新生儿出生体质量与孕期体质量指数变化的相关性

目的 探讨新生儿出生体质量与孕妇体质量指数变化的相关性.方法 选择2006年1月-2007年12月在我院产前检查并分娩且无内科并发症的孕妇1 000例,进行回顾性分析.分别测量并计算孕12周内、孕32周、分娩前孕妇身高和体质量、孕期体质量变化、孕期体质量指数变化,分析新生儿出生体质量与孕期体质量指数变化的相关性.结果 新生儿出生体质量与孕期体质量指数变化有正相关性.结论 孕期按孕周进行营养指导有利于减少围生期并发症,对胎儿生长受限者,应早于孕32周开始治疗,改善妊娠结局.     

产前BMI及孕期BMI增幅与分娩方式及新生儿体重的关系

目的:探讨孕妇产前BMI及孕期BMI增幅对分娩方式、新生儿体重的影响。方法:选取单胎初孕妇360人作为研究对象,产前BMI≥28为肥胖组、产前BMI28为正常组及孕期BMI增幅4为Ⅰ组,4≤BMI≤6为Ⅱ组,6为Ⅲ组。以分娩方式、新生儿出生体重为观察指标,对各组进行随访。结果:产前肥胖组剖宫产、新生儿体重明显增加(P0.05);孕期BMI增幅≥4孕妇剖宫产增加、孕期BMI增幅6孕妇巨大儿明显增加(P0.05)。结论:产前BMI及孕期BMI增幅与妊娠结局有关,控制孕期体重过度增长,可降低母婴并发症。     

出生体重与儿童体质指数、腰围身高比关系

目的 以儿童体质指数(body mass index,BMI)作为第一种肥胖(obesity-1)筛查指标,以腰围身高比(waist-to-height ratio,WHtR)作为第二种肥胖(obesity-2)筛查指标,分析出生体重与两种肥胖相关性。方法 选择上海市3所初中和3所小学3 960名7~18岁在校学生。遵循自愿原则,对所有合格入组学生(共3 687名)进行体格检查,并对学生监护人进行问卷调查。结果 Logistic二元回归分析结果显示,在出生体重≥2 500 g的儿童中,出生体重每增加1 000 g,其儿童期发生obesity-1的危险性增加1.3倍(OR=1.32,95%CI:1.1~1.59,P=0.003);发生obesity-2危险性增加1.22倍(OR=1.22,95%CI:1.0~1.47,P=0.041)。 结论 在出生体重≥2 500 g的儿童中,出生体重增加,发生两种肥胖危险性均增加。     

From infancy to pregnancy: birth weight, body mass index, and the risk of gestational diabetes

Obesity is a risk factor for gestational diabetes, whereas the role of the mother’s birth weight is more uncertain. We aimed to investigate the combined effect of mothers’ birth-weight-for-gestational-age and early pregnancy Body Mass Index (BMI) in relation to risk of gestational diabetes. Between 1973 and 2006, we identified a cohort of 323,083 women included in the Swedish Medical Birth Register both as infants and as mothers. Main exposures were mothers’ birth-weight-for-gestational-age (categorized into five groups according to deviation from national mean birth weight) and early pregnancy BMI (classified according to WHO). Rates of gestational diabetes increased with adult BMI, independently of birth-weight-for-gestational-age. However, compared to women with appropriate birth-weight-for-gestational-age [appropriate-for-gestational age (AGA); ?1 to +1 SD] and BMI (<25.0), women with obesity class II-III (BMI?≥?35.0) had an adjusted odds ratio (OR) of 28.7 (95?% confidence interval, CI 17.0–48.6) for gestational diabetes if they were born small-for-gestational-age [small for gestational age (SGA); <?2SD], OR?=?20.3 (95?% CI 11.8–34.7) if born large-for-gestational-age [large-for-gestational-age (LGA); >2SD], and OR?=?10.4 (95?% CI 8.4–13.0) if born AGA. Risk of gestational diabetes is not only increased among obese women, but also among women born SGA and LGA. Severely obese women born with a low or a high birth-weight-for-gestational-age seem more vulnerable to the development of gestational diabetes compared to normal weight women. Normal pre-pregnancy BMI diminishes the increased risk birth size may confer in terms of gestational diabetes. Therefore, the importance of keeping a healthy weight cannot be overemphasized.     

