Pre-pregnancy Body Mass Index Categories Research Articles

Maternal pre-pregnancy body mass index and related factors: A cross-sectional analysis from the Japan Environment and Children's Study.

Socioeconomic status and smoking are reportedly associated with underweight and obesity; however, their associations among pregnant women are unknown. This study aimed to investigate whether socioeconomic factors, namely educational attainment, household income, marital status, and employment status, were associated with pre-pregnancy body mass index (BMI) categories, including severe-moderate underweight (BMI ≤ 16.9 kg/m2), mild underweight (BMI, 17.0-18.4 kg/m2), overweight (BMI, 25.0-29.9 kg/m2), and obese (BMI ≥ 30.0 kg/m2) among Japanese pregnant women using data from the Japan Environment and Children's Study (JECS). In total, pregnant women were included 96,751. Age- and parity-adjusted multivariable multinomial logistic regression analyses assessed socioeconomic factors and smoking associations with falling within abnormal BMI categories (normal BMI as the reference group). Lower education and lower household were associated with overweight and obesity, and, especially, lowest education and household income had relatively higher point estimate relative ratios (RRs) of 3.97 and 2.84, respectively. Regarding the risks for underweight, however, only junior high school education had a significantly higher RR for severely to moderately underweight. Regarding occupational status, homemakers or the unemployed had a higher RR for severe-moderate underweight, overweight, and obesity. Unmarried, divorced, or bereaved women had significantly higher RRs for mildly underweight status. Quitting smoking early in pregnancy/still smoking had higher RRs for all four not having normal BMI outcomes; however, quitting smoking before pregnancy had a higher RR only for obese individuals. Lower educational attainment and smoking are essential intervention targets for obesity and severe-moderate underweight prevention in younger women. Lower household income is also a necessary target for obesity.

The impact of prepregnancy body mass index on pregnancy and neonatal outcomes.

The obesity epidemic in the United States is continuing to worsen. Obesity is a known risk factor for pregnancy morbidity. However, many studies use the patient's body mass index (BMI) at the time of delivery, do not stratify by class of obesity, or utilize billing codes as the basis of their study, which are noted to be inaccurate. This study aims to investigate the prepregnancy BMI class specific risks for pregnancy and neonatal complications based on a prepregnancy BMI class. We conducted a retrospective cohort study of40,256 pregnant women with 55,202 singleton births between October 16, 2007 and December 3, 2023. We assessed the risk of pregnancy and neonatal morbidity based on the maternal prepregnancy BMI category. The primary outcome was composite maternal morbidity, including hypertensive disorders of pregnancy (i.e.,gestational hypertension [GHTN] and preeclampsia), and gestational diabetes mellitus (GDM), adjusted for pregestational diabetes mellitus and chronic hypertension (cHTN). Secondary maternal outcomes included preterm premature rupture of membranes (PPROM), preterm delivery (PTD<37 and <32weeks), induction of labor (IOL), cesarean delivery (CD), and postpartum hemorrhage (PPH). Neonatal outcomes included a composite adverse outcome (including stillbirth, intraventricular hemorrhage (IVH), hypoglycemia, respiratory distress syndrome [RDS], APGAR [Appearance, Pulse, Grimace, Activity, and Respiration] <7 at 5 min, and neonatal intensive care unit [NICU] admission), birthweight, fetal growth restriction (FGR), and macrosomia. Composite maternal morbidity (odds ratio [OR] 4.40,confidence interval [CI] 3.70-5.22 for class III obesity [BMI≥40.0 kg/m2] compared with normal BMI), hypertensive disorders of pregnancy (HDP), GDM, PTD, IOL, CD, PPH, neonatal composite morbidity, hypoglycemia, RDS, APGAR<7 at 5 min, NICU admission, and macrosomia showed a significant increasing test of trend among BMI classes. Increased BMI was protective for FGR. Our data provides BMI-class specific odds ratios (ORs) for adverse pregnancy outcomes. Increased BMI class significantly increases the risk of HDP, GDM, IOL, CD, composite adverse neonatal outcomes, and macrosomia, and decreases the risk of FGR. Attaining a healthier BMI category prior to conception may lower pregnancy morbidity.

Validation of Long-term Recall of Pregnancy-related Weight in the Life-course Experiences And Pregnancy Study.

