Gestational Weight Gain and Maternal and Neonatal Outcomes in Term Twin Pregnancies in Obese Women

The association between neonatal birthweight discordance and preeclampsia in twin pregnancy

PURPOSE

To investigate the association between neonatal birthweight (NBW) discordance and preeclampsia (PE) in twin pregnancy.

METHODS

This was a single-center retrospective cohort study. Women with two live births in the First Affiliated Hospital of Sun Yat-sen University from January 2011 to June 2020 were eligible. They were classified into four groups based on the quartiles of NBW discordance in monochorionic (MC) and dichorionic (DC) twin pregnancy. The relationship between NBW discordance and the risk of PE was assessed by logistic regression, subgroup analyses was further analyzed.

RESULTS

A total of 1566 women were eligible for the final analysis, there were 445 MC cases and 1121 DC cases. No matter in monochorionic or dichorionic pregnancy, higher NBW discordance quartiles were associated with increased risks of PE. Compared with women in the lowest NBW discordance quartile, women in the highest NBW discordance quartile had approximately 3.6 and 6.0 times risk of PE in monochorionic and dichorionic pregnancy respectively. The association between quartiles of NBW discordance and the risk of PE were higher in dichorionic pregnancy than in monochorionic pregnancy. No matter in MC or DC pregnancy, no significant interaction effects were identified for maternal age, pregnancy body mass index, mode of conception and whether complicated with gestational diabetes mellitus.

CONCLUSIONS

The increased NBW discordance quartile was related to an increased risk of PE. Assessing estimated fetal weight discordance by using ultrasound in clinical practice to predict PE remained to be further researched.

Healthful Eating Behaviors among Couples Contribute to Lower Gestational Weight Gain

Through longitudinal analysis from the GLOWING cohort study, we examined the independent and joint relationships between couples' eating behaviors and gestational weight gain (GWG). Pregnant persons (n = 218) and their non-pregnant partners (n = 157) completed an Eating Inventory. GWG was calculated as gestation weight at 36 weeks minus that at 10 weeks. General linear models were used to examine the relationships between GWG and the pregnant persons, non-pregnant partners, and couples (n = 137; mean of pregnant persons and non-pregnant partners) cognitive restraint (range 0-21), dietary disinhibition (range 0-18), and perceived hunger (range 0-14), with higher scores reflecting poorer eating behaviors. The adjusted models included race/ethnicity, education, income, marital status, and age. The pregnant persons and their non-pregnant partners' cognitive restraint, dietary disinhibition, and perceived hunger scores were 9.8 ± 4.7, 4.8 ± 3.2, and 4.4 ± 2.5 and 6.6 ± 4.6, 5.4 ± 3.4, and 4.7 ± 3.2, respectively. Higher cognitive restraint scores among the pregnant persons and couples were positively associated with GWG (p ≤ 0.04 for both). Stratified analyses revealed this was significant for the pregnant persons with overweight (p ≤ 0.04). The non-pregnant partners' eating behaviors alone were not significantly associated with GWG (p ≥ 0.31 for all). The other explored relationships between GWG and the couples' eating behaviors were insignificant (p ≥ 0.12 for all). Among the pregnant persons and couples, reduced GWG may be achieved with higher levels of restrained eating. Involving non-pregnant partners in programs to optimize GWG may be beneficial.

Early Gestational Weight Gain and the Risk of Preeclampsia in Dichorionic Twin Pregnancies

OBJECTIVE

The purpose of our study was to evaluate the body mass index (BMI)-specific association between early gestational weight gain (GWG) in dichorionic twin pregnancies and the risk of preeclampsia.

STUDY DESIGN

We conducted a retrospective cohort study of all dichorionic twin pregnancies from 1998 to 2013. Data were obtained from a perinatal database and chart abstraction. Prepregnancy BMI was categorized as normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥30 kg/m2). Early GWG was defined as the last measured weight from 160/7 to 196/7weeks' gestation minus prepregnancy weight. GWG was standardized for gestational duration using BMI-specific z-score charts for dichorionic pregnancies. Preeclampsia was diagnosed using American College of Obstetricians and Gynecologists criteria and identified with International Classification of Diseases-9 coding. Early GWG z-score was modeled as a three-level categorical variable (≤ - 1 standard deviation [SD], 0, 3 +1 SD), where -1 to +1 was the referent group. We estimated risk differences and 95% confidence intervals (CIs) via marginal standardization.

