Reference charts for weight gain and body mass index during pregnancy obtained from a healthy cohort

Objective. To create reference charts for weight gain and body mass index (BMI) in pregnancy derived from longitudinal data obtained in a representative sample of the Argentinean population.

Methods. A prospective cohort of 1439 healthy pregnant women was selected from antenatal clinics in seven different urban regions in Argentina. Serial anthropometric measurements were made at weeks 12, 16, 20, 24, 28, 32, 36 and in the last pre-natal control. Centile curves of body weight and BMI by gestational age were developed using the LMS method.

Results. Mean weight gain at 38 weeks of gestation was 11.9 ± 4.4 kg. There were no differences in total weight gain between women who enter pregnancy with low, normal or overweight; only those women with a pre-pregnancy BMI in the range of obesity showed a significantly lower weight gain (10.2 ± 4.8 kg). At 12 weeks of pregnancy, BMI values of the 10th, 50th and 90th centiles were 19.3, 22.8 and 29.0, and at 38 weeks these values were 23.3, 27.4 and 33.8, respectively.

Conclusion. This BMI for gestational age chart, based on women who delivered normal birth weight infants and processed with modern statistical methods, represents an improvement in pre-natal care monitoring.     

Following the 2009 American Institute of Medicine recommendations for normal body mass index and overweight women led to an increased risk of fetal macrosomia among Taiwanese women

ObjectiveThis study aimed to investigate the risk of birth weights over 4000 g (macrosomia) in association with following the 2009 American Institute of Medicine (AIOM) recommendations.Materials and MethodsSeventy-six nondiabetic women who delivered a singleton, term macrosomic fetus and 82 women who delivered a singleton, term fetus weighing <4000 g were analyzed retrospectively. The relationship between the risk of macrosomia and gestational weight gain in different periods of pregnancy was investigated using logistic regression.ResultsThe incidence of macrosomia from January 2008 to December 2009 was 1.8% among the Taiwanese women. The incidences of cesarean delivery (54.5% vs. 18.2%, p < 0.001) and blood loss >1000 mL at delivery (35.5% vs. 6.1%, p < 0.0001) were associated with macrosomia. The risk of macrosomia among normal weight women with gestational weight gain greater than 13 kg increased four-fold [odds ratio (OR) = 4.88; 95% confidence interval (CI) 1.84–12.90]. For overweight women with total gestational weight gain >11.5 kg, the risk of macrosomia increased nine-fold (OR = 9.63; 95% CI 1.76–52.74).ConclusionMacrosomia resulted in more cesarean deliveries and greater maternal blood loss at birth. In Taiwan, to prevent macrosomia, we suggest that the total gestational weight gain should be <11.5 kg among normal weight women and within 10 kg for overweight women.     

The mutual effect of pregestational body mass index,maternal hyperglycemia and gestational weight gain on adverse pregnancy outcomes

Objective: To investigate the mutual effect of obesity, gestational diabetes (GDM) and gestational weight gain (GWG) on adverse pregnancy outcomes.

Methods: Charts of patients who delivered in our hospital between June 2001 and June 2006 singleton, live births >24 weeks gestation were reviewed. Univariate and multivariate logistic regression were used to assess pregnancy outcomes defined as large for gestational age (LGA), primary cesarean section (PCS) and a composite outcome of LGA and/or PCS.

Results: A total of 8595 women were included. Frequency of composite outcome increased with increasing body mass index (BMI), increasing hyperglycemia and above-recommended GWG. In the multivariate logistic regression analysis compared to women with normal BMI, odds ratio (OR) for composite outcome was 1.23 (95% confidence interval [CI] 1.06–1.44) in overweight women, OR?=?1.86 (1.51–2.31) in obese women and in severe obesity OR?=?2.97 (2.15–4.11).

Compared to normoglycemic women, odds for composite outcome in women with abnormal glucose challenge test OR?=?1.46 (1.20–1.79), impaired glucose tolerance OR?=?1.65 (1.14–2.4) and GDM OR?=?1.56 (1.16–2.10). Women with GWG above recommended had OR?=?1.58, (1.37–1.81) for composite outcome.

Conclusions: Higher pregestational BMI, maternal hyperglycemia and above-recommended GWG independently contribute to adverse pregnancy outcomes. Furthermore, there is mutual effect between these three factors and adverse outcomes. Appropriate pregestational weight and adequate GWG might reduce risk of adverse pregnancy outcomes.     

Prepregnancy body mass index, gestational weight gain, and pregnancy outcomes in China

Objective

To look for associations between pregnancy outcomes and prepregnancy body mass index and gestational weight gain among Han women from Shenyang province, China.

