Prevalence of self-reported infection during pregnancy among control mothers in the National Birth Defects Prevention...

Although specific maternal infections during pregnancy have been associated with birth defects and other adverse pregnancy outcomes, the prevalence of infections during pregnancy has not been well described.

We estimated the prevalence of self-reported infection among 4967 women with live-born infants without major birth defects. We assessed the prevalence of reported infections and fever by type of infection, specific illness, and maternal characteristics including race and age.

Overall, 63.6% of women reported at least one infection during pregnancy. Reports of infections were more common during pregnancy than in the 3 months before pregnancy. Nearly half (49.6%) of women reported a respiratory infection, 20.5% reported a fever, 17.1% reported a urinary tract infection, 4.2% reported a yeast infection, and 3.4% reported a sexually transmitted disease. A subanalysis of self-reported infection and preterm delivery was performed among primiparous mothers with singleton pregnancies, but no statistically significant differences in infection prevalence were found. Women younger than 35 years reported nonrespiratory infections more frequently than women aged 35 years or older (prevalence ratio [PR] 1.41; 95% confidence interval [CI]: 1.21-1.64). Prevalence of nonrespiratory infections was also higher among those who smoked than among those who did not (PR 1.33; 95% CI: 1.20-1.47).

Reported infections during pregnancy are common, implying that a small increase in risk for birth defects or other adverse pregnancy outcomes could have a significant public health effect and underscoring the importance of understanding the effects of prenatal infections.