Combined effects of prepregnancy body mass index and weight gain during pregnancy on the risk of preterm delivery

BACKGROUND: The association between excessive gestational weight gain and preterm delivery is unclear, as is the association between low gestational weight gain and preterm delivery among overweight and obese women. METHODS: Using data from the Pregnancy Risk Assessment Monitoring System in 21 states, we estimated the risk of very (20-31 weeks) and moderately (32-36 weeks) preterm delivery associated with a combination of prepregnancy body mass index (BMI) and gestational weight gain among 113,019 women who delivered a singleton infant during 1996-2001. We categorized average weight gain (kilograms per week) as very low (<0.12), low (0.12-0.22), moderate (0.23-0.68), high (0.69-0.79), or very high (>0.79). We categorized prepregnancy BMI (kg/m) as underweight (<19.8), normal (19.8-26.0), overweight (26.1-28.9), obese (29.0-34.9), or very obese (>or=35.0). We examined associations for all women and for all women with no complications adjusting for covariates. RESULTS: There was a strong association between very low weight gain and very preterm delivery that varied by prepregnancy BMI, with the strongest association among underweight women (adjusted odds ratio = 9.8; 95% confidence interval = 7.0-13.8) and the weakest among very obese women (2.3; 1.8-3.1). Very low weight gain was not associated with moderately preterm delivery for overweight or obese women. Women with very high weight gain had approximately twice the odds of very preterm delivery, regardless of prepregnancy BMI. CONCLUSIONS: This study supports concerns about very low weight gain during pregnancy, even among overweight and obese women, and also suggests that high weight gain, regardless of prepregnancy BMI, deserves further investigation.     

Maternal Obesity and Gestational Weight Gain in Rural Versus Urban Dwelling Women in South Carolina

Purpose: An unhealthy prepregnancy weight and/or gaining an inappropriate amount of weight during pregnancy increase the risk for poor pregnancy and birth outcomes. To our knowledge, no studies to date have examined differences in prepregnancy body mass index (BMI) and gestational weight gain (GWG) patterns by rurality. Methods: The 2004‐2006 South Carolina birth certificate data (n = 132,795) were used. Rurality of residence was determined using Rural‐Urban Commuting Area (RUCA) codes. Mothers were categorized as underweight (<18.5 kg/m²), normal weight (18.5‐24.9), overweight (25.0‐29.9), and obese (≥30.0) using their prepregnancy BMI and as having inadequate, adequate, or excessive GWG according to the Institute of Medicine's 2009 GWG guidelines. Chi‐square tests and adjusted multinomial logistic regression were used in analysis. Findings: Rural women had higher odds of being overweight and obese compared to urban women. This relationship was found to be partially explained by the higher proportion of minorities living in rural areas. The relationship between GWG and residence type varied by BMI category. Specifically, among normal weight women, rural women had increased odds of inadequate GWG. Among overweight women, rural women had decreased odds of excessive GWG. In obese women, rural women had decreased odds of both inadequate and excessive GWG. Conclusions: Rural women were more likely to have an unhealthy prepregnancy weight than urban women. However, rural residence was found to be protective against unhealthy GWG in overweight and obese women. Future research exploring reasons for these findings and confirmation of these results in other populations is necessary.     

