Pregnant women who faint (syncope) during pregnancy, especially in their first trimester, may have a higher risk of health problems for themselves and their babies according to new research published in Journal of the American Heart Association, the open access journal of the American Heart Association/American Stroke Association.
This is the first study to analyze the incidence and impact of fainting during pregnancy in a large population.
Researchers examined 481,930 pregnancies in Alberta, Canada between 2005 and 2014 for trends in timing, frequency and health complications for infants and women occurring in the first year after pregnancy among women who fainted during their pregnancies.
They found 4,667 women had a fainting episode and nearly a third (32.3 percent) of them occurred in the first trimester.
About 44 percent occurred in the second trimester and 23.6 percent in the third trimester, while 8 percent had more than one fainting episode.
Researchers also found:
- The incidence of congenital anomalies among children born of pregnancies with multiple fainting episodes was 4.9 percent, significantly higher than the 2.9 percent among children of pregnancies with only one fainting spell.
- The rate of premature birth, at 18.3 percent, was higher in pregnancies with fainting during the first trimester, compared to 15.8 percent during the second trimester, 14.2 percent in the third trimester and 15 percent for pregnancies without fainting.
- Within one year after delivery, women who fainted during pregnancy had higher rates of abnormal heart rhythms and fainting episodes, compared to women who didn’t faint during pregnancy.
- After an average follow-up of 4.5 to 5 years, the rates of congenital anomalies were 3.1 percent for children of pregnancies with syncope compared 2.6 percent for those without syncope.
“There are very limited data on the frequency of fainting during pregnancy,” said Padma Kaul, Ph.D., senior study author and professor of medicine at the University of Alberta in Canada.
In our study, fainting during pregnancy occurred in about 1 percent, or 10 per 1,000 pregnancies, but appears to be increasing by 5 percent each year.”
“Fainting during pregnancy has previously been thought to follow a relatively benign course,” Kaul said.
“The findings of our study suggest that timing of fainting during pregnancy may be important.
When the faint happens early during pregnancy or multiple times during pregnancy, it may be associated with both short and long term health issues for the baby and the mother.”
The data suggest that women who faint during pregnancy should have closer monitoring and potential follow-up with a cardiologist after the birth, she said.
Although the research provides real-world data on fainting during pregnancy in a large population base with universal health care, it has a few limitations.
Because the study is retrospective and observational it may underestimate the true incidence of syncope during pregnancy.
Researchers said their findings should be confirmed in other large population-based studies.
Incidence of Syncope During Pregnancy
Background We examined temporal trends, timing, and frequency, as well as adverse neonatal and maternal outcomes occurring in the first year postpartum among women experiencing syncope during pregnancy.
Methods and Results This was a retrospective study of pregnancies between January 1, 2005, and December 31, 2014, in the province of Alberta, Canada. Of 481 930 pregnancies, 4667 had an episode of syncope.
Poisson regression analysis found a 5% increase/year (rate ratio, 1.05; 95% CI, 1.04-1.06) in the age-adjusted incidence of syncope. Overall, 1506 (32.3%) of the syncope episodes first occurred in the first trimester, 2058 (44.1%) in the second trimester, and 1103 (23.6%) in the third trimester; and 8% (n=377) of pregnancies had >1 episode of syncope. Compared with women without syncope, women who experienced syncope were younger (age <25 years; 34.7% versus 20.8%; P<0.001), and primiparous (52.1% versus 42.4%; P<0.001).
The rate of preterm birth was higher in pregnancies with syncope during the first trimester (18.3%), compared with the second (15.8%) and third trimesters (14.2%) and pregnancies without syncope (15.0%; P<0.01).
The incidence of congenital anomalies among children born of pregnancies with multiple syncope episodes was significantly higher (4.9%) compared with children of pregnancies without syncope (2.9%; P<0.01).
Within 1 year after delivery, women with syncope during pregnancy had higher rates of cardiac arrhythmias and syncope episodes than women with no syncope during pregnancy.
Conclusions Pregnant women with syncope, especially when the syncopal event occurs during the first trimester, may be at a higher risk of adverse pregnancy outcomes as well as an increased incidence of cardiac arrhythmia and syncope postpartum.
More information: Safia Chatur et al. Incidence of Syncope During Pregnancy: Temporal Trends and Outcomes, Journal of the American Heart Association (2019). DOI: 10.1161/JAHA.118.011608
Journal information: Journal of the American Heart Association
Provided by American Heart Association