Method

A total of 2586 women were distributed across 4 prepregnancy categories according to the Chinese classification of body mass index, and to 4 end-of-pregnancy categories according to median weekly gestational weight gain.

Results

The risks for gestational hypertension, pre-eclampsia, gestational diabetes, and preterm premature rupture of membranes were higher for those who were overweight or obese before becoming pregnant (P < 0.05). Moreover, a gestational weight gain of 0.50 kg per week or greater was associated with a higher risk for gestational hypertension, preterm premature rupture of membranes, and fetal macrosomia (P < 0.05). Women in the highest quartile for weight gain (≥ 0.59 kg per week) were at higher risk for pre-eclampsia (P < 0.05).

Conclusion

A high prepregnancy body mass index and excessive gestational weight gain were associated with increased risks for adverse pregnancy outcomes.     

Maternal body mass index, delivery route, and induction of labor in a midwifery caseload

The purpose of this study was to identify the association between prepregnancy body mass index (BMI), weight gain in pregnancy, and newborn birth weight on route of delivery and induction of labor in patients receiving nurse-midwifery care. This retrospective cohort study examined the outcomes of 1500 consecutively delivered women who were cared for by two midwifery practices and delivered between January 1, 1998, and December 31, 2000. Cesarean delivery was significantly associated with the obese BMI (P < .001), nulliparity (P < .02), and newborn birth weight (P =.006). Prenatal weight gain did not have a significant correlation with cesarean birth (P = .24). In multivariable modeling, obese BMI, high newborn birth weight, nulliparity, and induction of labor increased the risk of cesarean birth. There was also a significant association between higher BMI and risk of induction of labor (P < .001). In a secondary analysis, obese BMI was associated with increased risk of induction in cases with ruptured membranes (OR 2.2; 95% CI 1.4-3.4) and postdates pregnancy (OR 2.0; 95% CI 1.1-3.4).     

孕前体质指数及孕期体重增长对妊娠过程及结局的影响

目的:探讨孕前体质指数(BMI)及孕期体重增长(GWG)与妊娠合并疾病及不良结局的关系。方法:回顾分析于复旦大学附属妇产科医院产科门诊定期产前检查并住院分娩的3541例足月单胎初产妇的临床资料。将产妇按孕前体质指数(BMI)和不同孕期体重增长(GWG)分组,采用logistic多因素回归分析孕前体质指数及孕期体重增长与妊娠合并疾病及结局的关系。结果:孕妇孕期体重平均增加(16.0±4.9)kg,新生儿平均出生体重(3341.6±425.9)g,低出生体重儿和巨大儿分别占2.1%及5.1%。根据IOM推荐孕期GWG分组,GWG过低、过高组孕妇与正常孕妇的巨大儿、剖宫产数、早产发生率比较,差异有统计学意义(P0.05)。孕前超重、肥胖能增加妊娠期糖尿病(OR=2.7,2.3)、妊娠期高血压疾病(OR=5.4,OR=7.7)、巨大儿(OR=1.6,OR=8.9)、剖宫产(OR=1.4,OR=1.7)的发生风险,而GWG过高增加剖宫产的发生风险(OR=1.5)。结论:孕前BMI不仅影响妊娠合并疾病的发生,也与妊娠结局密切相关。临床上应特别重视孕前宣教及体检,建议育龄期妇女达到合适的体质指数后怀孕。孕期过度体重增长增大了不良妊娠结局(巨大儿、剖宫产)的发生率,临床上可参照IOM推荐体重增长范围进行孕妇体重控制,加强孕期的健康教育和体重随访。同时建议利用大数据多方调研,得出适合中国各地区的孕期体重参考标准。     

Gestational weight gain and the risk of infant mortality amongst women with normal prepregnancy BMI: the Friedmann-Balayla model

Objective: The study of the association between gestational weight gain (GWG) and infant mortality is riddled with methodological concerns, particularly with limitations in accounting for gestational age-specific weight gain. In our study, we developed a new model, which accounts for gestational age, to determine whether insufficient or excessive GWG is associated with an increased risk of infant death amongst women with normal prepregnancy BMI (18.5–24.9?kg/m²).

Methods: We developed and implemented the Friedmann-Balayla model to mitigate gestational age-related biases in our assessment, and conducted a population-based cohort study using the CDC’s 2013 Period-Linked Birth-Infant Death data. The impact of GWG according to the 2009 IOM guidelines on the risk of infant mortality was estimated using logistic regression analysis, adjusting for relevant confounders.

