Postpartum weight retention in relation to gestational weight gain and pre-pregnancy body mass index: A prospective cohort study in Vietnam

BackgroundThe prevalence of maternal overweight and obesity is increasing in Asia. This study prospectively investigated the association between pre-pregnancy body mass index (BMI), gestational weight gain (GWG) and 12-month postpartum weight retention (PPWR) in a large cohort of Vietnamese mothers.MethodsOf the 2030 pregnant women recruited from three cities in Vietnam at 24–28 weeks of gestation, a total of 1666 mothers were followed up for 12 months after delivery and available for analysis. The outcome variable PPWR was determined by subtracting the pre-pregnancy weight from the 12-month postpartum measured weight, while GWG and pre-pregnancy BMI were classified according to the Institute of Medicine and WHO criteria for adults, respectively. Linear regression models were used to ascertain the association between pre-pregnancy BMI, GWG and PPWR accounting for the effects of plausible confounding factors.ResultsBoth pre-pregnancy BMI and GWG were significantly associated with PPWR (P < 0.001). The adjusted mean weight retention in underweight women before pregnancy (3.71 kg, 95% confidence interval (CI) 3.37–4.05) was significantly higher than that in those with normal pre-pregnancy weight (2.34 kg, 95% CI 2.13–2.54). Women with excessive GWG retained significantly more weight (5.07 kg, 95% CI 4.63–5.50) on average at 12 months, when compared to mothers with adequate GWG (2.92 kg, 95% CI 2.67–3.17).ConclusionsBeing underweight before pregnancy and excessive GWG contribute to greater weight retention twelve months after giving birth. Interventions to prevent postpartum maternal obesity should target at risk women at the first antenatal visit and control their weight gain during the course of pregnancy.     

Modifiable Determinants of Postpartum Weight Loss in Women with Obesity: A Secondary Analysis of the UPBEAT Trial

Pregnancy can alter a woman’s weight gain trajectory across the life course and contribute to the development of obesity through retention of weight gained during pregnancy. This study aimed to identify modifiable determinants associated with postpartum weight retention (PPWR; calculated by the difference in pre-pregnancy and 6 month postpartum weight) in 667 women with obesity from the UPBEAT study. We examined the relationship between PPWR and reported glycaemic load, energy intake, and smoking status in pregnancy, excessive gestational weight gain (GWG), mode of delivery, self-reported postpartum physical activity (low, moderate, and high), and mode of infant feeding (breast, formula, and mixed). At the 6 month visit, 48% (n = 320) of women were at or above pre-pregnancy weight. Overall, PPWR was negative (−0.06 kg (−42.0, 40.4)). Breastfeeding for ≥4 months, moderate or high levels of physical activity, and GWG ≤9 kg were associated with negative PPWR. These three determinants were combined to provide a modifiable factor score (range 0–3); for each added variable, a further reduction in PPWR of 3.0 kg (95% confidence interval 3.76, 2.25) occurred compared to women with no modifiable factors. This study identified three additive determinants of PPWR loss. These provide modifiable targets during pregnancy and the postnatal period to enable women with obesity to return to their pre-pregnancy weight.     

Pre-Pregnancy Weight Status Is Associated with Diet Quality and Nutritional Biomarkers during Pregnancy