Prepregnancy body mass index (BMI) and gestational weight gain (GWG) are determinants of maternal and child health. However, many studies of these factors rely on error-prone self-reported measures. Using data from Life-course Experiences And Pregnancy (LEAP), a US-based cohort, we assessed the validity of prepregnancy BMI and GWG recalled on average 8 years postpartum against medical record data treated as alloyed gold standard ("true") values. We calculated probabilities of being classified into a self-reported prepregnancy BMI or GWG category conditional on one's true category (analogous to sensitivities and specificities) and probabilities of truly being in each prepregnancy BMI or GWG category conditional on one's self-reported category (analogous to positive and negative predictive values). There was a tendency toward under-reporting prepregnancy BMI. Self-report misclassified 32% (95% confidence interval [CI] = 19%, 48%) of those in LEAP with truly overweight and 13% (5%, 27%) with obesity into a lower BMI category. Self-report correctly predicted the truth for 72% (55%, 84%) with self-reported overweight to 100% (90%, 100%) with self-reported obesity. For GWG, both under- and over-reporting were common; self-report misclassified 32% (15%, 55%) with truly low GWG as having moderate GWG and 50% (28%, 72%) with truly high GWG as moderate or low GWG. Self-report correctly predicted the truth for 45% (25%, 67%) with self-reported high GWG to 85% (76%, 91%) with self-reported moderate GWG. Misclassification of BMI and GWG varied across maternal characteristics. Findings can be used in quantitative bias analyses to estimate bias-adjusted associations with prepregnancy BMI and GWG.

Maternal Dietary Patterns During Pregnancy Are Linked to Hypertensive Disorders of Pregnancy Among a Predominantly Low-Income US Hispanic/Latina Pregnancy Cohort.

Diet during pregnancy may be a potential intervention for preventing hypertensive disorders of pregnancy that disproportionally burdens Hispanic/Latina women. The MADRES (Maternal And Developmental Risks from Environmental and Social stressors) study (n=451) is a prospective pregnancy cohort of predominantly low-income Hispanic/Latina women in Los Angeles, California, who completed up to 2 staff-administered 24-hour dietary recalls in the third trimester of pregnancy. Hypertensive disorders of pregnancy were abstracted from medical records and based on a physician's diagnosis or systolic or diastolic blood pressure (≥140 or ≥90 mm Hg, respectively) at ≥2 consecutive prenatal visits. Using multivariable logistic regression, we evaluated associations of 2 previously derived dietary patterns in this population (solid fats, refined grains, and cheese and vegetables, oils, and fruit) and the Healthy Eating Index 2015 with (1) gestational hypertension, (2) preeclampsia, and (3) any hypertensive disorder of pregnancy (either gestational hypertension or preeclampsia). In separate models, we additionally tested interactions with prepregnancy body mass index. Comparing highest-to-lowest quartiles, the solid fats, refined grains, and cheese dietary pattern was associated with an increased odds of any hypertensive disorder of pregnancy (odds ratio [OR], 3.99 [95% CI, 1.44-11.0]; Ptrend=0.014) and preeclampsia (OR, 4.10 [95% CI, 1.25-13.5]; Ptrend=0.036), whereas the vegetables, oils, and fruit pattern was associated with reduced odds of preeclampsia (OR, 0.32 [95% CI, 0.10-0.99]; Ptrend=0.041). Among the overweight prepregnancy body mass index category, inverse associations of vegetables, oils, and fruit and Healthy Eating Index 2015 with preeclampsia were more pronounced (both Pinteractions=0.017). Healthy Eating Index 2015 findings were generally nonsignificant. While the solid fats, refined grains, and cheese diet was strongly associated with preeclampsia during pregnancy, findings suggest the vegetables, oils, and fruit diet may be more relevant than Healthy Eating Index 2015 for preventing preeclampsia among low-income Hispanic/Latina women.

Severity of excessive gestational weight gain and risk of severe maternal morbidity

