Relationship between pre-pregnancy maternal BMI and optimal weight gain in singleton pregnancies

Seeking the optimal gestational weight gain according to the pre-pregnancy body mass index: a cross-sectional study from Shanghai, China

OBJECTIVES

Maternal nutritional status is closely related to fetal intrauterine development and an abnormal birth weight increases various disease risks across life stages. To better guide pregnancy weight gain, we aimed to explore the optimal weight gain for pregnant women with different body mass indexes (BMIs).

METHODS

This retrospective cohort study included 68,981 women with singleton live birth between January 2017 and October 2021 in maternity centres in Shanghai, China. The fluctuations of the incidence of small and large for gestational age (small for gestational age (SGA) and LGA, respectively) were recorded at different maternal pre-pregnancy BMI (p-BMI) and different gestational weight gain (GWG) groups to find the lowest point of abnormal fetal weight incidence. The optimal GWG was then determined using a linear regression equation.

RESULT

The lowest risk of LGA/SGA was associated with a maternal p-BMI of 19.46 kg/m2. For pregnant women with maternal p-BMI below 24 kg/m2, we confirmed an optimal GWG linear equation: opt GWG (kg) = -1.94 × p-BMI (kg/m²) + 51, which showed an excellent degree of fit. Women who were overweight and obese could not achieve the lowest risk of LGA/SGA despite controlling their GWG; hence, their BMI should be normalized before pregnancy.

CONCLUSION

By merely using the pre-pregnancy BMI, this study has established the optimal GWG equation, with the goal of achieving the appropriate fetal gestational age. It is a practical measure to ensure desirable pregnancy outcomes and meet the health economics requirements.

The exploration of optimal gestational weight gain after oral glucose tolerance test for Chinese women with gestational diabetes mellitus

Now, no recommendations of gestational weight gain (GWG) after gestational diabetes mellitus (GDM) diagnosis for Chinese women was made. This study aimed to explore the optimal GWG after oral glucose tolerance test (OGTT) for Chinese women with GDM. The GWG status of 11,570 women was retrospectively analyzed. Binary regression model and restricted cubic spline were used to estimate the association between GWG after OGTT and the predicted probability of adverse outcomes. Based on above, the optimal GWG was defined as the range that not exceed 1% increase in the predicted probability from the lowest point. Results shown that every increased one unit GWG after OGTT was associated with higher risks of macrosomia, cesarean section and LGA, and lower risk of preterm birth. According to the WHO and Working Group on Obesity in China (WGOC) recommended pre-pregnancy BMI category, the optimal GWG were proposed: 3.66 to 6.66 kg/3.66 to 6.66 kg in underweight group, 3.07 to 6.50 kg/3.02 to 6.40 kg in normal weight group, 1.06 to 2.73 kg/0 to 1.99 kg in overweight group, and not applicable/- 0.22 to 2.53 kg in obese group, respectively. Therefore, it is necessary to classified Chinese population based on the WGOC recommended pre-pregnancy BMI category, that influenced the contribution of pre-pregnancy BMI groups and the optimal GWG recommendation for GDM women with overweight or obesity.

Placenta and maternal endothelium during preeclampsia: Disruption of the glycocalyx explains increased inositol phosphoglycans and angiogenic factors in maternal blood

The etiology of the pregnancy syndrome preeclampsia is still unclear, while most hypotheses center on the placenta as the major contributor of the syndrome. Especially changes of the placental metabolism, including the use of glucose to produce energy, are important features. As an example, inositol phosphoglycan P-type molecules, second messengers involved in the glucose metabolism of all cells, can be retrieved from maternal urine of preeclamptic women, even before the onset of clinical symptoms. Alterations in the placental metabolism may subsequently lead to negative effects on the plasma membrane of the placental syncytiotrophoblast. This in turn may have deleterious effects on the glycocalyx of this layer and a disruption of this layer in all types of preeclampsia. The interruption of the glycocalyx in preeclampsia may result in changes of inositol phosphoglycan P-type signaling pathways and the release of these molecules as well as the release of soluble receptors such as sFlt-1 and sEndoglin. The release of placental factors later affects the maternal endothelium and disrupts the endothelial glycocalyx as well. This in turn may pave the way for edema, endothelial dysfunction, coagulation, all typical symptoms of preeclampsia.

Obesity class I and II and IOM 2009 gestational weight gain recommendations 5-9 kg. An audit on 10,000 term singleton deliveries

OBJECTIVES

To compare several maternal-fetal morbidities comparing the Institute of Medicine IOM 2009 recommendations (IOMR: 5-9 kg in all obese women) between women with adequate gestational weight gain (GWG) and Inadequate (less than 5 kg), and excessive those gaining more than 9 kg among obese women class I (30-34.9 kg/m²) and class II (35-39.9 kg/m²).

STUDY DESIGN

South-Reunion University's maternity (Reunion Island, Indian Ocean). 21-Year-observational cohort study (2001-2021). Epidemiological perinatal database with information on obstetrical and neonatal risk factors.

MAIN OUTCOME MEASURES

Cesarean sections, preeclampsia, means birthweight, rate of small (SGA) or large (LGA) for gestational age newborns and macrosomic babies (≥4 kg).

RESULTS

Among the singleton term live births (37 weeks onward) we could define the pre-pregnancy body mass index and GWG in 85.9% of cases. The final study population focused on 10,296 obese women (7138 obesity class I - 30-34.9 kg/m², 3158 obesity class II - 35-39.9 kg/m²). Concerning inadequate GWG (less than 5 kg), respectively for obese I and II, IOMR babies were heavier (plus 90 and 104 g, p < .001), were more prone to be LGA OR 1.61 and 1.69, p < .001, macrosomic OR 1.49 and 2.21, p < .0001, IOMR women had more cesarean sections OR 1.33, OR 1.45, p = .001, and for obese II a tendency for more term preeclampsia OR 1.83, p = .06.

CONCLUSION

This study demonstrates that for obese women these IOMR (5-9 kg) are mildly but significantly too high if we consider obesity class I and obviously too high for obesity class II (35-39.9 kg/m²).

Low gestational weight gain (+2.0 to 4.9 kg) for singleton-term gestations associated with favorable perinatal outcomes for all prepregnancy obesity classes

BACKGROUND

Previous studies that evaluated low gestational weight gain or weight loss among prepregnancy obesity classes have not determined the amount of gestational weight gain associated with the lowest risk of adverse perinatal outcomes and neonatal morbidity among singleton term births.