Urban and Rural Differences in Pregnancy Weight Gain in Guilan,Northern Iran

Objectives This study aimed to compare pregnancy weight gain and weight gain patterns in a group of Iranian women who attended urban and rural public health centers for prenatal care in Guilan, Iran. Design A secondary data analysis using routinely collected health centers data. Setting 12 randomly selected health centers in urban and rural areas in Guilan. Participants A total of 2,047 pregnant women (1,097 in urban areas and 950 in rural areas) who regularly attended health centers for prenatal care and delivered between June 2003 and August 2006. Measurements Data on prepregnancy weight, height, pregnancy weight gain, mother’s age, parity, education and infant birth weight were extracted from the health records. The women were categorized based on their prepregnancy body mass index as underweight, normal weight and overweight. Findings These results showed that among normal weight women, 41.1% of urban and 56.6% of rural women had weight gains below the Institute of Medicine (IOM) recommendation (P < 0.0001). Among underweight women, 48.1% of urban and 65.8% of rural women had weight gains below the IOM recommendation (P < 0.0001). Rural women with normal prepregnancy weight gained less weight than the urban women in the second trimester of their pregnancy (5.7 ± 2.9 kg vs. 4.6 ± 2.5 kg, P < 0.0001). The underweight rural women gained less weight in both the second and the third trimesters of their pregnancy than the urban women. While the overall prevalence of having low birth weight (LBW) infants for underweight women were 5.2% only 1.9 % of those who gained adequate pregnancy weight gain had LBW infants. Conclusion This study indicated that a considerable proportion of the women both in urban and rural areas in Guilan, Iran had inadequate pregnancy weight gain. These results showed that prenatal care in terms of pregnancy weight gain in the present health system is not satisfactory.     

Weight gain and nutritional intake in obese pregnant women: Some clues for intervention

Aim: Maternal obesity is associated with increased risk of adverse outcomes for mothers and offspring. Strategies to better manage maternal obesity are urgently needed; however, there is little evidence to assist the development of nutrition interventions during antenatal care. The present study aimed to assess maternal weight gain and dietary intakes of overweight and obese women participating in an exercise trial. Results will assist the development of interventions for the management of maternal overweight and obesity. Methods: Fifty overweight and obese pregnant women receiving antenatal care were recruited and provided dietary and weight data at baseline (12 weeks), 28 weeks, 36 weeks gestation and 6 weeks post‐partum. Data collected were compared with current nutritional and weight gain recommendations. Associations used Pearson's correlation coefficient, and ANOVA assessed dietary changes over time, P < 0.05. Results: Mean prepregnancy body mass index was 34.4 ± 6.6 kg/m². Gestational weight gain was 10.6 ± 6 kg with a wide range (?4.1 to 23.0 kg). 52% of women gained excessive weight (>11.5 kg for overweight and >9 kg for obese women). Gestational weight gain correlated with post‐partum weight retention (P < 0.001). Dietary intakes did not change significantly during pregnancy. No women achieved dietary fat or dietary iron recommendations, only 11% achieved adequate dietary folate, and 38% achieved adequate dietary calcium. Very few women achieved recommended food group servings for pregnancy, with 83% consuming excess servings of non‐core foods. Conclusion: Results provide evidence that early intervention and personalised support for obese pregnant women may help achieve individualised goals for maternal weight gain and dietary adequacy, but this needs to be tested in a clinical setting.     

Population-Based Assessment of the Risk of Primary Cesarean Delivery Due to Excess Prepregnancy Weight Among Nulliparous Women Delivering Term Infants

Objective: To estimate the risk of cesarean delivery due to excess prepregnancy body mass index (BMI) in a multistate, US population-based sample. Methods: We analyzed data from the population-based Pregnancy Risk Assessment Monitoring System (PRAMS) on 24,423 nulliparous women with single, term infants delivered between 1998 and 2000 in 19 states. We calculated BMI from self-reported weight and height. We assessed interactions between prepregnancy BMI and other risk factors. We estimated weighted relative risks and 95% confidence intervals for the association between prepregnancy BMI and cesarean section from multiple logistic regression models adjusting for demographic and medical risk factors from the PRAMS questionnaire or birth certificates. Results: The incidence of cesarean delivery increased with increased prepregnancy BMI, from 14.3% (0.8 standard error (SE)) for lean women (BMI < 19.8) to 42.6% (2.0 SE) for very obese women (BMI ≥ 35). The risk of cesarean section differed by presence of any medical, labor and/or delivery complication. Among women with any complication, the estimated adjusted RR for cesarean delivery was 1.1 (95% confidence interval (CI) 1.0–1.2) among overweight women, 1.3 (95% CI 1.1–1.4) among obese women, and 1.4 (95% CI 1.2–1.6) among very obese women compared with normal weight women. Among women without any complications, the estimated adjusted RR was 1.4 (95% CI 1.0–1.8) among overweight women, 1.5 (95% CI 1.1–2.1) among obese women, and 3.1 (95% CI 2.3–4.8) among very obese women. Conclusion: Excess prepregnancy weight increases the risk of cesarean delivery among nulliparous women giving birth to single, term infants, especially among very obese women without any complications.     

