Application of Japanese guidelines for gestational weight gain to multiple pregnancy outcomes and its optimal range in 101,336 Japanese women

Investigation of optimal weight gain during pregnancy: A retrospective analysis of the Japanese perinatal registry database

AIM

This study aimed to determine the weight gain during pregnancy that minimizes the predicted probability of various perinatal adverse events according to the pre-pregnancy body mass index (BMI) and make recommendations for optimal weight gain in Japan.

METHODS

The Japan Society of Obstetrics and Gynecology perinatal database for 2015-2017 was used. From the 719 723 deliveries included in this database, parturients with underlying diseases or missing data were excluded, and 419 114 deliveries were analyzed. A questionnaire survey was also conducted to weigh each perinatal adverse event. For each of the nine outcomes, a restricted cubic spline model was made to estimate the association between the "expected gestational weight gain at 40 weeks" and the outcome risk.

RESULTS

Since the classes of medical facilities were generally the same, weights were assigned according to the mean of the questionnaires rather than by the class of the facility. For each pre-pregnancy BMI, the weight gains during pregnancy that minimized the predicted probability of various adverse perinatal events were 12-15, 10-13, 7-10, and upper limit of 5 kg for the underweight, normal-weight, obese 1, and obese ≥2 groups, respectively.

CONCLUSIONS

The weight gain during pregnancy that minimizes the predicted probability of various perinatal adverse events according to the pre-pregnancy BMI was established.

Current Status of Maternal Gestational Weight Gain and Obstetric Outcomes in Japan

Introduction In 2021, the Japanese Ministry of Health, Labour and Welfare (JMHLW) revised the standard optimal gestational weight gain (GWG) to reduce the incidence of low-birth-weight infants (LBWI) in Japan. In this study, we examined whether maternal GWG increased and LBWI decreased after the revision. Materials and methods We reviewed the obstetric records of singleton pregnant Japanese women who delivered at our institute at ≥37 weeks' gestation in 2020 (before revision) and 2022 (after revision). Results The maternal GWG was significantly increased after the revision of the JMHLW guideline; however, the expected decrease in the incidence of LBWI was not achieved. Conclusion The maternal GWG met the new criteria in the revised guidelines and did not appear to contribute to the reduced incidence of LBWI.

A lower ratio of reduced to total albumin in serum is associated with protein nutritional status of pregnant women in Japan

Protein-energy undernutrition is potentially prevalent among Japanese pregnant women, and biomarkers that objectively indicate the protein nutritional status during pregnancy may help in implementing appropriate protein supplementation to these women. We hypothesized that a serum parameter of pregnant women, the ratio of reduced to total albumin (reduced ALB ratio), would be associated with protein intake during pregnancy. The serum reduced ALB ratio of pregnant women was compared with protein intake and with gestation outcomes (gestation length and infant birth weight) in an observational study of 115 Japanese pregnant women. The serum reduced ALB ratio in the third trimester tended to be positively correlated with gestation length (P = .07). Infant birth weights tended to be different between protein intake tertiles (P = .09); the mean infant birth weight was higher in the third tertile compared with the first and second tertiles. The protein intake of pregnant women was significantly and positively correlated with the serum reduced ALB ratio in the second trimester. The serum reduced ALB ratio reflects protein nutritional status during pregnancy and may contribute to healthier gestation outcomes.

Association between maternal factors and fetal macrosomia in full-term singleton births

BACKGROUND

Macrosomia, defined as a birth weight of ≥4000 g, is associated with a high risk of birth injury. Fetal growth is highly correlated with maternal conditions, and several maternal factors are associated with neonatal birth size. The current study aimed to assess maternal factors related to fetal macrosomia in a Taiwanese population.

METHODS

The medical records of pregnant mothers and their newborns were retrospectively reviewed. All singleton pregnancies delivered at and after 37 weeks of gestation were included in the analysis. Maternal and neonatal conditions were evaluated according to different birth weights.

