The Problem of Confounding in Studies of the Effect of Maternal Drug Use on Pregnancy Outcome

Table 7

Concomitant drug use in early pregnancy among 11,181 women who used antidepressants [2]. Odds ratios (ORs) with 95% confidence intervals (95% CI) for use of specific group categories in women using antidepressants compared with women who did not. Adjustment for year of birth, maternal age, parity, smoking in early pregnancy, and BMI.

Drug group	Number of users	OR	95% CI
Drugs for stomach ulcer and reflux	316	2.92	2.61–3.26
Drugs for inflammatory bowel disease	41	1.27	0.93–1.73
Insulin	49	1.13	0.85–1.50
Multivitamins	559	0.78	0.72–0.85
Folic acid	519	0.82	0.75–0.90
Oral contraceptives during pregnancy	160	3.52	3.02–4.11
Gonadotropins	22	0.85	0.56–1.28
Systemic corticosteroids	65	1.55	1.21–1.98
Thyroid drugs	317	1.89	1.69–2.11
Antibiotics	321	0.92	0.82–1.03
NSAIDs	300	1.21	1.08–1.36
Opioids	261	3.48	3.09–3.93
Minor analgesics	835	0.83	0.77–0.89
Anticonvulsants	110	3.17	2.63–3.82
Antipsychotics	283	7.13	6.39–7.97
Sedatives, hypnotics	1202	25.9	24.6–27.3
Drugs for rhinitis	146	0.92	0.78–1.09
Antiasthmatics	533	1.40	1.28–1.53
Antihistamines	1097	1.79	1.68–1.90