Maternal Body Mass Index and Self-Reported Postpartum Depressive Symptoms

Objectives: The association between extremes of body mass index (BMI) and depression in women has been documented, yet little is known about the relationship between obesity and postpartum depression (PPD). This study seeks to characterize the association between BMI and PPD. Methods: The 2000–2001 Utah data from Pregnancy Risk Assessment Monitoring System (PRAMS) were used to determine the proportion of women, stratified by prepregnancy body mass index, reporting postpartum depressed mood and stressors during pregnancy. Results: The prevalence of self-reported moderate or greater depressive symptoms was 27.7% (S.E. ±2.2) in underweight, 22.8% (±1.2) in normal weight, 24.8% (±2.9) in overweight and 30.8% (±2.5) in obese women. After controlling for marital status and income, normal BMI (19.8–25.9) was associated with the lowest rate of self-reported postpartum depressive symptoms. There was a two-fold increase in self-reported depressive symptoms requiring assistance among overweight and obese women compared to normal weight women (1.53% normal, 2.99% overweight, and 3.10% obese [p < 0.001]). Obese women were significantly more likely to report emotional and traumatic stressors during pregnancy than normal weight women. Conclusion: This population-based survey suggests a potential association between prepregnancy body mass index and self-reported postpartum depressive symptoms. Prospective studies of association between obesity and PPD, with improved diagnostic precision are warranted.     

Perinatal weight and risk of prenatal and postpartum depressive symptoms

PurposePrepregnancy obesity and weight changes accompanying pregnancy (gestational weight gain and postpartum weight retention) may be associated with risk of maternal depressive symptoms during pregnancy and in the postpartum. The few studies that have examined these relationships report conflicting findings.MethodsWe studied pregnant (n = 2112) and postpartum (n = 1686) women enrolled in Project Viva. We used self-reported prepregnancy and postpartum weight and measured prenatal weight to calculate prepregnancy body mass index (BMI), gestational weight gain (GWG), and postpartum weight retention at 6 months after birth. We assessed elevated depressive symptoms (EDS) with the Edinburgh Postnatal Depression Scale (≥13 on 0–30 scale) at midpregnancy and 6 months postpartum. We used logistic regression to estimate the odds of prenatal and postpartum EDS in relation to prepregnancy BMI, GWG, and postpartum weight retention.ResultsA total of 214 (10%) participants experienced prenatal EDS and 151 (9%) postpartum EDS. Neither prepregnancy BMI nor GWG was associated with prenatal EDS. Prepregnancy obesity (BMI ≥ 30 kg per m²) was associated with higher odds of postpartum EDS (odds ratio = 1.69, 95% confidence interval, 1.01–2.83) compared to normal prepregnancy weight in a model adjusted for age, race/ethnicity, nativity, education, marital status, household income, parity, pregnancy intention, and smoking.ConclusionsPrepregnancy obesity is associated with elevated depressive symptoms in the postpartum period. Given the current obesity epidemic in the US and the consequences of perinatal depression, additional prevention and screening efforts in this population may be warranted.     

