SEROTONIN SYNDROME AFTER TREATMENT OF NAUSEA AND VOMITING IN PREGNANCY

Abstract

Background: Nausea and vomiting in pregnancy (NVP) are common and may require ondansetron when first-line measures are inadequate. Although ondansetron is widely used, serotonin syndrome remains a rare but potentially serious adverse event with limited pregnancy-specific evidence. Objective: To assess the incidence of serotonin syndrome among pregnant women receiving ondansetron for severe NVP and to identify risk factors and clinical outcomes. Methods: This cross-sectional study included 100 pregnant women aged 18–45 years presenting to the Department of Obstetrics & Gynecology, Ittefaq Trust Hospital, Lahore. Severe NVP was considered a Pregnancy-Unique Quantification of Emesis score of ≥13 or when medical intervention was necessary. The sampling technique used was consecutive or non-probability sampling. Serotonin syndrome was determined using the Hunter Serotonin Toxicity Criteria. Data were analysed using SPSS version 26, and chi-square testing was done after stratification, with p≤0.05 accepted as significant. Results: Serotonin syndrome was identified in 12.0% of participants. The most common manifestations were tremor, agitation, hyperreflexia, sweating, and autonomic instability. Significant associations were observed with ondansetron dose >8 mg (p=0.008), treatment duration >5 days (p=0.001), BMI ≥25 kg/m² (p=0.014), gestational age >12 weeks (p=0.044), diabetes mellitus (p=0.015), hypertension (p=0.039), and anemia (p=0.022). No significant associations were found for age, parity, education, residence, occupation, lifestyle, socioeconomic status, and antenatal care. Conclusion: Serotonin syndrome was a significant number of pregnant women who were undergoing ondansetron therapy for their severe NVP. The dose and the duration of therapy were the most significant associations, which indicated careful clinical monitoring during the therapy in this particular study population.