RESULTS

We included 1,693 dichorionic twin pregnancies in the cohort. In adjusted analysis, the incidence of preeclampsia increased with increasing early GWG among women with normal BMI. Women with normal BMI and a GWG z-score < - 1 (equivalent to 2.6 kg by 20 weeks) had 2.5 fewer cases of preeclampsia per 100 births (95% CI: -4.7 to - 0.3) compared with the referent; those with GWG z-score > +1 (equivalent to gaining 9.8 kg by 20 weeks) had 2.8 more cases of preeclampsia per 100 (95 % CI: 0.1-5.5) compared with the referent. In adjusted analyses, early GWG had minimal impact on the risk of preeclampsia in women with overweight or obesity.

CONCLUSION

GWG of 2.6 kg or less by 20 weeks was associated with a decreased risk of preeclampsia among women pregnant with dichorionic twins and normal prepregnancy BMI. Current GWG guidelines focus on optimizing fetal weight and gestational length. Our findings demonstrate the importance of considering other outcomes when making GWG recommendations for twin pregnancy.

KEY POINTS

· Early GWG decreased with increasing BMI category.. · Among women with normal weight, as early GWG increased so did the risk of preeclampsia.. · There was no association between early GWG and preeclampsia among women with overweight or obesity..

Gestational weight gain adequacy among twin pregnancies in France

The objective of this paper is to describe gestational weight gain (GWG), to assess the applicability of the 2009 Institute of Medicine (IOM) guidelines, and to derive a GWG adequacy classification within a French cohort. We included twins from the national, prospective, population-based JUmeaux MODe d'Accouchement (JUMODA) cohort study (2014-2015). Following the IOM approach, we selected a 'standard' population of term pregnancies with 'optimal' birthweight (≥2500 g; n = 2562). GWG adequacy (insufficient; adequate; excessive) was defined using IOM recommendations (normal body mass index [BMI]: 16.8-24.5 kg [also utilized for underweight BMI]; overweight: 14.1-22.7 kg; obese: 11.4-19.1 kg). Additionally, using the IOM approach, we determined the 25th and 75th percentiles of GWG in our standard population to create a JUMODA-derived GWG adequacy classification. GWG and GWG adequacy were described, overall and by BMI and parity. In the JUMODA standard population of term twin livebirths with optimal birthweight, mean GWG was 16.1 kg (standard deviation 6.3). Using IOM recommendations, almost half (46.5%) of the women had insufficient and few (10.0%) had excessive GWG, with similar results regardless of BMI or parity. The 25th and 75th percentiles of GWG in the JUMODA standard population (underweight: 13-21 kg; normal weight: 13-20 kg; overweight: 11-19 kg; obese: 7-16 kg) were lower than the IOM recommendations. The IOM recommendations classified a relatively high percentage of French women as having insufficient and a low percentage as having excessive GWG. Additional research to evaluate recommendations in relation to adverse perinatal outcomes is needed to determine whether the IOM recommendations or the JUMODA-derived classification is more appropriate for French twin gestations.

Association between gestational weight gain and perinatal outcomes among twin gestations based on the 2009 Institute of Medicine (IOM) guidelines: a systematic review

BACKGROUND

Gestational weight gain (GWG) has been understudied among twin pregnancies. This systematic review aimed to review the data on the associations between GWG, based on the 2009 Institute of Medicine (IOM) guidelines and pregnancy outcomes among twin gestations.

METHODS

A systematic review was performed according to the PRISMA guidelines. A search for eligible studies published from January 2010 to August 2020 was conducted in the EMBASE, PubMed, Web of Science, ScienceDirect, and Cochrane databases. The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale. Data on study characteristics and main findings were extracted independently by two reviewers using a standard form. Outcomes of interest included (spontaneous) preterm birth (PTB), gestational hypertensive disorder (gestational hypertension and eclampsia), and small for gestational age (SGA).

RESULTS

Eighteen observational studies of twin gestations met the inclusion criteria. GWG below the IOM recommendations was reported to be associated with increased PTB and SGA while GWG above the recommendation was associated with increased gestational hypertensive disorder. However, the results were inconsistent. Methodological limitations, such as a retrospective design, the use of weekly GWG, a small sample size and insufficient adjustment, impeded the clarification of the association between GWG and perinatal outcomes. In addition, the optimal GWG for underweight women was not fully studied.

