort study utilizing data from the HCUP-NIS from 2004 to 2014, inclusively. A cohort of all deliveries during the study period was created. Within this group, all deliveries to women with PA were identified as part of the study group (n = 102), and the remaining deliveries were categorized as the reference group (n = 9,096,686).
Participants/materials, setting, methods
HCUP-NIS is the largest inpatient sample database in the USA and is comprised of hospital stays throughout the country. It provides information relating to seven million inpatient stays yearly, includes 20% of admissions, and represents over 96% of the American population. Multivariate logistic regression, controlling for confounders, was conducted to explore associations between PA and delivery outcomes. According to the Tri-Council Policy Statement (2018), IRB-approval was not required, given data was anonymous and publicly available.
Main results and the role of chance
Women with PA were older(P = 0.0001), more likely obese(10.8% vs. 3.6%), with higher rates of chronic hypertension(53.9% vs. 1.8%), thyroid disease(15.7% vs. 2.5%), pre-gestational diabetes(5.9% vs. 1%)(all P = 0.0001), and were more commonly African American and not Hispanic(P = 0.04) than the controls. There was no statistical difference between the two groups in the other demographic features including; income distribution(P = 0.45), hospital type (P = 0.63), rates of smoking(P = 0.99), illicit drug use(P = 0.73) or use of assisted reproductive technology(P = 0.94). After adjustment for significant confounders women with PA were more likely to experience gestational hypertension(aOR 3.6 95%CI:1.6–8.1, P = 0.001) and eclampsia(aOR 19.0, 95%CI:2.6–138.2, P = 0.004). Moreover, women with PA were more likely to deliver by operative vaginal delivery(aOR 9.7 95%CI:6.3–15.1, P = 0.0001). However, there was no increased risk for preeclampsia in women with PA(aOR 1.47 95%CI:0.78–2.76, P = 0.23). This finding was consistent even when not controlling for confounding effects including pre-gestational hypertention(OR 0.81 95%CI:0.26–2.56, P = 0.72. There were no differences in the number of women with PPROM(P = 0.81), preterm delivery(P = 0.88), placental abruptio(P = 0.7), maternal death(P = 0.99), hysterectomy(P = 0.99), cesarean section(P = 0.76), chorioamnionitis(P = 0.99), postpartum hemorrhage (P = 0.53), maternal infection(P = 0.99), pulmonary embolism(P = 0.99) or disseminated intravascular coagulation(P = 0.99) between the two groups. Furthermore, there was no difference in other neonatal outcomes including: small for gestational age(P = 0.18), fetal demise(P = 0.85) or congenital anomalies(P = 0.15).
Limitations, reasons for caution
This is a retrospective analysis utilizing an administrative database that relies on data coding accuracy and consistency.
Wider implications of the findings: Women with PA were more likely to experience adverse pregnancy outcomes, including gestational hypertension, eclampsia, and operative vaginal deliveries. Neonatal complications were not increased in PA. Surprisingly, there was no increased risk for preeclampsia in women with PA, which needs to be further studied.
Trial registration number
NA
The Effects of Epidural Analgesia during Labor on Maternal and Neonatal Outcomes