Results: Our cohort consisted of 1,517,525 singleton deliveries and 6138 infant deaths. Overall, relative to women achieving adequate GWG, neither women gaining insufficient nor excessive weight had greater odds of infant death during the first year of life (OR [95%CI]): 1.06 [0.97–1.17] (p?=?0.174), and 0.98 [0.91–1.04] (p?=?0.523), respectively. This relationship did not change when restricting our analysis to term or preterm deliveries or when conducting sensitivity analyses accounting for maternal morbidities (p?>?0.05).

Conclusion: Using this novel analytic approach, there does not appear to be an increased risk of infant mortality if GWG falls outside of the IOM guidelines in women with normal prepregnancy BMI. Future studies should apply this methodology to other BMI categories.     

Evaluating Body Mass Index–Specific Trimester Weight Gain Recommendations: Differences Between Black and White Women

Introduction: We compared the gestational weight gains of black and white women with the 2009 Institute of Medicine (IOM) recommendations to better understand the potential for successful implementation of these guidelines in clinical settings. Methods: Prenatal and birth data for 2760 women aged 18 to 40 years with term singleton births from 2004 through 2007 were abstracted. We examined race differences in mean trimester weight gains with adjusted linear regression and compared race differences in the distribution of women who met the IOM recommendations with chi‐square analyses. We stratified all analyses by prepregnancy body mass index. Results: Among normal‐weight and obese women, black women gained less weight than white women in the first and second trimesters. Overweight black women gained significantly less than white women in all trimesters. For both races in all body mass index categories, a minority of women (range 9.9%‐32.4%) met the IOM recommended gains for the second and third trimesters. For normal‐weight, overweight, and obese black and white women, 49% to 80% exceeded the recommended gains in the third trimester, with higher rates of excessive gain for white women. Discussion: Less than half of the sample gained within the IOM recommended weight gain ranges in all body mass index groups and in all trimesters. The risk of excessive gain was higher for white women. For both races, excessive weight gain began by the second trimester, suggesting that counseling about the importance of weight gain during pregnancy should begin earlier, in the first trimester or prior to conception.     

Impact of pre-gravid body mass index and body mass index change on preeclampsia and gestational diabetes in singleton and twin pregnancies

Abstract

Objective: To examine pre-gravid body mass index (BMI) and gestational BMI change impact on preeclampsia and gestational diabetes mellitus (GDM).

Methods: Retrospective population-based cohort study. Data from Slovenian National Perinatal Information System were analyzed for the period 2002–2011. Three singleton controls were matched by parity and maternal age to each twin pregnancy delivered at >36 weeks. Student’s t test was used to compare pre-gravid BMI and gestational BMI change in different groups (p?<?0.05 significant).

Results: 2046 twin and 6138 singleton pregnancies were included. Twin and singleton patients with preeclampsia or GDM had higher pre-gravid BMI (p?<?0.001). Gestational BMI change was smaller in twins with GDM (p?<?0.001), and not associated with preeclampsia (p?=?0.07). Smaller gestational BMI change in singleton pregnancies was associated with GDM (p?<?0.001), and greater BMI change with preeclampsia (p?=?0.004).

Conclusions: Pre-gravid BMI is more strongly associated with preeclampsia and GDM in twin and singleton pregnancies than gestational BMI change. Smaller gestational BMI change in GDM pregnancies reflect the importance of dietary counseling.     

The relationship between antenatal body attitudes,pre-pregnancy body mass index,and gestational weight gain

Objectivesan estimated 50% of women experience excessive gestational weight gain (GWG). Maternal body attitudes are associated with GWG, however this relationship is complex and may differ based on pre-pregnancy body mass index (BMI) or gestational age. The aim of this study was to explore the moderating role of maternal pre-pregnancy BMI on the relationship between body attitudes in early-to-mid and late pregnancy and GWG.Design/Participantspregnant women less than 18 weeks gestation were recruited for a postal questionnaire study via Australian pregnancy online forums, pregnancy and parenting magazines, and antenatal clinics. In early-mid pregnancy (Time 1; mean (M) = 16.81 weeks gestation, standard deviation (SD) = 1.18), participants reported demographics, pre-pregnancy weight, height, and body attitudes (salience of weight and shape, attractiveness, strength and fitness and feeling fat). In late pregnancy, body attitudes (Time 2; M = 32.65 weeks gestation, SD = 0.91) and weight (Time 3; M = 37.15 weeks gestation, SD = 1.55) were reported. Pre-pregnancy BMI and total GWG were calculated. Moderation analyses were conducted.Findingsin early-mid pregnancy, pre-pregnancy BMI moderated the relationship between feeling fat and GWG. Pre-pregnancy BMI did not moderate the relationship between body attitudes and GWG for salience of weight and shape, attractiveness or strength and fitness in early-mid pregnancy. In late pregnancy, pre-pregnancy BMI moderated the relationship between all four body attitude facets (salience of weight and shape, attractiveness, feeling fat and strength and fitness) and GWG.Conclusion/Implications for practicethe relationship between body attitudes and GWG was moderated by pre-pregnancy BMI, particularly in late pregnancy. It is recommended that antenatal health care providers monitor women's body attitudes throughout pregnancy to aid in the management of healthy GWG and promote positive maternal and infant health outcomes. This is particularly important for women entering pregnancy with an underweight/normal weight BMI.     