CONCLUSIONS

The maintenance of weight gain within the 2009 IOM guidelines would decrease the risks of adverse outcomes among twin pregnancies. However, rigorous studies are warranted to provide robust evidence to refine the optimal GWG among twin gestations.

Associations between prepregnancy body mass index, gestational weight gain, and pregnancy outcomes in women with twin pregnancies: A five-year prospective study

BACKGROUND

The purpose of this project was to investigate the relationship between prepregnancy body mass index (ppBMI), gestational weight gain (GWG), and pregnancy outcomes in women with twin pregnancies.

METHODS

A prospective cohort of 369 women with dichorionic diamniotic twin pregnancies was recruited from 2016 to 2020. According to ppBMI using Chinese BMI classifications, they were categorized into the underweight (BMI < 18.5 kg/m² ), normal (BMI 18.5-23.9 kg/m² ), and overweight and obese (BMI ≥ 24 kg/m² ) groups. In each ppBMI group, they were divided into two subgroups based on the presence or absence of the complications such as gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), and small for gestational age (SGA). The outcomes including GDM, HDP, and SGA were compared among three ppBMI groups, and the associations of GWG with these outcomes within each ppBMI category were analyzed.

RESULTS

Twin-pregnant women with overweight and obesity were at increased risks of HDP (aOR = 4.417 [95% CI = 1.826-9.415]) and SGA (2.288 [1.102-4.751]), whereas underweight women were prone to deliver SGA newborns (2.466 [1.157-5.254]). Women with GDM gained less weight during pregnancy than those without GDM within each ppBMI category. For overweight and obese women, greater GWG increased the incidence of HDP (1.235 [1.016-1.500]) and decreased the risk of SGA (0.818 [0.702-0.953]).

CONCLUSIONS

Both ppBMI and GWG in twin-pregnant women were strongly associated with HDP and SGA, but not GDM.

Gestational weight gain in twin gestations and pregnancy outcomes: a systematic review and meta-analysis

BACKGROUND

Data on the association of inappropriate gestational weight gain (GWG) and adverse outcomes in twin pregnancies are limited and inconsistent.

OBJECTIVES

To perform a systematic review and meta-analysis on the association between GWG and adverse outcomes in twin pregnancies.

SEARCH STRATEGY

Ovid, Medline, EMBASE and Cochrane Central databases from 1 January 1990 until 23 September 2020.

SELECTION CRITERIA

Interventional and observational studies evaluating the association between GWG and adverse outcomes in twin pregnancies.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent reviewers. Summary odds ratios (OR) were calculated using a random-effects model in a subset of studies that analysed GWG as a categorical variable in relation to the Institute of Medicine (IOM) recommendations. The primary outcome was preterm birth.

MAIN RESULTS

From 277 citations, 19 studies involving 36 023 women with twin pregnancies were included in the qualitative analysis, of which 14 were included in the meta-analysis. Overall, 56.8% of women experienced inappropriate GWG: 35.4% (95% CI 30.0-41.0%) gained weight below and 21.4% (95% CI 14.2-29.5%) gained weight above IOM recommendations. Compared with GWG within IOM guidelines, GWG below IOM guidelines was associated with preterm birth before 32 weeks of gestation (OR 3.38; 95% CI 2.05-5.58), and a reduction in the risk of pre-eclampsia (OR 0.68; 95% CI 0.48-0.97). GWG above IOM guidelines was associated with an increased risk of pre-eclampsia that was consistent across all body mass index categories.

CONCLUSIONS

Inappropriate GWG affects over half of twin pregnancies, so is a common and potentially modifiable risk factor for preterm birth and pre-eclampsia.

Maternal weight gain and pregnancy outcomes in twin gestations

BACKGROUND

Data on the optimal gestational weight gain in twin pregnancies are limited. As a result, the Institute of Medicine currently provides only provisional recommendations on gestational weight gain in this population.

OBJECTIVE

This study aimed to identify the optimal range of gestational weight gain in twin pregnancies and to estimate the association between inappropriate gestational weight gain and adverse pregnancy outcomes.