OBJECTIVE

This study aimed to evaluate the relationship of specific gestational weight gain categories of weight loss, stable weight, and low gain considered below the 2009 Institute of Medicine guidelines to perinatal outcomes and neonatal morbidity for singleton, term live births among prepregnancy obesity classes.

STUDY DESIGN

This was a retrospective cohort study of 18,476 women among 3 classes of prepregnancy obesity, based on measured prepregnancy weight, and delivering a live singleton pregnancy at ≥37 weeks of gestation at a Kaiser Permanente Northern California hospital (2009-2012). Variables from electronic medical records included perinatal outcomes, sociodemographics, and measured prepregnancy and delivery weights to calculate total gestational weight gain, used to define 5 gestational weight gain categories: weight loss (<-2.0 kg), stable weight (-2.0 to +1.9 kg), low gain (+2.0 to 4.9 kg), gain within guidelines (+5.0 to 9.1 kg; referent), and gain above guidelines (>9.1 kg). Logistic regression models estimated adjusted odds ratios and 95% confidence intervals of maternal and newborn perinatal outcomes (hypertensive disorders, cesarean delivery, size for gestational age, length of stay, neonatal intensive care unit admission) associated with gestational weight gain categories stratified by prepregnancy obesity classes 1, 2, and 3.

RESULTS

Low gain occurred in 8%, 12%, and 13% of women in obesity class 1 (body mass index, 30.0-34.9), class 2 (body mass index, 35.0-39.9), and class 3 (body mass index, ≥40), respectively. Compared with gestational weight gain within Institute of Medicine guidelines, low gain was associated with similar or improved maternal and newborn perinatal outcomes for all obesity classes without increased odds of neonatal intensive care unit admission, neonatal length of stay ≥3 days, or small for gestational age. The percentages of small for gestational age for the low gain category were 4.4%, 3.0%, and 4.3% among prepregnancy obesity classes 1, 2, and 3, respectively, and comparable with the gestational weight gain within the guideline category (P>.05). The adjusted odds ratios of small-for-gestational age were not statistically significant for all obesity classes; class 1 (1.16; 95% confidence interval, 0.79-1.71) , class 2 (1.05; 95% confidence interval 0.58-1.93), and class 3 (2.03; 95% confidence interval 0.97-4.27).

CONCLUSION

Lower gestational weight gain of +2.0 to 4.9 kg showed the most favorable perinatal outcomes, without higher small for gestational age or neonatal morbidity for all obesity classes.

Preeclampsia in 2023: Time for preventing early onset- and term preeclampsia: The paramount role of gestational weight gain

The 2023 goal is to halve the incidence of preeclampsia worldwide to reach 3 million cases per year vs the current approximately 7 million cases. Preventive treatment by low dose aspirin only halves the incidence of early-onset preeclampsia (EOP < 34 weeks gestation) in high-risk women. However, 90% of PE cases are the late onset form (LOP, 34 weeks onward) proportionally associated with increasing maternal pre-pregnancy BMI. In 2018, we published a new method to calculate individualized optimal gestational weight gain based on normal Gaussian distribution of neonatal birthweights (SGA 10%, LGA 10%) and demonstrated that this optimal gestational weight gain (GWG) follows a linear equation suitable for all maternal PRE-pregnancy BMIs (from lean to obesities classes 1-2-3). A similar linear equation has been published recently based on a 2022 US database of 200,000 multiple pregnancies. Subsequently, we demonstrated in a prospective population study that in overweight and obese women who are able to achieve an optimal GWG, the rate of term preeclampsia (> 37 week's gestation) halves. Providing individual app-based calculations of optimal individual GWG, all patients will be aware of their personal weight gain target over the pregnancy. CONCLUSION: Halving the incidence of early-onset- and term preeclampsia worldwide by prevention is now theoretically achievable. Appropriate and timely start of low-dose Aspirin and providing women clear advice on their optimal GWG are they ingredients to achieve this goal.

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

IMPORTANCE

The existing gestational weight gain (GWG) recommendations for twin pregnancies are lacking for underweight individuals and are not stratified by obesity class.

OBJECTIVE

To identify optimal GWG ranges associated with reduced adverse perinatal outcomes stratified by prepregnancy body mass index (BMI) categories in twin pregnancies.

DESIGN, SETTING AND PARTICIPANTS

This population-based cohort study of twin pregnancies using data from the National Center for Health Statistics was conducted between January 1, 2014, and December 31, 2018. Statistical analysis was performed from October 24, 2021, to May 7, 2022. The study population comprised 262 604 individuals between 18 and 45 years of age with live-born twins without congenital malformation between 24 and 42 weeks of gestation. Two approaches were used to determine the optimal GWG ranges: a statistics-based approach calculating IQRs of GWG in a low-risk population, and an outcome-based approach identifying GWG thresholds below or above which an adverse perinatal outcome increased.

EXPOSURE

Gestational weight gain.

MAIN OUTCOMES AND MEASURES

Preterm birth less than 36 weeks, gestational hypertensive disorders, small for gestational age status, large for gestational age status, and a composite outcome defined as any occurrence of the individual outcomes.

RESULTS

The main sample comprised 200 810 individuals with twin pregnancies (mean [SD] maternal age, 30.4 [5.5] years; 1624 [0.8%] American Indian or Alaska Native, 13 031 [6.5%] Asian or Pacific Islander, 36 423 [18.1%] Black, and 149 732 [74.6%] White; and 137 409 [68.4%] multiparous). In the low-risk subgroup (n = 61 794), the IQRs of the total GWG after 36 weeks of gestation as assessed using a statistics-based approach and based on BMI group were 15.9 to 22.7 kg for underweight, 15.4 to 22.7 kg for normal weight, 12.7 to 22.2 kg for overweight, 10.0 to 20.0 kg for class 1 obesity, 7.7 to 18.1 kg for class 2 obesity, and 5.9 to 16.3 kg for class 3 obesity. The absolute risk of the composite outcome showed U-shaped associations with GWG across BMI categories. The optimal GWG ranges by 36 weeks identified using an outcome-based approach and BMI group were 17.5 to 24.9 kg for underweight, 15.0 to 24.9 kg for normal weight, 15.0 to 24.9 kg for overweight, 10.0 to 19.9 kg for class 1 obesity, 7.5 to 17.4 kg for class 2 obesity, and 5.0 to 9.9 kg for class 3 obesity. The multivariable logistic models assessed using the validation sample (n = 49 275) showed that GWG defined outside those optimal ranges was associated with preterm birth at less than 36 weeks, gestational hypertensive disorders, and small or large for gestational age.

