Pre-pregnancy BMI-specific optimal gestational weight gain for women in Japan

Association between inadequate weight gain according to the institute of medicine 2009 guidelines and pregnancy outcomes in women with thyroid disorders

PURPOSE

Gestational weight gain (GWG) is an important contributor to pregnancy outcomes in the general obstetric population and different subgroups. The corresponding information in women with thyroid conditions is limited. We aimed to evaluate the relationship between GWG according to institute of medicine (IOM) and pregnancy outcomes in women with thyroid disorders.

METHODS

We performed a retrospective analysis of 620 pregnant women either treated with levothyroxine (N = 545) or attended because of hyperthyroidism during pregnancy (N = 75).

RESULTS

The associations between GWG according to IOM and pregnancy outcomes were present both in women treated with thyroid hormone and women followed by hyperthyroidism, most of them related to the fetal outcomes. In women treated with levothyroxine, insufficient GWG was associated with gestational diabetes mellitus (GDM) (odds ratio (OR) 2.32, 95% confidence interval (CI) 1.18, 4.54), preterm birth (OR 2.31, 95% CI 1.22, 4.36), small-for-gestational age newborns (OR 2.38, 95% CI 1.09, 5.22) and respiratory distress (OR 6.89, 95% CI 1.46, 32.52). Excessive GWG was associated with cesarean delivery (OR 1.66, 95% CI 1.10, 2.51) and macrosomia (OR 2.75, 95% CI 1.38, 5.49). Large-for-gestational age newborns were associated with both insufficient GWG (OR 0.25, 95% CI 0.11, 0.58) and excessive GWG (OR 1.80, 95% CI 1.11, 2.92). In women followed by hyperthyroidism, excessive GWG was associated with large-for-gestational age newborns (OR 5.56, 95% CI 1.03, 29.96).

CONCLUSION

GWG according to IOM is associated with pregnancy outcomes both in women treated with thyroid hormone and women followed by hyperthyroidism.

Association between infant birth weight and gestational weight gain in Japanese women with diabetes mellitus

AIMS/INTRODUCTION

In 2021, the guidelines on gestational weight gain (GWG) were revised and increased by 2-3 kg in Japan. This study aimed to investigate whether the revised guidelines would increase the incidence of babies with excessive birth weight in mothers with diabetes.

MATERIALS AND METHODS

This retrospective study included 369 deliveries of women with diabetes whose pre-pregnancy body mass index was below 30 kg/m2 between 1982 and 2021. The primary outcome measure was large for gestational age (LGA). We compared the incidence of LGA between women who gained weight within the previous guidelines and women who gained weight within the revised guidelines. We also compared the incidence of macrosomia, preeclampsia, small for gestational age (SGA), and low birth weight.

RESULTS

The incidence of LGA was not significantly different between women who gained weight within the revised guidelines and those within the previous guidelines (34.6% [95% confidence interval 25.6-44.6%] for the revised guidelines vs 28.9% [21.6-37.1%] for the previous guidelines; P = 0.246). Neither was the incidence of macrosomia or preeclampsia significantly different (8.7% [4.0-15.8%] vs 5.6% [2.5-10.8%] and 5.8% [2.1-12.1%] vs 6.3% [2.9-11.7%]; P = 0.264 and 0.824, respectively), while women who gained weight within the revised guidelines had a lower incidence of SGA (1.9% [0.2-6.8%] vs 10.6% [6.0-16.8%]; P = 0.001) and low birth weight (1.0% [0.02-5.2%] vs 7.0% [3.4-12.6%]; P = 0.023).

CONCLUSIONS

The revised GWG guidelines could be beneficial in women with diabetes in terms of delivering babies with appropriate birth weight.

Optimal range of gestational weight gain for singleton pregnant women: a cohort study based on Chinese specific body mass index categories

BACKGROUND

The purpose was to explore the optimal proportion of GWG in Chinese singleton pregnant women according to Chinese specific body mass index (BMI) categories.

METHODS

A retrospective cohort study with 16,977 singleton pregnant women was conducted. Among the including subjects, 2/3 of which were randomly imported into the training set for calculating the optimal GWG ranges using the percentile method, the Odd Ratio (OR) method, and the combined risk curve method. And another third of the subjects were used to evaluate the GWG ranges obtained. The detection rate of adverse outcomes of pregnant women was used to evaluate the applicability of GWG obtained. The range corresponding to the lowest detection rate is the recommended GWG range in this study.

RESULTS

According to the percentile method, the suitable GWG of pregnant women with underweight, normal weight, overweight or obesity before pregnancy were 12.0 ∼ 17.5 kg, 11.0 ∼ 17.0 kg, and 9.0 ∼ 15.5 kg, respectively. According to the OR method, the suitable GWG range were 11 ∼ 18 kg, 7 ∼ 11 kg, and 6 ∼ 8 kg, respectively. According to the combined risk curve method, the suitable GWG range were 11.2 ∼ 17.2 kg, 3.6 ∼ 11.5 kg, and - 5.2 ∼ 7.0 kg, respectively. When the GWG for different BMI categories were 11 ∼ 18 kg, 7 ∼ 11 kg, and 6 ∼ 8 kg, the pregnant women have the lowest detection rate of adverse maternal and infant outcomes.

CONCLUSIONS

The recommended GWG based on this study for underweight, normal, overweight or obese pregnant women were 11 ∼ 18 kg, 7 ∼ 11 kg, and 6 ∼ 8 kg, respectively.

Perinatal Outcomes of Diet Therapy in Gestational Diabetes Mellitus Diagnosed before 24 Gestational Weeks

To evaluate perinatal outcomes and risk factors for large for gestational age (LGA; birth weight over 90 percentile) in gestational diabetes diagnosed before 24 gestational weeks and treated with diet therapy alone until delivery (Diet Early gestational diabetes mellitus (Diet Early GDM)), we assessed the maternal characteristics and perinatal outcomes of patients with early GDM (n = 309) and normal glucose tolerance (NGT; n = 309) at Keio University Hospital. The gestational weight gain (GWG) expected at 40 weeks was significantly lower in the Diet Early GDM group than in the NGT group. The Diet Early GDM group exhibited a significantly lower incidence of low birth weight (<2500 g) and higher Apgar score at 5 min than the NGT group. Multiple logistic regression analysis revealed that the pre-pregnancy body mass index and GWG expected at 40 weeks were significantly associated with LGA for Diet Early GDM. No differences were observed in random plasma glucose levels in the first trimester, 75 g oral glucose tolerance test values, and initial increase or subsequent decrease between the two groups. Dietary early GDM did not exhibit a worse prognosis than NGT. To prevent LGA, it might be important to control maternal body weight not only during pregnancy but also before conception.

Practical weight management to minimize pregnancy complications and promote women's health: the possibility of interpregnancy care

Pregnancy is an excellent opportunity to provide medical interventions to women. It is also a stress test used to predict health. Numerous studies have demonstrated that the pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) are critical factors for pregnancy complications such as hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), large or small gestational age infants, and spontaneous preterm birth (sPTB). These complications are associated with an increased risk of cardiovascular disease (CVD), which is a leading cause of mortality in women. In addition, complications adversely affect the short- and long-term prognoses of children. Optimal GWG to reduce complications is recommended based on pre-pregnancy BMI; however, racial differences should also be noted. The values in the Japanese guidelines are lower than those in the American Institute of Medicine guidelines. The Asian BMI thresholds for CVD risk are also lower than those in Europe. Therefore, weight management should be based on racial/genetic background. Interpregnancy weight gain or loss has also been reported to be associated with the risk of pregnancy complications; however, few studies have been conducted in Asian populations. Our previous reports suggested that avoiding an excess of 0.6 kg/m2/year of annual BMI gain may reduce the risk of HDP or GDM, and insufficient gain of < 0.25 kg/m2/year may increase sPTB recurrence. Annual BMI is useful for practical weight control during interpregnancy. Based on these findings, effective approaches should be established to improve the health of women and their offspring.

Association of prepregnancy body mass index and gestational weight gain trajectory with adverse pregnancy outcomes-a prospective cohort study in Shanghai

OBJECTIVES

The objective was to investigate the associations of maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) trajectories with adverse pregnancy outcomes (APOs).

DESIGN

This was a prospective cohort study.

SETTING

This study was conducted in Shanghai Pudong New Area Health Care Hospital for Women and Children, Shanghai, China.

PRIMARY AND SECONDARY OUTCOME MEASURES

A cohort study involving a total of 2174 pregnant women was conducted. Each participant was followed to record weekly weight gain and pregnancy outcomes. The Institute of Medicine classification was used to categorise prepregnancy BMI, and four GWG trajectories were identified using a latent class growth model.

RESULTS

The adjusted ORs for the risks of large for gestational age (LGA), macrosomia, gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) were significantly greater for women with prepregnancy overweight/obesity (OR=1.77, 2.13, 1.95 and 4.24; 95% CI 1.3 to 2.42, 1.32 to 3.46, 1.43 to 2.66 and 2.01 to 8.93, respectively) and lower for those who were underweight than for those with normal weight (excluding HDP) (OR=0.35, 0.27 and 0.59; 95% CI 0.22 to 0.53, 0.11 to 0.66 and 0.36 to 0.89, respectively). The risk of small for gestational age (SGA) and low birth weight (LBW) was significantly increased in the underweight group (OR=3.11, 2.20; 95% CI 1.63 to 5.92, 1.10 to 4.41; respectively) compared with the normal-weight group; however, the risk did not decrease in the overweight/obese group (p=0.942, 0.697, respectively). GWG was divided into four trajectories, accounting for 16.6%, 41.4%, 31.7% and 10.3% of the participants, respectively. After adjustment for confounding factors, the risk of LGA was 1.54 times greater for women in the slow GWG trajectory group than for those in the extremely slow GWG trajectory group (95% CI 1.07 to 2.21); the risk of SGA and LBW was 0.37 times and 0.46 times lower for women in the moderate GWG trajectory group and 0.14 times and 0.15 times lower for women in the rapid GWG trajectory group, respectively; the risk of macrosomia and LGA was 2.65 times and 2.70 times greater for women in the moderate GWG trajectory group and 3.53 times and 4.36 times greater for women in the rapid GWG trajectory group, respectively; and the women in the other three trajectory groups had a lower risk of GDM than did those in the extremely slow GWG trajectory group, but there was not much variation in the ORs. Notably, different GWG trajectories did not affect the risk of HDP.