出生队列效应对体质指数遗传度的影响

目的 探索不同出生队列BMI遗传度的变化情况。方法 基于中国双生子登记系统丽水和青岛两个时点的双生子,按照出生年份分为1958年及以前出生、1959-1961年出生、1962-1970年出生和1971年及以后出生的4个出生队列,在各个时点分别拟合结构方程,计算不同出生队列在不同年龄的遗传度。结果 每个出生队列中,2012年时的体重、BMI高于2001年;出生于1971年及以后的双生子无论体重和BMI均低于其余出生队列。遗传因素能解释BMI的表型变异为54%~76%;出生于1959-1961年的双生子,BMI的遗传度随年龄上升,其余出生队列遗传度较为稳定。结论 BMI受遗传因素影响较大,出生于1959-1961年的双生子,随着年龄增长,遗传因素对BMI的影响增加。     

Maternal feeding practices,child eating behaviour and body mass index in preschool-aged children: a prospective analysis

Background  

Previous research has found associations between parental feeding practices and children's eating behaviour and weight status. Prospective research is needed to elucidate these relationships.     

孕前体重指数、孕期体重增加与新生儿窒息的关系

目的 了解孕前体重指数(BMI)、孕期体重增加与新生儿窒息发生危险的关系.方法 数据来自"中美预防出生缺陷和残疾合作项目"中嘉兴地区的围产保健监测数据库.研究对象为1995-2000年在嘉兴地区参加婚前/孕前体检且分娩单胎活产儿孕满20周的83 030名孕产妇.运用χ2检验或趋势χ2检验比较不同BMI组或其他特征人群新生儿窒息发病率的差别,利用多元logistic回归分析孕前BMI、孕期体重增加与新生儿窒息发生危险之间的关系.结果 新生儿窒息发病率为11.3%(95% CI:11.1%～11.6%).新生儿窒息发病率从BMI＜18.5 kg/m2组的11.0%(95% CI:10.5%～11.5%)逐渐升至BMI≥25.0 kg/m2组的12.9%(95% CI:11.6%～14.4%),自孕期体重增加＜0.3 kg/wk的12.4%(95% CI:11.9%～13.0%)逐渐降至≥0.5 kg/wk的10.6%(95% CI:10.1%～11.0%).孕前BMI≥25.0 kg/m2组的新生儿重度窒息发生率高于BMI更低组.在调整了地区、年龄、文化程度、职业、产次、产前检查次数、孕期高危因素、产时高危因素、孕周和出生体重后,以BMI＜18.5 kg/m2组为参照组,BMI为18.5～22.9 kg/m2、23.0～24.9 kg/m2和≥25.0 kg/m2组发生新生儿窒息的OR值分别为1.03(95% CI:0.97～1.09)、1.06(95% CI:0.96～1.16)和1.14(95% CI:1.00～1.31).进一步调整孕期增重后,上述OR值分别为1.02(95% CI:0.95～1.09)、1.01(95% CI:0.90～1.13)和1.08(95% CI:0.92～1.28).以孕期体重增加≥0.5 kg/wk组作为参照,孕期体重增加为0.3～kg/wk和＜0.3 kg/wk组发生新生儿窒息的OR值分别为1.06(95% CI:1.01～1.12)和1.09(95% CI:1.02～1.20).结论 孕期体重增加＜0.5 kg/wk加大新生儿窒息发生的危险,提示临床上宜对妇女孕前的BMI进行监测,并据此进行孕前指导和孕期管理,以保持合理的孕期体重,降低新生儿窒息的发生危险.     

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.     