CONCLUSIONS AND RELEVANCE

This population-based cohort study found that optimal GWG ranges were similar for individuals with underweight and normal weight but decreased with increasing severity of obesity. The current US Institute of Medicine GWG recommendations may be too high for individuals with moderate or severe obesity.

Gestational Weight Gain Below Instead of Within The Guidelines per Class of Maternal Obesity: A Systematic Review and Meta-Analysis of Obstetrical and Neonatal Outcomes

OBJECTIVE

To systematically investigate a wide range of obstetrical and neonatal outcomes with respect to gestational weight gain (GWG) below the current IOM and ACOG guidelines compared to within the guidelines and to stratify outcomes by the class of obesity and by the type of study analysis.

DATA SOURCES

We systematically searched studies on PubMed, Scopus, Embase, and Cochrane Library from 2009 to April 30, 2021.

STUDY ELIGIBILITY CRITERIA

Studies reporting on obstetrical and neonatal outcomes of singleton pregnancies with respect to GWG below the current IOM and ACOG guidelines compared to within the guidelines, investigated in obesity overall (BMI> 30 kg/m²), and/or class of obesity (I: BMI 30-34.9 kg/m², II: BMI 35-39.9 kg/ m² and III: BMI> 40 kg/m²).

METHODS

Among the studies that met criteria, multiple obstetrical and neonatal outcomes were tabulated and compared between pregnancies with weight gain below the guidelines and those with weight gain within the guidelines, further classified by the class of obesity if applicable. Primary outcomes included small for gestational age (SGA), large for gestational age (LGA), preeclampsia (PE), and gestational diabetes mellitus (GDM). Secondary outcomes included cesarean section (CS), preterm birth (PTB), postpartum weight retention, and composite neonatal morbidity. Meta-analysis of univariate and adjusted multivariate analysis studies were conducted. The random-effect model was used to pool the mean differences or odds ratios (OR) and the corresponding 95% confidence intervals (CIs). Heterogeneity was assessed using the I² value. Newcastle Ottawa Scale (NOS) was used to assess individual study quality.

RESULTS

Total of 54 studies reporting on 30,245,946 pregnancies were included, of which 11,515,411 pregnancies were in the univariate analysis and 18,730,535 pregnancies in the adjusted multivariate analysis. In the meta-analysis of univariate studies, compared to women who gained within the guidelines, those who gained below the guidelines had higher odds for SGA in obesity class I and II (OR:1.30 (95% CI 1.17, 1.45), I² 0%, P<0.00001, and OR: 1.56 (95% CI 1.31, 1.85), I² 0%, P<0.00001), respectively), however, the incidence of SGA was below the expected limits (<10%) and was not associated with increased neonatal morbidity. Furthermore, after adjusting for covariates, that difference was no statistically significant anymore. The difference was not statistically significant for class III obesity. Following adjusted multivariate analysis, no significant differences in SGA rates were noted for all classes of obesity between groups. Significantly lower odds for LGA were seen in GWG below guidelines in obesity class I, II, and III (OR: 0.69 (95% CI 0.64, 0.73), I² 0%, P<0.00001, OR: 0.68 (95% CI 0.63, 0.74), I² 0%, P<0.00001, and OR: 0.65 (95% CI 0.57, 0.75), I² 34%, P<0.00001, respectively), and similar findings were seen in the adjusted multivariate analysis. Women with weight gain below guidelines had significantly lower odds for PE in obesity class I, II, and III (OR: 0.71 (95% CI 0.63, 0.79),), I² 0%, P<0.00001, OR: 0.82 (95% CI 0.73, 0.91), I² 0%, P<0.00001, and OR: 0.82 (95% CI 0.70, 0.94), I² 0%, P=0.006, respectively), and similar findings were seen in the adjusted multivariate analysis. No significant differences were seen in GDM between groups. Regarding PTB, available univariate analysis studies only reported on overall obesity and mixed iatrogenic and spontaneous PTB showing significant increase in the odds of PTB (OR: 1.42 (95% CI 1.40, 1.43), I² 0%, P<0.00001) in women with low weight gain, while adjusted multivariate studies in overall obesity and in all three classes and showed no significant differences of PTB between groups. Women with low weight gain had significantly lower odds for CS in obesity class I, II, and III (OR: 0.76 (95% CI 0.72, 0.81), I² 0%, P<0.00001, OR: 0.82 (95% CI 0.77, 0.87), I² 0%, P<0.00001, and OR: 0.87 (95% CI 0.82, 0.91), I² 0%, P<0.00001, respectively), and similar findings were seen in the adjusted multivariate analysis. There was significantly lower odds for postpartum weight retention (OR: 0.20 (95% CI 0.05, 0.82)), I² 0%, P=0.03) and lower odds for composite neonatal morbidity in the overall obesity group with low GWG (OR: 0.93 (95% CI 0.87, 0.99)), I² 19.6%, P=0.04).

CONCLUSION

Contrary to previous reports, the current systematic review and meta-analysis showed no significant increase in SGA rates in pregnancies with weight gain below the current guidelines for all classes of maternal obesity. Furthermore, gaining below the guidelines was associated with lower LGA, PE, and CS rates. Our study provides the evidence that the current recommended GWG is high for all classes of obesity. These results provide pertinent information supporting the notion to revisit the current GWG recommendations for women with obesity and furthermore to classify them by the class of obesity rather than one overall obesity category as is done in the current recommendations.