Although the positive association between pre-pregnancy overweight and obesity with excessive gestational weight gain is well known, it is not clear how pre-pregnancy weight status is associated with gestational weight gain through maternal diet during pregnancy. This study aimed to examine the relationship between pre-pregnancy weight status and diet quality and maternal nutritional biomarkers during pregnancy. Our study included 795 U.S. pregnant women from the National Health and Nutrition Examination Survey, 2003–2012. Pre-pregnancy body mass index (BMI) was calculated based on self-reported pre-pregnancy weight and height. The cutoff points of <18.5 (underweight), 18.5–24.9 (normal), 25.0–29.9 (overweight), and 30 kg/m² (obese) were used to categorize pregnant women’s weight status. Diet quality during pregnancy was assessed by the Healthy Eating Index (HEI)-2010 based on a 24-h recall. Multivariable logistic regressions were used to estimate the odds ratios (OR) and 95% confidence intervals (CI). For all pregnant women included in this study, the mean HEI-2010 (±standard error of the mean (SEM)) was 50.7 (±0.9). Women with obese pre-pregnancy BMI demonstrated significantly lower HEI-2010 compared to those with underweight and normal pre-pregnancy BMI, respectively. In an unadjusted model, women with pre-pregnancy obesity BMI had increased odds for being in the lowest tertile of HEI-2010 (33.4 ± 0.5) compared to those with underweight pre-pregnancy BMI (OR 5.0; 95% CI 2.2–11.4). The inverse association between pre-pregnancy overweight and obesity status and diet quality during pregnancy persisted even after we controlled for physical activity levels (adjusted OR (AOR) 3.8; 95% CI 1.2–11.7, AOR 5.4; 95% CI 2.0–14.5, respectively). Serum folate concentration (ng/mL) was significantly higher in underweight women compared to overweight women (23.4 ± 1.7 vs. 17.0 ± 0.8, p < 0.05). Serum iron concentration (ng/dL) was significantly higher in normal weight women compared to overweight women (86.2 ± 5.0 vs. 68.9 ± 3.0, p < 0.05). An inverse association was found between pre-pregnancy weight status and diet quality and maternal nutritional biomarkers during pregnancy. Poor diet quality as measured by HEI-2010 was shown among overweight and obese women. Nutrition education and interventions need to be targeted to those women entering pregnancy as overweight and obese.     

Health Status and Health Insurance Coverage of Women with Live-Born Infants: An Opportunity for Preventive Services After Pregnancy

Most women in the US have access to health care and insurance during pregnancy; however women with Medicaid-paid deliveries lose Medicaid eligibility in the early postpartum period. This study examined the association between health insurance coverage at the time of delivery and health conditions that may require preventive or treatment services extending beyond pregnancy into the postpartum period. We used 2008 Pregnancy Risk Assessment Monitoring System data from 27 states (n = 35,980). We calculated the prevalence of maternal health conditions, including emotional and behavioral risks, by health insurance status at the time of delivery. We used multivariable logistic regression to assess the association between health insurance coverage, whether Medicaid or private, and maternal health status. As compared to women with private health insurance, women with Medicaid-paid deliveries had higher odds of reporting smoking during pregnancy (adjusted odds ratio [AOR]: 1.85, 95 % confidence interval [CI]: 1.56–2.18), physical abuse during pregnancy (AOR: 1.73, 95 % CI: 1.24–2.40), having six or more stressors during pregnancy (AOR: 2.48, 95 % CI: 1.93–3.18), and experiencing postpartum depressive symptoms (AOR: 1.24, 95 % CI: 1.04–1.48). There were no significant differences by insurance status at delivery in pre-pregnancy overweight/obesity, pre-pregnancy physical activity, weight gain during pregnancy, alcohol consumption during pregnancy, or postpartum contraceptive use. Compared to women with private insurance, women with Medicaid-paid deliveries were more likely to experience risk factors during pregnancy such as physical abuse, stress, and smoking, and postpartum depressive symptoms for which continued screening, counseling, or treatment in the postpartum period could be beneficial.     

孕前体质指数及孕期增重对新生儿出生体重影响的前瞻性队列研究

目的  分析孕妇孕前体质指数(body mass index, BMI)及孕期增重(gestational weight gain, GWG)与新生儿出生体重的关联性, 并探究孕妇孕前及孕中体重动态变化对新生儿低出生体重(low birth weight, LBW)及巨大儿的影响。 方法  收集中国孕产妇队列·协和纳入的孕早期孕妇孕前体重, 并随访至分娩后, 收集分娩前体重及新生儿出生结局。将孕妇孕前BMI分为低体重组、正常体重组及超重/肥胖组, 将GWG分为适宜、不足及过多组。采用多因素多分类(多项)Logistic回归分析模型探讨孕前BMI及GWG与新生儿出生体重的关系。 结果  孕前BMI及GWG与子代出生体重相关(均有P < 0.05)。孕前超重/肥胖(OR=2.339, 95%CI:1.674~2.282, P < 0.001)、GWG过多(OR=1.398, 95%CI:1.188~1.978, P=0.048)显示为巨大儿的危险因素, GWG不足(OR=1.479, 95%CI:1.461~1.679, P=0.035)显示为LBW的危险因素, GWG过多会降低LBW的发生风险(OR=0.428, 95%CI:0.225~0.817, P=0.010)。低BMI-GWG不足(OR=1.335, 95%CI:1.048~2.319, P=0.048)是LBW的危险因素; 正常BMI-GWG过多(OR=1.088, 95%CI:1.016~1.675, P=0.038)和超重/肥胖-GWG过多(OR=1.498, 95%CI:1.244~2.017, P=0.046)是巨大儿的危险因素。 结论  孕前BMI及GWG是影响新生儿出生体重的重要因素, 提示女性应合理控制孕前及孕中体重变化。     