RESULTS

A total of 4262 infants were enrolled in our study. The mean birth weight was 3156 ± 383 g, including 77 (1.8%) cases with birth weight ≥4000 g, and 154 (3.6%) infants with birth weight <2500 g. The mean maternal body weight before delivery was 67.6 ± 10.0 kg. The mean 6-month gestational weight gain (6mGWG) was 12.3 ± 4.2 kg, and the mean maternal body mass index (BMI) was 26.2 ± 3.6 kg/m 2 . The maternal weight, height, and 6mGWG, gestational age, and placental weight were significantly positively correlated with neonatal birth weight. The odds ratios of macrosomia were 3.1 in neonates born to mothers with a 6mGWG of ≥15 kg, 6.3 in those born to mothers with gestational diabetes mellitus, and 4.1 in those born to mothers with a BMI of ≥30 kg/m 2 . Newborn macrosomia was associated with adverse events in pregnant mothers and newborn infants.

CONCLUSION

Gestational diabetes mellitus, 6mGWG, and maternal BMI are significantly correlated with neonatal macrosomia in full-term singleton births. Further, neonatal macrosomia is an important cause of maternal and neonatal morbidity. Hence, pregnant women should undergo maternal counseling for weight management before and during pregnancy, and the appropriate delivery method should be identified to prevent perinatal adverse events.

Associations between Maternal Diet, Human Milk Macronutrients, and Breast-Fed Infant Growth during the First Month of Life in the SMILE Iwamizawa in Japan

Maternal diet may affect human milk macronutrients, but it remains to be elucidated whether this is also influential in infant growth. This study aimed to examine (1) how maternal diet influences human milk macronutrients, and (2) to what extent the variation in milk macronutrients affects infant growth during the first month of life. In 71 Japanese lactating women, maternal dietary information was collected from the brief-type self-administered diet history questionnaire, and anthropometry of mother-infant dyads was collected from medical records. Macronutrients in milk were analyzed by a Human Milk Analyzer. Maternal retinol intake was associated with the carbohydrate content in human milk at 1-month postpartum (standardized β coefficient: 0.287; p = 0.038). Moreover, the energy content in human milk was associated with an increase in the weight standard deviation score based on the WHO growth standard at 1 month of age (standardized β coefficient: 0.399; p = 0.046). Nevertheless, the milk macronutrient was not associated with the risk of infant growth abnormalities. In conclusion, a part of the maternal diet impacts macronutrient contents in human milk, but milk macronutrients have a limited effect on infant growth only within the normal growth curve during the first month of life.

Relationship of anthropometric measurements with glycated hemoglobin and 1-h blood glucose after 50 g glucose challenge test in pregnant women: A longitudinal cohort study in Southern Thailand

AIMS

To assess correlations of anthropometric measurements with glycated hemoglobin (HbA1c) and 1-h blood glucose after a 50 g glucose challenge test during the first and late second trimesters and explore their relationships of anthropometric measurements with neonatal birth weight.

METHODS

A longitudinal study was conducted among pregnant Thai women with gestational age ≤14 weeks. Anthropometric measurements, using body mass index, body compositions, and circumferences, and skinfold thickness, were measured at four-time points: ≤14, 18-22, 24-28, and 30-34 weeks of gestation. HbA1c and 1-h blood glucose were examined at ≤14 and 24-28 weeks. Neonatal birth weight was recorded.

RESULTS

Of 312 women, HbA1c was more correlated with anthropometric measurements during pregnancy than 1-h blood glucose. At 24-28 weeks, women with high/very high body fat percentage were more likely to have higher HbA1c. Women with high subscapular skinfold thickness were more likely to have higher 1-h blood glucose at ≤14 and 24-28 weeks. High hip circumference significantly increased neonatal birth weights.

CONCLUSION

Anthropometric measurements were longitudinally correlated with HbA1c and 1-h blood glucose, higher in the late second than first trimesters, as well as neonatal birth weight. The mechanisms to explain the relationship of different anthropometric measurements are required to be further studied.