Both obesity and excessive gestational weight gain are associated with severe maternal morbidity, but there is limited literature evaluating whether the risk of severe maternal morbidity is further increased by the degree or severity of excessive gestational weight gain. This study aimed to determine whether pregnant patients with excessive gestational weight gain who gained more than 50 lb were at increased risk of severe maternal morbidity compared with those who only moderately exceeded recommended gestational weight gain guidelines. A secondary objective was to determine whether patients who gained 10 lb more than the recommended upper limit of total weight gain for a given prepregnancy body mass index group were at increased risk of severe maternal morbidity compared with those who exceeded that upper limit by a lesser amount. This was a retrospective cohort study of all patients with live, term, singleton deliveries with excessive gestational weight gain from 7 hospitals within a large health system in New York between January 2019 and February 2020. Excessive gestational weight gain was defined as exceeding the recommended upper limit of total weight gain for a given prepregnancy body mass index category using the National Academy of Medicine gestational weight gain guidelines: >40 lb for a body mass index of <18.5 kg/m2, >35 lb for a body mass index of 18.5 to 24.9 kg/m2, >25 lb for a body mass index of 25.0 to 29.9 kg/m2, and >20 lb for a body mass index of ³30.0 kg/m2. Patient height and weight data were self-reported at the time of delivery hospitalization and retrieved from the electronic medical record system. Patients were classified into 2 excessive gestational weight gain groups: moderate (≤50 lb) or severe (>50 lb). Patients with missing body mass index or gestational weight gain were excluded. The primary exposure was severe excessive gestational weight gain. The primary outcome was severe maternal morbidity, defined using the Centers for Disease Control and Prevention criteria. Logistic regression was used to model the likelihood of severe maternal morbidity, adjusting for race and ethnicity, nulliparity, advanced maternal age, gestational diabetes mellitus, and maternal mood disorder. For the secondary analysis, severe maternal morbidity rates were compared between patients who exceeded their body mass index-specific upper limit of total weight gain by ≥10 lb and those who exceeded it by <10 lb. A total of 11,506 patients were included for analysis, and 1965 patients (17.1%) had severe excessive gestational weight gain. The overall rate of severe maternal morbidity was 3.3%. Severe maternal morbidity occurred in 85 of 1965 patients (4.3%) with severe excessive gestational weight gain and 292 of 9541 patients (3.1%) with moderate excessive gestational weight gain. On regression analysis, after adjustment for covariate factors, patients with a severe excessive gestational weight gain were 39% more likely to experience severe maternal morbidity than those with moderate excessive gestational weight gain (adjusted odds ratio, 1.39; 95% confidence interval, 1.08-1.79). Patients with excessive gestational weight gain of ≥10 lb above the recommended body mass index-specific upper limit for gestational weight gain were 32% more likely (adjusted odds ratio, 1.32; 95% confidence interval, 1.07-1.62) to experience severe maternal morbidity than patients who exceeded that upper limit by <10 lb. Patients with live, term, singleton pregnancies who gain more than 50 lb are at increased risk of severe maternal morbidity compared with those who only moderately exceed gestational weight gain guidelines. Similarly, patients who gain ≥10 lb above the recommended body mass index-specific upper limit for gestational weight gain are at increased risk. Further study is warranted to determine the most effective interventions to manage gestational weight gain and mitigate maternal risk.

Gestational weight gain in women with type 1 and type 2 diabetes mellitus is related to both general and diabetes-related clinical characteristics.

To assess predictors of gestational weight gain (GWG), according to the Institute of Medicine (IOM) 2009, in women with type 1 and type 2 diabetes. This was a retrospective cohort study conducted at a tertiary center. GWG based on the IOM was assessed both uncorrected and corrected for gestational age. General and diabetes-related clinical characteristics were analyzed as predictors. We evaluated 633 pregnant women with type 1 and type 2 diabetes. GWG uncorrected for gestational age was inadequate (iGWG) in 20.4%, adequate in 37.1%, and excessive (eGWG) in 42.5% of the women. Predictors included general (height, prepregnancy body mass index category, and multiple pregnancy) and diabetes-related clinical characteristics. Neuropathy and follow-up length were associated with iGWG (odds ratio (OR) 3.00, 95% CI 1.22-7.37; OR 0.92, 95% CI 0.86-0.97, respectively), while pump use and third-trimester insulin dose were associated with eGWG (OR 1.68, 95% CI 1.07-2.66; OR 3.64, 95% CI 1.88-7.06, respectively). Independent predictors for corrected GWG and sensitivity analyses also included general and diabetes-related clinical characteristics. In this cohort of women with type 1 and type 2 diabetes, non-adequate GWG was common, mainly due to eGWG, and associated clinical characteristics were both general and diabetes-related. Current clinical care of these women during pregnancy may favor weight gain.

Excessive gestational weight gain and emotional eating are positively associated with postpartum depressive symptoms among taiwanese women

BackgroundExcessive gestational weight gain and emotional eating may be associated with postpartum depression symptoms. This study was designed to identify how gestational weight gain and eating behaviors are related to postpartum depression (PPD) symptoms among women in Taiwan.MethodsA cross-sectional study was conducted from March 2022 to October 2022 with 318 postpartum women recruited in Taipei, Taiwan. Gestational weight gain (GWG) for the total pregnancy period was recorded as inadequate, adequate, or excessive, based on the 2009 Institute of Medicine recommendations (IOM), accounting for pre-pregnancy body mass index category. Eating behavior at one month postpartum was measured on a 16-item 5-point Likert scale with three subscales: uncontrolled, restrained, and emotional. Maternal depressive symptoms were measured using the Edinburgh Postnatal Depression Scale with a cutoff score of 13.ResultsThe prevalence of postpartum depression symptoms (Edinburgh Postnatal Depression Scale ≥ 13) was 23.9% at one month postpartum. Logistic regression analysis revealed that excessive gestational weight gain and emotional eating were positively associated with postpartum depression symptoms at that time.ConclusionEvidence presented here suggests that emotional eating and excessive GWG are associated with PPD symptoms in a Taiwanese population. In addition, it should be a public health priority to ensure a particular focus on mental health during the postpartum period. Healthcare providers should discourage pregnant women from unhealthy eating habits by targeting appropriate GWG and focusing on demand eating to reduce PPD in the postpartum period.

Maternal exposure to phthalates and total gestational weight gain in the LIFECODES birth cohort.

