Nausea and vomiting during pregnancy associated with lower incidence of preterm births: the Japan Environment and Children's Study (JECS)

• Published in: BMC pregnancy and childbirth 2018-06, Vol.18 (1), p.268-268, Article 268
• Main Authors: Mitsuda, Naomi, Eitoku, Masamitsu, Yamasaki, Keiko, Sakaguchi, Masahiko, Yasumitsu-Lovell, Kahoko, Maeda, Nagamasa, Fujieda, Mikiya, Suganuma, Narufumi
• Format: Article
• Language: English
• Subjects: Adult; Clinical outcomes; Cohort Studies; Epidemiology; Female; Health risk assessment; Humans; Incidence; Infant, Newborn; Japan - epidemiology; JECS; Nausea; Nausea - complications; Nausea - epidemiology; Nausea and vomiting during pregnancy; Pregnancy; Pregnancy Complications - epidemiology; Premature birth; Premature Birth - epidemiology; Premature Birth - etiology; Preterm birth; Retrospective Studies; Risk Assessment - methods; Vomiting; Vomiting - complications; Vomiting - epidemiology; Womens health
• ISSN: 1471-2393; 1471-2393
• DOI: 10.1186/s12884-018-1911-1

Nausea and vomiting during pregnancy (NVP) is considered to be associated with favorable fetal outcomes, such as a decreased risk for spontaneous abortion. However, the relationship between NVP and preterm births remains unknown. This study was conducted to evaluate the association between NVP and the risk of preterm births. The dataset of a birth cohort study, the Japan Environment and Children's Study (JECS), was retrospectively reviewed. Participants' experience of NVP prior to 12 gestational weeks were evaluated by a questionnaire administered from 22 weeks of pregnancy to 1 month before delivery. NVP responses were elicited against four choices based on which the study population was divided into four subcohorts. Preterm birth was the main study outcome. Logistic regression analysis was used to quantify an association between NVP and risk of preterm birth. Of 96,056 women, 79,460 (82.7%) experienced some symptoms of NVP and 10,518 (10.9%) experienced severe NVP. Compared to those who did not experience NVP, women with severe NVP had lower odds for preterm birth [adjusted odds ratio (aOR) 0.84, 95% confidence interval (95% CI) 0.74-0.95]. An even lower OR was found among very preterm birth and extremely preterm birth (aOR 0.44, 95% CI 0.29-0.65). An inverse association exists between NVP and preterm births, especially, very preterm births and extremely preterm births.