CONCLUSIONS

As independent risk factors, excessively high and low prepregnancy BMI and GWG can increase the risk of APOs.

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.

The exploration of optimal gestational weight gain after oral glucose tolerance test for Chinese women with gestational diabetes mellitus

Now, no recommendations of gestational weight gain (GWG) after gestational diabetes mellitus (GDM) diagnosis for Chinese women was made. This study aimed to explore the optimal GWG after oral glucose tolerance test (OGTT) for Chinese women with GDM. The GWG status of 11,570 women was retrospectively analyzed. Binary regression model and restricted cubic spline were used to estimate the association between GWG after OGTT and the predicted probability of adverse outcomes. Based on above, the optimal GWG was defined as the range that not exceed 1% increase in the predicted probability from the lowest point. Results shown that every increased one unit GWG after OGTT was associated with higher risks of macrosomia, cesarean section and LGA, and lower risk of preterm birth. According to the WHO and Working Group on Obesity in China (WGOC) recommended pre-pregnancy BMI category, the optimal GWG were proposed: 3.66 to 6.66 kg/3.66 to 6.66 kg in underweight group, 3.07 to 6.50 kg/3.02 to 6.40 kg in normal weight group, 1.06 to 2.73 kg/0 to 1.99 kg in overweight group, and not applicable/- 0.22 to 2.53 kg in obese group, respectively. Therefore, it is necessary to classified Chinese population based on the WGOC recommended pre-pregnancy BMI category, that influenced the contribution of pre-pregnancy BMI groups and the optimal GWG recommendation for GDM women with overweight or obesity.

Evaluating the application of the 2009 Institute of Medicine gestational weight gain guidelines on pregnant Chinese women

BACKGROUND

The 2009 Institute of Medicine (IOM) gestational weight gain (GWG) guidelines were initially developed for pregnant women in the United States.

OBJECTIVE

This study aimed to investigate whether the IOM guidelines were suitable for pregnant Chinese women.

METHODS

A retrospective cohort study comprising 20,593 singleton pregnant women was conducted at the Beijing Obstetrics and Gynaecology Hospital (1 January 2018 to 31 December 2019). Applicability was evaluated by comparing the GWG corresponding to the lowest point of the predicted composite risk curve with the 2009 IOM GWG Guidelines. The IOM Guidelines serve as the standard for the GWG categories and the pre-pregnancy body mass index. An exponential function model was used to fit the weight gain during pregnancy and the probability of caesarean section, preterm birth, small for gestational age, and large for gestational age. A quadratic function model was used to fit the combined probability of the above-mentioned adverse pregnancy outcomes. The applicability of the IOM guidelines was evaluated by comparing the weights corresponding to the lowest predicted probability with the GWG range recommended by the IOM guidelines.

RESULTS

According to the 2009 IOM GWG Guidelines, 43% of the women achieved adequate weight, almost 32% gained excessive weight, and 25% gained inadequate weight. The GWG range proposed by the IOM included the lowest predicted probability value for underweight women and exceeded the lowest predicted probability for normal weight, overweight, and obese women.

CONCLUSIONS

The 2009 IOM guidelines were suitable for Chinese women whose pre-pregnancy body mass index was classified as underweight. The guidelines were not suitable for normal, overweight, or obese pre-pregnancy body mass index classifications. Therefore, based on the above evidence, the 2009 IOM guidelines are not suitable for all Chinese women.

Maternal diet and interactions with nutritional evaluation during pregnancy

This narrative review aims to describe the knowledge regarding nutritional evaluation and monitoring in pregnant women. We discuss care provided by non-specialists in nutrition, regarding dietary information and risks during pregnancy, from a theoretical or conceptual viewpoint. A narrative review was conducted following a literature search when scientific databases were investigated, including SciELO, LILACS, Medline, PubMed, theses, government reports, books, and chapters in books. Finally, the material was fully read, categorized, and critically analyzed. National and international protocols of prenatal nutritional care were included and discussed. Different protocols describe the complexity of evaluating and monitoring nutrition among pregnant women during the prenatal period according to each country. The understanding of social conditions and eating habits has an important role in providing nutritional advice during pregnancy. The lack of dietitians in care overwhelms the healthcare workers and characterizes a missed opportunity. Therefore, it is important to consider rapid support tools that can track adverse nutritional status, and ways to recommend a diet that meets eating habit dynamics, according to the reality of each public health system.

Clinical features of women with thrombotic microangiopathy in pregnancy: A case series from a single Japanese tertiary perinatal care center

AIM

Although perinatal thrombotic microangiopathy has become increasingly understood, the racial characteristics of patients with this condition remain unclear. Herein, we report the characteristics of patients with perinatal thrombotic microangiopathy at a single institution in Japan.

METHODS

We conducted a retrospective study over a 5-year period from January 1, 2017, to December 31, 2021, using the electronic medical records of pregnant women who delivered at the perinatal center of our hospital. We extracted the data of those who developed perinatal thrombotic microangiopathy and evaluated their characteristics at the time of disease onset, final diagnosis, and maternal and fetal outcomes.

RESULTS

Of the 10 224 deliveries that occurred during the 5-year period, only seven patients (0.06%) had perinatal thrombotic microangiopathy. The median pre-pregnant body mass index was 18.65 kg/m2 (minimum 17.3 kg/m2 , maximum 20.7 kg/m2 ). More than half of the patients were conceived by in-vitro fertilization, and 42% these had twin deliveries. Four patients had a history of rheumatic disease. The other three patients without underlying diseases developed thrombotic microangiopathy with HELLP syndrome, and one patient transitioned to atypical hemolytic uremic syndrome.

CONCLUSIONS

Based on low body mass index and in-vitro fertilization, which are characteristic of Japanese women, medical complications and twin pregnancies may be a risk for thrombotic microangiopathy. Additionally, depending on the cause of thrombotic microangiopathy, its timing and onset differed.

Effective gestational weight gain advice to optimize infant birth weight in Japan based on quantile regression analysis

The optimal range of gestational weight gain (GWG) was recently raised in Japan. This may help reduce small-for-gestational-age (SGA) infants, but may also increase large-for-gestational-age (LGA) infants. This study performed hypothetical experiments to determine effective GWG advice based on quantile regression analysis. In a total of 354,401 singleton pregnancies registered in the perinatal database of the Japan Society of Obstetrics and Gynecology (2013-2017), the proportions of SGA and LGA were 9.33% and 11.13%, respectively. Using regression coefficients of GWG across the birth weight-for-gestational-age quantile distribution, we analyzed changes in their proportions by simulating a uniform 3-kg extra increase in GWG or an increase or decrease based on GWG adequacy. A hypothetical experiment of a uniform increase in GWG resulted in SGA and LGA proportions of 7.26% (95% confidence interval 7.15-7.36) and 14.51% (14.37-14.66), respectively. By contrast, assuming a 3-kg increase in women with inadequate GWG and a 3-kg decrease in women with excessive GWG resulted in SGA and LGA proportions of 8.42% (8.31-8.54) and 11.50% (11.37-11.62), respectively. Our real-world data analysis suggests that careful adjustment of GWG based on GWG adequacy will be effective in optimizing infant birth weight in Japan.

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.

Association between shift work in early pregnancy, snacking, and inappropriate weight gain during pregnancy: The Japan Environment and Children's Study

OBJECTIVES

This study aimed to investigate the relationship between night shifts and snacking behaviors during pregnancy using Japanese maternal-infant longitudinal data from a large-scale study.

METHODS

This study used the Japan Environment and Children's Study dataset jecs-ta-20190930, released in October 2019. After simple analysis using analysis of variance and multiple comparisons, crude odds ratios (cOR) and adjusted odds ratios (aORs) were calculated. To evaluate eating habits, we examined habitual fast food and snacks (e.g., potato chips, corn puffs and tortilla chips) consumption, midnight snacks, and regular missing breakfast.

RESULTS

There was no significant association between inappropriate weight gain during pregnancy and night shift work in early pregnancy. The aOR for consuming snacks more than once a week after noticing pregnancy for shift workers was 1.34 (95% confidence interval 1.27-1.41; p < 0.001) compared with worker without night shiftwork. The aOR for shift workers consuming fast food more than three times a week during pregnancy was 1.40 (95% confidence interval 0.79-2.33; p > 0.05).

CONCLUSIONS

Pregnant night shift workers did not show excessive weight gain but had an increased frequency of consumption of snack foods compared with pregnant dayshift workers.

