[Associations of Dairy Consumption during Pregnancy and Neonatal Birth Body Mass: a Prospective Study]

To investigate the dairy product intake during pregnancy in Southwest China and to explore its relationship with neonatal birth body mass.

A prospective study was conducted to select healthy singleton pregnant women at 8-14 weeks of gestation in a maternal and fetal health care institution in Chengdu City. Dairy product consumption during the first, second, third trimester of pregnancy were collected by 24-hour dietary recalls at 8-14 weeks, 24-28 weeks and 32-36 weeks of pregnancy, respectively, and the total milk intake and milk consumption rate were calculated. According to the dietary guidelines for Chinese pregnant women (2016), the recommended amount of milk (300 g/d) was used as the standard to calculate the compliance rate. The respondents were divided into three groups: no dairy consumption group, insufficient dairy consumption group and suitable dairy consumption group. The gestational age at delivery and neonatal birth body mass were collected by the hospital information system. Logistic regression model was used to analyze the association between milk intake during pregnancy and neonatal birth body mass.

A total of 962 pregnant women were included. The average milk intake in the first, second and third trimester of pregnancy were 125.0 (0, 236.1) g/d, 208.3 (0, 284.7) g/d and 250.0 (150.0, 416.7) g/d, respectively, with the compliance rates of 12.6%, 33.2% and 48.4%, respectively. The average neonatal birth body mass was (3 225.0±399.8) g. The incidence of small for gestational age (SGA) and large for gestational age (LGA) was 8.3% and 3.9%, respectively. Compared with no dairy consumption group in the second trimester of pregnancy, the risk of SGA was lower in suitable dairy consumption group (odds ratio (OR)=0.786, 95% confidence interval (CI): 0.385-0.976). Compared with no dairy consumption group in the third trimester of pregnancy, the risk of SGA was lower in insufficient dairy consumption group and suitable dairy consumption group (OR=0.672, 95%CI: 0.477-0.821 and OR=0.497, 95%CI: 0.116-0.807, respectively). No association was observed between milk intake in the first trimester and neonatal birth body mass, and milk intake in the second and third trimester of pregnancy was not associated with the risk of LGA.

Insufficient milk intake of pregnant women is a significant problem in southwest China and needs to be improved. Milk intake during pregnancy is associated with neonatal birth body mass, and increased milk intake in the second and third trimester of pregnancy may reduce the risk of SGA.