(202) Spontaneous Abortion and Drug Exposure. Case-Control Study with SIDIAP Database

Publication Number: 533

Background: Drug use during pregnancy has been understudied due to limited access to women participation in clinical trials for ethical concerns. Database studies can help to fill this gap by providing data on drug exposure during pregnancy and its outcomes in women and their offspring

Objectives: To describe drug exposure during the first trimester of gestation and to estimate its relation with spontaneous abortion

Methods: Case-control study of pregnancy episodes in women aged 12-50 from SIDIAP database matched 1:2 by age of the mother (+/-3) at each episode. SIDIAP contains Primary Health Care electronic records of the Catalan Health Institute. We created a cohort of pregnancy episodes occurring during 2011-2020. Cases: all pregnancies ending in spontaneous abortion [(maximum end at 120 days from pregnancy start date (PSD)]. Controls: all pregnancies ending in labour (also C section). Variables: smoking, alcohol intake and BMI from 12 months before to 120 days after PSD. Medical conditions up to 120 days after PSD and obstetric history of previous pregnancies during the study period. Drug exposure: dispensation of any drug 30 days before to 120 days after PSD or at spontaneous abortion date, whichever occurs first. Outcome: association of drug exposure with abortion. Statistical analysis: descriptive data, crude (ORcrude) and adjusted (ORadj) odds ratios with 95% confidence intervals (95%CI), calculated using conditional logistic regression. Adjusted for those variables and for drugs accounting ≥3% cases and with significant differences in chi-square test (p < 0.05)

Results: 60,380 spontaneous abortions were matched with 120,312 completed pregnancies. Spontaneous abortion episodes reported more tobacco, 4.5% vs 3.6%, and alcohol, 10% vs 7%, than pregnancies. Cases and controls showed similar rates of medical conditions, with statistical differences for anxiety 30.2% vs 25.5%, respectively, obesity 12.6% vs 10.9%, and respiratory diseases 10.6% vs 9.1%. Cases and controls showed similar rates for episodes without drug exposure 33.5% vs 33.1% respectively]. Iodine therapy, vitamin B12 and folic acid and iron were associated to a reduced risk for spontaneous abortions [ORadj 0.74 (95%CI 0,73–0.75), 0.77 (0.76-0.79) and 0.87 (0.85-0.90)]. Anxiolytics [1.26, (1.21-1.31), antidepressants [1.11 (1.06-1.16)], antihistamines [1.20 (1.15-1.24)] and NSAID, 1.58 (1.54-1.62) showed risk

Conclusions: Exposure to drugs during the 1st trimester of pregnancy could be associated with abortion, as seen for anxiolytics, antidepressants, antihistamines and NSAID, but not for preventive prenatal supplements. Special attention to drugs used in women at gestational age must be made, as exposure in the 1st trimester is often unintentional as they are unaware of their pregnancy