Factors associated with low birthweight among late preterm singletons in Japan using pregnancy birth registry data

Late preterm (LP, born between 34 0/7 and 36 6/7 weeks of gestation) infants may experience several adverse outcomes, similar to those experienced by low birthweight (LBW, birthweight <2500 g) infants. However, while LP infants are often born with LBW, the association between LP and LBW remains unknown. This study aimed to investigate LBW rate and independent risk factors for LBW in LP singleton neonates. We retrospectively analyzed data of LP singleton neonates, born between 2013 and 2017, from the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System. The exclusion criteria included stillbirths and infants with missing data. Logistic regression analyses were performed to investigate maternal and perinatal factors associated with LBW in LP singletons. LBW was observed in 62.5% (n = 35,113) of 56,160 LP singleton births. In the multiple logistic regression analysis, LBW in LP neonates was independently associated with modifiable maternal factors, including pre-pregnancy underweight, inadequate gestational weight gain, and smoking during pregnancy, as well as non-modifiable factors, including younger maternal age, nulliparity, hypertensive disorder of pregnancy, preeclampsia, cesarean section delivery, and female offspring. According to the Japanese pregnancy birth registry data, more than half of LP neonates were LBW. We previously discussed the issue of LBW regarding infants with different backgrounds, as there are many different causes of LBW. Several risk factors should be subdivided and considered for the risk of LP and LBW.

The Associated Factors of Low Birthweight Among Term Singletons in Japan: A Pregnancy Birth Registry Analysis

BACKGROUND

Progress in reducing the global low birthweight (LBW) has been insufficient. Although the focus has been on preventing preterm birth, evidence regarding LBW in term births is limited. Despite its low preterm birth prevalence, Japan has a higher LBW proportion than other developed countries. This study aimed to examine the prevalence of LBW in term singleton births and its associated factors using a national database.

METHODS

We retrospectively analyzed the data of neonates registered in the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System who were born 2013-2017. Exclusion criteria included stillbirths, delivery after 42 gestational weeks, and missing data. Logistic regression analyses were performed to investigate the maternal and perinatal factors associated with LBW in term singletons using the data of 715,414 singleton neonates.

RESULTS

The overall prevalence of LBW was 18.3%, and 35.7% of LBWs originated from singleton term pregnancies. Multiple logistic regression analyses indicated that both modifiable and non-modifiable factors were independently associated with LBW in term neonates. The modifiable maternal factors included pre-pregnancy underweight, inadequate gestational weight gain, and smoking during pregnancy, while the non-modifiable factors included younger maternal age, nulliparity, hypertensive disorders of pregnancy, cesarean section delivery, female offspring, and congenital anomalies.

CONCLUSION

Using the Japanese pregnancy birth registry data, more than one-third of LBWs were found to originate from singleton term pregnancies. Both modifiable and non-modifiable factors were independently associated with LBW in term neonates. Prevention strategies on modifiable risk factor control will be effective in reducing LBW worldwide.

Risk of fetal undergrowth in the management of gestational diabetes mellitus in Japan

AIMS/INTRODUCTION

In Japan, the increasing frequency of underweight among women of reproductive age and the accompanying increase in the rate of low birth weight (LBW) are social issues. The study aimed to establish a prospective registry system for gestational diabetes mellitus (GDM) in Japan and to clarify the actual status of GDM according to the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria.

MATERIALS AND METHODS

Pregnant women with gestational diabetes mellitus and those in the normal glucose tolerance (NGT) group were enrolled in the Diabetes and Pregnancy Outcome for Mother and Baby study from October 2015. Pregnant women with positive glucose screening in early and mid-to-late pregnancy underwent a 75 g oral glucose tolerance test by gestational week 32. Gestational diabetes mellitus was diagnosed according to IADPSG criteria. Women with a positive glucose screening test at mid-to-late pregnancy but NGT were enrolled as references (NGT group). Treatment for gestational diabetes mellitus and maternal and neonatal pregnancy data were prospectively collected on outcomes.

RESULTS

In total 1,795 singleton pregnancies (878 women with GDM and 824 NGT women) were analyzed. The risk of LBW and small-for-gestational age in the GDM group was significantly higher than in the NGT group. A similar relationship was found for LBW risk in the non-overweight/obese group but not in the overweight/obese group.

CONCLUSIONS

We established a prospective GDM registry system in Japan. In the management of GDM in Japan, suppression of maternal weight gain may be associated with reduced fetal growth, especially in non-overweight/obese women with GDM; however, further investigation is required.

Prevalence of Overweight and Obese Prepregnancy BMI and Excessive Gestational Weight Gain Using Asian-Specific Cutoffs Among Asian and Mixed-Asian Women Living in Hawaii: A Retrospective Cohort Study

INTRODUCTION

The use of Asian-specific Body Mass Index (aBMI) cutoffs may be more appropriate than general World Health Organization BMI (gBMI) cutoffs in determining recommended gestational weight gain (GWG) for Asian women. Since aBMI cutoffs are lower than gBMI, more Asian women will be reclassified into higher aBMI categories from gBMI. The prevalence of reclassification and its impact on GWG are not known.

METHODS

We utilized the electronic health records of 8886 Kaiser Permanente Hawaii members aged ≥ 18 with a singleton live birth. Prepregnancy BMI was first classified using gBMI criteria, then aBMI criteria. BMI categories were "underweight", "normal", "overweight" and "obese"; GWG was classified into lower ("lGWG"), met ("mGWG"), and exceed ("eGWG") GWG per WHO recommendations. Self-reported race/ethnicity include Asian, Asian + Pacific Islander, and Asian + white. Multiple logistic regression was used to estimate adjusted odds of reclassification. The Cochran-Mantel-Haenszel test was used to evaluate associations between race/ethnicity and GWG.

RESULTS

 > 40% of women in each racial/ethnic group were reclassified. Asian + Pacific Islander women had significantly higher odds of being reclassified (p < .0001). In the normal gBMI and aBMI category, Asian + Pacific Islander women had the largest eGWG group. In the overweight gBMI category, Asian + Pacific Islander women had the largest eGWG group; in the overweight aBMI category, Asian + white women had the largest eGWG group.

DISCUSSION

A sizable percent of women were reclassified into higher BMI categories when aBMI was applied. Mixed-race Asian women were more likely to exceed GWG recommendations than Asian women.

Combination of Risks of BMI and Health-Related Lifestyles on Kidney Function in the Prediabetic Japanese Population: A Prospective Cohort Study

Diabetic overweight patients are more likely to show the progression of kidney damage than the general population. The majority of people in the early stages of kidney damage do not recognize the importance of risk modification, mainly due to the asymptomatic nature of the disease. This study aimed to examine specific risk combinations of lifestyle and BMI regarding the deterioration of kidney function and to explore whether there are gender-based differences among the prediabetic population. Prediabetic participants with normal kidney function were identified via annual health examination from April 2016 to March 2019. The information on health status and lifestyle was collected at enrollment. The study subjects were followed until March 2021 to observe the progression of kidney damage. There were 2241 participants enrolled in this study. Smoking (HR = 3.5, p < 0.001), eating snacks (HR = 3.2, p < 0.001), not engaging in regular exercise (HR = 2.9, p < 0.001), and not having adequate sleep (HR = 3.0, p < 0.001) showed accelerated risks for kidney damage progression among the prediabetic population in males. These lifestyle effects were not observed in females. In conclusion, risk-based modification of lifestyle behavior is important to prevent kidney function damage among the overweight prediabetic population in males.

The perinatal outcomes by gestational weight gain range at 30 weeks of gestation among pre-pregnancy underweight women

AIMS

To evaluate the perinatal outcomes by gestational weight gain (GWG) range at 30 weeks of gestation among underweight pregnant women (pre-pregnancy body mass index ≤ 18.5 kg/m² ) in Japan.

METHODS

This retrospective study was conducted at a hospital in Japan from 2003 to 2020. The underweight pregnant women (UPW; n = 3643) were divided into quartile groups based on the weight gain at 30 weeks of gestation: group Q1 ≤ 5.7 kg, 5.7 kg < Q2 ≤ 7.2 kg, 7.2 kg < Q3 ≤ 8.8 kg, and 8.8 kg < Q4. Clinical characteristics and outcomes were compared using the t-test, chi-square test, and multivariable logistic regression analysis.

RESULTS

The cumulative incidences of preterm births were 7.5% (n = 70), 5.0% (n = 45), 5.4% (n = 50), and 4.9% (n = 44), and the birth rates of small for gestational age (SGA) infants were 15.7% (n = 147), 9.6% (n = 87), 6.9% (n = 64), and 5.9% (n = 53) in Q1, Q2, Q3, and Q4, respectively. Multivariable analysis revealed that Q1 was significantly associated with preterm births (adjusted odds ratio [aOR] = 1.6; 95% confidence interval [CI] = 1.0-2.3), and Q1 and Q2 were significantly associated with SGA (adj. OR = 3.0; 95% CI = 2.2-4.3; adj. OR = 1.7; 95% CI = 1.2-2.5, respectively). None of the quartile groups were significantly associated with the incidence of primary cesarean sections, gestational diabetes mellitus, and macrosomia.

CONCLUSIONS

In UPW, GWG at 30 weeks of ≤5.7 kg and ≤7.2 kg are associated with preterm birth and SGA rates, respectively.

A prospective analysis of optimal total weight gain ranges and trimester-specific weight gain rates for Chinese pregnant women

BACKGROUND

Gestational weight gain (GWG) criteria recommended by the Institute of Medicine may not be appropriate for Asians. Our aims are to investigate the association between GWG and adverse pregnancy outcomes, and to propose optimal total GWG and rates of GWG for Chinese women.

METHODS

Prospective data of 51,125 mother-child pairs from 27 hospitals and community health care centers from Guizhou, Yunnan and Sichuan provinces in China between 2014 and 2018 were analyzed. Generalized Additive Models were performed to determine the associations of GWG with the risk of aggregated adverse outcomes (gestational diabetes mellitus, preeclampsia, cesarean delivery, stillbirth, preterm birth, macrosomia, large for gestational age, and small for gestational age). The range that did not exceed a 2.5% increase from the lowest risk of aggregated adverse outcomes was defined as the optimal GWG range.

