Pregnancy outcome following gestational exposure to organic solvents - A prospective controlled study

Context Numerous women of childbearing age are exposed occupationally to or ganic solvents. Previous retrospective studies have reported conflicting re sults regarding teratogenic risk. Objective To evaluate pregnancy and fetal outcome following maternal occupa tional exposure to organic solvents. Design A prospective, observational, controlled study, Setting An antenatal counseling service in Toronto, Ontario. Patients One hundred twenty-five pregnant women who were exposed occupation ally to organic solvents and seen during the first trimester between 1987 a nd 1996. Each pregnant woman who was exposed to organic solvents was matche d to a pregnant woman who was exposed to a nonteratogenic agent on age (+/- 4 years), gravidity (+/-1), and smoking and drinking status. Main Outcome Measure Occurrence of major congenital malformations. Results Significantly more major malformations occurred among fetuses of wo men exposed to organic solvents than controls (13 vs 1; relative risk, 13.0 ; 95% confidence interval, 1.8-99.5). Twelve malformations occurred among t he 75 women who had symptoms temporally associated with their exposure, whi le none occurred among 43 asymptomatic exposed women (P<.001), (One malform ation occurred in a woman for whom such information was missing.) More of t hese exposed women had previous miscarriage while working with organic solv ents than controls (54/117 [46.2%] vs 24/125 [19.2%]; P < .001). However, e xposed women who had a previous miscarriage had rates of major malformation that were similar to exposed women who had no previous miscarriage. Conclusions Occupational exposure to organic solvents during pregnancy is a ssociated with an increased risk of major fetal malformations, This risk ap pears to be increased among women who report symptoms associated with organ ic solvent exposure. Women's exposure to organic solvents should be minimiz ed during pregnancy. Symptomatic exposure appears to predict higher fetal r isk for malformations.