Excessive gestational weight gain contributes to adverse maternal and neonatal outcomes. Environmental exposures such as phthalates may lead to metabolic dysregulation, and studies suggest possible associations between maternal phthalate exposure and altered gestational weight gain. We assessed the association between nine maternal phthalate metabolites and measures of total gestational weight gain (pre-pregnancy to median 35.1 weeks of gestation) in a case-control study nested within LIFECODES (N=379), a prospective birth cohort from Boston, Massachusetts (2006-2008). Our primary outcome was total gestational weight gain z score, a measure independent of gestational age that can provide a less biased estimate of this association. Our secondary outcomes were total gestational weight gain, rate of gestational weight gain, and adequacy ratio. The results were stratified by pre-pregnancy body mass index category. We found that concentrations of mono-(3-carboxypropyl) phthalate (MCPP) and mono-n-butyl phthalate (MBP) were positively associated with total gestational weight gain z scores among participants with obesity: adjusted mean difference (95% Confidence Interval [CI]) =0.242 (0.030 - 0.455) and 0.105 (-0.002 - 0.212) corresponding to an excess weight gain of 1.81kg and 0.77kg at 35 weeks of gestation per interquartile range-increase in MCPP and MBP, respectively. Also, among participants with obesity, MBP demonstrated a potential non-linear relationship with gestational weight gain in cubic spline models. These findings suggest that phthalates may be related to higher gestational weight gain, specifically, among individuals with pre-pregnancy obesity. Future research should investigate whether pregnant people with obesity represent a subpopulation with sensitivity to phthalate exposures.

Optimal gestational weight gain in women with twin pregnancies and gestational diabetes mellitus: a population-based study in the United States

There is limited evidence regarding optimal gestational weight gain in women with twin pregnancies and gestational diabetes mellitus. This study aimed to examine the association between gestational weight gain and perinatal outcomes among women with gestational diabetes mellitus and twin pregnancies and to explore the gestational weight gain targets by prepregnancy body mass index category. A national population-based cohort study of twin pregnancies with gestational diabetes mellitus was conducted between 2014 and 2020. Women with gestational diabetes mellitus aged between 18 and 45 years with live-born twins without congenital malformations between 24 and 42 weeks of gestation were included in the analysis. Two approaches were used to determine the optimal gestational weight gain targets by body mass index category: an interquartile range method to calculate targets in low-risk gestational diabetes mellitus pregnancies and a logistic model method to identify the odds ratio targets at which a composite adverse outcome decreased. Of 29,308 women with gestational diabetes mellitus and twin pregnancies, 8239 (28.1%) were normal-weight, 7626 (26.0%) were overweight, and 13,443 (45.9%) were obese. The continuous standardized gestational weight gain by 36 weeks was associated with preterm birth <36 weeks, large-for-gestational-age infants, small-for-gestational-age infants, and gestational hypertensive disorders. The interquartile range targets were 13.6 to 20.9 kg, 10.9 to 20.4 kg, and 7.7 to 17.7 kg for normal-weight, overweight, and obese women, respectively. The odds ratio targets were 14.1 to 20.0 kg, 12.1 to 16.0 kg, and 6.1 to 12.0 kg for normal-weight, overweight, and obese women, respectively. Gestational weight gain outside these targets was associated with preterm birth <36 weeks, large-for-gestational-age and small-for-gestational-age infants, and gestational hypertensive disorders, and exhibited significant population attributable fractions for preterm birth <36 weeks, large-for-gestational-age infants, and gestational hypertensive disorders across body mass index categories. Compared with the Institute of Medicine guidelines, more stringent gestational weight gain targets would be beneficial for improved perinatal outcomes in women with gestational diabetes mellitus and twin pregnancies.

The impact of IOM recommendations on gestational weight gain among US women: An analysis of birth records during 2011-2019.

The prevailing guidelines of the Institute of Medicine (IOM) of United States on gestational weight gain (GWG) are based on women's prepregnancy body mass index (BMI) categories. Previous research has shown that the guidelines issued in 1990 and revised in 2009 had no effect. We investigate the effectiveness of new guidelines issued in 2009 analyzing the records of all singleton births in the U.S. during 2011-2019 (34.0 million observations). We use the discontinuity in recommended guidelines at the threshold values of BMI categories in a regression discontinuity (RD) research design to investigate the effect of IOM guidelines on GWG. We also use an RD analysis in a difference in difference (DID) framework where we compare the effect on women who had any prenatal care to others who did not receive prenatal care. The naïve RD estimator predicts an effect in the expected direction at the threshold BMI values of 18.5 and 25.0 but not at 30.0. After the DID based correction, the RD analyses show that the GWG, measured in kg, drop at the BMI values of 18.5, 25.0 and 30.0 by 0.189 [CI: 0.341, 0.037], 0.085 [CI: 0.179, -0.009] and 0.200 [CI: 0.328, 0.072] respectively when the midpoint of the recommended range in kg drops by 1.5, 4.5 and 2.25. This implies a responsiveness of 12.6%, 1.9% and 8.9% respectively to changes in guidelines at these BMI values. The findings show that the national guidelines have induced some behavioral changes among US women during their pregnancy resulting in a change in GWG in the expected direction. However, the magnitude of the change has not been large compared to the expectations, implying that the existing mechanisms to implement these guidelines have not been sufficiently strong.