RESULTS

Among all participants, U-shaped prospective association was found between GWG and the risk of aggregated adverse pregnancy outcomes. The optimal GWG range of 8.2-13.0 kg was proposed for underweight, 7.3-12.5 kg for normal weight, and 2.0-9.4 kg for overweight/obese women. Meanwhile, a higher GWG rate in the first two trimesters than that in the last trimester was suggested, except for overweight/obese women. After stratified by maternal age, mothers ≥35 years were suggested to gain less weight compared to younger mothers.

CONCLUSIONS

To keep a balance between maternal health and neonatal growth, optimal GWG ranges based on Asia-specific BMI categories was suggested for Chinese women with different pre-gravid BMIs and maternal ages.

Optimal gestational weight gain in Chinese pregnant women with gestational diabetes mellitus: A large retrospective cohort study

AIM

To examine the optimal gestational weight gain (GWG) for Chinese pregnant women with gestational diabetes mellitus (GDM) based on the Chinese-specific body mass index (BMI) classification.

METHODS

A retrospective cohort study was conducted using the 2017-2020 data from pregnant women with GDM in a tertiary hospital. A quadratic function model and the total predicted probability of adverse pregnancy outcomes were developed to obtain the optimal GWG. Differences in the incidence of adverse pregnancy outcomes between our optimal GWG recommendations and the Institute of Medicine (IOM) 2009 GWG guidelines were also analyzed.

RESULTS

A total of 8103 pregnant women with GDM were analyzed. Based on the Chinese-specific BMI classification, the optimal GWG range was 11.0-17.5 kg for underweight women, 3.7-9.7 kg for normal-weight women, -0.6 to 4.8 kg for overweight women, and - 9.8 to 4.2 kg for obese women. Excessive GWG had a higher risk of large for gestational age (LGA) (OR: 2.99, 95% CI: 2.42-3.70), macrosomia (OR: 2.35, 95% CI: 1.77-3.12), pre-eclampsia (OR: 1.91, 95% CI: 1.37-2.65), gestational hypertension (OR: 1.65, 95% CI: 1.24-2.19), cesarean section (OR: 1.29, 95% CI: 1.15-1.44), postpartum hemorrhage (OR: 1.29, 95% CI: 1.02-1.64); insufficient GWG had a higher risk of small for gestational age (OR: 1.82, 95% CI: 1.20-2.75). Compared to the IOM 2009 GWG guidelines, the prevalence of macrosomia, LGA, and postpartum hemorrhage were significantly lower in pregnant women following the implementation of our recommended GWG range (p < 0.05).

CONCLUSIONS

Compared to the IOM 2009 GWG recommendations, our optimal GWG recommendations for Chinese pregnant women were more sensitive.

The roles of newborn anthropometrics in the association between maternal weight gain and childhood cardiovascular risks

OBJECTIVE

The aim was to study the association between newborn anthropometrics and childhood cardiovascular risks and whether newborn anthropometrics mediate the effect of maternal gestational weight gain (GWG) on childhood risks.

METHODS

Data of 926 mother-child dyads from the Hyperglycemia and Adverse Pregnancy Outcomes study were analyzed. Newborn anthropometrics were treated as predictors and mediators by using a regression model and causal mediation model, respectively.

RESULTS

Newborn sum of skinfolds (SSF) was associated with childhood diastolic blood pressure (DBP) and pulse wave velocity (coefficients [95% CI]: 0.13 [0.06 to 0.20]; 0.08 [0.004 to 0.15]), whereas newborn ponderal index (PI) was inversely associated with childhood systolic blood pressure (SBP), DBP, and pulse wave velocity (-0.08 [-0.15 to -0.01]; -0.08 [-0.14 to -0.008]; -0.09 [-0.16 to -0.03]). Newborn SSF mediated the effects of maternal excessive GWG on childhood SSF and DBP (proportion of total effect 9% and 8%, respectively). In contrast, a significant negative mediation through newborn PI was found for the effect of maternal excessive GWG on childhood DBP (-8%) and its effect on childhood SBP through birth weight (-27%).

CONCLUSIONS

Childhood cardiovascular risks are positively associated with newborn SSF but inversely associated with newborn PI. Newborn SSF mediates the impact of excessive maternal GWG on childhood BP, but birth weight and newborn PI negatively mediate it.

Gestational weight gain in the REVAMP pregnancy cohort in Western India: Comparison with international and national references

Objective

To determine the trimester specific gestational weight gain (GWG) in a population of pregnant women from Western India and compare it with the Intergrowth-21st international and an Indian reference (GARBH-Ini cohort-Group for Advanced Research on BirtH outcomes).

Study design

A prospective longitudinal observational study was undertaken in Pune, West India and data for gestational weight gain was collected [the REVAMP study (Research Exploring Various Aspects and Mechanisms in Preeclampsia)]. Generalized Additive Models for Location, Scale and Shape method (GAMLSS model) were used to create GWG centile curves according to gestational age, stratified by BMI at recruitment (n = 640) and compared with Intergrowth-21st reference and GARBH-Ini cohort. Multivariable regression analysis was used to evaluate the relationship between GWG and antenatal risk factors.

Results

The median GWG was 1.68, 5.80, 7.06, and 11.56 kg at gestational ages 18, 26, 30, and 40 weeks, respectively. In our study, pregnant women gained less weight throughout pregnancy compared to Intergrowth-21st study, but more weight compared to the GARBH-Ini cohort centile curves in all the BMI categories. GWG in overweight/obese women (BMI ≥ 25) was significantly lower (<0.001) as compared to underweight (BMI < 18.5), or normal weight women (BMI ≥ 18.5 and <25). The median GWG at 40 weeks in underweight, normal and overweight/obese women was 13.18, 11.74, and 10.48 kg, respectively. Higher maternal BMI, older maternal age, higher parity and higher hemoglobin concentrations were associated with lower GWG, while taller maternal height was associated with greater GWG.

Conclusion

GWG of Indian women is lower than the prescriptive standards of the Intergrowth charts.

Preconception Dietary Inflammatory Index and Risk of Gestational Diabetes Mellitus Based on Maternal Body Mass Index: Findings from a Japanese Birth Cohort Study

We aimed to examine the impact of a preconception pro-inflammatory diet on gestational diabetes mellitus (GDM) using singleton pregnancy data from the Japan Environment and Children’s Study involving live births from 2011 to 2014. Individual meal patterns before pregnancy were used to calculate the dietary inflammatory index (DII). Participants were categorized according to DII quartiles 1−4 (Q1 and Q4 had the most pro-inflammatory and anti-inflammatory diets, respectively). The participants were stratified into five groups by pre-pregnancy body mass index (BMI): G1 to G5 (<18.5 kg/m2, 18.5 to <20.0 kg/m2, 20.0 to <23.0 kg/m2, 23.0 to <25.0 kg/m2, and ≥25.0 kg/m2, respectively). A multiple logistic regression model was used to estimate the effect of the anti-inflammatory diet on GDM, early diagnosed (Ed)-GDM, and late diagnosed (Ld)-GDM in each BMI group. Trend analysis showed that the risk of GDM, Ed-GDM, and Ld-GDM increased with increased pre-pregnancy BMI values. In the G4 group, the risk of Ed-GDM increased in Q2 and Q4. This study suggests that, although higher maternal BMI increases the risk of GDM, the effect of a preconception pro-inflammatory diet on the occurrence of GDM depends on pre-pregnancy BMI. This result may facilitate personalized preconception counseling based on maternal BMI.

Gestational weight gain as a risk factor for dystocia during first delivery: a multicenter retrospective cohort study in Japan

Background

Dystocia is a common obstetric complication among nulliparous women, which requires medical intervention and carries the risk of negative maternal and neonatal outcomes. Our aim was to examine the association between body mass index (BMI) and the occurrence of dystocia. We also identified cutoffs of gestational weight gain, based on pre-pregnancy BMI, associated with the risk of dystocia.

Methods

This was a multicenter, retrospective, cohort study conducted in two tertiary Maternal–Fetal medicine units in Fukushima, Japan. The study population included nullipara women who delivered at either of the two units between January 1, 2013, and December 31, 2020. Women (n = 2597) were categorized into six groups (G) based on their pre-pregnancy BMI: G1 (< 18.5 kg/m²), G2 (18.5 to < 20.0 kg/m²), G3 (20.0 to < 23.0 kg/m²), G4 (23.0 to < 25.0 kg/m²), G5 (25.0 to < 30.0 kg/m²), and G6 (≥ 30.0 kg/m²). Using G3 as a reference, multiple logistic regression analyses were performed to estimate the risk of dystocia for each BMI category. Receiver operating characteristic curve analyses were performed to determine the cutoff value of gestational weight gain for the risk of dystocia.

Results

The highest BMI category (G6) was an independent risk factor for dystocia (adjusted odds ratio, 3.0; 95% confidence interval, 1.5–5.8). The receiver operating characteristic curve analysis revealed no association between gestational weight gain and the occurrence of dystocia in G5 and G6 (P = 0.446 and P = 0.291, respectively). For G1 to G4, AUC and predictive cutoffs of gestational weight gain for dystocia were as follows: G1, AUC 0.64 and cutoff 11.5 kg (P < 0.05); G2, AUC 0.63 and cutoff 12.3 kg (P < 0.05); G3, AUC 0.67 and cutoff 14.3 kg (P < 0.01); and G4, AUC 0.63 and cutoff 11.5 kg (P < 0.05).

