Cardiovascular Events During Pregnancy: Implications for Adverse Pregnancy Outcomes in Individuals With Autoimmune...

This study examined maternal cardiovascular (CV) events relative to adverse pregnancy outcomes (APOs) among individuals with autoimmune rheumatic diseases (ARDs), primary antiphospholipid syndrome (APS), and those with neither.

Using a California population-based birth cohort (2005-2020), we identified those with CV events (CVEs), ARDs, and APS through International Classification of Diseases, 9th and 10th revisions, Clinical Modification codes in maternal discharge records. Selected APOs identified from birth certificates were preterm birth (PTB; < 37 weeks' gestation), small-for-gestational-age infants (SGA; birth weight < 10th percentile for age and sex), and a composite of either outcome. Adjusted risk ratios (aRRs) for adverse outcomes and their 95% CIs were calculated.

CVEs occurred more frequently in individuals with ARDs (265 of 19,340 [1.4%]) and primary APS (428 of 7758 [5.5%]) than those without (17,130 of 7,004,334 [0.3%]). The presence vs absence of CVEs was associated with a greater incidence of adverse outcomes in ARD (53.2% vs 26.6%), APS (30.6% vs 20.7%), and non-ARD/APS pregnancies (28.2% vs 15.2%). CVEs were associated with increased risks of SGA in all groups (aRRs 1.2-1.5) and PTB in ARD (aRR 1.6, 95% CI 1.3-2.0) and non-ARD/APS (aRR 1.7, 95% CI 1.7-1.8) pregnancies.

CVEs were associated with modestly increased risks (20-70%) for PTB, SGA, or both across the groups. Notably, > 50% of ARD pregnancies with CVEs experienced APOs. Given that ARD and APS pregnancies have higher (although still low) rates of CVEs and have higher baseline risks of APOs than the general population, the additional burden conferred by CVEs is clinically important.