Insufficient maternal gestational weight gain and infant neurodevelopment at 12 months of age: the Japan Environment and Children's Study

Abnormal maternal gestational weight gain (GWG) increases the risk of obstetric-related complications. This investigation examined the impact of GWG on infant neurodevelopmental abnormalities at 12 months of age using the data of a nationwide Japanese cohort study. Questionnaire data were obtained from the ongoing Japan Environment and Children's Study cohort study. Maternal GWG was subdivided as below, within, or above the reference values of the Institution of Medicine pregnancy weight guidelines. The Ages and Stages Questionnaire, third edition (ASQ-3) is a parent-reported developmental screening instrument for children across five domains: communication, gross motor, fine motor, problem-solving, and personal-social. Multiple logistic regression analysis was employed to identify correlations between GWG and developmental delay defined as ASQ-3 scores of less than two standard deviations below the mean. A total of 30,694 mothers with singleton live births and partners who completed the questionnaire were analyzed. The prevalence of mothers below, within, and above the GWG guidelines was 60.4% (18,527), 32.1% (9850), and 7.5% (2317), respectively. We recorded 10,943 infants (35.7%) who were outliers in at least one ASQ-3 domain. After controlling for covariates, GWG below established guidelines was associated with a significantly higher risk of developmental delay for the communication (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.09-1.34), gross motor (OR 1.14, 95% CI 1.05-1.24), fine motor (OR 1.13, 95% CI 1.04-1.24), problem-solving (OR 1.09, 95% CI 1.01-1.18), and personal-social (OR 1.15, 95% CI 1.07-1.24) domains.Conclusion: This large survey revealed a possible deleterious effect of insufficient maternal GWG on infant neurodevelopment.Trial registration: The Japan Environment and Children's Study (JECS) was registered in the UMIN Clinical Trials Registry on January 15, 2018 (number UMIN000030786). What is Known: • Inappropriate maternal gestational weight gain may cause obstetric complications and adverse birth outcomes. • Excess maternal weight gain may result in gestational diabetes, hypertension, eclampsia, caesarean delivery, and macrosomia, while insufficient maternal weight gain has been associated with pre-term birth and small for gestational age. What is New: • This study provides important information on a possible adverse effect of insufficient maternal gestational weight gain on offspring neurodevelopment at 12 months of age. • Our findings indicate a need to reconsider the optimal body mass index and gestational weight gain for women desiring pregnancy.

Clinical Observation of Effects of Prepregnancy Body Mass Index and Weight Gain during Pregnancy on Neonatal Weight and Delivery Outcome

Objective. The increase of BMI before pregnancy and during pregnancy will lead to hypertensive disorder in pregnancy (HDP) and abnormal glycolipid metabolism, as well as increase the risk of neonatal weight abnormalities and adverse pregnancy outcome. This study retrospectively analyzed the clinical data of 358 women who were admitted to the obstetrics department of our hospital from January 2018 to July 2019. And the relationship between prepregnancy BMI, BMI increase during pregnancy and delivery methods, postpartum hemorrhage, neonatal weight, premature delivery, neonatal asphyxia, gestational diabetes mellitus (GDM), and hypertension during pregnancy (HDP) was observed and compared. The results show that both high BMI before pregnancy and excessive weight gain during pregnancy can lead to the incidence of abnormal birth weight and adverse birth outcome increase. Therefore, in order to reduce the incidence of neonatal weight abnormalities and adverse birth outcomes and to prevent the adverse effects during pregnancy and postpartum, clinically, obese women should be guided to eat according to reasonable diet and exercise to control their weight.

The effect of a lifestyle training package on physical activity and nutritional status in obese and overweight pregnant women: A randomized controlled clinical trial

AIM

The aim of this study was to determine the effect of a lifestyle training package that consisted of a 60- to 90-min session of group training, educational booklet and text messages on physical activity and nutritional status in obese and overweight pregnant women.

METHODS

In this randomized controlled trial, 140 obese or overweight women (gestational age: 16-20 weeks) covered by health centres in Tehran, Iran, were equally randomized into two parallel groups using block randomization and stratified by the body mass index. Participants completed the Food Frequency Questionnaire and International Physical Activity Questionnaire at baseline and fourth and eighth weeks after intervention. Participants were 38 obese and 102 overweight women who were later followed-up.