Conclusion

A pre-pregnancy BMI > 30.0 kg/m² was an independent risk factor for dystocia. For women with a pre-pregnancy BMI < 25.0 kg/m², the risk of dystocia increases as a function of gestational weight gain. These findings could inform personalized preconception care for women to optimize maternal and neonatal health.

Optimal gestational weight gain to reduce the risk of hypertension disorders of pregnancy among women with obesity: A single tertiary referral center study in Japan

AIM

To examine the effect of weight gain during pregnancy on hypertension disorders of pregnancy among women with a prepregnancy body mass index ≥30.0 kg/m² .

METHODS

This retrospective cohort study included 257 Japanese women (116 primipara; 141 multipara) with singleton pregnancies with a prepregnancy body mass index ≥ 30.0 kg/m² , who gave birth during 2013 to 2020 at Ohta Nishinouchi Hospital. Multiple logistic regression analyses were performed to identify the effect of gestational weight gain on early-onset (<34 weeks), late-onset (≥34 weeks), and overall hypertension disorders of pregnancy.

RESULTS

The prevalence of hypertension disorders of pregnancy in primiparas and multiparas was 28.4% and 11.3%, respectively. By multiple logistic regression analysis, gestational weight gain during pregnancy increased the risk of early-onset (adjusted odds ratio: 1.20, 95% confidence interval: 1.03-1.39, p < 0.05) and overall hypertension disorders of pregnancy (adjusted odds ratio: 1.12, 95% confidence interval: 1.03-1.22, p < 0.05) among primiparas. Based on receiver operating characteristic curve analyses for early-onset (area under the curve 0.67, 95% confidence interval: 0.56-0.78; p < 0.05) and overall hypertension disorders of pregnancy (area under the curve 0.76, 95% confidence interval: 0.61-0.91; p < 0.05) among primiparas, we determined the cut-off weight gain during pregnancy for early-onset and overall hypertension disorders of pregnancy as 3.85 kg, with sensitivity/specificity of 0.76/0.59 and 0.91/0.53, respectively.

CONCLUSION

We recommend that the optimal gestational weight gain for reducing HDP be under 3.85 kg. This information may facilitate personalized pre-conception counseling among women with obesity.

Risk scores for predicting small for gestational age infants in Japan: The TMM birthree cohort study

This study aimed to construct a prediction model for small-for-gestational-age (SGA) infants in Japan by creating a risk score during pregnancy. A total of 17,073 subjects were included in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study, a prospective cohort study. A multiple logistic regression model was used to construct risk scores during early and mid-gestational periods (11–17 and 18–21 weeks of gestation, respectively). The risk score during early gestation comprised the maternal age, height, body mass index (BMI) during early gestation, parity, assisted reproductive technology (ART) with frozen-thawed embryo transfer (FET), smoking status, blood pressure (BP) during early gestation, and maternal birth weight. The risk score during mid-gestation also consisted of the maternal age, height, BMI during mid-gestation, weight gain, parity, ART with FET, smoking status, BP level during mid-gestation, maternal birth weight, and estimated fetal weight during mid-gestation. The C-statistics of the risk scores during early- and mid-gestation were 0.658 (95% confidence interval [CI]: 0.642–0.675) and 0.725 (95% CI: 0.710–0.740), respectively. In conclusion, the predictive ability of the risk scores during mid-gestation for SGA infants was acceptable and better than that of the risk score during early gestation.

Association of different kinds of obesity with diabetic retinopathy in patients with type 2 diabetes

INTRODUCTION

Although obesity is one of the established risk factors of diabetes mellitus, the relationship between obesity and diabetic retinopathy (DR) remains unclear in different studies. This study aimed to investigate the association of DR with four obesity-related indexes, including body mass index (BMI), waist to hip ratio (WHR), waist to height ratio (WHtR) and body adiposity index (BAI) in patients with diabetes.

RESEARCH DESIGN AND METHODS

We prospectively enrolled 2305 patients with diabetes (2305 eyes) in the Guangzhou Diabetic Eye Study between November 2017 and December 2019 to investigate the prevalence and the association of different types of obesity with DR using BMI, WHR, WHtR and BAI. DR, diabetic macular oedema (DME) and vision-threatening DR (VTDR) were selected as primary outcomes. BMI was categorised as normal (18.5-22.9 kg/m²), overweight (23.0-25.0 kg/m²) and obese (>25.0 kg/m²); WHR, WHtR and BAI were categorised into quarters.

RESULTS

A total of 336 (14.58%), 93 (4.03%) and 98 (4.25%) developed DR, DME and VTDR, respectively. The prevalence of DR, DME and VTDR was higher in patients with higher BMI/WHR or lower WHtR/BAI. In the univariate regression model, WHR correlated positively with DR, while WHtR and BAI correlated negatively with DR, DME and VTDR. The association remained independent of age, sex and lipid metabolism parameters. In the multivariate model, obese presented as a protective factor for DME and VTDR, while the second quarter of WHtR(Q2-WHtR) presented as a risk factor.

CONCLUSIONS

As high as 67.8% of patients with diabetes were overweight or obese. Obese presented as a significant protective factor of VTDR, while Q2-WHtR presented as a significant risk factor. Therefore, more attention should be paid to centripetal obesity as well as general obesity. Further research is also needed to focus on the improvement of sex-specific weight management in patients with diabetes.

Gestational weight gain and risk of postpartum depression: A meta-analysis of observational studies

The association between gestational weight gain (GWG) and postpartum depression (PPD) is still controversial. The present study aimed to assess the association between GWG and the risk of developing PPD by means of a meta-analysis. PubMed, Web of Science, Embase, Cochrane Library, China Biology Medicine disk, Chinese National Knowledge Infrastructure, Weipu, and Wanfang database were searched up to May 19, 2021 to identify relevant studies that evaluated the association between GWG and PPD. Meta-analysis was conducted by using RevMan software and Stata software. Subgroup and sensitivity analyses were carried out to explore the potential heterogeneity source, and Begg's funnel plots and Begg's linear regression test were performed to assess the potential publication bias. A total of sixteen studies involving 100,438 participants were identified in this study. Overall, the total, excessive and inadequate GWG was significantly associated with a higher risk of developing PPD. These results emphasize the necessity of strengthening the prevention and intervention of excessive and inadequate weight gain during pregnancy to promote maternal and infant health. However, further studies on the association between GWG at different stages of pregnancy and the risk of developing PPD are warranted.

Weight Gain and Nutrition during Pregnancy: An Analysis of Clinical Practice Guidelines in the Asia-Pacific Region

Nutrition and weight gain during pregnancy can influence the life-course health of offspring. Clinical practice guidelines play an important role in ensuring appropriate nutrition and weight gain among pregnant women. This study aims to identify clinical practice guidelines on gestational weight gain and/or maternal nutrition across the Asia-Pacific region and to determine the quality of the guidelines and variability in the recommendations. Through a systematic search of grey literature from 38 Asia-Pacific countries, 23 published guidelines were obtained. Of these, 10 eligible clinical practice guidelines reporting nutrition- or/and weight-related recommendations for pregnant women were selected and reviewed. Guideline quality was determined using the Assessment of Guidelines for Research Evaluation II (AGREE II) instrument. Of the 10 guidelines, 90% were classified as low-quality in the AGREE II appraisal. Several variations were found with respect to recommendations on gestational weight gain, including those specific to Asian populations. The recommendations on dietary advice, additional energy intake, and nutritional supplementation during pregnancy were varied. Clinical practice guidelines on weight gain and nutrition in pregnancy across the Asia-Pacific region are generally of poor quality, reflecting significant variation, and need to be improved to ensure pregnant women receive appropriate advice. (PROSPERO registration no. CRD42021291395).

Lack of catch-up in weight gain may intermediate between pregnancies with hyperemesis gravidarum and reduced fetal growth: the Japan Environment and Children’s Study

Background

Women with nausea and vomiting of pregnancy (NVP) have higher birth weight infants, while those with hyperemesis gravidarum, a severe manifestation of NVP, have lower birth weight infants. We aimed to investigate the associations between maternal weight loss (a consequence of hyperemesis gravidarum), NVP, and infant birth weight.

Methods

This study was a secondary analysis of a nationwide birth cohort in Japan. Singleton pregnancies delivered at 28–41 weeks of gestation were included in the analysis. Women were categorized based on their weight change in the 1^st trimester (as a proportion to their pre-pregnancy weight: >  + 3%, > 0 to + 3%, > -3 to 0%, > -5 to -3%, ≤ -5%) and severity of NVP (no nausea, only nausea, vomiting but able to eat, vomiting and unable to eat). The effects of weight change and severity of NVP on infant birth weight and small for gestational age (SGA) were assessed using regression models. We further examined how these effects could be modified by maternal weight gain up to the 2^nd trimester.

Results

Among 91,313 women, 5,196 (5.7%) lost ≥ 5% of their pre-pregnancy weight and 9,983 (10.9%) experienced vomiting and were unable to eat in the 1^st trimester. Women with weight loss ≥ 5% in the 1^st trimester had infants 66 (95% CI: 53, 78) g lighter and higher odds of SGA (aOR: 1.29; 95% CI: 1.14, 1.47) than women who gained > 3% during the same period. However, when adjusting for weight gain up to the 2^nd trimester, women with weight loss ≥ 5% in the 1^st trimester had infants 150 (95% CI: 135, 165) g heavier and lower odds of SGA (aOR: 0.39; 95% CI: 0.33, 0.46) than those who gained > 3% during the same period. In contrast, women with more severe NVP tended to have infants with larger birth weight and lower odds of SGA compared to women without NVP. These trends were strengthened when adjusting for weight gain up to the 2^nd trimester.