Maternal Obesity and Risk of Low Birth Weight,Fetal Growth Restriction,and Macrosomia: Multiple Analyses

The associations between maternal pre-pregnancy obesity and low birth weight (LBW, <2500 g) remain inconclusive. Therefore, birth weight in a Polish prospective cohort of 912 mothers was investigated depending on the pre-pregnancy body mass index (BMI). The whole cohort and the subgroup of gestational weight gain (GWG) in the range of the Institute of Medicine (IOM) recommendations, as well as ‘healthy’ women (who did not develop diabetes or hypertension in this pregnancy) were investigated. Adjusted odds ratios (AOR) of the newborn outcomes (with 95% confidence intervals, CI) for obesity (BMI ≥ 30 kg/m²) vs. normal BMI (18.5−24.9 kg/m²) were calculated using multiple logistic regression. Risk profiles (in the Lowess method) were presented for BMI values (kg/m²) and threshold BMI values were calculated. (1) In the cohort, LBW affected 6.6% of pregnancies, fetal growth restriction (FGR) 2.3%, and macrosomia 10.6%. (2) The adjusted risk of macrosomia was more than three-fold higher for obesity compared to normal BMI in the whole cohort (AOR = 3.21 (1.69−6.1), p < 0.001) and the result was maintained in the subgroups. A 17-fold higher adjusted LBW risk for obesity was found (AOR = 17.42 (1.5−202.6), p = 0.022), but only in the normal GWG subgroup. The FGR risk profile was U-shaped: in the entire cohort, the risk was more than three times higher for obesity (AOR = 3.12 (1.02−9.54), p = 0.045) and underweight (AOR = 3.84 (1.13−13.0), p = 0.031). (3) The risk profiles showed that the highest BMI values were found to be associated with a higher risk of these three newborn outcomes and the threshold BMI was 23.7 kg/m² for macrosomia, 26.2 kg/m² for LBW, and 31.8 kg/m² for FGR. These results confirm the multidirectional effects of obesity on fetal growth (low birth weight, fetal growth restriction, and macrosomia). The results for LBW were heavily masked by the effects of abnormal gestational weight gain.     

Gestational Weight Gain and Postpartum Weight Retention in a Cohort of Nova Scotian Women

Excess gestational weight gain (GWG) may predispose mothers to becoming overweight or obese. The aim of this study was to investigate the association between GWG, according to the American Institute of Medicine (IOM) guidelines, and postpartum weight retention (PPWR). A cohort of 12,875 women from Nova Scotia, Canada with at least two consecutively recorded pregnancies was identified through a population-based perinatal database between 1993 and 2010. GWG was calculated as the difference between delivery and prepregnancy weights. PPWR, analyzed as a continuous variable in linear regression models, was calculated via interpregnancy weight change. Fifty eight percent of the total study population gained in excess of the IOM guidelines. Mean PPWR, adjusted for age and prepregnancy body mass index (BMI) among women with excess GWG was 5.0 kg (95 % CI 4.9–5.2), greater than women with adequate (2.1 kg, 95 % CI 1.8–2.3) or inadequate GWG (0.3 kg, 95 % CI 0–0.7). Effect modification by prepregnancy BMI was observed; the relationship between excess GWG and increased PPWR was observed in all prepregnancy BMI categories, yet was greatest among underweight women (7.5 kg, 95 % CI 6.6–8.3). Effect modification by parity was also observed; in contrast to multiparous women, primiparous women who gained in excess of GWG guidelines retained more postpartum weight (5.3 kg, 95 % CI 5.1–5.5 vs. 4.3 kg, 95 % CI 4.0–4.7). This study demonstrates that excess GWG is associated with an increase in the amount of weight retained after pregnancy. Interventions targeted to promote optimal GWG are warranted.     