The association between high blood pressure,physical fitness,and body mass index in adolescents

BACKGROUND: The aim of this study was to analyze the association of fitness and fatness with blood pressure (BP) and hypertension.This was a cross-sectional study of 13,557 boys and girls 15-20 years of age. Fitness was estimated from a shuttle run test, fatness from body mass index (BMI), and BP was measured sitting after 5 min of rest. Other lifestyle variables were self-reported. RESULTS: Boys had a higher systolic BP (SBP) than girls. A low physical fitness level and high BMI were independently associated with a high BP and risk of having hypertension in both girls and boys. Interaction was found between BMI and fitness. In a stratified analysis an odds ratio (OR) of 3.99 was found for hypertension in girls with a BMI > 25 kg m(-2) compared to lean girls if all had a low fitness level, and an OR of 2.14 for a high BMI in girls with a high fitness level. In boys, OR for high versus low BMI were 3.23 in the low fit and 2.34 and 2.50 in the middle and upper tertile of fitness, respectively. CONCLUSIONS: Fitness and BMI were independently associated to BP. BMI was a stronger predictor of hypertension in those with a low fitness level, especially in girls.     

Larger infant size at birth reduces the negative association between maternal prepregnancy body mass index and breastfeeding duration

Women who are overweight or obese prepregnancy have shorter durations of producing milk (PM) and feeding breast milk exclusively (FBM-ex) than normal-weight women. We proposed that infant size at birth may reduce the negative associations between prepregnancy BMI and the durations of PM and FBM-ex. We used data from 2798 participants in the Infant Feeding Practices Study II and characterized infant size at birth as weight-for-gestational age (WGA). To assess possible mediation of the associations between maternal BMI and the durations of PM and FBM-ex by infant size at birth, Baron and Kenny's methods, the Sobel test, and bootstrapping were used. As expected, prepregnancy BMI was negatively associated (P < 0.0001) with the durations of PM and FBM-ex; it also was positively associated (P < 0.0001) with infant size at birth. However, infant WGA was positively associated (P < 0.0003) with the durations of PM and FBM-ex after adjustment for BMI. Thus, the negative associations between BMI and the durations of PM and FBM-ex were reduced by infant WGA; i.e. the statistical removal of infant size at birth increased the magnitude of the negative associations between BMI and the durations of PM and FBM-ex. Thus, the tendency of heavier mothers to deliver heavier infants reduces the true magnitude of the association between maternal prepregnancy BMI and shortened breastfeeding duration.     

孕妇身体质量指数与新生儿出生体重的关系

目的 探讨孕妇身体质量指数对新生儿出生体重的影响.方法 选择符合纳入标准的妊娠期妇女90例为研究对象.测量孕妇临产时身体质量指数、血糖、新生儿出生体重等指标,分析其间的关系.结果 90例孕妇的血糖水平为5.3±1.2 mmol/L、年龄为26.2±6.0岁、身体质量指数为23.8±3.9 kg/m2,新生儿出生体重为3 425.4±1 433.0g.新生儿出生体重与孕妇身体质量指数、年龄成正相关(身体质量指数偏相关系数:r=0.817,P=0.000;年龄偏相关系数:r=0.228,P=0.033),且孕妇身体质量指数与新生儿出生体重呈线性关系.结论 孕妇身体质量指数与新生儿出生体重存在正相关关系,检测孕妇身体质量指数对新生儿出生体重有一定的预测价值.     

Correlates of body mass index, weight goals, and weight-management practices among adolescents

The study examined associations among physical activity, cigarette smoking, body mass index, perceptions of body weight, weight-management goals, and weight-management behaviors of public high school adolescents. The CDC Youth Risk Behavior Survey provided a cross-sectional sample (n = 3,089) of public high school students in South Carolina. Logistic regression models were constructed separately for four race-gender groups. Adjusted odds ratios and 95% confidence intervals were calculated to determine the magnitude of associations. Based on self-reported height and weight, 13% of students were overweight, while 15% were at risk for becoming overweight. However, 42% of students were trying to lose weight, and 22% were trying to maintain current weight. Female students were less likely than male students to be overweight, but more likely to be attempting to lose weight. Extreme weight control practices were reported by 27% of the sample. Among Black females trying to lose weight, positive associations were observed for strengthening exercises (OR = 1.55), but that relationship was associated inversely in Black males (OR = .600). Among White females, attempted weight loss was associated with strengthening exercises (OR = 1.72) and cigarette smoking (OR = 1.54). For White males, attempted weight loss was associated positively with vigorous exercise (OR = 1.41) and inversely related to moderate exercise (OR = .617). Effective weight-management practices for adolescents should focus on appropriate eating behaviors, physical activity, and low-fat/calorie diets. Multicomponent weight management interventions should be conducted within a coordinated school health framework.     

