ArticleNagoya journal of medical science2026
Secular trends in the prevalence of low birthweight infants in Japan from 1980 to 2020: a joinpoint regression analysis.
Article in Nagoya journal of medical science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Japan has a higher prevalence of low birthweight infants (LBW, < 2500 g) than other developed countries. In this study, we aimed to clarify the descriptive epidemiological characteristics of LBW prevalence in Japan from 1980 to 2020. LBW prevalence data were obtained from the Vital Statistics of Japan. Trends in crude and age-standardized LBW prevalence rates for total and singleton births separately and rates for full-term births, as well as age-specific prevalence rates by maternal age at delivery, were analyzed using joinpoint regression. The crude LBW rate increased slowly from 5.18 per 100 births in 1980, rose sharply from the late 1980s, peaked at 9.62 in 2007, and then declined slowly to 9.22 in 2020 for the total births. The annual percent changes were 1.35% (1980-1987), 3.37% (1987-2000), 1.81% (2000-2006), and -0.24% (2006-2020), with an average annual percent change (APC) of 1.51%. Age-standardized rates for the singleton and full-term births showed a similar trend. Age-specific rates showed a sharp increase for approximately 10 years after 1985, followed by a decline in the group > 35 years of age. The rate for the 15-19 age group increased gradually, with no change point (APC = 0.60). These findings likely reflect changes in maternal and socio-environmental factors-such as increased maternal age, undernutrition, lower body mass index (BMI), and expanded use of assisted reproductive technology and perinatal care-and emphasize the importance of preconception care and maternal health care, including nutrition and life-course approaches, to reduce low birthweight risk.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.