STUDY DESIGN

This was a retrospective cohort study of all women with twin pregnancies that were followed up in a single, tertiary center between 2000 and 2014. We used 2 approaches to identify the optimal range of gestational weight gain: a statistical approach (the interquartile range of gestational weight gain in low-risk pregnancies with normal outcomes) and an outcome-based approach (by identifying thresholds of gestational weight gain below or above which the rate of adverse outcomes increases). The primary outcome was preterm birth. Associations of gestational weight gain below or above the normal range with the study outcomes were estimated using logistic regression analysis and were expressed as adjusted odds ratio with 95% confidence intervals. These associations were stratified by prepregnancy body mass index group.

RESULTS

A total of 1274 women with twin pregnancies met the study criteria: 43 were classified as underweight, 777 were normal weight, 278 were overweight, and 176 were obese. Our estimates of the optimal gestational weight gain range were similar to those recommended by the Institute of Medicine except for the obese category, in which our optimal gestational weight gain range at 37 weeks (9.3-16.3 kg) was lower than in the provisional Institute of Medicine recommendations (11.3-19.1 kg). Nearly half of our cohort experienced inappropriate gestational weight gain: 30% (n=381) gained weight below and 17% (n=216) gained weight above current Institute of Medicine recommendations. In the normal weight group, gestational weight gain below recommendations was associated with an increased risk of preterm birth and birthweight at the <10th centile and with a reduction in the risk of hypertensive disorders, whereas gestational weight gain above recommendations was associated with an increased risk of hypertensive disorders and a reduction in the risk of birthweight at the <10th centile. Associations were less consistent in the overweight and obese groups.

CONCLUSION

These findings identify gestational weight gain as a potentially modifiable risk factor for preterm birth and other pregnancy complications in twin gestations. Further prospective studies are needed to determine whether interventions aimed at optimizing gestational weight gain can improve the outcomes of these high-risk pregnancies.

Gestational Weight Gain in Twin Pregnancies and Maternal and Child Health: An Updated Systematic Review

Background: The Institute of Medicine (IOM) has provisional gestational weight gain (GWG) guidelines for women pregnant with twins due to limited data in this population. To better inform guidelines, the objective of this systematic review was to build on prior work and examine recent data on the associations of GWG with maternal and child health in twin pregnancies. Materials and Methods: In February 2021, Ovid MEDLINE, Embase, CINAHL, and Cochrane Library were searched. Observational studies were eligible if published from January 1, 2013 through February 23, 2021, and examined associations of GWG with maternal or child health outcomes after accounting for gestational age at delivery and pre-pregnancy body mass index. Heterogeneity across studies precluded the use of meta-analytic methods. Results: A total of 29 studies were included. For maternal outcomes, excessive GWG was associated with an increased risk of hypertensive disorders of pregnancy; whereas studies examining gestational diabetes and delivery method reported mixed findings. For child outcomes, inadequate GWG was associated with lower birthweight, small for gestational age, and preterm birth. Adequate or excessive GWG was associated with later gestational age at delivery. Conclusions: This study advances an earlier review by including a more diverse array of maternal and child outcomes. Many of the limitations noted in the original review persist; for example, no studies examined the associations of GWG and outcomes beyond birth. Although it appears that GWG within the IOM guidelines is associated with more optimal outcomes, additional methodologically rigorous studies are needed to better inform evidence-based guidelines.

Gestational Weight Gain and Its Effects on Maternal and Neonatal Outcome in Women With Twin Pregnancies: A Systematic Review and Meta-Analysis