A multivitamin supplementation and education intervention as an effective means of increasing multivitamin use among postpartum women of Mexican origin

Postpartum Hispanic women in the USA are at elevated risk for neural tube defects in subsequent pregnancies from the combined effects of ethnicity, folate depletion from the prior pregnancy and lactation, and high parity rates with short inter-birth intervals. This study evaluated an education programme and distribution of a 3-month starter package of multivitamins among Hispanic women attending nutrition clinics for low-income women in El Paso, Texas. At 1-6 weeks postpartum, 329 subjects were selected to receive education only, multivitamins only, education and multivitamins, or no intervention. Multivariable regression obtained odds ratios (OR) and 95% confidence intervals [CI] to measure the association between intervention status and self-reported multivitamin use at least four times per week at 6 and 12 months postpartum, while controlling for potential confounding variables. Multivitamin distribution was related to consumption at both 6 months (OR = 3.5 [95% CI 1.1, 11.2]) and 12 months (OR = 6.5 [95% CI 1.5, 28.3]). Multivitamins plus education was most effective in increasing multivitamin use at both periods: 6 months (OR = 4.0 [95% CI 1.53, 11.7]) and 12 months (OR = 6.4 [95% CI 1.7, 24.2]). At enrolment, 66% of women regularly took vitamins, and approximately 35% took them at both 6 and 12 months postpartum. The education intervention alone was not associated with multivitamin use at either 6 months (OR = 0.79 [95% CI 0.3, 2.4]) or 12 months (OR = 3.1 [95% CI 0.8, 12.1]). Multivitamin use declines precipitously during postpartum at the time Hispanic women may be susceptible to a subsequent pregnancy. This study provides evidence that multivitamin starter packs sustain multivitamin usage up to 1 year postpartum for a specific high-risk group, but the effect of educational intervention alone should be further studied.     

孕前体质指数、孕期增重与婴幼儿血红蛋白的关系

目的 探讨孕前体质指数（body mass index,BMI）、孕期增重与婴幼儿血红蛋白的关系。方法 选择按期体检与分娩的孕妇及婴儿作为研究对象,孕妇一般情况及分娩情况将由问卷调查的方式收集。并采用单因素分析和多因素Logistic回归模型进行数据分析。结果 受检对象共980例,按孕前BMI分组,孕前消瘦者占19.0%,孕前体重正常者占71.0%,孕前超重肥胖者占10.0%。孕期增重按美国国家科学院（institute of medicine,IOM）标准分组,孕期增重低于IOM推荐标准者占27.8%,符合IOM推荐标准者占31.4%,高于IOM推荐标准者占40.8%。贫血发生率为49.7%。单因素分析中孕前BMI、孕期增重对贫血均有统计学意义（均有P<0.05）。同时多因素分析显示,孕前消瘦者（OR=2.027,95%CI：1.433～2.867）,孕期增重不足者（OR=2.499,95%CI：1.772～3.523）是婴幼儿贫血的危险因素。结论 孕前BMI、孕期增重情况可能是婴幼儿贫血的危险因素,控制孕前BMI、孕期增重情况可以有效降低贫血的发生风险。     

我国北方地区单胎足月初产妇孕期体重增长适宜范围

目的:探讨我国北方地区足月妊娠妇女孕期体重增长的适宜范围。方法:收集我国北方地区5 072例单胎足月初产妇孕前、孕期及产后42天资料,按照中国成人体重指数(BM I)分类要求将5 072例孕妇分组,了解各组的孕期体重增长情况,分析各组不同孕期体重增长对母儿不良妊娠结局发生率的影响,从而为各组推荐孕期体重增长的适宜范围。结果:5 072例孕妇中,孕前BM I<18.5 kg/m2,18.5～23.9 kg/m2及≥24 kg/m2的孕妇分别占16.8%,66.8%及16.4%,不良妊娠结局发生率最低的孕期体重增长范围分别为12～18 kg,10.0～16.0 kg及8.0～14.0 kg,(P<0.05),推荐的孕期体重增长范围分别为12～18 kg,10.0～16.0 kg及8.0～14.0 kg。结论:我国北方地区孕前低、正常、超重及肥胖组孕妇的平均孕期体重增长均较高,建议其孕期体重增长范围分别控制在12～18 kg,10.0～16.0 kg及8.0～14.0 kg。     

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.     

