Syncope is defined as the temporary loss of consciousness due to cerebral hypoperfusion. The condition may be due to several underlying cardiovascular conditions that range from life-threatening conditions such as arrhythmia to benign conditions, such as vasovagal episodes. Pregnant women have several cardiovascular changes that increase their risk of developing syncope. These changes include increased heart rate and blood volume, reduction in systemic vascular resistance, and eccentric left ventricular hypertrophy.

This is a retrospective study that examined the temporal trends, timing, and frequency, as well as adverse neonatal and maternal outcomes occurring in the first year postpartum women experiencing syncope during pregnancy. The author of the study wrote, “There are currently limited data on the incidence of syncope in pregnancy. While most reports suggest a benign course for both mother and child, there are no long?term follow?up data. Given this paucity of evidence, we sought to describe temporal trends in the incidence of syncope during pregnancy using a large, contemporary, population?based cohort of women in a defined geographic area with a single?payer health care system with universal access.”

Out of 4,81,930 pregnancies that were registered between January 1, 2005, and December 31, 2014, in the province of Alberta, Canada, 4,667 had the episode of syncope.  The incidence of syncope was found to be a 5 % increase per year, which was calculated through Poisson regression analysis. 32.3% of the syncope occurred in the first trimester while 44.1% was registered in the second trimester. The third semester registered 23.6% of syncope episodes. 377 pregnancies had more than 1 episode of syncope. The preterm birth was higher in pregnancies, those have the syncope in the first trimester (18.3%) as compared to second (15.8%) and third trimester (14.2%). Pregnancies without syncope have a preterm rate of 15%. The study also found that women with multiple episodes of syncope have high incidences (4.9%) of congenital anomalies as compared to women without syncope (2.9%). The study also observed that within 1 year after delivery, higher rates of cardiac arrhythmias and syncope episodes were found in women with syncope during pregnancy than women with no syncope during pregnancy.

Source

Chatur S, Islam S, Moore LE, Sandhu RK, Sheldon RS, Kaul P. Incidence of Syncope During Pregnancy: Temporal Trends and Outcomes. J Am Heart Assoc. 2019 May 21;8(10):e011608. doi: 10.1161/JAHA.118.011608. PMID: 31088190; PMCID: PMC6585338.