Background: The incidence of twin pregnancies has risen recently. Such pregnancies are associated with an increased risk for poor maternal and infant outcomes. Gestational weight gain, particularly in singleton pregnancies, has been well-linked with maternal and infant outcomes. The aim of the current meta-analysis was to evaluate the effects of gestational weight gain on maternal and fetal outcomes in women with twin pregnancies. Methods: A systematic search was conducted using the PubMed, Scopus, and Google Scholar databases. Studies, either retrospective or prospective in design, evaluating the effects of gestational weight gain (defined using Institute of Medicine (IOM) guidelines) maternal and/or fetal/neonatal outcomes in women with twin pregnancies were included. Statistical analysis was performed using STATA software. Results: Eleven studies were included in the meta-analysis. Mothers with inadequate weight gain had increased risk for gestational diabetes mellitus (OR 1.19; 95% CI: 1.01, 1.40) and decreased risk for gestational hypertension (OR 0.58; 95% CI: 0.49, 0.68) and cesarean section (OR 0.94; 95% CI: 0.93, 0.96). Neonates born to mothers with inadequate weight gain were susceptible to increased risk for preterm delivery (OR 1.17; 95% CI: 1.03, 1.34), very preterm delivery (gestational age <32 weeks) (OR 1.84; 95% CI: 1.36, 2.48), small for gestational age status (OR 1.41; 95% CI: 1.15, 1.72), low birth weight status (<2,500 g) (OR 1.27; 95% CI: 1.17, 1.38), and neonatal intensive care unit (NICU) admission (OR 1.16; 95% CI: 1.08, 1.24). The pooled findings indicate an increased risk for gestational hypertension (OR 1.82; 95% CI: 1.60, 2.06) and cesarean section (OR 1.07; 95% CI: 1.05, 1.08) among mothers with excessive weight gain. Neonates born to mothers with excessive weight gain were susceptible to increased risk for preterm delivery and very preterm delivery, but were associated with a decreased risk for low birth weight status and small for gestational age status. Conclusions: Gestational weight gain in twin pregnancy, either lower or higher than IOM recommended guidelines, is associated with poor maternal and neonatal outcomes. Our findings call for incorporating counseling on optimal weight gain during pregnancy as part of routine antenatal visits.

Gestational weight gain in twin pregnancies in Korea: application of the 2009 Institute of Medicine recommendations

Objective

To investigate the effect of gestational weight gain (GWG) on maternal and neonatal outcomes based on the Institute of Medicine (IOM) guidelines for twin pregnancies.

Methods

This study included women with twin pregnancies who delivered at Seoul National University Bundang Hospital. Based on the weight gain per gestational week according to the 2009 IOM guidelines, the subjects were divided into the following 3 groups: inadequate, adequate, and excessive GWG. We compared the maternal and neonatal outcomes of each group.

Results

A total of 1,738 twin pregnancies were included in our study. Of these cases, 881, 694, and 163 (50.7%, 39.9%, and 9.4%, respectively) twin pregnancies were categorized into the inadequate, adequate, and excessive GWG groups, respectively. In the inadequate GWG group, the risks of preterm birth <34 weeks (aOR, 2.33, 95% confidence interval [CI], 1.63–3.34) and delivering neonates who were small for gestational age (aOR, 1.92, 95% CI, 1.42–2.60) were increased, and the risk of preeclampsia (aOR, 0.49, 95% CI, 0.32–0.76) was decreased. The excessive GWG group had an increased risk of the neonates being large for gestational age (aOR, 1.79, 95% CI, 1.15–2.81).

Conclusion

The 2009 IOM recommendations for GWG can be applied to Korean women with twin pregnancies to help achieve optimal maternal and neonatal outcomes. However, more than half of the women were categorized as having inadequate weight gain according to the guidelines. Further studies should be performed to obtain Korean national references for GWG in twin pregnancies.

Gestational weight gain charts for twin pregnancies in Southeast China

Background

To establish age-standardized charts of weight gain for term twin pregnancies in Southeast China.

Methods

We designed a retrospective study on data from women pregnant with twins, a gestational age beyond 36 weeks and an average weight ≥ 2500 g. We established hierarchical linear regression models to express gestational weight gain patterns.

Results

We analyzed data from 884 women pregnant with twins (151 underweight, 597 normal weight, and 136 overweight). Our final models fit the crude weight measurement data well. The means of weight gain generally decreased as the pre-pregnancy BMI increased. For each BMI category, the mean weight gains increased with the gestational age and the standard deviation increased slightly. The mean weight gains were 18.82 ± 6.73, 18.53 ± 6.74, and 16.97 ± 6.95 kg at 37 weeks in underweight, normal weight, and overweight women, respectively.

Conclusion

The weight gain chart can be used to estimate maternal weight gain to be gestational age–standardized z scores by pre-pregnancy BMI and may serve as an innovative tool for perinatal care providers to guide the weight gain of women pregnant with twins.

Challenges for better care based on the course of maternal body mass index, weight gain and multiple outcome in twin pregnancies: a population-based retrospective cohort study in Hessen/Germany within 15 years

Introduction

Studies on maternal weight, gestational weight gain and associated outcomes in twin pregnancies are scarce. Therefore, we analyzed these items in a large cohort.