Cross-sectional analysis of factors associated with prior contraceptive use among hospitalized obstetric patients in Kabul, Afghanistan

OBJECTIVE: This study was conducted to assess prevalence and correlates of prior contraceptive use among hospitalized obstetric patients in Kabul, Afghanistan. STUDY DESIGN: Medically eligible (e.g., conditions not requiring urgent medical attention, such as eclampsia, or not imminently delivering [dilation > or =8 cm]) obstetric patients admitted to three Kabul public hospitals were consecutively enrolled in this cross-sectional study. An interviewer-administered questionnaire assessed demographic information, health utilization history, including prior contraceptive use, and intent to use contraception. Correlates of prior contraceptive use were determined with logistic regression. RESULTS: Of 4452 participants, the mean age was 25.7 years (SD, +/-5.7 years), 66.4% reported pregnancy before the presenting gestation, 88.4% had > or =1 prenatal care visit and 82.4% reported the current pregnancy was desired. Most (67.4%) had no formal education. One fifth (22.8%) reported using contraception before this pregnancy. Among women with any pregnancy before the current gestation (98.6% of prior users), prior contraceptive use was independently associated with having lived outside Afghanistan in the last 5 years (adjusted odds ratio [AOR], 1.35; 95% confidence interval [CI], 1.12-1.63), having a skilled attendant at the last birth (AOR, 1.35; 95% CI, 1.07-1.71), having a greater number of living children (AOR, 1.30; 95% CI, 1.20-1.41), longer mean birth interval (years) (AOR, 1.21; 95% CI, 1.11-1.38) and higher educational level (AOR, 1.16; 95% CI, 1.09-1.22). Immediate desire for another pregnancy and spousal disapproval were the most common reasons for not utilizing contraception. CONCLUSION: Prior contraceptive use is low among the women in Kabul, Afghanistan, particularly for younger less educated women. Programming in Kabul to strengthen postpartum contraceptive counseling should address barriers to contraceptive use, including immediate desire for pregnancy and spousal attitudes.     

产妇久坐行为对产后一年体重滞留影响的研究

  目的  了解山西省东南部地区产妇体重滞留现状及其影响因素,为制定合理的体重改善策略和措施提供依据。  方法  于2015年7月 — 2017年6月,采用前瞻性队列研究方法,纳入待分娩孕妇635人,于产后6个月进行追踪调查,观察指标包括一般情况、孕前体重、孕期增重和产后6个月体重。  结果  635名纳入研究的孕妇中,产后6个月随访到的有效人数为495人,应答率为77.95 %。研究对象产前平均体质指数（BMI）为（20.27 ± 2.28）kg/cm²,分娩后6个月平均BMI为（23.12 ± 2.74）kg/cm²,平均体重滞留为（2.68 ± 2.48）kg。超重和肥胖妇女比率由产前的16.36 %到产后6个月的24.65 %。295名（59.6 %）研究对象超过了美国医学研究会（IOM）2009年推荐的孕期增重标准至少1 kg,104名（21.01 %）研究对象超过标准5 kg。经多元线性回归分析,影响本地区产妇产后6个月体重滞留的影响因素为孕期增重、产后抑郁症患病情况和孕前BMI。  结论  怀孕期间以及产后6个月内需要进行体重管理以及心理卫生干预,以减少肥胖和肥胖相关疾病的发生率。     