Conclusions

Our study suggests the possibility that reduced fetal growth in pregnancies with hyperemesis gravidarum may be caused by the lack of catch-up in gestational weight gain up to the 2^nd trimester.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04542-0.

Effect of gestational weight gain on preeclampsia among underweight women: A single tertiary referral center study in Japanese women

AIM

To examine the effect of weight gain during pregnancy on preeclampsia among women with a prepregnancy body mass index < 18.5 kg/m² .

METHODS

This retrospective cohort study included 479 Japanese women with singleton pregnancies and a prepregnancy body mass index < 18.5 kg/m² , who gave birth between 2013 and 2019 at Ohta Nishinouchi Hospital. The study included 22 (18 with preeclampsia and four with gestational hypertension) and 457 patients with and without hypertensive disorders of pregnancy, respectively.

RESULTS

The prevalence of hypertensive disorders of pregnancy and preeclampsia was 4.6% and 3.8%, respectively. With weight gain during pregnancy (continuous variable) set as a reference, multiple logistic regression revealed that excessive weight gain during pregnancy increased the risk of preeclampsia (adjusted odds ratio: 1.13, 95% confidence interval: 1.00-1.28, p < 0.05) and hypertensive disorders of pregnancy (adjusted odds ratio: 1.15, 95% confidence interval: 1.03-1.29, p < 0.05). Based on receiver operating characteristic curve analyses (area under the curve 0.65, 95% confidence interval: 0.50-0.80; p < 0.05), we determined the cutoff value of weight gain during pregnancy for the occurrence of preeclampsia among women with body mass index < 18.5 kg/m² to be 13.0 kg, with sensitivity and specificity of 0.50 and 0.78, respectively.

CONCLUSION

This study indicates that excessive weight gain during pregnancy increases preeclampsia risk among underweight women and provides new recommendations for weight gain during pregnancy for such women. Further research regarding the pathogenesis of preeclampsia for underweight women is warranted.

Severity of low pre-pregnancy body mass index and perinatal outcomes: the Japan Environment and Children's Study

Background

The extremes of maternal pre-pregnancy body mass index (BMI) are known to be risk factors associated with obstetric and adverse perinatal outcomes. Among Japanese women aged 20 years or older, the prevalence of underweight (BMI < 18.5 kg/m²) was 11.5% in 2019. Maternal thinness is a health problem caused by the desire to become slim. This study aimed to investigate the association between the severity of maternal low pre-pregnancy BMI and adverse perinatal outcomes, including preterm birth (PTB), low birth weight (LBW), and small-for-gestational age (SGA).

Methods

We conducted a prospective cohort study using data from the Japan Environment and Children’s Study, which recruited pregnant individuals between 2011 and 2014. Pre-pregnancy BMI was categorized as severe-moderate underweight (BMI < 16.9 kg/m²), mild underweight (BMI, 17.0–18.4 kg/m²), low-normal weight (BMI, 18.5–19.9 kg/m²), high-normal weight (BMI, 20.0–22.9 kg/m²), overweight (BMI, 23.0–24.9 kg/m²), and obese (BMI ≥ 25.0 kg/m²). The high-normal weight group was used as the reference for statistical analyses. Adjusted logistic regression was performed to evaluate the association between pre-pregnancy BMI and PTB, LBW, and SGA.

Results

Of 92,260 singleton pregnant individuals, the prevalence was 2.7% for severe-moderate underweight, 12.9% for mild underweight, and 24.5% for low-normal weight. The prevalence of adverse outcomes was 4.6% for PTB, 8.1% for LBW, and 7.6% for SGA. The adjusted odds ratios (aORs) for PTB were 1.72 (95% confidence interval [CI], 1.46–2.03) for severe-moderate underweight and 1.26 (95% CI, 1.14–1.39) for mild underweight. The aORs of LBW were 2.55 (95% CI, 2.27–2.86) for severe-moderate underweight, 1.64 (95% CI, 1.53–1.76) for mild underweight, and 1.23 (95% CI, 1.16–1.31) for low-normal weight. The aORs of SGA were 2.53 (95% CI, 2.25–2.84) for severe-moderate underweight, 1.66 (95% CI, 1.55–1.79) for mild underweight, and 1.29 (95% CI, 1.21–1.38) for low-normal weight.

Conclusions

A dose-response relationship was found between the severity of low pre-pregnancy BMI and PTB, LBW, and SGA. Even low-normal BMI (18.5–19.9 kg/m²) increased the risk of LBW and SGA. This study provides useful information for pre-conception counseling in lean individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04418-3.

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.

Predictors of later insulin therapy for gestational diabetes diagnosed in early pregnancy

Interventions for gestational diabetes mellitus (GDM), diagnosed in early pregnancy, have been a topic of controversy. This study aimed to elucidate factors that predict patients with GDM diagnosed before 24 gestational weeks (early GDM: E-GDM) who require insulin therapy later during pregnancy. Furthermore, we identified patients whose impaired glucose tolerance should be strictly controlled from early gestation onward. Women diagnosed with GDM were categorized based on the gestational age at diagnosis into E-GDM (n = 388) or late GDM (L-GDM, diagnosed after 24 weeks, n = 340) groups. Clinical features were compared between the groups, and the predictors for insulin therapy was evaluated in the E-GDM group. There were no significant between-group differences in terms of perinatal outcomes (e.g., gestational weeks at delivery, fetal growth, hypertensive disorder of pregnancy), with the exception of the Apgar score at 5 min. Moreover, there was no significant difference in the frequency of insulin therapy during pregnancy between the two groups. Using multiple logistic regression analysis, pre-pregnancy body mass index (BMI) ≥25 kg/m², a family history of diabetes, and higher fasting plasma glucose (FPG), 1 h-plasma glucose (PG), and 2 h-PG values increased insulin therapy risk during pregnancy in the E-GDM group. Furthermore, since E-GDM patients with abnormal levels of FPG, as well as 1 h-PG or 2 h-PG, and those with pre-pregnancy BMI ≥25 kg/m² and a family history of diabetes had a higher risk of later insulin therapy during pregnancy, they may require more careful follow-up in the perinatal period.

Validation of a Strict Obesity Definition Proposed for Asians to Predict Adverse Pregnancy Outcomes in Korean Pregnant Women

BACKGROUND

People are generally considered overweight and obese if their body mass index (BMI) is above 25 kg/m² and 30.0 kg/m², respectively. The World Health Organization proposed stricter criteria for Asians (≥ 23 kg/m²: overweight, ≥ 25 kg/m²: obese). We aimed to verify whether this criteria could predict adverse pregnancy outcomes in Korean women.

METHODS

We included 7,547 Korean women from 12 institutions enrolled between June 2016 and October 2018. Women with no pre-pregnancy BMI data, not Korean, or lost to follow-up were excluded, leaving 6,331. The subjects were categorized into underweight, normal, overweight, class I obesity, and class II/III obesity based on a pre-pregnancy BMI of < 18.5, 18.5-22.9, 23.0-24.9, 25.0-29.9, and ≥ 30.0 kg/m², respectively.

RESULTS

Overall, 13.4%, 63.0%, 11.8%, 9.1%, and 2.6% of women were underweight, normal, and overweight and had class I obesity and class II/III obesity, respectively. In the multivariable analysis adjusted for maternal age, a higher BMI significantly increased the risk of preeclampsia, gestational diabetes, preterm delivery caused by maternal-fetal indications, cesarean section, large for gestational age, and neonatal intensive care unit admission.

CONCLUSION

Adverse pregnancy outcomes started to increase in those with a pre-pregnancy BMI ≥ 23.0 kg/m² after adjusting for maternal age. The modified obesity criteria could help predict adverse pregnancy outcomes in Koreans.

Trimester-specific associations between extracellular vesicle microRNAs and fetal growth

OBJECTIVE

Placenta-derived extracellular vesicles and their cargoes, especially microRNAs (EV-miRNAs), may contribute to fetal and placental development. During pregnancy, the levels of several maternal blood EV-miRNAs, including miRNAs of placental origin, vary among individuals and change throughout gestation. However, the effects of these miRNAs on fetal growth and trimester-specificity have not been fully elucidated. The purpose of this study is to test the hypothesis that the serum levels of two extracellular vesicles (EV)-miRNAs (miR-127-3p and miR-26b-5p), which may be involved in fetoplacental regulation, would be significantly associated with fetal growth in a trimester-specific manner.

MATERIALS AND METHODS

This is a single-center birth cohort of maternal serum samples obtained at both the second and third trimesters. To minimize the influence of confounding factors, the analysis was limited to singleton vaginal deliveries, resulting in 27 participants being included in this study. EV RNAs were isolated using a membrane affinity method, and the relative expression levels of miR-127-3p and miR-26b-5p were measured using the RT-qPCR method with miR-484 as control. The associations between the two EV-miRNAs and fetal and placental growth were evaluated using a linear regression model and compared between the two trimesters.

RESULTS

EV-miR-127-3p levels tended to correlate inversely with the z-scores of birth weight for gestational age (BWGA) and placental weight for gestational age (PWGA) in the second trimester, but not in the third trimester. EV-miR-26b-5p levels were positively associated with birth weight in the second trimester, but this association was weakened in the third trimester.

CONCLUSION

Our results suggest a trimester-specific association of circulating miRNA levels with fetal and placental growth. The precise roles of EV-miR-127-3p and EV-miR-26b-5p in fetal and placental development warrant further investigation.

Effect of gestational weight gain on placental weight: A single tertiary referral center study of Japanese women

AIM

The effect of gestational weight gain on placental weight has not been elucidated. We aimed to examine the effect of body weight gain during pregnancy on the Japanese standardized z-score of placental weight, based on the pre-pregnancy body mass index.

