35: Medication effects on maternal serum screening

Maternal ethnicity and diabetes affect the concentration of maternal serum analytes in aneuploidy screening, but little is known about the effect of medications on analyte concentrations. Since medications can alter the activity of metabolic enzymes, we sought to determine whether certain drug classes are associated with alterations in concentrations of “Quad screen” analytes or the overall screen-positive rate. IRB-approved, retrospective cohort of singleton gestations with a Quad screen performed in our laboratory 12/04-6/07. Information on medications (by class) taken at time of Quad screen was abstracted from our computerized prenatal database. Mean multiples of the median (MoM) for each analyte (after routine adjustment for weight and ethnicity) and the overall screening result were abstracted from the laboratory database and compared between the exposed (those taking the class of agent) and controls (those not taking that class of agent). 6,482 women were included. AFP mean MoM was higher in women taking immunosuppressants compared to controls (1.4 vs 1.1, p=0.02) and these women more frequently were screen positive for NTDs (12.8 vs 1.6%, p<0.0001). Methadone and immunosuppressants were associated with lower mean estriol MoM (0.9 vs 1.1, p=0.04). Mean hCG levels were lower in women taking methadone (0.8 vs 1.1, p=0.005), but higher with anti-emetics (1.1 vs 1.0, p=0.009). Mean inhibin A MoM was increased in women on drugs for asthma, epilepsy, hypertension, and depression (all p<0.02). Women taking anti-depressants and anti-epileptics were more likely to have a positive screen for trisomy 21 than controls (6.7 vs 3.9%, p=0.04; 9.7 vs 3.9%, p=0.02, respectively). Various drug classes affect the 4 analytes used for Quad screening and the screen-positive rate. Whether adjustment of results based on medication usage improves screening performance warrants further investigation.