Maternal risk factors for congenital syphilis: a case-control study.

This study estimated the strength of association between maternal cocaine use and congenital syphilis after adjustment for other factors, especially the use of prenatal care. The authors reviewed medical chart and laboratory data for 75 liveborn infants treated for congenital syphilis at Harlem Hospital Center (New York City) in 1987, 150 matched control infants, and their mothers. Cocaine use was determined from universal maternal medical histories and infant toxicology screenings, and the sensitivity of each method of ascertainment was evaluated. With the use of either maternal history or positive infant urine toxicology as evidence of cocaine use, 66.2% (49/74) of case infants versus 16.1% (24/149) of control infants were judged to have been exposed to cocaine in utero (odds ratio (OR) = 9.1, 95% confidence interval (Cl) 4.7-29.2). However, in multiple logistic regression, lack of prenatal care was the single variable with the highest adjusted odds ratio (adjusted OR = 11.0, 95% Cl 1.3-93.1); maternal cocaine use had the second-highest adjusted odds ratio (adjusted OR = 4.9, 95% Cl 1.8-13.0). Thus, despite the emergence of maternal cocaine use as a new risk factor, underutilization of prenatal care remains the strongest predictor of congenital syphilis.