Psychosocial and pharmacological factors associated with prenatal smoking in women with psychiatric disorders

Background Cigarette smoking during pregnancy increases risks for adverse maternal and child outcomes. Individuals with psychiatric disorders—particularly schizophrenia spectrum disorders (SSD)—have higher smoking prevalence than the general population. However, it remains unclear whether, during pregnancy, SSDs exhibit higher smoking rates than those with other psychiatric disorders (non-SSD), and how psychosocial and pharmacological characteristics influence smoking in SSDs. Methods A total of 174 pregnant individuals with psychiatric disorders (SSD, n  = 33; non-SSD, n  = 141), identified from medical records at a single institution between 2006 and 2024, were evaluated. Smoking status, individual characteristics, and psychotropic use at the third trimester were assessed. Differences in smoking status between SSDs and non-SSDs, and factors associated with smoking during pregnancy were examined. Results In the third trimester, current smoking was more prevalent in SSDs (90.0%, n  = 10) than in non-SSDs (10.3%, n  = 39) (χ²=26.0, p  = 3.47×10⁻ ⁷ ), and cigarettes smoked per day (CPD) was higher in SSDs ( beta  = 0.36, p  = 3.03×10 ^− 6 ). Among SSDs, current smokers had lower educational attainment, used a greater number of psychotropic drugs, including antipsychotics, had higher antipsychotic chlorpromazine-equivalent dose (CPZeq), and had a higher prevalence of having no intention to breastfeed than non-current smokers. Logistic regression demonstrated significant associations between smoking and lower education, higher CPZeq, multiple psychotropics, and no intention to breastfeed ( p <  0.05). CPD correlated significantly with the number of antipsychotics used (B = 0.5, p  = 6.42×10⁻⁴). Conclusion Smoking during late pregnancy was more prevalent in SSDs, and smoking was associated with both psychosocial and pharmacological characteristics. Targeted interventions to promote breastfeeding and the implementation of antipsychotic monotherapy may help reduce smoking during pregnancy and improve maternal–child outcomes.