体质指数在评定巨大儿中的价值

目的 通过比较新生儿出生体质量及体质指数(BMI)两种标准判定巨大儿的差异,探讨BMI用于评定巨大儿中的价值.方法 选取2004年1月-12009年4月中国医科大学附属盛京医院住院产妇(无任何妊娠期合并症及并发症)分娩的单胎、足月、出生体质量>2500 g的5522例新生儿,其中4989例出生体质量为2510-4000 g(<4000 g组),533例t≥4000 g(≥4000 g组).测量新生儿的体质量、身长.根据受试者工作特征(ROC)曲线得出BMI界值及敏感度和特异度,以BMI界值重新作为巨大儿判定标准进行判断分析.结果 (1)当新生儿身长为40～43 cm时,平均出生体质量为(3010 ±351)g,BMI为(17.0 ±2.7)kg/m2;身长为48～51 cm时,平均出生体质量为(3450±313)g,BMI为(13.2 ±1.4)kg/m2;身长56～60 cm时,出生体质量为(4332±456)g,BMI为(12.5±1.3)kg/m2.随着身长增加,出生体质量逐渐增加,而BMI逐渐下降.(2)ROC曲线得出,巨大儿的BMI界值为14.2 kg/m2,敏感度为78.4%,特异度为85.0%,曲线下面积为0.892.(3)以BMI 14.2kg/m2作为界值±4000 g组的新生儿中有111例新生儿为非巨大儿(20.8%,111/533),422例为巨大儿(79.2%,422/533);<4000 g组的新生儿中有728例新生儿为巨大儿(14.59%,728/4989),4261例新生儿为非巨大儿(85.41%,4261/4989).以14.2 kg/m2为界值,≥4000 g组中的巨大儿和非巨大儿的身长[分别为(52.2 ±1.8)及(55.6 ±1.3)cm]比较,差异有统计学意义(P<0.01);<4000 g组中的巨大儿和非巨大儿的身长[分别为(49.0 ±2.2)及(50.8 ±2.2)cm]比较,差异也有统计学意义(P<0.01).以14.2 kg/m2作为BMI界值,两组中总的巨大儿发生率为20.83%(1150/5522).结论 新生儿出生体质量和BMI两种标准在判定巨大儿之间存在差别,且身长因素与两种判定结果之间的差异有相关性,表明身长在判定巨大儿时起着重要作用.在巨大儿的诊断及管理中,有必要以BMI14.2 kg/m2作为界值判定巨大儿.     

Weight gain regardless of pre-pregnancy BMI and influence of fetal gender in response to labor induction in postdate pregnancy

Abstract

Objective: To evaluate whether maternal weight and body mass index (BMI) and their increase throughout pregnancy are associated with the response to labor induction in postdate pregnancies.

Methods: A total of 376 nulliparous women carrying singleton postdate pregnancies with unfavorable cervix were enrolled. We considered as primary outcome vaginal delivery within 24?h after induction, and outcomes were divided into responders (n?=?258) and non-responders (n?=?107) to the induction of labor to perform the statistical analyses.

Results: In the total population of study, women who successfully delivered within 24?h differed significantly from the remaining patients in terms of maternal weight gain (p?=?0.009) and BMI increase (p?=?0.02) during pregnancy. In addition, males were significantly more (p?=?0.005) than females among newborns of women not responding to induction of labor. In the multivariate analysis, maternal weight gain and fetal sex significantly influenced the induction response. The occurrence of a failed induction of labor was more likely in patients presenting a greater maternal weight gain (cut-off 12?kg) and male fetus.

Conclusion: Weight gain over 12?kg regardless of pre-pregnancy weight and male fetal gender are two novel potential risk factors for the prediction of failure to induction of labor in postdate pregnancy.