Association of Optimal Gestational Weight Gain Ranges With Perinatal Outcomes Across Body Mass Index Categories in Twin Pregnancies

The existing gestational weight gain (GWG) recommendations for twin pregnancies are lacking for underweight individuals and are not stratified by obesity class. To identify optimal GWG ranges associated with reduced adverse perinatal outcomes stratified by prepregnancy body mass index (BMI) categories in twin pregnancies. This population-based cohort study of twin pregnancies using data from the National Center for Health Statistics was conducted between January 1, 2014, and December 31, 2018. Statistical analysis was performed from October 24, 2021, to May 7, 2022. The study population comprised 262 604 individuals between 18 and 45 years of age with live-born twins without congenital malformation between 24 and 42 weeks of gestation. Two approaches were used to determine the optimal GWG ranges: a statistics-based approach calculating IQRs of GWG in a low-risk population, and an outcome-based approach identifying GWG thresholds below or above which an adverse perinatal outcome increased. Gestational weight gain. Preterm birth less than 36 weeks, gestational hypertensive disorders, small for gestational age status, large for gestational age status, and a composite outcome defined as any occurrence of the individual outcomes. The main sample comprised 200 810 individuals with twin pregnancies (mean [SD] maternal age, 30.4 [5.5] years; 1624 [0.8%] American Indian or Alaska Native, 13 031 [6.5%] Asian or Pacific Islander, 36 423 [18.1%] Black, and 149 732 [74.6%] White; and 137 409 [68.4%] multiparous). In the low-risk subgroup (n = 61 794), the IQRs of the total GWG after 36 weeks of gestation as assessed using a statistics-based approach and based on BMI group were 15.9 to 22.7 kg for underweight, 15.4 to 22.7 kg for normal weight, 12.7 to 22.2 kg for overweight, 10.0 to 20.0 kg for class 1 obesity, 7.7 to 18.1 kg for class 2 obesity, and 5.9 to 16.3 kg for class 3 obesity. The absolute risk of the composite outcome showed U-shaped associations with GWG across BMI categories. The optimal GWG ranges by 36 weeks identified using an outcome-based approach and BMI group were 17.5 to 24.9 kg for underweight, 15.0 to 24.9 kg for normal weight, 15.0 to 24.9 kg for overweight, 10.0 to 19.9 kg for class 1 obesity, 7.5 to 17.4 kg for class 2 obesity, and 5.0 to 9.9 kg for class 3 obesity. The multivariable logistic models assessed using the validation sample (n = 49 275) showed that GWG defined outside those optimal ranges was associated with preterm birth at less than 36 weeks, gestational hypertensive disorders, and small or large for gestational age. This population-based cohort study found that optimal GWG ranges were similar for individuals with underweight and normal weight but decreased with increasing severity of obesity. The current US Institute of Medicine GWG recommendations may be too high for individuals with moderate or severe obesity.

Maternal Pre-pregnancy Body Mass Index Categories and Infant Birth Outcomes: A Population-Based Study of 9 Million Mother-Infant Pairs.

Background and AimsInfant adverse birth outcomes have been suggested to contribute to neonatal morbidity and mortality and may cause long-term health consequences. Although evidence suggests maternal prepregnancy body mass index (BMI) categories associate with some birth outcomes, there is no consensus on these associations. We aimed to examine the associations of maternal prepregnancy BMI categories with a wide range of adverse birth outcomes.MethodsData were from a population-based retrospective cohort study of 9,282,486 eligible mother–infant pairs in the U.S. between 2016 and 2018. Maternal prepregnancy BMI was classified as: underweight (<18.5 kg/m2); normal weight (18.5–24.9 kg/m2); overweight (25.0–29.9 kg/m2); obesity grade 1 (30–34.9 kg/m2); obesity grade 2 (35.0–39.9 kg/m2); and obesity grade 3 (≥40 kg/m2). A total of six birth outcomes of the newborn included preterm birth, low birthweight, macrosomia, small for gestational age (SGA), large for gestational age (LGA), and low Apgar score (5-min score <7).ResultsMaternal prepregnancy overweight and obesity increased the likelihood of infant preterm birth, with odds ratios (ORs) (95% CIs) of 1.04 (1.04–1.05) for overweight, 1.18 (1.17–1.19) for obesity grade 1, 1.31 (1.29–1.32) for obesity grade 2, and 1.47 (1.45–1.48) for obesity grade 3, and also for prepregnancy underweight (OR = 1.32, 95% CI = 1.30–1.34) after adjusting for all potential covariates. Prepregnancy overweight and obesity were associated with higher odds of macrosomia, with ORs (95% CIs) of 1.53 (1.52–1.54) for overweight, 1.92 (1.90–1.93) for obesity grade 1, 2.33 (2.31–2.35) for obesity grade 2, and 2.87 (2.84–2.90) for obesity grade 3. Prepregnancy overweight and obesity was associated with higher odds of LGA, with ORs (95% CIs) of 1.58 (1.57–1.59) for overweight, 2.05 (2.03–2.06) for obesity grade 1, 2.54 (2.52–2.56) for obesity grade 2, and 3.17 (3.14–3.21) for obesity grade 3. Prepregnancy overweight and obesity were also associated with higher odds of low Apgar score, with ORs (95% CIs) of 1.12 (1.11–1.14) for overweight, 1.21 (1.19–1.23) for obesity grade 1, 1.34 (1.31–1.36) for obesity grade 2, and 1.55 (1.51–1.58) for obesity grade 3.ConclusionOur findings suggest maintaining or obtaining a healthy body weight for prepregnancy women could substantially reduce the likelihood of important infant adverse birth outcomes.