Prenatal weight gains related to the birth of healthy-sized infants to low-income women

Prepregnancy weight status and weight gain during pregnancy are major independent variables associated with infant birth weight. This study quantitated the influence of weight gain on birth weight and identified rates and total amounts of weight gain related to the birth of healthy-sized infants to healthy low-income women who entered pregnancy underweight, at normal weight, overweight, or obese. Data used in the study were obtained from randomly sampled prenatal health records from Maternal and Infant Care (MIC) projects in Cleveland and Minneapolis. Subsamples of healthy mothers who delivered healthy-sized infants were identified from each sample, and rates and total amounts of weight gain by prepregnancy weight status group were calculated. There were 384 healthy mother and healthy-sized infant pairs in the Cleveland subsample and 75 such pairs in the Minneapolis sample. Multiple regression analysis revealed that the influence of prenatal weight gain and birth weight varied depending on prepregnancy weight status. Prenatal weight gains related to the birth of healthy-sized infants (newborns with birth weights of 3,000 to 4,500 gm) to healthy mothers in the Cleveland MIC sample averaged 33 lb for underweight, 32 lb for normal weight, 29 lb for overweight, and 19 lb for obese women. Except for obese women, rates and total amount of weight gain associated with the birth of healthy-sized infants were equivalent for the two samples.     

Prepregnancy body mass index and gestational weight gain as risk factors for preeclampsia and transient hypertension

PURPOSE: Recent studies suggest prepregnancy obesity is a risk factor for preeclampsia, although only a handful of studies have examined the effect of gestational weight gain. The authors analyzed the effect of prepregnancy body mass index (BMI) and weight gain during pregnancy on risk of preeclampsia and transient hypertension.METHODS: Subjects were participants in a prospective cohort study of women who received prenatal care from thirteen obstetric practices in southern Connecticut (4/88-12/91). The women were interviewed in-person before 16 weeks gestation and in the immediate postpartum period. All subjects' hospital delivery charts were abstracted. BMI was categorized as: <19.8 (underweight), 19.8-26 (normal: referent), 26-29 (overweight), >29 (obese). A gestational weight gain index, created using multiple linear regression, compared observed weight gain to the weight gain expected after adjustment for significant covariables (e.g. gestational aged at delivery). Logistic regression was used to estimate risk of preeclampsia (N = 44) and transient hypertension (N = 172) associated with prepregnancy BMI and gestational weight gain.RESULTS: Obese women had a mild increased risk of preeclampsia (OR = 1.81; 0.73-4.52); women in the other BMI categories had risks similar to that of normal BMI subjects. In contrast, risk of transient hypertension was substantially decreased among underweight women (OR = 0.35; 0.14-0.87) and substantially increased among obese women (OR = 3.43; 2.27-5.21). Higher than expected gestational weight gain did not increase the risk of preeclampsia. In contrast, risk of transient hypertension was increased over twofold among women in the highest quartile of the weight gain index (OR = 2.55; 1.66-3.92).CONCLUSIONS: Obesity appears to be a strong risk factor for transient hypertension and a milder risk factor for preeclampsia. High gestational weight gain was associated with increased risk of transient hypertension but not preeclampsia.     

Combined associations of prepregnancy body mass index and gestational weight gain with the outcome of pregnancy

BACKGROUND: Although both maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) may affect birth weight, their separate and joint associations with complications of pregnancy and delivery and with postpartum weight retention are unclear. OBJECTIVES: We aimed to investigate the combined associations of prepregnancy BMI and GWG with pregnancy outcomes and to evaluate the trade-offs between mother and infant for different weight gains. DESIGN: Data for 60892 term pregnancies in the Danish National Birth Cohort were linked to birth and hospital discharge registers. Self-reported total GWG was categorized as low (<10 kg), medium (10-15 kg), high (16-19 kg), or very high (>or=20 kg). Adjusted associations of prepregnancy BMI and GWG with outcomes of interest were estimated by logistic regression analyses. RESULTS: High and very high GWG added to the associations of high prepregnancy BMI with cesarean delivery and were strongly associated with high postpartum weight retention. Moreover, greater weight gains and high maternal BMI decreased the risk of growth restriction and increased the risk of the infant's being born large-for-gestational-age or with a low Apgar score. Generally, low GWG was advantageous for the mother, but it increased the risk of having a small baby, particularly for underweight women. CONCLUSIONS: Heavier women may benefit from avoiding high and very high GWG, which brings only a slight increase in the risk of growth restriction for the infant. High weight gain in underweight women does not appear to have deleterious consequences for them or their infants, but they may want to avoid low GWG to prevent having a small baby.     

