Population-based case-control study of the common cold during pregnancy and congenital abnormalities.

The common cold is the most frequent maternal disease during pregnancy. The possible association between different congenital abnormalities and the common cold in pregnant women was evaluated in the data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities between 1980 and 1996. Of 22,843 cases with congenital abnormalities, 3,827 (16.8%) had mothers with the common cold, while of 38,151 population controls without congenital abnormalities, 5,475 (14.4%) (adjusted prevalence odds ratio: POR: 1.26 with 95% CI: 1.20-1.32). Of 834 malformed controls with Down syndrome, 114 (17.3%) had mothers with the common cold (POR: 0.96 with 95% CI: 0.80-1.16). Nearly half of mothers with the common cold had secondary complications with antifever therapy. The comparison of cases with 25 congenital abnormalities and population control mothers with medically recorded common cold during the second and third months of gestation showed that five congenital abnormality groups: congenital hydrocephaly (3.6, 1.3-9.7), cleft lip+/-palate (2.3, 1.5-3.6), posterior cleft palate (2.3, 1.2-4.1), limb deficiencies (2.2, 1.1-4.1) and multiple CAs (2.0, 1.4-2.9) had adjusted POR 2 or more. The comparison of cases with different congenital abnormalities and malformed controls (including offspring with Down syndrome) as referent, indicated a higher prevalence of the common cold during the second and third month of gestation only in the mothers of cases with cleft lip+/-palate (adjusted POR: 1.7 with 95% CI: 1.2-2.5), however, congenital hydrocephaly, neural-tube defects and multiple CAs had also mothers with a somewhat higher occurrence of the common cold. The possible association between the common cold during early pregnancy and the above mentioned congenital abnormalities may be connected mainly with the indirect effect of secondary complications of maternal common cold, particularly high fever because antifever drugs were able to prevent the possible teratogenic effect of the common cold.