MATERNAL LYME-DISEASE AND CONGENITAL-MALFORMATIONS - A CORD-BLOOD SEROSURVEY IN ENDEMIC AND CONTROL AREAS

This report describes a cohort study of over 5000 infants and their mo thers who participated in a cord blood serosurvey designed to examine the relationship between maternal exposure to Lyme disease and adverse pregnancy outcome. Based on serology and reported clinical history, m others of infants in an endemic hospital cohort are 5 to 20 times more likely to have been exposed to B. burgdorferi as compared with mother s of infants in a control hospital cohort. The incidence of total cong enital malformations was not significantly different in the endemic co hort compared with the control cohort, but the rate of cardiac malform ations was significantly higher in the endemic cohort [odds ratio (OR) 2.40; 95% confidence interval (CI) 1.25, 4.59] and the frequencies of certain minor malformations (haemangiomas, polydactyly, and hydrocele ), were significantly increased in the control group. Demographic vari ations could only account for differences in the frequency of polydact yly. Within the endemic cohort, there were no differences in the rate of major or minor malformations or mean birthweight by category of pos sible maternal exposure to Lyme disease or cord blood serology. The di sparity between observations at the population and individual levels r equires further investigation. The absence of association at the indiv idual level in the endemic area could be because of the small number o f women who were actually exposed either in terms of serology or clini cal history. The reason for the findings at the population level is no t known but could be because of artifact or population differences.