“What My Doctor Didn't Tell Me”: Examining Health Care Provider Advice to Overweight and Obese Pregnant Women on Gestational Weight Gain and Physical Activity

BackgroundAppropriate gestational weight gain (GWG) is vital, as excessive GWG is strongly associated with postpartum weight retention and long-term obesity. How health care providers counsel overweight and obese pregnant women on appropriate GWG and physical activity remains largely unexplored.MethodsWe conducted semistructured interviews with overweight and obese women after the birth of their first child to ascertain their experiences with GWG. A grounded theory approach was used to identify themes on provider advice received about GWG and physical activity during pregnancy.ResultsTwenty-four women were included in the analysis. Three themes emerged in discussions regarding provider advice on GWG: 1) Women were advised to gain too much weight or given no recommendation for GWG at all, 2) providers were perceived as being unconcerned about excessive GWG, and 3) women desire and value GWG advice from their providers. On the topic of provider advice on exercise in pregnancy, three themes were identified: 1) Women received limited or no advice on appropriate physical activity during pregnancy, 2) women were advised to be cautious and limit exercise during pregnancy, and 3) women perceived that provider knowledge on appropriate exercise intensity and frequency in pregnancy was limited.ConclusionsThis study suggests that provider advice on GWG and exercise is insufficient and often inappropriate, and thus unlikely to positively influence how overweight and obese women shape goals and expectations in regard to GWG and exercise behaviors. Interventions to help pregnant women attain healthy GWG and adequate physical activity are needed.     

Insulin and the “Thrifty” Woman: The Influence of Insulin During Pregnancy on Gestational Weight Gain and Postpartum Weight Retention

Objectives: To test Neel's hypothesis among pregnant women: a high maternal insulin concentration in early pregnancy increases the risk of weight gain, overweight, and obesity among nondiabetic, low-income gravidas of racial and ethnic minority groups from Camden, New Jersey. Methods: Fasting insulin was obtained from 461 gravidas at entry to prenatal care. Insulin quartile was related to rate of gestational weight gain and excess weight gain during pregnancy (90th percentile) and to retained weight and excess weight retention at 4–6 weeks postpartum (90th percentile). The relationship between excess retained weight and excessive insulin increase (90th percentile) was also examined. Results: Compared with gravidas with an insulin concentration in the lowest three quartiles, gravidas with the highest insulin quartile had a significantly higher rate of gestational weight gain (nonobese women only) and average weight retained postpartum (all women). Compared with an insulin concentration in the lowest three quartiles, the highest insulin quartile was associated with a 2.05-fold (95% confidence interval [CI] = 1.07–3.93) risk of an excessive rate of gestational weight gain and a 3.58-fold (95% CI = 1.87–6.84) risk of excess weight retained postpartum. Excess weight retained postpartum was linked to a 2.63-fold (95% CI = 1.00–6.89) risk of an excessive increase in insulin concentration postpartum. Conclusions: Our results support Neel's hypothesis and suggest that a high maternal insulin concentration is associated with increased gestational weight gain and increased weight retention postpartum. High insulin concentration may contribute to pregnancy-related changes in weight and thus may be linked to maternal overweight and obesity postpartum as well as to future risk of gestational and Type 2 diabetes mellitus.     