Methods

Data from 10,603/13,725 total twin pregnancies from the perinatal database in Hessen, Germany between 2000 and 2015 were used after exclusion of incomplete or non-plausible data sets. The course of maternal and perinatal outcomes was evaluated by linear and logistic regression models.

Results

The rate of twin pregnancies increased from 1.5 to 1.9% (p < 0.00001). Mean maternal age and pre-pregnancy weight rose from 31.4 to 32.9 years and from 68.2 to 71.2 kg, respectively (p < 0.001). The rates of women with a body mass index ≥ 30 kg/m² increased from 11.9 to 16.9% with a mean of 24.4–25.4 kg/m² (p < 0.001). The overall increase of maternal weight/week was 568 g, the 25th quartile was 419, the 75th quartile 692 g/week. The total and secondary caesareans increased from 68.6 to 73.3% and from 20.6 to 39.8%, respectively (p < 0.001). Rates of birthweight < 1500 g and of preterm birth < 28 and from 28 to 33 + 6 weeks all increased (p < 0.01). No significant changes were observed in the rates of stillbirth, perinatal mortality and NICU admissions.

Conclusion

The global trend of the obesity epidemic is equally observed in German twin pregnancies. The increase of mean maternal weight and the calculated quartiles specific for twin pregnancies help to identify inadequate weight gain in twin gestations. Policy makers should be aware of future health risks specified for singleton and twin gestations.

Gestational Weight Gain and Adverse Birth Outcomes in Twin Pregnancies

OBJECTIVE

To evaluate the association between gestational weight gain in twin pregnancies and small-for-gestational-age (SGA) and large-for-gestational-age (LGA) birth, preterm birth before 32 weeks of gestation, cesarean delivery, and infant death within each prepregnancy body mass index (BMI) category.

METHODS

Data in this population-based study came from Pennsylvania-linked infant birth and death records (2003-2013). We studied 54,836 twins born alive before 39 weeks of gestation. Total pregnancy weight gain (kg) was converted to gestational age-standardized z scores. Multivariable modified Poisson regression models stratified by prepregnancy BMI were used to estimate associations between z scores and outcomes. A probabilistic bias analysis, informed by an internal validation study, evaluated the effect of BMI and weight gain misclassification.

RESULTS

Gestational weight gain z score was negatively associated with SGA and positively associated with LGA and cesarean delivery in all BMI groups. The relation between weight gain and preterm birth was U-shaped in nonobese women. An increased risk of infant death was observed for very low weight gain among normal-weight women and for high weight gain among women without obesity. Most excess risks of these outcomes were observed at weight gains at 37 weeks of gestation that are equivalent to less than 14 kg or more than 27 kg in underweight or normal-weight women, less than 11 kg or more than 28 kg in overweight women, and less than 6.4 kg or more than 26 kg in women with obesity. The bias analysis supported the validity of the conventional analysis.

CONCLUSION

Very low or very high weight gains were associated with the adverse outcomes we studied. If the associations we observed are even partially reflective of causality, targeted modification of pregnancy weight gain in women carrying twins might improve pregnancy outcomes.

The effect of gestational weight gain on perinatal outcomes among Chinese twin gestations based on Institute of Medicine guidelines

BACKGROUND

Gestational weight gain (GWG) has implications for perinatal outcomes, the guidelines for maternal weight gain, however, remain understudied among twin pregnancies. This study aimed to assess the associations between perinatal outcomes and GWG among twin pregnancies, based on the US institute of Medicine (IOM) 2009 guidelines.

METHODS

A retrospective cohort study of pregnant women with viable twins ≥26 weeks of gestation, was conducted in Foshan, China, during July 2015 and June 2018. Maternal BMI was categorized based on Chinese standard and GWG was categorized as below, within and above the IOM 2009 recommendations. Underweight women were excluded for analysis. Perinatal outcomes were compared among these groups. To assess the independent impact of GWG on the perinatal outcomes, conventional multivariable regression and general estimated equation (GEE) were utilized for maternal outcomes and neonatal outcomes, respectively.

