Individual and Regional Characteristics Associated with Maternal Smoking During Pregnancy in Japan: Healthy Parents and Children 21

Trends in Primary Tooth Emergence Pattern and Associated Factors in Japanese Infants

OBJECTIVE

The purposes of this study were to analyse trends in primary tooth emergence patterns and to identify physical factors potentially associated with them.

METHODS

The participants were 27,454 infants who underwent routine 18-month-old health examinations in Ebetsu City, Japan, between 1980 and 2012. This study was conducted using data from infants' 18-month-old health examinations over a 33-year period. The mean number of emerged primary teeth was analysed by sex using a general linear model. For logistic regression analysis, the proportion of infants with 16 emerged teeth or more at 18 months old was used as a dependent variable. Examination year; birth order; birth weight; weight, height, and chest girth at 18 months old; number of fused teeth; and mother's age were used as independent variables.

RESULTS

The mean number of emerged primary teeth decreased over the 33-year period. Birth weight and weight and height at 18 months old decreased, and the proportion of low-birth-weight (<2500 g) infants increased over the 33-year period. On general linear model analysis, the yearly change in the mean number of emerged primary teeth was -0.0188 for boys and -0.0181 for girls. Birth weight and weight and height at 18 months old were significantly associated with the presence of 16 emerged primary teeth or more, according to the logistic regression analysis.

CONCLUSIONS

The results demonstrated that, over the 33-year period examined, the mean number of emerged primary teeth decreased and birth weight and weight and height at 18 months old were associated with the pattern of tooth emergence.

Factors Associated With Smoking Relapse Among Women in Japan From Pregnancy to Early Parenthood

OBJECTIVE

To identify factors, including mental health, associated with smoking relapse among women in Japan from pregnancy to early parenthood.

DESIGN

Secondary analysis of data from an ongoing cross-sectional study conducted between 2013 and 2016.

SETTING

We mailed questionnaires to all women who received a maternal and child health handbook from a municipality in Fukushima Prefecture or who underwent a maternal health checkup and gave birth in Fukushima Prefecture.

PARTICIPANTS

Of the 28,562 women who responded to the questionnaire, 6,747 who previously smoked and quit around the time they registered their pregnancies were included in the analysis.

METHODS

Participants were divided into groups according to smoking relapse status: a nonrelapse group, which included those who maintained smoking cessation, and a relapse group, which included those who quit smoking but later relapsed. We further classified the latter group into those who quit smoking before or after pregnancy registration. We used a logistic regression model with forced entry to calculate adjusted odds ratios.

RESULTS

Of the 6,747 participants who previously smoked, 881 (13.1%) relapsed. Regardless of the timing of smoking cessation, younger age and living in a specific region of Fukushima Prefecture were associated with smoking relapse. Relapse was associated with symptoms of depression in participants who quit smoking before registration and with multiparity in participants who quit smoking after registration of their pregnancies.

CONCLUSIONS

Support for women at risk of smoking relapse after pregnancy requires consideration of regional characteristics and incorporation of family and mental health support with a focus on younger women.

Maternal factors associated with smoking during gestation and consequences in newborns: Results of an 18-year study

BACKGROUND

Tobacco use is one of the most important causes of obstetric and perinatal pathologies. Its frequency during pregnancy is high and could be related to various socioeconomic and cultural characteristics of the mothers.

AIM

The aim of this study is to determine the trend and prevalence of smoking in pregnant mothers in our area over the years and the socio-cultural or obstetric factors associated with smoking as well as the repercussions on the newborns related to its consumption.

METHODS

Retrospective study of 18,959 mothers of healthy newborns in the maternity ward of the regional hospital during the years 2002-2019. The variable under study was maternal smoking during pregnancy compared with various maternal, obstetric, and perinatal factors.

RESULTS

A mean percentage of 20.4% of the mothers smoked, with significantly decreasing percentages over the years. There was a significant association between smoking and mothers' age, origin, level of education, the occurrence of previous abortions, parity, type of breastfeeding at discharge, type of delivery, low birth weight, and need for neonatal resuscitation.

CONCLUSIONS

This defines a profile of pregnant smokers on whom it is important to act: young, Spanish, with a low level of education, multiparous, and with previous miscarriages. Its repercussions are also evident with a lower birth weight in newborns. Knowledge of these factors will make it possible to design more effective intervention strategies to reduce smoking during pregnancy.

RELEVANCE FOR PATIENTS

Any effort that reduces smoking habits can improve the health status of mothers and newborns and the first step is to know who are risk pregnants.

Factors associated with birthweight decline in Japan (1980-2004)

BACKGROUND

Birthweight has been declining consistently for more than 30 years in Japan. This rapid rise in low birthweight is one of the worst among the countries of the Organization for Economic Co-operation and Development. We examined potential determinants of birthweight decline in Japan.

METHODS

We used population-based birth certificate data from vital statistics records and retrieved 40,968,266 birth certificates of neonates born between 1980 and 2004. We analyzed time trends using linear regression analysis in examining whether the decline in birthweight could be explained by obstetrical variables such as gestational age and multiple gestations.

RESULTS

From 1980 to 2004, we observed a decline in mean birthweight with a yearly effect of - 8.07 g, which became steeper after 1985, persisted until 1999, and plateaued thereafter. After adjusting for gestational age, gender, birth order, multiple gestations, and fathers' age, the yearly effect between 1980 and 2004 persisted at - 5.13 g.

CONCLUSION

Recent decreases in birthweight among Japanese neonates were not fully explained by trends in gestational age, gender, birth order, multiple gestations, and fathers' age. Thus, additional factors such as pre-pregnancy maternal body mass index (BMI) and maternal diet should be considered. Reducing the rate of induced deliveries and improving the BMI or diet of young women should be a public health priority.