Weight gain during pregnancy: A narrative review on the recent evidences

Gestational weight gain is necessary for the normal fetus development, in fact a series of studies have evidenced that both low and excessive gestational weight gain is associated with negative fetal-neonatal outcomes. So, evidences on the optimal gestational weight gain across the ranges of the pre-pregnancy maternal body mass index are necessary. In this context, while for normal weight and underweight the recommendations of IOM are clearly stated and supported by well designed and conducted clinical studies, those for the obese pregnant women are even today debated. Pre-pregnancy obesity is associated with high risk to develop hypertension, gestational diabetes, cesarean section and high birth weight. The Institute of Medicine guidelines, in 2009, recommended that women with obesity gain 11-20 lb at a rate of 0.5 lb/week during the second and third trimesters of pregnancy. Successively, taking into account a series of meta-analysis, the American College of Obstetricians and Gynecologists emphasized that the IOM weight gain targets for obese pregnant women are too high. However the high risk to have babies small for gestational age, related to a low weight gain or a losing of weight during pregnancy, has also been demonstrated. More recent studies have taken into consideration the maternal and fetal outcomes of obese pregnant women with different obesity class (I,II,III) and different weight gain during pregnancy. The analysis of these studies, discussed in this narrative review, show that the appropriate gestational weight gain should be personalized considering the three obesity class; furthermore both an upper and lower limit of gestational weight gain should be reconsidered in order to prevent the negative maternal and fetal outcomes in these women.

Gestational weight gain and postpartum weight retention in Tasmanian women: The Baby-bod Study

Many factors can negatively impact perinatal outcomes, including inappropriate gestational weight gain (GWG). Despite having the greatest potential to influence maternal and infant health, there is a lack of consensus regarding the GWG consistent with a healthy pregnancy. To date, GWG in Northern Tasmania remains understudied. We investigated how maternal pre-pregnancy body mass index (BMI) is related to weight gain during pregnancy and weight retention post-partum, and how maternal pre-pregnancy BMI is related to the mode of delivery. Approximately 300 Tasmanian mothers (n = 291 for mode of delivery and n = 282 for GWG) were included in this study. Analysis of variance and chi square tests were conducted to assess differences in BW of mothers across BMI categories and differences between categorical variables; respectively. Based on pre-pregnancy BMI, mothers were assigned to one of three groups, with healthy weight (<25 kg m-2), with overweight (25–29.9 kg m-2), or with obesity (>30 kg m-2). Pre-pregnancy BMI and body weight (BW) were significantly associated (p<0.001) with post-partum BW at 3 and 6 months. Only 25% of mothers with a normal weight BMI, 34% with overweight and 13% with obesity, achieved the Institute of Medicine (IOM) recommendation for GWG. Interestingly, a number of women in our cohort lost weight during gestation (1.5, 9 and 37% in <25, 25–29.9 and >30 kg m-2 groups, respectively). Further, women with obesity showed the lowest level of BW fluctuation and retained less weight post-partum. The highest number of caesarean sections were observed in mothers who exceeded GWG recommendations. Most mothers either exceeded or failed to achieve IOM recommendations for GWG. To improve the generalisability of these findings, this study should be replicated in a larger representative sample of the Tasmanian maternal population.

Maternal characteristics associated with gestational weight gain in France: a population-based, nationally representative study

OBJECTIVES

To provide nationally representative estimates of gestational weight gain (GWG) and identify maternal characteristics associated with inadequate GWG in France.

DESIGN

A population-based study using data from the French National Perinatal Survey: 2010 and 2016.

SETTING

All maternity units in metropolitan, mainland France (n=535 in 2010; n=493 in 2016).

PARTICIPANTS

Singleton live births with GWG data (N=24 850).

PRIMARY OUTCOME MEASURES

GWG was calculated as end of pregnancy minus pre-pregnancy weight (kg) and categorised as 'insufficient', 'adequate', or 'excessive' using 2009 Institute of Medicine thresholds. Classification accounted for pre-pregnancy body mass index (BMI) (kg/m²; underweight (<18.5), normal weight (18.5-24.9), overweight (25-29.9), obese (≥30)) and gestational age at birth. We estimated average GWG and the percentage of women in each GWG category. Polytomous logistic regression identified characteristics associated with GWG adequacy.

RESULTS

Average GWG was 13.0 kg (SD 5.6), with 26.8% of women gaining insufficiently, 37.0% adequately and 36.1% excessively. Among other factors, insufficient GWG was associated with underweight (vs normal weight; adjusted OR (aOR) 1.4, 95% CI 1.2 to 1.5) and obese (aOR 1.5, 95% CI 1.4 to 1.7) BMI. Excessive GWG was associated with overweight (aOR 2.8, 95% CI 2.6 to 3.1) and obese BMI (aOR 3.3, 95% CI 2.9 to 3.6). Examining obesity classes separately, odds of insufficient GWG increased from obesity class I to III, while odds of excessive GWG decreased from obesity class I to III. Primiparity (insufficient: aOR 0.9, 95% CI 0.9 to 1.0; excessive: aOR 1.2, 95% CI 1.2 to 1.3), maternal characteristics indicative of lower socioeconomic status, and continuing or quitting smoking during pregnancy were also associated with inadequate GWG.

CONCLUSIONS

In France, insufficient and excessive GWG are common. For optimal outcomes, clinician education, with special attention to the needs of higher risk/vulnerable groups, is needed to ensure all women receive appropriate advice for recommended GWG.

Maternal Weight Gain and Infant Birth Weight in Women with Class III Obesity

OBJECTIVE

The aim of this study is to describe the impact of maternal weight gain on infant birth weight among women with Class III obesity.

STUDY DESIGN

Retrospective cohort of women with body mass index (BMI) ≥40 kg/m² at initial prenatal visit, delivered from July 2013 to December 2017. Women presenting 14/0 weeks of gestational age (GA), delivering preterm, or had multiples or major fetal anomalies excluded. Maternal demographics and complications, intrapartum events, and neonatal outcomes abstracted. Primary outcomes were delivery of large for gestational age or small for gestational age (SGA) infant. Bivariate statistics used to compare women gaining less than Institute of Medicine (IOM) recommendations (LTR) and women gaining within recommendations (11-20 pounds/5-9.1 kg) (at recommended [AR]). Regression models used to estimate odds of primary outcomes.

RESULTS

Of included women (n = 230), 129 (56%) gained LTR and 101 (44%) gained AR. In sum, 71 (31%) infants were LGA and 2 (0.8%) were SGA. Women gaining LTR had higher median entry BMI (46 vs. 43, p < 0.01); other demographics did not differ. LTR women were equally likely to deliver an LGA infant (29 vs. 34%, p = 0.5) but not more likely to deliver an SGA infant (0.8 vs. 1%, p > 0.99). After controlling for confounders, the AOR of an LGA baby for LTR women was 0.79 (95% CI: 0.4-1.4).

