Dietary Intake and Its Association with Birth Outcomes in Women with Nausea and Vomiting during the Second Trimester of Pregnancy: A Prospective Cohort Study in Japan

Nausea and vomiting in pregnancy (NVP) is a common symptom. Although the influence of NVP during the first trimester on dietary intake and birth outcomes has been revealed, no study has focused on NVP during the second trimester. This study aimed to reveal whether NVP severity during the second trimester is associated with dietary intake, gestational weight gain (GWG), birth weight, and delivery week. Participants completed a questionnaire at 18–27 gestational weeks. NVP severity was assessed using the modified Pregnancy-Unique Quantification of Emesis and Nausea scale in the questionnaire. Dietary habits were assessed using a brief-type diet history questionnaire. In total, 825 responses were analyzed: 202 (24.5%), 135 (16.4%), and 8 (1.0%) women reported mild, moderate, and severe NVP, respectively; 480 (58.2%) women did not have NVP during the second trimester. No significant association was observed between energy and nutrient intake and no/mild and moderate/severe NVP. Women with moderate/severe NVP had lower total GWG than those with no/mild NVP (p = 0.007). There was no significant difference in low birth weight and preterm birth rates (p = 0.246 and p = 0.604). This is the first study to investigate whether NVP severity during the second trimester is associated with dietary intake and birth outcomes.