Maternal Weight Gain During Pregnancy and Child Weight at Age 3 Years

Objectives To determine the importance of pregnancy weight gain as a predictor of overweight (Body Mass Index [BMI] >85th percentile) in offspring at age 3 years and if its influence varies by maternal BMI. Methods Chi-square and logistic regression analyses were conducted on a sample of 208 mother-child pairs from an earlier observational cohort study on postpartum weight retention. Results In the final reduced regression model, maternal early pregnancy BMI was positively and significantly associated with overweight in offspring, as were birth weight above the sample median of 3,600 g and maternal smoking during pregnancy (P ≤ 0.01). In addition, a significant interaction was found between maternal BMI and gestational weight gain (P = 0.03). The risk of offspring overweight that is associated with 5 excess pounds of net pregnancy weight gain increases with maternal BMI. Conclusions Excess pregnancy weight gain is associated with increased risk of child overweight at age 3 years and its impact is greater among high and obese BMI women than it is in normal BMI women. Reducing maternal BMI in the preconception period in overweight women and preventing excessive weight gain in pregnancy for all women appear to be appropriate strategies to address the childhood obesity epidemic.     

孕前体重指数及其孕期增加对妊娠结局的影响

目的:定量评价孕前体重指数及孕期体重指数增加情况对我国北方孕妇妊娠结局的影响。方法:收集2007～2009年在沈阳3家医院分娩的3741名单胎妊娠初产妇,按照孕前体重指数(BMI)分为4组:低体重组(BMI18.5kg/m2)、正常体重组(18.5kg/m2≤BMI24kg/m2)、超重组(24kg/m2≤BMI28kg/m2)和肥胖组(BMI≥28kg/m2)。按照孕期BMI增加情况分为3组:A组(BMI增加4)、B组(BMI增加4～6)、C组(BMI增加6)。Logistic回归评估不良妊娠结局的危险度,结果用RR和95%CI表示。结果:①和正常体重组相比,孕前低体重、超重和肥胖组的孕妇患子痫前期的RR分别为0.53(95%CI0.29～0.97)、2.84(95%CI2.05～3.94)和5.35(95%CI3.47～8.49);患妊娠期糖尿病的RR分别为0.35(95%CI0.16～0.78)、3.40(95%CI2.44～4.75)和4.95(95%CI2.91～7.06);剖宫产和出生大于胎龄儿(LGA)的风险也随孕前体重的增加而增加。②和B组相比,C组增加了子痫前期(RR1.85,95%CI1.40～2.44)、妊娠期糖尿病(RR1.39,95%CI1.05～1.86)、剖宫产(RR1.37,95%CI1.15～1.63)及出生LGA(RR1.98,95%CI1.44～2.73)的相对危险性,但降低了出生SGA的风险。A组降低了子痫前期、剖宫产和出生LGA的风险,但增加了早产(34周)和出生SGA的风险。结论:孕前体重指数过高及孕期体重指数增加过度可以明显增加孕妇子痫前期、妊娠期糖尿病和剖宫产的风险。应加强健康教育,适度控制孕期体重,合理营养减少肥胖,对预防妊娠并发症,改善妊娠结局是有必要的。     

Perceived weight status may contribute to education inequalities in five-year weight change among mid-aged women

Objectives: To examine education differences in five‐year weight change among mid‐aged adults, and to ascertain if this may be due to socioeconomic differences in perceived weight status or weight control behaviours (WCBs). Methods: Data were used from the Australian Diabetes, Obesity and Lifestyle Study. Mid‐aged men and women with measured weights at both baseline (1999–2000) and follow‐up (2004–2005) were included. Percent weight change over the five‐year interval was calculated and perceived weight status, WCBs and highest attained education were collected at baseline. Results: Low‐educated men and women were more likely to be obese at baseline compared to their high‐educated counterparts. Women with a certificate‐level education had a greater five‐year weight gain than those with a bachelor degree or higher. Perceived weight status or WCBs did not differ by education among men and women, however participants that perceived themselves as very overweight had less weight gain than those perceiving themselves as underweight or normal weight. WCBs were not associated with five‐year weight change. Conclusions and Implications: The higher prevalence of overweight/obesity among low‐educated women may be a consequence of greater weight gain in mid‐adulthood. Education inequalities in overweight/obesity among men and women made be due (in part) to overweight or obese individuals in low‐educated groups not perceiving themselves as having a weight problem.     