RESULTS

A total of 645 mothers with twin pregnancies were included, of whom 15.0, 41.4 and 43.6% gained weight below, within and above guidelines, respectively. Compared to weight gain within guidelines, inadequate weight gain was associated with increased risks in spontaneous preterm birth < 37 weeks (aOR:3.55; 95% CI: 1.73-7.28) and < 35 weeks (aOR:2.63; 95% CI: 1.16-5.97). Women who gained weight above guidelines were more likely to have gestational hypertension disorder (aOR: 2.36; 95% CI: 1.32-4.21), pre-eclampsia (aOR: 2.59; 95% CI: 1.29-5.21) and have fetuses weighted >90th percentile and less likely to have fetuses weighted < 2500 g and < 1500 g.

CONCLUSIONS

Maintenance of gestational weight gain within the normal range could decrease the risk of adverse perinatal outcomes. However, the causality between pre-eclampsia and gestational weight gain requires further investigations.

Correlation between second trimester weight gain and perinatal outcomes in dichorionic twin pregnancies: The LoTiS cohort study

PURPOSE

To investigate how second trimester gestational weight gain relates to perinatal outcomes in twin pregnancies of the LoTiS cohort in Chongqing, China.

METHODS

A cohort study was conducted among women with dichorionic twin pregnancies; pregnancies that culminated in delivery at ≥20 gestational weeks were included in the analysis (n = 177). Data were collected through the Longitudinal Twin Study (LoTiS). The second trimester was divided into two periods: 12-20 and 21-28 gestational weeks. Correlations between maternal weight gain and perinatal outcomes were estimated using linear or logistic regression models; the crude OR and adjusted OR were calculated.

RESULTS

The average total gestational weight gain for the whole pregnancy was 17.71 ± 4.98 kg and average gestational weight gains during 12-20 gestational weeks and 20-28 gestational weeks were 5.11 ± 1.81 kg and 5.84 ± 2.05 kg, respectively. Insufficient gestational weight gain was associated with higher risk of preterm birth (OR = 0.92, 95% CI 0.86-0.99) and spontaneous preterm birth (OR = 0.89, 95% CI 0.82-0.97). Reduced gestational weight gain during 12-20 gestational weeks was associated with higher risk of small for gestational age. Additionally, the mean birth weight of a twin pair increased by 45.78 g or 13.03 g when gestational weight gain during 12-20 weeks or total gestational weight gain increased by 1 kg.

CONCLUSION

Maternal weight gain in the early second trimester was correlated with birth weight in dichorionic twins.

Gestational Weight Gain per Pre-Pregnancy Body Mass Index and Birth Weight in Twin Pregnancies: A Cohort Study in Wuhan, China

To assess the relationship between gestational weight gain (GWG) of twin-pregnancy women and twin birth weights, as well as to evaluate whether pre-pregnancy body mass index (BMI) influences this relationship. A cohort study was conducted in Wuhan, China, between 1/01/2011 and 8/31/2017. Women with twin pregnancies who delivered live and non-malformed twins were included (6,925 women and 13,850 infants), based on the Wuhan Maternal and Child Health Management Information System. Logistic regression models were employed to examine the association between GWG and paired small for gestational age (SGA, defined as birth weight <10th percentile for gestational age and sex)/SGA and linear regression models were utilized to explore the relationship between GWG and sum of birth weights. The associations of GWG based on both the IOM and Chinese recommendations and SGA/SGA pairs were obtained, as well as the stratified analyses by pre-pregnancy BMI. Additionally, the sum birth weight of one twin pair increased by 15.88 g when the GWG increased by 1 kg. GWG below the IOM and Chinese recommendations was associated with an increased risk of SGA/SGA pairs in all pre-pregnancy BMI categories. However, in underweight, overweight, and obese women, the association between GWG above the IOM and Chinese recommendations and SGA/SGA pairs changed with adjustment.

Assessing Weight Gain by the 2009 Institute of Medicine Guidelines and Perinatal Outcomes in Twin Pregnancy