Prepregnancy body mass index, vaginal inflammation, and the racial disparity in preterm birth

The authors sought to quantify the overall and race/ethnic-specific relations between prepregnancy body mass index and both preterm birth and vaginal inflammation. Data from a cohort of 11,392 women who enrolled in the multicenter Vaginal Infections and Prematurity Study (1984-1989) at 23-26 weeks' gestation were used. Compared with a prepregnancy body mass index of 22, a body mass index of 16 increased the risk of preterm birth by 90% (odds ratio = 1.9, 95% confidence interval (CI): 1.5, 2.6), and a body mass index of 18 increased the risk by 40% (odds ratio = 1.4, 95% CI: 1.2, 1.7). Ethnicity substantially modified the magnitude of the body mass index effect and the shape of the preterm birth risk curve, with underweight having a greater impact on preterm birth among Blacks and Hispanics than among Whites. Low body mass index increased the risk of a high level of neutrophils (> 5 per oil immersion field) and a high vaginal pH measurement (> or = 5.0) among Black women; for a body mass index of 16 versus 22, the odds ratio = 1.7 (95% CI: 1.1, 2.6). Compared with Black women with a body mass index of 22, Blacks with a body mass index of 16 had a 1.7-fold increased risk for a high level of neutrophils and a high vaginal pH measurement, while those with a body mass index of 18 had a 1.3-fold increased risk.     

Maternal cigarette smoking during pregnancy and infant ponderal index at birth in the Swedish Medical Birth Register, 1991-1992

OBJECTIVES: This study examined the effect of maternal smoking during pregnancy on infant body proportion. METHODS: The ponderal index, defined as birthweight divided by crown-heel length cubed, was examined in 207,607 infants from the Swedish Medical Birth Register for 1991 and 1992. RESULTS: Infant ponderal index was used as the outcome variable in an ordinary least squares continuous regression, which included early pregnancy smoking status, gestational age, and birthweight among the predictors. Ponderal index increased by 0.030 (+/- 0.0014) among infants of moderate smokers and by 0.040 (+/- 0.0017) among infants of heavy smokers, showing a dose response. CONCLUSIONS: Smoking differentially alters the trajectory of weight vs length growth in the fetus.     

Family social class, maternal body mass index, childhood body mass index, and age at menarche as predictors of adult obesity

BACKGROUND: Obesity is an increasingly prevalent nutritional disorder throughout the world and is a risk factor for many chronic diseases. The prevalence of obesity increases with age. OBJECTIVE: The objective was to evaluate the associations between BMI at 31 y of age and family social class during early childhood, maternal body mass index (BMI) before pregnancy, BMI at birth and at 1 and 14 y of age, and age at menarche. DESIGN: This was a longitudinal study of the northern Finland birth cohort for 1966. Subjects were measured at birth and at 1, 14, and 31 y of age. The analysis was restricted to individuals for whom BMI data were available for all measurement points (n = 2876 males and 3404 females). RESULTS: The mean BMI at birth was highest in offspring from the highest social classes, but BMI was inversely related to social class at 1 y. BMI, the waist-to-hip ratio, and the proportion of obese subjects were inversely related to social class at 31 y. The heavier the mother, the heavier the offspring from birth to 31 y. The paired analyses between maternal BMI and daughter's BMI at 31 y showed no significant difference in BMI after adjustment for the age difference. BMI at 14 y was the most important predictor of BMI at 31 y. Early menarche in females was associated with a higher BMI at 14 and 31 y. CONCLUSIONS: Differences in BMI by social class are formed at least partly during early childhood. Low social class of the child's family, a high maternal BMI before pregnancy, a high BMI during adolescence, and early menarche are predictors of obesity in adulthood.