Associations Between Gestational Weight Gain and Adverse Birth Outcomes: A Population-Based Retrospective Cohort Study of 9 Million Mother-Infant Pairs.

BackgroundGestational weight gain (GWG) reflects maternal nutrition during pregnancy. However, the associations between maternal GWG and adverse birth outcomes are inconclusive.ObjectiveWe aimed to examine the associations between maternal GWG and adverse birth outcomes according to maternal pre-pregnancy body mass index (BMI) categories in a large, multiethnic and diverse population in the U.S.Study DesignWe used nationwide birth certificate data from the National Vital Statistics System to examine the association of GWG (below, within and above the Institute of Medicine [IOM] guidelines) with six adverse birth outcomes (preterm birth, low birthweight, macrosomia, small for gestational age [SGA], large for gestational age [LGA], and low Apgar score) according to the pre-pregnancy BMI categories (underweight to obesity grade 3). Multivariable logistic regression analyses were performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs).ResultsA total of 9,191,842 women aged 18–49 years at delivery with live singleton births were included. Among them, 24.5% of women had GWG below IOM guidelines, 27.6% within the guidelines, and 47.9% above the guidelines. Compared with maternal GWG within guidelines, GWG below guidelines was associated with higher odds of preterm birth (OR = 1.52, 95%CI = 1.51–1.53), low birthweight (OR = 1.46, 95%CI = 1.45–1.47) and SGA (OR = 1.44, 95%CI = 1.43–1.45). In contrast, maternal GWG above guidelines was associated with higher odds of macrosomia (OR = 2.12, 95%CI = 2.11–2.14) and LGA (OR = 2.12, 95%CI = 2.11–2.14). In addition, maternal GWG below or above guidelines had slightly higher odds of low Apgar score (below guidelines: OR = 1.04, 95%CI = 1.03–1.06, above guidelines: OR = 1.17, 95%CI = 1.15–1.18). The results were largely similar among women with GWG below or above guidelines across pre-pregnancy BMI categories of underweight, overweight, and obesity grade 1 to grade 3.ConclusionPregnant women with GWG below or above the IOM guidelines have increased odds of selected adverse infant birth outcomes. Monitoring maternal GWG could enable physicians to provide tailored nutrition and exercise advice as well as prenatal care to pregnant women to reduce the likelihood of adverse birth outcomes.

Application of Institute of Medicine's Gestational Weight Gain Recommendations in Asian Population: A Scoping Review

Background. Gestational weight gain (GWG) is an important factor of the well-being of both mother and fetus. Latest recommendation by Institute of Medicine (IOM) was issued in 2009 based on women population in United States, and is classified based on World Health Organization (WHO) body mass index (BMI) cutoffs. Recommendation for Asian population is not currently available. This review aims to review the evidence of the application of said guidelines in Asian population. Method. Articles were searched using Google Scholar and PubMed. Articles published in 2016 or above, with single pregnancies and unlimited to pre-pregnancy BMI categories were selected. Of 1,239 potential articles, 29 were chosen for full-text screening and 9 were included in this review. Result. Mixed trends were found when assessing adequacy of GWG in relation to pre-pregnancy BMI. Article analyzing optimal GWG showed a higher and wider range compared to IOM. Inadequate GWG is associated with a higher risk of small for gestational age (SGA) while excessive GWG is associated with large for gestational age (LGA). Significant differences were found when different categorizations of BMI are used with IOM guidelines. Conclusion. Asian women rarely gain adequate weight by IOM standard. This might lead to increased risk of adverse pregnancy outcomes, such as SGA and LGA. Further researches are needed to study appropriate optimal GWG for Asian population, and/or to modify IOM guidelines to be applied better in Asian population.