CONCLUSION

In this cohort of morbidly obese women, gaining less than IOM recommendations did not impact risk of having an LGA infant, without increasing risk of an SGA infant.

Epidemiological evidence that severe obese women (pre-pregnancy BMI ≥40 kg/m2) should lose weight during their pregnancy

OBJECTIVES

Defining the optimal gestational weight gain (optGWG) allowing to have "normal shaped" babies (10% of Small for gestational age, SGA, and10% of large LGA babies) in severe obese women (pre-pregnancy BMI ≥40 kg/m²).

STUDY DESIGN

South-Reunion University's maternity (Reunion Island, Indian Ocean). 20 year-observational cohort study (2001-2019). Epidemiological perinatal data base with information on obstetrical and neonatal risk factors. All consecutive term (37-42 weeks gestation) singleton pregnancies (>21 weeks) live birth pregnancies delivered in the maternity.

MAIN OUTCOME MEASURES

OptGWG to obtain newborns as close as possible of the 10% SGA/LGA goal for each BMI categories, 15-19.9, 20-24.9 …, as well as severe obese ≥40 kg/m².

RESULTS

Of the 71,318 singleton term live births (37 weeks onward), we could define the maternal pre-pregnancy body mass index and the GWG in of 61,764 patients (86.6%). Severe obese 40 kg/m² losing 5-9.9 kg have 12.9% of LGA and 11.9% of SGA babies. Those losing 10 kg and more 12.7% of LGA and 7.3% of SGA. Our formerly proposed linear equation (validated from 15 to 40 kg/m²) may be prolonged at 45 kg/m².   opGWG(kg)=-1.2pp BMI(Kg/m2)+42±2kg.

CONCLUSION

In our population, a 32 kg/m² obese should gain 3.6 kg (instead of 5-9 kg, IOM 2009). A very obese 40 kg/m² should lose 6 kg, and a severe obese 45 kg/m² lose 12 kg.

Optimal gestational weight gain in Chinese pregnant women by Chinese-specific BMI categories: a multicentre prospective cohort study

OBJECTIVE

To establish optimal gestational weight gain (GWG) in Chinese pregnant women by Chinese-specific BMI categories and compare the new recommendations with the Institute of Medicine (IOM) 2009 guidelines.

DESIGN

Multicentre, prospective cohort study. Unconditional logistic regression analysis was used to evaluate the OR, 95 % CI and the predicted probabilities of adverse pregnancy outcomes. The optimal GWG range was defined as the range that did not exceed a 1 % increase from the lowest predicted probability in each pre-pregnancy BMI group.

SETTING

From nine cities in mainland China.

PARTICIPANTS

A total of 3731 women with singleton pregnancy were recruited from April 2013 to December 2014.

RESULTS

The optimal GWG (ranges) by Chinese-specific BMI was 15·0 (12·8-17·1), 14·2 (12·1-16·4) and 12·6 (10·4-14·9) kg for underweight, normal weight and overweight pregnant women, respectively. Inappropriate GWG was associated with several adverse pregnancy outcomes. Compared with women gaining weight within our proposed recommendations, women with excessive GWG had higher risk for macrosomia, large for gestational age and caesarean section, whereas those with inadequate GWG had higher risk for low birth weight, small for gestational age and preterm delivery. The comparison between our proposed recommendations and IOM 2009 guidelines showed that our recommendations were comparable with the IOM 2009 guidelines and could well predict the risk of several adverse pregnancy outcomes.

CONCLUSIONS

Inappropriate GWG was associated with higher risk of several adverse pregnancy outcomes. Optimal GWG recommendations proposed in the present study could be applied to Chinese pregnant women.

Nutrition and Metabolic Adaptations in Physiological and Complicated Pregnancy: Focus on Obesity and Gestational Diabetes

Pregnancy offers a window of opportunity to program the future health of both mothers and offspring. During gestation, women experience a series of physical and metabolic modifications and adaptations, which aim to protect the fetus development and are closely related to both pre-gestational nutritional status and gestational weight gain. Moreover, pre-gestational obesity represents a challenge of treatment, and nowadays there are new evidence as regard its management, especially the adequate weight gain. Recent evidence has highlighted the determinant role of nutritional status and maternal diet on both pregnancy outcomes and long-term risk of chronic diseases, through a transgenerational flow, conceptualized by the Development Origin of Health and Diseases (Dohad) theory. In this review we will analyse the physiological and endocrine adaptation in pregnancy, and the metabolic complications, thus the focal points for nutritional and therapeutic strategies that we must early implement, virtually before conception, to safeguard the health of both mother and progeny. We will summarize the current nutritional recommendations and the use of nutraceuticals in pregnancy, with a focus on the management of pregnancy complicated by obesity and hyperglycemia, assessing the most recent evidence about the effects of ante-natal nutrition on the long-term, on either maternal health or metabolic risk of the offspring.

Relative Contribution of Gestational Weight Gain, Gestational Diabetes, and Maternal Obesity to Neonatal Fat Mass

Maternal nutritional and metabolic status influence fetal growth. This study investigated the contribution of gestational weight gain (GWG), gestational diabetes (GDM), and maternal obesity to birthweight and newborn body fat. It is a secondary analysis of a prospective study including 204 women with a pregestational body mass index (BMI) of 18.5-24.9 kg/m² and 219 women with BMI ≥ 30 kg/m². GDM was screened in the second and third trimester and was treated by dietary intervention, and insulin if required. Maternal obesity had the greatest effect on skinfolds (+1.4 mm) and cord leptin (+3.5 ng/mL), but no effect on birthweight. GWG was associated with increased birthweight and skinfolds thickness, independently from GDM and maternal obesity. There was an interaction between third trimester weight gain and GDM on birthweight and cord leptin, but not with maternal obesity. On average, +1 kg in third trimester was associated with +13 g in birthweight and with +0.64 ng/mL in cord leptin, and a further 32 g and 0.89 ng/mL increase in diabetic mothers, respectively. Maternal obesity is the main contributor to neonatal body fat. There is an independent association between third trimester weight gain, birthweight, and neonatal body fat, enhanced by GDM despite intensive treatment.