孕前体重指数和孕期体重增长与早产的关系

目的:探讨孕前体重指数和孕期体重增长与早产的关系。方法:回顾性分析2003年1月2005年1月我院592例单胎早产孕妇孕前体重指数和孕期体重增长情况。结果:排除混杂因素影响,孕前体重过低或孕前体重正常而孕期体重增长不足的孕妇发生早产的AOR值和95%可信区间分别是5.96(1.26,46.5)和3.96(1.82,9.62)。结论:孕前体重过低或孕前体重正常的孕妇若孕期体重增长不足会增加早产的危险。     

Maternal Diet and Weight at 3 Months Postpartum Following a Pregnancy Intervention with a Low Glycaemic Index Diet: Results from the ROLO Randomised Control Trial

Pregnancy increases the risk of being overweight at a later time period, particularly when there is excessive gestational weight gain. There remains a paucity of data into the effect of low glycaemic index (GI) pregnancy interventions postpartum. Aim: To examine the impact of a low glycaemic index diet during pregnancy on maternal diet 3 months postpartum. Methodology: This analysis examined the diet, weight and lifestyle of 460 participants of the ROLO study 3 months postpartum. Questionnaires on weight, physical activity, breastfeeding, supplement use, food label reading and dietary habits were completed. Results: The intervention group had significantly greater weight loss from pre-pregnancy to 3 months postpartum than the control group (1.3 vs. 0.1 kg, p = 0.022). The intervention group reported greater numbers following a low glycaemic index diet (p < 0.001) and reading food labels (p = 0.032) and had a lower glycaemic load (GL) (128 vs. 145, p = 0.014) but not GI (55 vs. 55, p = 0.809) than controls. Conclusions: Low GI dietary interventions in pregnancy result in improved health-behaviours and continued reported compliance at 3 months postpartum possibly through lower dietary GL as a result of portion control. Greater levels of weight loss from pre-pregnancy to 3 months postpartum in the intervention group may have important positive implications for overweight and obesity.     

Pre-pregnancy body mass index change between pregnancies and preterm birth in the following pregnancy

Maternal pre-pregnancy body mass index (BMI) may affect the risk of preterm birth. However, it is unclear how changes in BMI between pregnancies modify the risk of preterm birth in the following pregnancy. We studied this effect in the Collaborative Perinatal Project, when obesity was uncommon and the prevalence of induction of labour was low. This analysis included 1892 primiparae whose first enrolled (index) pregnancy was a singleton livebirth and the second enrolled (outcome) pregnancy was a consecutive singleton pregnancy (both pregnancies within 20–51 weeks of gestation). We used the Cox regression model to calculate the hazard ratio (HR) of preterm birth at the outcome pregnancy as a function of reduced BMI (<25^th percentile of change) and increased BMI (>75^th percentile), compared with stable BMI (25^th–75^th percentile), adjusted for pre-pregnancy BMI at the index pregnancy and other covariates.
Body mass index reduction was associated with a non-significant increased risk of preterm birth, adjusted HR 1.17 [95% confidence interval 0.90, 1.53]; BMI increase had effects close to null (adjusted HR 1.08 [0.83, 1.41]). In the model with linear BMI change, each 1 kg/m² increase was associated with an HR of 0.96 [0.89, 1.03]. The estimates associated with a BMI reduction were higher in women whose index pregnancy ended preterm (HR 1.49 [0.90, 2.44]) and in those with BMI < 25 kg/m² at the index pregnancy (HR 1.30 [0.98, 1.71]). This study involved mainly low-to-normal weight women with spontaneous deliveries, and might suffer from type II error owing to small sample size. The effect of BMI change in overweight and obese women needs to be studied using contemporary data.     

Association Between Gestational Weight Gain According to Body Mass Index and Postpartum Weight in a Large Cohort of Danish Women

