Sustained decline in birth weight and increased rate of preterm infants born small for gestational age in Japan.

ABSTRACT:

Background

Birth weights have continued to decline in Japan in recent years. However, secular trend changes such as the birth weight relative to the week of gestation remain to be explored. This study aimed to determine the trends over time in mean birth weight and small for gestational age (SGA) rate for each gestational week.

Methods

We used a large dataset of 27,015,792 births obtained from birth certificates between 1997 and 2021. Births from 22 to 41 weeks of gestation were evaluated in six groups (22-24, 25-27, 28-31, 32-33, 34-36, and 37-41 weeks of gestational age). For each group, secular trend changes in the z-scores calculated from standard birth weight values were assessed. Time trends in the proportion of SGA and mean birth weight z-scores were eva

SUBMITTER: Moriichi A 

PROVIDER: S-EPMC11472726 | biostudies-literature | 2024

REPOSITORIES: biostudies-literature