SYSTEMIC ANTIBIOTIC USE DURING PREGNANCY AND CHILDHOOD CANCER IN THE OFFSPRING
Research suggests the majority of women are prescribed at least one drug during pregnancy, and that there is an association between systemic antibiotics taken during pregnancy and childhood cancers. However, studies to date have been unable to consider timing and dosage, and provided inconclusive results.
METHODS:
A nested case-control design was used to study associations between use of systemic antibiotics during pregnancy and cancer in childhood. By means of the nationwide registers of Denmark we identified women who filled prescriptions from three months before conception up to the child’s birth, from 1995 to 2008. Each cancer case, aged 0 to 14 years (n=1,157, including 475 leukemia, 153 central and sympathetic nervous system tumors, and 80 renal tumors), was matched by birthdate and sex with three population-based controls (n=3,471). Conditional logistic regression was used to estimate odds ratios (OR) with 95% confidence intervals (95% CIs), adjusted for parity, maternal smoking during pregnancy, and maternal age and maternal education at time of birth.
RESULTS:
About 39% of mothers redeemed prescriptions for systemic antibiotics during the exposure window. The OR of the association between childhood cancer and exposure to antibiotics was 1.04 (95% CI: 0.91, 1.20), based on 455 exposed cases (39%) and 1,333 exposed controls (38%). Point estimates were greatest for those exposed in the third trimester (OR=1.14; 95% CI: 0.93, 1.40) and for those exposed to doses in the highest tertile (OR=1.15; 95% CI: 0.93, 1.41).
CONCLUSIONS:
There were no associations between prenatal exposure to systemic antibiotics and childhood cancer. However, research in this area requires large sample sizes, particular to consider types of childhood cancer and effects of timing and dosage for specific antibiotics. We plan to investigate these further with the addition of data from the Swedish national registers and the California Childhood Leukemia Study.