Maternal anthropometric factors and risk of primary cesarean delivery.

OBJECTIVES: This study examined absolute and proportional gestational weight gain and prepregnancy body mass index as predictors of primary cesarean delivery. METHODS: Data were derived from a prospective study of pregnancy outcome risk factors in 2301 women in greater New Haven, Conn, who had singleton deliveries by primary cesarean (n = 312) or vaginal delivery (n = 1989) and for whom height, prepregnancy weight, and weight gain were available. Women were divided into 4 body mass index groups (underweight, low average, high average, and obese) and further subdivided into 8 groups according to median proportional or absolute weight gain. RESULTS: Risk of cesarean delivery increased with increasing body mass index and gestational weight gain greater than the median for one's body mass index. Proportional weight gain was more predictive of cesarean delivery than absolute weight gain. Underweight women gaining more than 27.8% of their prepregnancy weight had a 2-fold adjusted relative risk of cesarean delivery. CONCLUSIONS: Proportional weight gain is an important predictor of cesarean delivery for underweight women; high body mass index is also predictive of increased risk.     

Obesity and gestational weight gain: cesarean delivery and labor complications

OBJECTIVE: To assess the association between pre-gestational obesity and weight gain with cesarean delivery and labor complications. METHODS: A total of 4,486 women 20-28 weeks pregnant attending general prenatal care clinics of the national health system in Brazil from 1991 to 1995 were enrolled and followed up through birth. Body mass index categories based on prepregnancy weight and total weight gain were calculated. Associations between body mass index categories and labor complications were adjusted through logistic regression analysis. RESULTS: Obesity was present in 308 (6.9%) patients. Cesarean delivery was performed in 164 (53.2%) obese, 407 (43.1%) pre-obese, 1,045 (35.1%) normal weight and 64 (24.5%) underweight women. The relative risk for cesarean delivery in obese women was 1.8 (95% CI: 1.5-2.0) compared to normal weight women. Greater weight gain was particularly associated with cesarean among the obese (RR 4th vs 2nd weight gain quartile 2.2; 95% CI: 1.4-3.2). Increased weight at the beginning of pregnancy was associated with a significantly higher adjusted risk of meconium with vaginal delivery and perinatal death and infection in women submitted to cesarean section. Similarly, greater weight gain during pregnancy increased the risk for meconium and hemorrhage in women submitted to vaginal delivery and for prematurity with cesarean. CONCLUSIONS: Pre-gestational obesity and greater weight gain independently increase the risk of cesarean delivery, as well as of several adverse outcomes with vaginal delivery. These findings provide further evidence of the negative effects of prepregnancy obesity and greater gestational weight gain on pregnancy outcomes.     

Pregravid body mass index is associated with early introduction of complementary foods

ObjectiveTo determine whether women who entered pregnancy overweight or obese were less likely to follow American Academy of Pediatrics guidelines for introducing complementary foods to infants after 4 months of age. In addition, we explored whether psychological factors accounted for any of the effect of pregravid body mass index on age of complementary food introduction.DesignA prospective cohort study from 2001 to 2005 that recruited pregnant women between 15 to 20 gestational weeks with follow-up through 12 months postpartum from University of North Carolina hospitals (n=550).Statistical analysisMultinomial models were used to estimate relative risk ratios. The outcome was age of complementary food introduction, categorized as younger than 4 months of age, 4 to 6 months, and 6 months or later (referent). Maternal body mass index was categorized as underweight (<18.5), normal weight (18.5 to 24.9), and overweight/obese (≥25). A series of regression analyses tested mediation by psychological factors measured during pregnancy (depressive symptoms, stress, and anxiety).ResultsMore than a third of the study population (35.7% of 550) entered pregnancy overweight/obese. The majority of participants (75.3%) introduced foods to their infants between 4 and 6 months of age. Compared with normal-weight women, those who were overweight/obese before pregnancy were more likely (relative risk ratios=2.22 [95% CI 1.23 to 4.01]) to introduce complementary foods before the infant was 4 months old, adjusting for race, education, and poverty status. Depressive symptoms, stress, and anxiety did not account for any of the effect of pregravid overweight/obesity on early food introduction.ConclusionsThe results suggest that overweight and obese women are more likely to introduce complementary foods early and that psychological factors during pregnancy do not influence this relationship. Future studies need to explore why overweight/obese women are less likely to meet the American Academy of Pediatrics recommendations for the introduction of complementary food.     