Objective The objective is to estimate the impact of maternal weight gain outside the 2009 Institute of Medicine recommendations on perinatal outcomes in twin pregnancies. Study Design Twin pregnancies with two live births between January 1, 2004 and December 31, 2014 delivered after 23 weeks Finger Lakes Region Perinatal Data System (FLRPDS) and Central New York Region Perinatal Data System were included. Women were classified into three groups using pre-pregnancy body mass index (BMI). Perinatal outcomes in women with low or excessive weekly maternal weight gain were assessed using normal weekly weight gain as the referent in each BMI group. Results Low weight gain increased the risk of preterm delivery, birth weight less than the 10th percentile for one or both twins and decreased risk of macrosomia across all BMI groups. There was a decreased risk of hypertensive disorders in women with normal pre-pregnancy weight and an increased risk of gestational diabetes with low weight gain in obese women. Excessive weight gain increased the risk of hypertensive disorders and macrosomia across all BMI groups and decreased the risk of birth weight less than 10th percentile one twin in normal pre-pregnancy BMI group. Conclusion Among twin pregnancies, low weight gain is associated with low birth weight and preterm delivery in all BMI groups and increased risk of gestational diabetes in obese women. Our study did not reveal any benefit from excessive weekly weight gain with potential harm of an increase in risk of hypertensive disorders of pregnancy. Normal weight gain per 2009 IOM guidelines should be encouraged to improve pregnancy outcome in all pre-pregnancy BMI groups.

Pre-pregnancy BMI, gestational weight gain and risk of preeclampsia: a birth cohort study in Lanzhou, China

BACKGROUND

To evaluate the independent and joint effects of maternal pre-pregnancy BMI and gestational weight gain (GWG) on the risk of preeclampsia and its subtypes.

METHODS

A birth cohort study was conducted from 2010 to 2012 in Lanzhou, China. Three hundred fourty seven pregnant women with preeclampsia and 9516 normotensive women at Gansu Provincial Maternity and Child Care Hospital were included in the present study. Unconditional logistic regression models were used to evaluate the associations between pre-pregnancy BMI, GWG, and risk of preeclampsia and its subtypes.

RESULTS

Compared to women with normal pre-pregnancy BMI, those who were overweight/obese had an increased risk of preeclampsia (OR = 1.81; 95%CI: 1.37-2.39). Women with excessive GWG had an increased risk of preeclampsia (OR = 2.28; 95%CI: 1.70-3.05) compared to women with adequate GWG. The observed increased risk was similar for mild-, severe- and late-onset preeclampsia. No association was found for early-onset preeclampsia. Overweight/obese women with excessive GWG had the highest risk of developing preeclampsia compared to normal weight women with no excessive weight gain (OR = 3.78; 95%CI: 2.65-5.41).

CONCLUSIONS

Our results suggested that pre-pregnancy BMI and GWG are independent risk factors for preeclampsia and that the risk might vary by preeclampsia subtypes. Our study also proposed a potential synergistic effect of pre-pregnancy BMI and GWG that warrants further investigation.

Examining the provisional guidelines for weight gain in twin pregnancies: a retrospective cohort study

BACKGROUND

Weight gain during pregnancy has an important impact on maternal and neonatal health. Unlike the Institute of Medicine (IOM) recommendations for weight gain in singleton pregnancies, those for twin gestations are termed "provisional", as they are based on limited data. The objectives of this study were to determine the neonatal and maternal outcomes associated with gaining weight below, within and above the IOM provisional guidelines on gestational weight gain in twin pregnancies, and additionally, to explore ranges of gestational weight gain among women who delivered twins at the recommended gestational age and birth weight, and those who did not.

METHODS

A retrospective cohort study of women who gave birth to twins at ≥20 weeks gestation, with a birth weight ≥ 500 g was conducted in Nova Scotia, Canada (2003-2014). Our primary outcome of interest was small for gestational age (<10th percentile). In order to account for gestational age at delivery, weekly rates of 2nd and 3rd trimester weight gain were used to categorize women as gaining below, within, or above guidelines. We performed traditional regression analyses for maternal outcomes, and to account for the correlated nature of the neonatal outcomes in twins, we used generalized estimating equations (GEE).

RESULTS

A total of 1482 twins and 741 mothers were included, of whom 27%, 43%, and 30% gained below, within, and above guidelines, respectively. The incidence of small for gestational age in these three groups was 30%, 21%, and 20%, respectively, and relative to gaining within guidelines, the adjusted odds ratios were 1.44 (95% CI 1.01-2.06) for gaining below and 0.92 (95% CI 0.62-1.36) for gaining above. The gestational weight gain in women who delivered twins at 37-42 weeks with average birth weight ≥ 2500 g and those who delivered twins outside of the recommend ranges were comparable to each other and the IOM recommendations.

CONCLUSIONS

While gestational weight gain below guidelines for twins was associated with some adverse neonatal outcomes, additional research exploring alternate ranges of gestational weight gain in twin pregnancies is warranted, in order to optimize neonatal and maternal outcomes.