Significance of hyperglycaemia in first trimester pregnancy (SHIFT): A pilot study and literature review

International guidelines recommend screening for overt diabetes in early pregnancy. Women in their first trimester with fasting plasma glucose (FPG) levels that would be diagnostic of gestational diabetes mellitus (GDM) in later pregnancy are being identified and treated despite uncertainty regarding the risks and benefits. The evidence for the current diagnostic criteria and management recommendations in early GDM are reviewed. The results of a prospective observational study assessing the progression to GDM and prespecified maternal-fetal outcomes in women with mild fasting hyperglycaemia in the first trimester suggest that women with FPG 5.1-5.6 mmol/L may warrant proactive management in early pregnancy.

Gestational weight gain and rate of late-onset preeclampsia: a retrospective analysis on 57 000 singleton pregnancies in Reunion Island

OBJECTIVES

To investigate in singleton term pregnancies (≥37 weeks gestation) if applying optimal gestational weight gains (optGWG) on our population could have an effect on the incidence of late-onset preeclampsia (LOP).

DESIGN

18.5-year-observational cohort study (2001-2019).

SETTINGS

Centre Hospitalier Universitaire Hospitalier Sud Reunion's maternity (French overseas department, Indian Ocean), the only maternity providing services to take care of all preeclamptic cases in an area with approximately 360 000 inhabitants.

MAIN OUTCOMES AND MEASURES

Simulation rates of LOP between women achieving optimal versus inappropriate GWG (insufficient and excessive) in the non-overweight, overweight and class I-III obesity categories.

RESULTS

Among 66 373 singleton term pregnancies with a live birth, and 716 LOP (≥37 weeks, LOP37), the GWG could be determined in 87% of cases. In a logistic regression model validating the independent association of optGWG, maternal ages and body mass index (BMI), primiparity, smoking habit, chronic hypertension with term preeclampsia, optGWG reduced the risk of LOP37, aOR 0.74, p=0.004. Primiparity, higher maternal BMI, chronic hypertension and higher maternal age increased the risk of LOP37. The 'protective' effect of optGWG appeared stronger in patients with overweight and obesity in a linear manner: 0.57% versus 1.07% (OR 0.53, p=0.003), overweight; class I obese (30-34.9 kg/m²), 0.70% vs 1.56% (OR 0.44, p=0.01); severe obesity (≥35 kg/m²) 0.86% vs 2.55% (OR 0.33, p=0.06). All patients with overweight/obesity together, OR 0.42, p<0.0001.

CONCLUSIONS

Overweight and obesity may not result in a higher risk of developing LOP at term when a optGWG is achieved. The results of this large retrospective population cohort study suggest that targeted and strictly monitored interventions on achieving an optGWG might represent an effective method to reduce the rate of LOP and would have the potential to halve its rate in women with overweight/obesity. These findings suggest a potentially achievable pathway to actively counterbalance the morbid effects of high BMIs, so we solicit adequately powered prospective trials.

Time to change weight gain recommendations for pregnant women with obesity

Obesity during pregnancy is a major health problem in the United States. In this issue of the JCI, Most et al. fill an important gap in our understanding of energy homeostasis in pregnancy. The researchers measured energy intake, energy expenditure, and body composition in obese pregnant women. They demonstrated that energy intake need not increase in order for obese women to gain the recommended amounts of weight during pregnancy. Additionally, all of the gestational weight gain scenarios (inadequate, recommended, or excess) resulted in similar maternal and fetal perinatal outcomes. This evidence should guide new recommendations on this important topic.

Q fever seroprevalence in parturient women: the EQRUN cross-sectional study on Reunion Island

Background

Q fever (Coxiella burnetii infection) has been associated with adverse perinatal outcomes. After investigating the obstetrical importance of Q fever on Reunion island and demonstrating an association between incident Q fever and miscarriage, we conducted a cross-sectional serosurvey to assess the prevalence of Coxiella burnetii infection among parturient women.

Methods

Between January 9 and July 24, 2014, within the level-4 maternity of Saint Pierre hospital and the level-1 maternity of Le Tampon, we proposed to screen all parturient women for Coxiella burnetii serology. Seropositivity was defined using indirect immunofluorescence for a dilution of phase 2 IgG titre ≥1:64. Further dilutions were chosen to discriminate recent or active infections from past or prevalent infections (< 1:128) and classify these as either possible (1:128), or probable (≥1:256). Recurrent miscarriage, stillbirth, preterm birth, small-for-gestational as well as a composite outcome of these adverse pregnancy outcomes were compared according to seropositivity using bivariate analysis or propensity score matching of seropositive and seronegative women on confounding factors.

Results

Among 1112 parturient women screened for Q fever over this 7-month period, 203 (18.3%) were seropositive. Overall weighted seroprevalence was of 20.1% (95%CI, 17.7–22.5%). Weighted seroprevalence of probable infections was 4.7% (95%CI 3.4–5.9%), while > 90% of positive serologies corresponded to past infections or false positives. Seropositivity was associated with none of the abovementioned adverse perinatal outcomes, whether in unpaired or matched analyses on propensity score.

Conclusion

The magnitude and the pattern of seroprevalence suggest that Q fever is endemic on Reunion island. In this context, we found no significant contribution of prevalent Coxiella burnetii infection to adverse pregnancy outcomes. Although reassuring, these data put in our endemic context, with a previously demonstrated increased risk of incident Q fever associated miscarriage, encourage us to protect pregnant women against the risk of new infection, periconceptional or early in pregnancy.