QuickStats: Rate of Cesarean Delivery, by Maternal Prepregnancy Body Mass Index Category* - United States, 2020.

QuickStats: Rate of Cesarean Delivery, by Maternal Prepregnancy Body Mass Index Category* - United States, 2020.

Gestational body weight gain and risk of low birth weight or macrosomia in women of Japan: a nationwide cohort study

ObjectiveBoth maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) influence maternal and pediatric outcomes. We sought to clarify the impact of prepregnancy BMI-specific GWG and its patterns on the risk of low birth weight (LBW) or macrosomia using data from a large nationwide study in Japan.MethodsThis cohort study (n = 98,052) used data from the Japan Environment and Children’s Study (JECS). The outcome variables in this study were LBW and macrosomia. We stratified the subjects into groups according to prepregnancy BMI.ResultsGWG from pre-pregnancy to the first trimester had a small effect on the risk of LBW and macrosomia. From the first to second trimesters, insufficient GWG was associated with the risk of LBW, and from the second trimester to delivery, a GWG of less than 2 kg was associated with the risk of LBW. These associations were commonly observed in all prepregnancy BMI categories. Irrespective of the GWG from pre-pregnancy to the first trimester, GWG from the first to second trimesters affects LBW and/or macrosomia. Irrespective of the GWG from the first to second trimesters, GWG from the second trimester to delivery affects LBW and/or macrosomia. LBW or macrosomia was associated with the prevalence of a sustained low or high BMI percentile until three years of age, respectively.ConclusionsThe present large national cohort study indicates that the risk of LBW or macrosomia is associated with GWG in women in Japan; the significance of this risk depends on the GWG patterns.

Insulin Concentration in Human Milk in the First Ten Days Postpartum: Course and Associated Factors.

Human milk (HM) is better tolerated than formula in preterm infants. Insulin, which is naturally present in HM but not in formula, has been suggested as a key factor for feeding tolerance, as it appears to stimulate intestinal maturation. Its precise concentrations during the early postnatal period, however, remains unknown. The objective of this study was to assess the natural timecourse of the HM insulin concentration during the first ten days postpartum. The effect of preterm delivery, maternal obesity, and diurnal rhythm were also assessed. HM was collected from 31 non-diabetic mothers (21 preterm [gestational age (GA) < 37 weeks]; 10 at-term [GA ≥ 37 weeks]) on ≥ 4 time-points per day during the first five days, and once on the tenth day postpartum. The HM insulin concentration declined rapidly within the first three days postpartum (day 1: 516 [312-1058] pmol/L; day 3: 157 [87-299] pmol/L), after which the concentration remained relatively stable. The insulin concentrations were higher in HM from obese mothers than from non-obese mothers (P < 0.001). Preterm delivery did not significantly affect HM insulin concentrations when adjusted for maternal pre-pregnancy body mass index category (P = 0.270). Diurnal rhythm was characterized by an insulin concentration decline throughout the night (P = 0.001), followed by an increase in the morning (P = 0.001). The HM insulin concentration declines rapidly in the first three days postpartum, follows a diurnal rhythm, and is higher in obese mothers compared to non-obese mothers. HM insulin concentrations are not affected by preterm delivery.

High pre-pregnancy BMI with a history of gestational diabetes mellitus is associated with an increased risk of type 2 diabetes in Korean women.

Despite the importance of pre-pregnancy body mass index (BMI) and a history of gestational diabetes mellitus (GDM) in the progression of GDM to type 2 diabetes, few studies have evaluated the combined effect of high pre-pregnancy BMI and GDM status on the future development of type 2 diabetes in Korean women. This study aimed to examine the relationship of pre-pregnancy BMI and GDM history with the risk of type 2 diabetes among Korean women. In addition, the effects of pre-pregnancy BMI and current BMI on the risk of type 2 diabetes were evaluated. Women who gave birth in the Health Examinees Study of the Korean Genome and Epidemiology Study from 2004 to 2013 (n = 59,258) were included in this study. Multivariable logistic regression was used to examine the association of pre-pregnancy BMI categories (underweight: <18.5 kg/m2; normal: 18.5–22.9 kg/m2; overweight: 23.0–24.9 kg/m2; obese: ≥25.0 kg/m2) and GDM history with the risk of type 2 diabetes after controlling for the following covariates: age, education, income, smoking status before the first pregnancy, alcohol consumption, regular exercise, menarche age, first pregnancy age, and first pregnancy outcome. Compared to women with normal pre-pregnancy BMIs, women with overweight and obese pre-pregnancy BMIs had higher odds of developing type 2 diabetes (adjusted odds ratio [AOR]: 1.13, 95% confidence interval [CI]: 1.02–1.25 and AOR: 1.29, 95% CI: 1.10–1.50, respectively) after controlling for covariates. Women with pre-pregnancy BMIs <23 kg/m2 and current BMIs ≥23 kg/m2 had increased odds of developing type 2 diabetes (AOR: 1.64, 95% CI: 1.51–1.78) compared to those with pre-pregnancy BMIs <23 kg/m2 and current BMIs <23 kg/m2. Among women without a history of GDM, those with overweight and obese pre-pregnancy BMIs had increased odds of developing type 2 diabetes compared to those with normal pre-pregnancy BMIs (AOR: 1.12, 95% CI: 1.01–1.24 and AOR: 1.23, 95% CI: 1.05–1.44, respectively). Among women with GDM, those with obese pre-pregnancy BMIs had increased odds of developing type 2 diabetes (AOR: 3.84, 95% CI: 1.52–9.87). This study showed that there was a higher likelihood of developing type 2 diabetes in women who were overweight or obese before pregnancy with a history of GDM compared to their counterparts without a history of GDM. Furthermore, high pre-pregnancy BMI or high current BMI increased the risk of type 2 diabetes in Korean women, regardless of GDM history. This emphasizes the importance of maintaining a healthy weight status before and after pregnancy to prevent the future risk of type 2 diabetes.