METHODS

This retrospective cohort study included Japanese women with singleton pregnancies who gave birth during 2013-2019 at Ohta Nishinouchi Hospital. Participants (n = 3610) were categorized by their pre-pregnancy body mass index: G1 (<18.5 kg/m² ), G2 (18.5 to <20.0 kg/m² ), G3 (20.0 to <23.0 kg/m² ), G4 (23.0 to <25.0 kg/m² ), and G5 (≥25.0 kg/m² ). Multiple linear regression analysis was used to identify associations between insufficient or excessive gestational weight gain in each body mass index category and z-score of placental weight, with adjustments for maternal age, assisted reproductive technology, and maternal pre-pregnancy conditions, such as hypertension, diabetes mellitus, myoma uteri, and uterine anomalies.

RESULTS

Among the 3610 women assessed, 479, 692, 1292, 435, and 711 were in G1-G5, respectively. In G1, G3, and G4, excessive weight gain increased the placental weight z-score ([B: 0.50, 95% confidence interval [CI]: 0.23-0.76], [B: 0.19, 95% CI: 0.19-0.33], and [B: 0.18, 95% CI: 0.10-0.26]). Insufficient weight gain decreased the placental weight z-score in G3 (B: -0.19, 95% CI: -0.33 to -0.06) and G4 (B: -0.21, 95% CI: -0.29 to -0.13) women.

CONCLUSION

The effect of weight gain during pregnancy on placental size varies by pre-pregnancy body mass index. This result may guide personalized pre-conception counseling to improve the outcomes of offspring.

Comparison between American Institute of Medicine Guidelines and Local Recommendation for Gestational Weight Gain in Taiwanese Primiparous Women

OBJECTIVES

American Institute of Medicine (IOM) recommends different ranges of gestational weight gain (GWG) based on pre-pregnancy body mass index (BMI). In Taiwan, IOM guidelines are implemented concurrently with the local recommendation for GWG (10-14 kg). This study compared between the two sets of guidelines in relation to adverse perinatal outcomes.

METHODS

We analyzed 31,653 primiparas with singletons from 2011 to 2016 annual National Breastfeeding Surveys. Logistic regressions for preterm birth, small for gestational age (SGA), large for gestational age (LGA), cesarean section and excessive postpartum weight retention (EPWR) were fitted separately for GWG categorized according to IOM and Taiwan ranges. Areas under the receiver-operator curves (AUC) and the predicted probabilities for each outcome were compared in each BMI group.

RESULTS

AUC for both guidelines ranged within 0.51-0.73. Compared to Taiwan recommendation, IOM ranges showed lower probabilities of SGA for underweight (0.11-0.15 versus 0.14-0.18), of LGA for obese (0.12-0.15 versus 0.15-0.18), of EPWR for overweight (0.19-0.30 versus 0.27-0.39), and obese (0.15-0.22 versus 0.25-0.36); and higher probabilities of EPWR for underweight (0.17-0.33 versus 0.14-0.22). CONCLUSIONS FOR PRACTICE: Discriminative performance of IOM and Taiwan recommendations was poor for the five adverse birth outcomes, and no preference for either set of recommendations could be inferred from our results. In the absence of specific GWG guidelines, health care workers may provide inconsistent information to their patients. Future research is needed to explore optimal GWG ranges that can reliably predict locally relevant perinatal outcomes for mother and child.

Application of the Nutrient-Rich Food Index 9.3 and the Dietary Inflammatory Index for Assessing Maternal Dietary Quality in Japan: A Single-Center Birth Cohort Study

The maternal diet can potentially influence the life-course health of the child. A poor-quality maternal diet creates nutrient deficiencies and affects immune–metabolic regulation during pregnancy. The nutrient-based overall dietary quality can be assessed using the Nutrient-Rich Food Index 9.3 (NRF9.3), which measures adherence to the national reference daily values of nutrient intake. Pro- and anti-inflammatory nutrient intake can be assessed using the energy-adjusted dietary inflammatory index (E-DII), a comprehensive index of diet-derived inflammatory capacity. Using these indices, we assessed the overall dietary quality and inflammatory potential of pregnant women during mid-gestation in an urban area of Japan (n = 108) and found that there was a strong inverse correlation between the NRF9.3 and E-DII scores. Comparison of the scores among the tertiles of NRF9.3 or E-DII indicated that dietary fiber, vitamin C, vitamin A, and magnesium mainly contributed to the variability of both indices. Intake of vegetables and fruits was positively associated with high NRF9.3 scores and negatively associated with high E-DII scores, after adjustment for maternal age, pre-pregnancy body mass index, and educational level. Consistent with the previous studies that used dietary pattern analysis, this study also demonstrated that vegetables and fruits were the food groups chiefly associated with high dietary quality and low inflammatory potential among pregnant Japanese women.

Optimal gestational weight gain for Chinese women - analysis from a longitudinal cohort with childhood follow-up

BACKGROUND

Maternal gestational weight gain (GWG) influences not only on pregnancy outcome but also impacts on mothers' and children's long-term health. However, there is no consensus on recommendations of optimal GWG in Asians or the Chinese population.

METHODS

We performed a secondary analysis of the birth outcome of Chinese women who had joined the "Hyperglycemia and Adverse Pregnancy Outcome" study in Hong Kong and their children's cardiometabolic risk at 7-year of age. Optimal ranges of GWG were derived from models based on the probabilities of small for gestational age and large for gestational age (model 1), lean and fat infants (model 2) and the integration of model 1 and 2 (model 3), and were compared with that recommended by the Institute of Medicine (IOM) on children's cardiometabolic risk.

FINDINGS

GWG range derived from model 2 is associated with 8 cardiometabolic risk factors, while that from models 1 and 3 are associated with 1 and 7 of them respectively. Mothers whose GWG lie within the recommended range increases from 40.8% according to the IOM recommendation to 50.2% according to that derived from model 2.

INTERPRETATION

Optimal GWG derived from model 2 (i.e. 14.0-18.5 kg, 9.0-16.5 kg and 5.0-11.0 kg for underweight, normal weight and overweight Chinese women, respectively) appeared to be associated with the lowest cardiometabolic risk in the offspring.

FUNDING

General Research Fund of the Research Grants Council of the Hong Kong SAR, China (grants CUHK 473408 and, in part, CUHK 471713).

Weight gain during twin pregnancy with favorable pregnancy outcomes in Japan: A retrospective investigation for new criteria based on perinatal registry data

In 2009, the United States Institute of Medicine (IOM) reported the optimal gestational weight gain (GWG) during twin pregnancy based on the pre-pregnancy body mass index (BMI). However, there are ethnic variations in the relationship between GWG and pregnancy outcomes. We aimed to establish the criteria for optimal GWG during twin pregnancy in Japan. The study included cases of dichorionic diamniotic twin pregnancy registered in the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System between 2013 and 2017. We analyzed data for cases wherein both babies were appropriate for gestational age and delivered at term. Cases were classified into four groups based on the pre-pregnancy BMI: underweight (BMI <18.5 kg/m2), normal weight (18.5 kg/m2 ≤BMI< 25.0 kg/m2), overweight (25.0 kg/m2 ≤BMI< 30.0 kg/m2), and obese (BMI ≥30.0 kg/m2) and we calculated the 25th-75th percentile range for GWG for the cases. The 3,936 cases were included. The GWG ranges were 11.5-16.5 kg, 10.3-16.0 kg, 6.9-14.7 kg, and 2.2-11.7 kg in the underweight, normal weight, overweight, and obese groups, respectively. Thus, in the current study, the optimal GWG during twin pregnancy was lower than that specified by the IOM criteria. Factoring this in maternal management may improve the outcomes of twin pregnancies in Japan.

What are the causes for low birthweight in Japan? A single hospital-based study

Low-birthweight (LBW; <2,500 g) babies are at a higher risk of poor educational achievement, disability, and metabolic diseases than normal-birthweight babies in the future. However, reliable data on factors that contribute to LBW have not been considered previously. Therefore, we aimed to examine the distribution of the causes for LBW. A retrospective review of cases involving 4,224 babies whose mothers underwent perinatal care at Keio University Hospital between 2013 and 2019 was conducted. The LBW incidence was 24% (1,028 babies). Of the 1,028 LBW babies, 231 babies were from multiple pregnancies. Of the 797 singleton LBW babies, 518 (65%) were born preterm. Obstetric complications in women with preterm LBW babies included premature rupture of membrane or labor onset (31%), hypertensive disorders of pregnancy (HDP, 64%), fetal growth restriction (24%), non-reassuring fetal status (14%), and placental previa/vasa previa (8%). Of the 279 term LBW babies, 109 (39%) were small for gestational age. Multiple logistic regression analyses revealed the following factors as LBW risk factors in term neonates: low pre-pregnancy maternal weight, inadequate gestational weight gain, birth at 37 gestational weeks, HDP, anemia during pregnancy, female sex, and neonatal congenital anomalies. HDP was an LBW risk factor not only in preterm births but also in term births. Our results suggest that both modifiable and non-modifiable factors are causes for LBW. It may be appropriate to consider a heterogeneous rather than a simple classification of LBW and to evaluate future health risks based on contributing factors.

Epidemiological evidence that severe obese women (pre-pregnancy BMI ≥40 kg/m2) should lose weight during their pregnancy

OBJECTIVES

Defining the optimal gestational weight gain (optGWG) allowing to have "normal shaped" babies (10% of Small for gestational age, SGA, and10% of large LGA babies) in severe obese women (pre-pregnancy BMI ≥40 kg/m²).