Concentration and distribution of parabens, triclosan, and triclocarban in pregnant woman serum in China

Despite mass production and widespread use of parabens, triclosan (TCS), and triclocarban (TCC) in a range of personal care products, little is known about their concentrations and distribution in pregnant woman serum in China. In this study, 5 parabens (methyl- (MeP), ethyl- (EtP), butyl- (BuP), heptyl- (HeP) and benzyl-parabens (BzP)) and 4 their metabolites (methyl protocatechuate (OH-MeP), ethyl protocatechuate (OH-EtP), 3,4-dihydroxybenzoic acid (3,4-DHB) and 4-hydroxybenzoic acid (4-HB)), TCS, and TCC were measured, by using solid-phase extraction (SPE) and ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) techniques, in pregnant woman serum samples collected from 13 provinces in China. Total concentrations of parabens (∑PBs), their metabolites (∑MBs), and TCC and TCS (∑AAs) in serum ranged from 0.221-18.6 (geometric mean (GM): 2.47), 47.4-598 (212), and 0.101-5.84 (1.01) ng/mL, respectively. MeP, EtP, 4-HB and TCS were the dominant compounds, and their GM concentrations were 1.86, 0.239, 211 and 1.00 ng/mL, respectively. Geographical distribution of target chemicals in serum was determined. Concentrations of MeP (5.49 ng/mL) and EtP (0.895 ng/mL) in sera from the Northeast China were higher than those from other regions (MeP: 0.987-3.54, EtP: 0.07-0.254 ng/mL; p < 0.05). The highest 4-HB concentrations were found in sera from the Southwest China (GM: 286 ng/mL), whereas the TCS concentrations in sera from the North China (1.18 ng/mL) were higher than those found for other regions (p < 0.05). The estimated daily intakes (EDIs; range: 49.5-126 μg/kg body weight (bw)/day) showed that the Chinese women were in a low health risk from exposure to such chemicals. This is the first study to report concentration profiles of parabens, TCS and TCC in pregnant woman serum in China.

Body Composition During Pregnancy Differs by Obesity Class

OBJECTIVE

The aim of this study is to characterize changes in body composition during pregnancy in women with obesity.

METHODS

Fifty-four healthy women with obesity (class 1, 30-34.9 kg/m² : n = 25; class 2, 35-39.9 kg/m² : n = 21; class 3, ≥ 40.0 kg/m² : n = 8) expecting a singleton pregnancy were studied. Body composition was measured in early pregnancy (13-16 weeks), midpregnancy (24-27 weeks), and late pregnancy (35-37 weeks) using air displacement plethysmography, stable isotopes, and skinfold thickness measurements. Fasting glucose, insulin, and leptin were measured.

RESULTS

The gain in fat-free mass was lower in the second trimester compared with the third (2.7 ± 0.2 to 5.3 ± 0.2 kg; P < 0.001), whereas fat mass accumulation declined over time (0.6 ± 0.3 to -0.7 ± 0.4 kg; P = 0.005). Women with class 1 and 2 obesity gained 1.1 ± 0.7 kg of fat mass during pregnancy, while women with class 3 obesity lost 4.1 ± 0.6 kg (both P < 0.001). The difference in fat accumulation between obesity classes was observed only in the second trimester (P = 0.02). Gestational weight gain was associated positively with changes in plasma concentrations of insulin, leptin, and insulin resistance (all P < 0.01).

CONCLUSIONS

Gestational weight gain in pregnancy differs by obesity class and trimester. Women with class 3 obesity gain less body weight and fat mass. Fat mass gain is most likely preventable in the second trimester.

Pregnancy outcomes of Q fever: prospective follow-up study on Reunion island

BACKGROUND

Q fever has been associated with perinatal complications. We conducted a prospective follow-up study to assess both the incidence of adverse pregnancy outcomes (APOs) associated with Coxiella burnetii infection and the contribution of Q fever to APOs.

METHODS

Between May 1 and October 31, 2013, within the regional perinatal health care centre of Saint Pierre, Reunion island, we investigated unexplained miscarriages, stillbirths, preterm births or small-for-gestational age children. Seropositivity for C. burnetii antibodies was defined using indirect immunofluorescence for a phase 2 IgG titre ≥1:64. Acute Q fever was defined for a high phase 2 IgG titre ≥1:256 (compatible with recent or active infection) or the detection of C. burnetii genome in miscarriage products and placentas. Incidence rate ratios (IRR) for Q fever related APOs (taken as a composite outcome or individually) were assessed using Poisson regression models for dichotomous outcomes controlling major confounders.

RESULTS

Over a 6-month period, 179 pregnant women suspected or diagnosed with an APO were investigated for Q fever, of whom 118 met the definition for an APO. Of these, 19 were seropositive and 10 presented a profile indicative of an acute infection. For three women with an acute Q fever, the chronology between the onset of infection, the APO (2 miscarriages, 1 preterm birth) and the seroconversion suggested causality in the pathogenesis. The cumulative incidence of Q fever related APOs was estimated between 2.2‰ and 5.2‰, whether causality was required or not. Both C. burnetii exposure and acute Q fever were independently associated with APOs (IRR 1.55, 95% CI 1.31-1.84; IRR 1.47, 95% CI 1.15-1.89, respectively).

CONCLUSIONS

In the endemic context of Reunion island, acute Q fever may lead to APOs. To limit the burden of Q fever on reproduction, pregnant women should be kept away from farms and avoid direct contact with ruminants.

Evidence from 3-month-old infants shows that a combination of postnatal feeding and exposures in utero shape lipid metabolism

We tested the hypothesis that both postnatal feeding and conditions in utero affect lipid metabolism in infants. Infants who experienced restrictive growth conditions in utero and others exposed to maternal hyperglycaemia were compared to a control group with respect to feeding mode. Dried blood spots were collected from a pilot subset of infant participants of the Cambridge Baby Growth Study at 3mo. Groups: (a) a normal gestation (control, n = 40), (b) small for gestational age (SGA, n = 34) and (c) whose mothers developed hyperglycaemia (n = 59). These groups were further stratified by feeding mode; breastfed, formula-fed or received a mixed intake. Their phospholipid, glyceride and sterol fractions were profiled using direct infusion mass spectrometry. Statistical tests were used to identify molecular species that indicated differences in lipid metabolism. The abundance of several phospholipids identified by multivariate analysis, PC(34:1), PC(34:2) and PC-O(34:1), was 30-100% higher across all experimental groups. SM(39:1) was around half as abundant in in utero groups among breastfed infants only. The evidence from this pilot study shows that phospholipid metabolism is modulated by both conditions in utero and postnatal feeding in a cohort of 133 Caucasian infants, three months post partum.

"…or else I close my ears" How women with obesity want to be approached and treated regarding gestational weight management: A qualitative interview study

INTRODUCTION

The importance of helping pregnant women maintain a healthy lifestyle and prevent excessive gestational weight gain is well recognized, but pregnant women do not always perceive communication about body weight as respectful or helpful. Furthermore, fear of inducing shame or guilt can prohibit some midwives from talking about body weight, especially if the woman has obesity. We aimed to explore what women of reproductive age with obesity regard to be the most important and relevant aspects when discussing gestational weight management.

