Association of the common cold in the first trimester of pregnancy with birth defects.

ABSTRACT

OBJECTIVE: To examine the association between the common cold with or without fever in the first 3 months of pregnancy and birth defects in offspring. DESIGN: A case-control study. SETTING: Data are from the Shanghai Birth Defects Monitoring Program, conducted in 29 hospitals in Shanghai, China from October 1, 1986 to September 30, 1987. SUBJECTS: A total of 986 birth defects cases, 990 frequency-matched live birth controls, and 159 stillbirth controls. RESULTS: Modestly elevated risk of birth defects was identified among women who reported having a cold with or without fever in the first trimester of pregnancy. Notably increased relative risks were observed for anencephalus (odds ratio [OR] = 3.9, 95% confidence interval [CI] = 2.0 to 7.7), spina bifida (OR = 4.1, 95% CI = 1.7 to 9.7), hydrocephalus (OR = 2.3, 95% CI = 1.1 to 5.1), cleft lip (OR = 2.2, 95% CI = 1.4 to 3.4), and undescended testicle (OR = 1.8, 95% CI = 1.0 to 3.0). Our study further found that the overall relative risks were consistent by using two different control groups, suggesting that this association was unlikely to be due to recall or report bias. CONCLUSION: Common cold in the first trimester of pregnancy may be associated with an increased risk of birth defects in offspring. However, these findings should be interpreted cautiously.