Maternal and infant hospitalization costs associated with maternal pre-pregnancy body mass index in California, 2007–2011

Background In the United States, the number of pregnant women who are overweight or obese is increasing. While such individuals are at increased risk of pregnancy complications, data regarding costs associated with pre-pregnancy body mass index (BMI) and maternal and infant outcomes are lacking. Objective To estimate maternal and infant costs associated with pre-pregnancy BMI in a large cohort of pregnant women. Materials and methods We conducted a retrospective cohort study of women with singleton, non-anomalous births in California from 2007 to 2011. Women with preexisting diabetes mellitus and chronic hypertension were excluded. Hospitalization costs were estimated separately for women and infants using hospital charges adjusted using a cost-to-charge ratio. These costs included hospitalization costs for admission for delivery only. We estimated the differences in median costs between seven categories of pre-pregnancy BMIs, including underweight (BMI <18.5), normal weight (BMI 18.5–24.9), overweight (BMI 25.0–29.9), class I obesity (BMI 30.0–34.9), class II obesity (BMI 35.0–39.9), class III obesity (BMI 40.0–49.9) and obesity with BMI ≥50.0. We also performed stratified analyses by mode of delivery and gestational age at delivery. We examined the length of stay for women and infants and estimated the gestational age at delivery. Analyses were conducted utilizing Kruskal-Wallis equality-of-populations rank tests with a significance cutoff of 0.05. Results In a California cohort of 1,722,840 women, 787,790 (45.7%) had a pre-pregnancy BMI that was considered overweight or obese. The median maternal and infant costs of each pre-pregnancy BMI strata were significantly different when compared to other strata, with underweight and normal weight women having the lowest median costs ($11,581 and $11,721, respectively) and the most obese category (BMI ≥50) having the highest costs ($15,808). When stratified by mode of delivery and gestational age at delivery, this remained true. Hospitalization costs for women and infants with severe maternal morbidity were also significantly different based on maternal BMI. Comment The hospitalization costs associated with each strata of BMI were significantly different when compared to each other and when stratified by mode of delivery and prematurity. This analysis allows for a greater understanding of the health care costs associated with different maternal pre-pregnancy BMI classes.

Gestational weight gain and adverse pregnancy outcomes by pre-pregnancy BMI category in women with chronic hypertension: A cohort study.

It is important to understand relationships of gestational weight gain with adverse pregnancy outcomes in women with chronic hypertension, given their high baseline risk of adverse outcomes. We assessed associations of gestational weight gain with adverse pregnancy outcomes in women with chronic hypertension by pre-pregnancy body mass index categories. We identified 14,369 women with chronic hypertension using electronic health records from 3 integrated health care delivery systems (2005-2014). Gestational weight gain-for-gestational age charts were used to calculate gestational weight gain z-scores, which account for gestational age. Modified Poisson regression models using generalized estimating equations were used to calculate relative risks and 95% confidence intervals, adjusted for sociodemographic and medical characteristics. Preeclampsia, preterm delivery, cesarean delivery, neonatal intensive care unit admission, birthweight (extracted from the electronic health record). In women with normal weight or overweight, low gestational weight gain (z-score<-1) was associated with 27-28% greater risk of preterm delivery and 48-82% greater risk of small-for-gestational age birthweight, while high gestational weight gain (z-score>1) was associated with 40-90% greater risk of preeclampsia and 59-113% greater risk of large-for-gestational age birthweight. In women with obesity, low gestational weight gain was associated with 27-54% lower risk of several adverse pregnancy outcomes, including preeclampsia and cesarean delivery. In women with chronic hypertension and normal weight or overweight, moderate gestational weight gain may confer the lowest risk of adverse outcomes. In women with chronic hypertension and obesity, low gestational weight gain may be necessary for the lowest risk of adverse pregnancy outcomes.