STUDY DESIGN

South-Reunion University's maternity (Reunion Island, Indian Ocean). 20 year-observational cohort study (2001-2019). Epidemiological perinatal data base with information on obstetrical and neonatal risk factors. All consecutive term (37-42 weeks gestation) singleton pregnancies (>21 weeks) live birth pregnancies delivered in the maternity.

MAIN OUTCOME MEASURES

OptGWG to obtain newborns as close as possible of the 10% SGA/LGA goal for each BMI categories, 15-19.9, 20-24.9 …, as well as severe obese ≥40 kg/m².

RESULTS

Of the 71,318 singleton term live births (37 weeks onward), we could define the maternal pre-pregnancy body mass index and the GWG in of 61,764 patients (86.6%). Severe obese 40 kg/m² losing 5-9.9 kg have 12.9% of LGA and 11.9% of SGA babies. Those losing 10 kg and more 12.7% of LGA and 7.3% of SGA. Our formerly proposed linear equation (validated from 15 to 40 kg/m²) may be prolonged at 45 kg/m².   opGWG(kg)=-1.2pp BMI(Kg/m2)+42±2kg.

CONCLUSION

In our population, a 32 kg/m² obese should gain 3.6 kg (instead of 5-9 kg, IOM 2009). A very obese 40 kg/m² should lose 6 kg, and a severe obese 45 kg/m² lose 12 kg.

Lack of concern about body image and health during pregnancy linked to excessive gestational weight gain and small-for-gestational-age deliveries: the Japan Environment and Children's Study

Background

Pregnant women in Japan express various reasons for limiting gestational weight gain (GWG). We aimed to identify and characterise groups where the women share common reasons to limit GWG and to examine how these groups are associated with inappropriate GWG and abnormal foetal size.

Methods

We prospectively studied information from the Japan Environment and Childrens Study (JECS) on 92,539 women who gave birth to live singletons from 2011 through 2014. Pregnant women were recruited during early pregnancy. Their reasons for limiting GWG and other information were collected through self-reported questionnaires and medical records. We applied latent class analysis to group the women based on their reported reasons. We used multinomial logistic regression to compare the risks of inappropriate (inadequate and excessive) GWG and abnormal foetal size (determined by new-born weight for gestational age) between the identified groups.

Results

We identified three groups: Group 1 (76.7%), concerned about delivery and new-born health (health-conscious women); Group 2 (14.5%), concerned about body shape, delivery, and new-born health (body-shape- and health-conscious women); and Group 3 (8.8%), women without strong reasons to limit GWG (women lacking body-shape and health consciousness). Compared with Group 1 members, Group 2 members tended to be younger, have lower pre-pregnancy weight, be unmarried, be nulliparous, have practiced weight loss before pregnancy, and not have chronic medical conditions. Group 3 members tended to be less educated, unmarried, multiparous, smokers, and have a higher prevalence of pre-pregnancy underweight and previous caesarean delivery. Relative to Group 1, Group 2 had a lower unadjusted risk for inadequate GWG (relative risk ratio [RRR]=0.86, 95% CI: 0.810.90) and large-for-gestational-age birth (RRR=0.91, 95% CI 0.860.97), whereas Group 3 had a higher unadjusted risk for excessive GWG (RRR=1.36, 95% CI: 1.291.43) and small-for-gestational-age (SGA) births (RRR=1.15, 95% CI: 1.051.25).

Conclusions

In this Japanese nationwide birth cohort study, pregnant women who were less conscious about body shape and health had complex risks for excessive GWG and SGA birth. Health care providers should consider a womans perception of GWG when addressing factors affecting GWG and foetal growth.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03827-0.

Optimal gestational weight gain in Chinese pregnant women by Chinese-specific BMI categories: a multicentre prospective cohort study

OBJECTIVE

To establish optimal gestational weight gain (GWG) in Chinese pregnant women by Chinese-specific BMI categories and compare the new recommendations with the Institute of Medicine (IOM) 2009 guidelines.

DESIGN

Multicentre, prospective cohort study. Unconditional logistic regression analysis was used to evaluate the OR, 95 % CI and the predicted probabilities of adverse pregnancy outcomes. The optimal GWG range was defined as the range that did not exceed a 1 % increase from the lowest predicted probability in each pre-pregnancy BMI group.

SETTING

From nine cities in mainland China.

PARTICIPANTS

A total of 3731 women with singleton pregnancy were recruited from April 2013 to December 2014.

RESULTS

The optimal GWG (ranges) by Chinese-specific BMI was 15·0 (12·8-17·1), 14·2 (12·1-16·4) and 12·6 (10·4-14·9) kg for underweight, normal weight and overweight pregnant women, respectively. Inappropriate GWG was associated with several adverse pregnancy outcomes. Compared with women gaining weight within our proposed recommendations, women with excessive GWG had higher risk for macrosomia, large for gestational age and caesarean section, whereas those with inadequate GWG had higher risk for low birth weight, small for gestational age and preterm delivery. The comparison between our proposed recommendations and IOM 2009 guidelines showed that our recommendations were comparable with the IOM 2009 guidelines and could well predict the risk of several adverse pregnancy outcomes.

CONCLUSIONS

Inappropriate GWG was associated with higher risk of several adverse pregnancy outcomes. Optimal GWG recommendations proposed in the present study could be applied to Chinese pregnant women.

Gestational weight gain and risk factors for postpartum depression symptoms from the Japan Environment and Children's Study: a prospective cohort study

BACKGROUND

The relationship between postpartum depression symptoms (PPDS) and gestational weight gain is controversial. We aimed to examine the risk of gestational weight gain for PPDS at 1 month postpartum based on the pre-pregnancy body mass index (BMI).

METHODS

A prospective cohort study recruited 80 927 Japanese women 2011-2014. They categorized according to their pre-pregnancy BMI into group 1 (<18.5 kg/m²), group 2 (18.5 to <20.0 kg/m²), group 3 (20.0 to <23.0 kg/m²), group 4 (23.0 to <25.0 kg/m²), and group 5 (≧25.0 kg/m²). Multiple logistic regression analysis was performed for each BMI category to identify potential risk factors of insufficient or excessive gestational weight gain associated with PPDS, following adjustments for maternal age, education, annual household income, smoking, parity, mode of delivery, cessation of breast feeding, psychological stress, and daily energy intakes during pregnancy.

RESULTS

Among participants in group 3, insufficient gestational weight gain was a risk factor for PPDS (adjusted odds ratio: 1.24, 95% confidence interval: 1.14-1.36). This result was not modified by intermediate factors.

LIMITATIONS

The criteria of appropriate gestational weight gain were determined from the adverse pregnancy outcomes not validated for PPDS. Other confounding factors for PPDS like psychotic disorders were not examined.

CONCLUSIONS

For women with a pre-pregnancy BMI between 20.0 and <23.0 kg/m², insufficient gestational weight gain is a risk factor for PPDS. Therefore, monitoring gestational weight gain is recommended for the early detection of PPDS in these women.

Maternal pre-pregnancy body mass index and foetal acidosis in vaginal and caesarean deliveries: The Japan Environment and Children's Study

A high maternal body mass index (BMI) is associated with increased risks of asphyxia-related neonatal morbidity. We evaluated the association between maternal pre-pregnancy BMI and foetal acidosis while accounting for the mode of delivery. Participants from the Japan Environment and Children's Study with singleton pregnancies after 22 weeks of gestation who gave birth during 2011-2014 were included. The participants (n = 71,799) were categorised into five groups according to the pre-pregnancy BMI: G1 (BMI < 18.5 kg/m2), G2 (18.5 to < 20.0 kg/m2), G3 (20.0 to < 23.0 kg/m2), G4 (23.0 to < 25.0 kg/m2), and G5 (≥ 25.0 kg/m2). Foetal acidosis was defined as umbilical artery pH (UmA-pH) < 7.20 or < 7.10. Multiple logistic regression analyses were used to evaluate the effect of pre-pregnancy BMI on foetal acidosis risk, accounting for the mode of delivery. In Japanese women, pre-pregnancy BMI ≥ 25.0 kg/m2 significantly increased the likelihood of foetal acidosis in newborns delivered vaginally. We found no association between pre-pregnancy BMI and foetal acidosis in newborns delivered via caesarean section. Counselling for body weight control before pregnancy and adequate management and selection of the mode of delivery in pregnant women with a high BMI who are in labour may be essential to avoid foetal acidosis.

Suggested Gestational Weight Gain for Chinese Women and Comparison with Institute of Medicine Criteria: A Large Population-Based Study

OBJECTIVE

To establish suggested gestational weight gain (GWG) using several distinct methods in a Chinese population.

METHODS

This study analyzed data from the medical records of singleton pregnancy women during 2011-2017 in Beijing, China. Suggested GWG was calculated using four distinct methods. In method 1, suggested GWG was identified by the interquartile method. Subsequently, risk models for small for gestational age (SGA) and large for gestational age (LGA) with respect to GWG were constructed. GWG was treated as a continuous variable in method 2, and as a categorized variable in methods 3 and 4.

RESULTS

An average GWG of 15.78 kg with a prevalence of LGA at 19.34% and SGA at 2.12% was observed among the 34,470 participants. Methods 1 and 2 did not yield clinically applicable results. The suggested GWGs were 11-17/11-16 kg, 9-19/9-15 kg, 4-12/4-10 kg, and 0-12/0-6 kg by method 3/method 4 for underweight, normal-weight, overweight, and obese women, respectively. The GWG range suggested by method 3 resulted in a larger proportion of participants (62.03%) within range, while the suggested GWG range by method 4 was associated with a lower risk of LGA compared to that conferred by the Institute of Medicine (IOM) criteria.

CONCLUSION

This study suggests a modest GWG goal compared to IOM recommendations based on a large Chinese cohort.