RESULTS

After the intervention, the mean weekly intake of the vegetable and fruit subgroups was significantly higher; and intake of fats and oils and the confections subgroups were significantly lower in the intervention compared with the control group (p  < 0.05). Although physical activity was higher in the intervention group, 8 weeks after the intervention, this difference was not statistically significant (p > 0.05).

CONCLUSIONS

The training package appears to offer a suitable strategy for adjusting the intake of the recommended food subgroups in obese and overweight pregnant women.

Gestational weight gain in sub-Saharan Africa: Estimation based on pseudo-cohort design

Background

Inadequate or excess gestational weight gain (GWG) leads to multiple undesirable birth outcomes. Yet, in sub-Saharan Africa (SSA) little is known about the weight gain pattern in pregnancy. The purpose of the study is to estimate the average gestational weight gain (GWG) in sub-Saharan Africa (SSA) and to examined whether there had been recent improvements or not.

Methods

Based on cross-sectional anthropometric data extracted from multiple Demographic and Health Surveys conducted in SSA, we estimated the average GWG in the region. Pseudo-cohort design was used to reconstruct GWG trajectories based on aggregated data of 110,482 women extracted from 30 recent surveys. Trend in GWG between 2000 and 2015 was determined using the data of 11 SSA countries. Pre-pregnancy weight was estimated based on the weight of non-pregnant women at risk of conception.

Results

On average, women in SSA gain inadequate weight (6.6 kg, 95% confidence interval, 6.0–7.2) over pregnancy. No meaningful gain was observed in the first trimester; whereas, women in the second and third trimesters put on 2.2 and 3.2 kg, respectively. The highest weight gain (10.5, 8.2–12.9 kg) was observed in Southern African sub-region and the lowest in Western Africa (5.8, 5.0–6.6 kg). The GWG among women who had secondary or above education (9.5, 8.2–10.9 kg) was higher than women with lower education (5.0, 4.3–5.8 kg). Likewise, GWG in women from richest households (9.0, 7.2–10.7 kg) was superior to those from poorest households (6.1, 5.3–7.0 kg). The estimated recent (2015–20) mean GWG (6.6, 5.8–7.4 kg) was not significantly different from what had been at beginning of the new millennium (6.7, 5.9–7.5 kg).

Conclusion

In SSA GWG is extremely low and is not showing improvements.

Maternal Serum Albumin Redox State Is Associated with Infant Birth Weight in Japanese Pregnant Women

Background: Plasma albumin (ALB) reflects protein nutritional status in rats, but it is not clear whether it is associated with dietary protein insufficiency in pregnant women and/or their risk of low birth weight delivery. This study aimed to investigate whether maternal serum ALB redox state reflects maternal protein nutritional status and/or is associated with infant birth weights. Methods: The relationship between the serum reduced ALB ratio and infant birth weight was examined in an observational study of 229 Japanese pregnant women. A rat model simulating fetal growth restriction, induced by protein-energy restriction, was used to elucidate the relationship between maternal nutritional status, maternal serum ALB redox state, and birth weight of the offspring. Results: In the human study, serum reduced ALB ratio in the third trimester was significantly and positively correlated with infant birth weight. In the rat study, serum reduced ALB ratio and birth weight in the litter decreased as the degree of protein-energy restriction intensified, and a significant and positive correlation was observed between them in late pregnancy. Conclusions: Maternal serum reduced ALB ratio in the third trimester is positively associated with infant birth weight in Japanese pregnant women, which would be mediated by maternal protein nutritional status.

Hypertensive Disorders during Pregnancy (HDP), Maternal Characteristics, and Birth Outcomes among Japanese Women: A Hokkaido Study

