A risk-benefit assessment of pharmacological and nonpharmacological treatments for nausea and vomiting of pregnancy.

Despite evidence of fetal safety, most antiemetics are contraindicated in pregnancy. We summarise a risk-benefit analysis of the literature on safety and effectiveness of pharmacotherapy and nontraditional therapy for nausea and vomiting of pregnancy (NVP) to provide evidence-based guidelines on the management of NVP. The medical literature was scanned for controlled studies on the human teratogenicity and effect of various antiemetics in pregnant women. Data were pooled based on drug/therapy class and summarised to determine relative risk with 95% confidence interval (for malformations and failure rates for NVP) and homogeneity (chi-square test). Evidence from controlled trials has demonstrated the safety and efficacy of the following drugs for the treatment of varying degrees of NVP: doxylamine/pyridoxine+/-dicycloverine (dicyclomine), antihistamine H1 receptor antagonists, and phenothiazines (as a group). However, pooled data for doxylamine/pyridoxine+/-dicycloverine, H1 antagonists and phenothiazines were not homogeneous. Other therapies, such as pyridoxine alone, metoclopramide, ondansetron and the corticosteroids may be beneficial in managing NVP. However, limited efficacy studies and the paucity of well-controlled safety studies may limit the use of some of these agents among patients not responsive to first-line agents. Well-controlled safety and effectiveness trials in patients with NVP are lacking for nonpharmacological treatments (e.g. acupressure). NVP can be managed safely and effectively. Further trials must be conducted in order to determine the true effectiveness of certain agents in patients with NVP.