METHODS

Qualitative interview study using focus groups and individual semi-structured interviews with 17 women of reproductive age (19-39 y) with obesity. Thematic analysis was used to analyze the data.

RESULTS

We identified three themes: 1) Importance of obtaining vital medical information; 2) A wish to feel understood and treated with respect; 3) Midwives' approach is crucial in sensitive key situations, which include bringing up the subject of body weight, weighing, providing weight-related information, coaching lifestyle modification, dealing with emotional reactions and ending a conversation.

CONCLUSIONS

A majority of the interviewed women wished to receive information about risks about obesity and gestational weight gain, and recommendations on weight management. However, the risk of midwives offending someone by raising the topic may be increased if the pregnant woman believe that gestational weight gain is uncontrollable by the individual. Also, several situations during maternity care meetings can be stigmatizing and make women less receptive to advice or support. Women suggest that a good working alliance is likely to be achieved if midwives have knowledge about the causes of obesity, take interest in the patients' background, have a non-judgmental approach and refrain from giving unsolicited advice.

Energy Intake Requirements in Pregnancy

Energy intake requirements in pregnancy match the demands of resting metabolism, physical activity, and tissue growth. Energy balance in pregnancy is, therefore, defined as energy intake equal to energy expenditure plus energy storage. A detailed understanding of these components and their changes throughout gestation can inform energy intake recommendations for minimizing the risk of poor pregnancy outcomes. Energy expenditure is the sum of resting and physical activity-related expenditure. Resting metabolic rate increases during pregnancy as a result of increased body mass, pregnancy-associated physiological changes, i.e., cardiac output, and the growing fetus. Physical activity is extremely variable between women and may change over the course of pregnancy. The requirement for energy storage depends on maternal pregravid body size. For optimal pregnancy outcomes, women with low body weight require more fat mass accumulation than women with obesity, who do not require to accumulate fat mass at all. Given the high energy density of fat mass, these differences affect energy intake requirements for a healthy pregnancy greatly. In contrast, the energy stored in fetal and placental tissues is comparable between all women and have small impact on energy requirements. Different prediction equations have been developed to quantify energy intake requirements and we provide a brief review of the strengths and weaknesses and discuss their application for healthy management of weight gain in pregnant women.

Effect of maternal weight gain according to the Institute of Medicine recommendations on pregnancy outcomes in a Chinese population

Objective

This study aimed to analyze the effects of maternal weight on adverse pregnancy outcomes.

Methods

Data were retrospectively collected from a hospital in Wuhan, China. A total of 1593 pregnant women with singletons were included. Adverse outcomes during pregnancy, such as small for gestational age (SGA), large for gestational age (LGA), and hypertensive disorders in pregnancy (HDP) were analyzed.

Results

The risks of low birth weight, SGA, and preterm birth were significantly higher in the inadequate gestational weight gain (GWG) group compared with the adequate GWG group. GWG over the guidelines was related to a higher risk of macrosomia, LGA, cesarean section, and HDP than GWG within the guidelines. The risks of low birth weight (OR = 5.082), SGA (OR = 3.959), preterm birth (OR = 3.422), and gestational diabetes mellitus (OR = 1.784) were significantly higher in women with a normal pre-pregnancy body mass index (BMI) and inadequate GWG compared with women with a normal pre-pregnancy BMI and adequate GWG. The risks of macrosomia (OR = 3.654) and HDP (OR = 1.992) were increased in women with normal pre-pregnancy BMI and excessive GWG.

Conclusion

Women with an abnormal BMI and inappropriate GWG have an increased risk of adverse maternal and infant outcomes. Weight management during the perinatal period is required.

Association of serum ghrelin with weight gain during pregnancy in overweight and normal women

PURPOSE

Despite the fact that the ghrelin hormone plays pivotal role in the process of weight gain, its correlation with weighing during pregnancy has not been elucidated. Hence, the present study was conducted to evaluate the correlation between plasma ghrelin levels and gestational weight gain in overweight and normal women.

METHODS

This prospective cohort study was conducted in 27 overweight and 18 normal body mass index (BMI) pregnant women referring to Tehran health care centers. Weight gain during all trimesters of pregnancy was measured and the blood samples were collected at 8-12 (first trimester) and 16-20 weeks (second trimester) of pregnancy. The plasma total ghrelin concentration was measured by ELISA method.

RESULTS

The overweight pregnant women exhibited significantly lower weight gain at the second (p = 0.002), third trimesters (p = 0.005) as well as total weighing during pregnancy (p = 0.001) compared to the normal BMI pregnant women. There was no significant difference in plasma ghrelin levels between the groups from the first to the second trimesters of pregnancy (p > 0.05). Moreover, no correlation was found between ghrelin levels and gestational weight gain in the overweight and normal groups.

CONCLUSIONS

Our results indicate that the increased level of serum ghrelin could not be considered as a key mediator for weight gain difference during pregnancy of overweight women.

Maternal Nutritional and Water Homeostasis as a Presage of Fetal Birth Weight

Birth weight is a key determinant of perinatal outcomes which affect physical development and metabolic function. In this study, we evaluated the potential role of maternal body composition and nutritional status in programing fetal birth weight. This was a longitudinal study that included 29 pregnant women and their full-term newborns. Maternal dietary energy and fluid intake and body adipose tissue were assessed. In addition, we measured the serum content of copeptin, aldosterone, and angiotensin II in maternal and umbilical cord blood. The measurements were done across the three trimesters of pregnancy, on average, at 11.6 weeks, 18.3 weeks, and 30.2 weeks. Each newborn's birth weight was determined at the percentile line, using the World Health Organization (WHO) standards based on the gestational age, gender, and weight. We found no appreciable relation of fetal birth weight to the maternal dietary and fluid intakes, and the content of angiotensin II, aldosterone, or copeptin. However, birth weight correlated with increases in body adipose tissue in early pregnancy stages. Further, birth weight correlated positively with copeptin and adversely with angiotensin II in cord blood. We conclude that the present findings may be helpful in the assessment of a critical level of body adipose tissue in women of child-bearing age, above which the potential risk of macrosomia appears. The female population of child-bearing age needs a continual update on the nutritional knowledge to prevent modifiable maternal and fetal perinatal complications.