Our aim was to investigate the association between gestational weight gain (GWG) and postpartum weight retention (PWR) in pre-pregnancy underweight, normal weight, overweight or obese women, with emphasis on the American Institute of Medicine (IOM) recommendations. We performed secondary analyses on data based on questionnaires from 1,898 women from the “Smoke-free Newborn Study” conducted 1996–1999 at Hvidovre Hospital, Denmark. Relationship between GWG and PWR was examined according to BMI as a continuous variable and in four groups. Association between PWR and GWG according to IOM recommendations was tested by linear regression analysis and the association between PWR ≥ 5 kg (11 lbs) and GWG by logistic regression analysis. Mean GWG and mean PWR were constant for all BMI units until 26–27 kg/m². After this cut-off mean GWG and mean PWR decreased with increasing BMI. Nearly 40% of normal weight, 60% of overweight and 50% of obese women gained more than recommended during pregnancy. For normal weight and overweight women with GWG above recommendations the OR of gaining ≥ 5 kg (11 lbs) 1-year postpartum was 2.8 (95% CI 2.0–4.0) and 2.8 (95% CI 1.3–6.2, respectively) compared to women with GWG within recommendations. GWG above IOM recommendations significantly increases normal weight, overweight and obese women’s risk of retaining weight 1 year after delivery. Health personnel face a challenge in prenatal counseling as 40–60% of these women gain more weight than recommended for their BMI. As GWG is potentially modifiable, our study should be followed by intervention studies focusing on GW.     

The effects of maternal body mass index on pregnancy outcome

The increasing prevalence of obesity is presenting a critical challenge to healthcare services. We examined the effect of Body Mass Index in early pregnancy on adverse pregnancy outcome. We performed a population register-based cohort study using data from the North Western Perinatal survey (N = 99,403 babies born during 2004–2006), based at The University of Manchester, UK. The main outcome measures were Caesarean section delivery, preterm birth, neonatal death, stillbirth, Macrosomia, small for gestational age and large for gestational age. The risk of preterm birth was reduced by almost 10% in overweight (RR = 0.89, [95% CI: 0.83, 0.95]) and obese women (RR = 0.90, [95% CI: 0.84, 0.97]) and was increased in underweight women (RR = 1.33, [95% CI: 1.16, 1.53]). Overweight (RR = 1.17, [95% CI: 1.09, 1.25]), obese (RR = 1.35, [95% CI: 1.25, 1.45]) and morbidly obese (RR = 1.24, [95% CI: 1.02, 1.52]) women had an elevated risk of post-term birth compared to normal women. The risk of fetal macrosomia and operative delivery increased with BMI such that morbidly obese women were at greatest risk of both (RR of macrosomia = 4.78 [95% CI: 3.86, 5.92] and RR of Caesarean section = 1.66 [95% CI: 1.61, 1.71] and a RR of emergency Caesarean section = 1.59 [95% CI: 1.45, 1.75]). Excessive leanness and obesity are associated with different adverse pregnancy outcomes with major maternal and fetal complications. Overweight and obese women have a higher risk of macrosomia and Caesarean delivery and lower risk of preterm delivery. The mechanism underlying this association is unclear and is worthy of further investigation.     

天津地区双胎孕妇妊娠期增重趋势探讨

目的 初探天津地区不同孕前BMI双胎孕妇妊娠期增重趋势和各妊娠期推荐增重范围。方法 回顾性分析2010年1月至2018年11月在天津市分娩且有完整产检的1 346例健康双胎孕妇数据,按照孕前BMI分为体重不足组（BMI<18.5,n=117）、标准体重组（18.5≤BMI≤23.9,n=783）、超重组（24.0≤BMI≤27.9,n=320）、肥胖组（BMI≥28.0,n=126）。绘制各组孕妇的妊娠期体重增长曲线,按P²5～P75计算不同组别双胎孕妇妊娠早、中、晚期适宜增重范围,分析孕前BMI与新生儿体重的关系。结果 孕前BMI与年龄呈正相关（r=0.06,P<0.05）,与分娩孕周呈负相关（r=-0.12,P<0.001）,双胎之间出生体重呈正相关（r=0.69,P<0.001）。四组孕妇妊娠期适宜增重范围分别是:体重不足组20.27（17.00～24.24）kg,标准体重组20.95（16.64～25.66）kg,超重组16.94（13.39～20.62）kg,肥胖组16.44（11.29～21.79）kg,差异有统计学意义（P<0.01）。孕前BMI与双胎新生儿出生体重之间差异无统计学意义（P>0.05）。结论 本研究初步得出我国北方城市天津不同孕前BMI双胎孕妇在妊娠早、中、晚期的适宜增重范围及增重速度,为现有指南中缺少的孕前体重不足组双胎孕妇的妊娠期增重范围提供参考。