Hypertension during pregnancy causes a greater risk of adverse birth outcomes worldwide; however, formal evidence of hypertensive disorders during pregnancy (HDP) in Japan is limited. We aimed to understand the association between maternal characteristics, HDP, and birth outcomes. In total, 18,833 mother-infant pairs were enrolled in the Hokkaido study on environment and children’s health, Japan, from 2002 to 2013. Medical records were used to identify hypertensive disorders and birth outcomes, namely, small for gestational age (SGA), SGA at full term (term-SGA), preterm birth (PTB), and low birth weight (LBW). The prevalence of HDP was 1.9%. Similarly, the prevalence of SGA, term-SGA, PTB, and LBW were 7.1%, 6.3%, 7.4%, and 10.3%, respectively. The mothers with HDP had increased odds of giving birth to babies with SGA (2.13; 95% Confidence Interval (CI): 1.57, 2.88), PTB (3.48; 95%CI: 2.68, 4.50), LBW (3.57; 95%CI: 2.83, 4.51) than normotensive pregnancy. Elderly pregnancy, low and high body mass index, active and passive smoking exposure, and alcohol consumption were risk factors for different birth outcomes. Therefore, it is crucial for women of reproductive age and their families to be made aware of these risk factors through physician visits, health education, and various community-based health interventions.

Maternal Prepregnancy Body Mass Index, Gestational Weight Gain, and Risk of Adverse Perinatal Outcomes in Taiwan: A Population-Based Birth Cohort Study

Epidemiological studies have shown that maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) are associated with increased risk of perinatal outcomes. However, the evidence of such associations in Asian populations is limited. We conducted a secondary data analysis to investigate the relationships of prepregnancy BMI and GWG with the risks of adverse perinatal outcomes, including gestational diabetes (GDM), gestational hypertension (GHTN), preeclampsia, cesarean delivery, preterm birth, low birth weight (LBW), and macrosomia. We categorized prepregnancy BMI by the WHO classification and GWG by the Institute of Medicine guidelines. We performed adjusted logistic regression models to estimate the odds ratios of adverse perinatal outcomes. A total of 19,052 women were included; prepregnancy overweight and obesity were associated with a greater risk of GDM, GHTN, preeclampsia, cesarean delivery, preterm birth, and macrosomia. Women with excessive GWG had a greater risk of GHTN, preeclampsia, cesarean delivery, and macrosomia. In conclusion, regardless of the range of GWG during pregnancy, maternal prepregnancy BMI is significantly associated with the risk of adverse perinatal outcomes in Taiwan. Public health attention regarding obesity reduction before conception and prenatal counseling for optimal GWG is needed to mitigate the risk of poor perinatal outcomes.

Comparison of three classification systems of Prepregnancy Body Mass Index with Perinatal Outcomes in Japanese Obese Pregnant Women: A retrospective study at a single center

In Japan, pregnant women are diagnosed as obese if the prepregnancy body mass index (BMI) is ≥25 kg/m². However, this is different from other countries. The Institute of Medicine (IOM) classifies prepregnancy BMI as underweight (BMI <18.5 kg/m²), normal weight (BMI 18.5-24.9 kg/m²), overweight (BMI 25.0-29.9 kg/m²), and obese (BMI ≥30 kg/m²). In addition to these four categories, the American College of Obstetricians and Gynecologists (ACOG) classifies prepregnancy BMI as obesity class I (BMI 30.0-34.9 kg/m²), obesity class II (BMI 35.0-39.9 kg/m²), and obesity class III (BMI ≥40 kg/m²). We conducted a retrospective cohort study to compare obstetric outcomes by the three different categorizations in 6,066 pregnant women who gave birth between 2010 and 2019. According to Japanese classification, 668 (11%) pregnant women were classified as obese, and significant odds ratios (OR) were observed for hypertensive disorders of pregnancy (HDP; 3.32), gestational diabetes mellitus (GDM; 3.39), large for gestational age (LGA; 2.91), and macrosomia (4.01). According to the classification of IOM, 474 (7.8%) and 194 (3.1%) were classified as overweight and obese pregnant women, respectively. Specifically, a high OR was observed in obese pregnant women for HDP (5.85) and GDM (5.0). ACOG classification categorized 474 (7.8%) pregnant women as overweight, 141 (2.3%) as obesity class I, 41 (0.6%) as obesity class II, and 12 (0.2%) as obesity class III. In obesity class III, a significantly high OR was observed for HDP (12.89), GDM (8.37), and LGA (5.74). The Japanese classification may be useful for low-risk pregnancies, whereas IOM classification may be applicable to identify high-risk pregnancies. ACOG criteria may be useful for step-wise assessments of HDP and GDM risks in Japanese pregnant women; however, the number of class II and III obese pregnant women was small.