孕前超重、孕期过度增重与巨大儿发生风险的前瞻性队列研究

目的 探讨巨大儿发生与孕前超重、孕期过度增重的直接关联及关联强度。方法 2015年1月起在上海市浦东新区妇幼保健院建立孕妇队列,创建孕妇健康档案,收集孕期及分娩信息,包括一般人口学特征、孕前体重、孕期增重、分娩体重、孕期健康状况及各种孕期并发症、分娩情况等,计算孕前BMI及孕期增重,收集新生儿出生体重,了解巨大儿发生与孕前超重、孕期过度增重之间的关系。结果 巨大儿发生率为6.6%（149/2 243）。不同孕前BMI组巨大儿发生率差异有统计学意义（P=0.001）。在控制了孕妇年龄、孕产史等因素后,logistic回归分析结果显示,与孕前BMI适宜的孕妇比,孕前BMI超重以及肥胖的孕妇生产巨大儿的风险均增加（OR=3.12,95%CI：1.35~7.22,P=0.008; OR=2.99,95%CI：1.17~7.63,P=0.022）。不同孕期增重组巨大儿发生率差异有统计学意义（P=0.002）。在控制了孕妇年龄、孕产史、孕期并发症等因素后,logistic回归分析结果显示,与孕期增重适宜的孕妇比,孕期增重不足的孕妇生产巨大儿的风险降低（OR=0.52,95%CI：0.30~0.90,P=0.019）。而孕期过度增重在调整了各种孕期指标后,与孕期增重适宜的孕妇比,巨大儿发生风险差异有统计学意义（OR=1.41,95%CI：0.96~2.09,P=0.084）。结论 孕前超重或肥胖是巨大儿发生的风险因素。     

Association of Prenatal Physical Activity and Gestational Weight Gain: Results from the First Baby Study

BackgroundIn response to increasing rates of excessive gestational weight gain (GWG) and evidence of postpartum weight retention and long-term overweight and obesity, the Institute of Medicine (IOM) revised their guidelines for GWG in 2009. Prenatal physical activity is recommended, although its role in preventing excessive GWG is unclear. We sought to understand the association between prenatal physical activity and GWG in a longitudinal cohort.MethodsDuring a baseline survey at 34 weeks, women (n = 3,006) reported their height, prepregnancy weight, and physical activity during pregnancy. GWG was self-reported at 1-month postpartum. Multivariable logistic regression adjusting for age, race/ethnicity, education, poverty status, marital status, gestational age at the time of delivery, and smoking was used to model the association between adequate physical activity during pregnancy and exceeding the IOM recommendations for GWG.FindingsOverweight women were most likely to exceed the IOM recommendations for GWG (78.7%), followed by obese women and normal weight women (65.0% and 42.4%, respectively). The majority of women participated in some physical activity during pregnancy, with 41.2% engaging in 60 to 149 minutes and 32.1% engaging in at least 150 minutes of physical activity per week. In adjusted analysis, meeting the physical activity guidelines was associated with a 29% (confidence interval, 0.57–0.88) lower odds of exceeding the IOM recommendations for GWG compared with inactive women.ConclusionsFindings of high rates of excessive GWG, especially among women with overweight and obesity, are concerning given the associated health burdens. The association of guideline-concordant physical activity with appropriate GWG suggests this is an important target for future interventions.