Impact of inter-pregnancy BMI change on perinatal outcomes: a retrospective cohort study

Dietary Regulation of Lipid Metabolism in Gestational Diabetes Mellitus: Implications for Fetal Macrosomia

The primary therapeutic approach for managing hyperglycemia today is diet therapy. Lipids are not only a source of nutrients but also play a role in initiating adipocyte differentiation in the fetus, which may explain the development of fetal macrosomia and future metabolic disorders in children born to mothers with gestational diabetes mellitus (GDM). Alterations in the maternal blood lipid profile, influenced by adherence to a healthy diet in mothers with GDM and the occurrence of fetal macrosomia, represent a complex and not fully understood process. The aim of this study was to examine the characteristics of the blood plasma lipid profile in pregnant women with GDM across all trimesters based on adherence to diet therapy. The clinical part of the study followed a case-control design, including 110 women: 80 in the control group, 20 in a GDM group adhering to the diet, and 10 in a GDM group not adhering to the diet. The laboratory part was conducted as a longitudinal dynamic study, with venous blood samples collected at three time points: 11-13, 24-26, and 30-32 weeks of pregnancy. A significant impact of diet therapy on the composition of blood lipids throughout pregnancy was demonstrated, starting as early as the first trimester. ROC analysis indicated high effectiveness of the models developed, with an AUC of 0.98 for the 30- to 32-week model and sensitivity and specificity values of 1 and 0.9, respectively. An association was found between dietary habits, maternal blood lipid composition at 32 weeks, and newborn weight. The changes in lipid profiles during macrosomia development and under diet therapy were found to be diametrically opposed, confirming at the molecular level that diet therapy can normalize not only carbohydrate metabolism but also lipid metabolism in both the mother and fetus. Based on the data obtained, it is suggested that after further validation, the developed models could be used to improve the prognosis of macrosomia by analyzing blood plasma lipid profiles at various stages of pregnancy.

Interpregnancy weight change and neonatal and infant outcomes: A systematic review and meta-analysis

PURPOSE

To synthesize evidence regarding the association between interpregnancy weight change (IPWC) in consecutive pregnancies and neonatal or infant outcomes in the subsequent pregnancy.

METHODS

Search strategy was implemented in MEDLINE, EMBASE, Web of Science, Scopus and Cochrane Library from their inception to 13 November 2023. The most adjusted odds ratio (OR) or risk ratio estimates provided by original studies were used to calculate pooled risk ratios and their corresponding 95 % confidence intervals (CI) with the DerSimonian and Laird random effects method. Publication bias was assessed by funnel plots and Egger's method, and risk of bias was assessed with The NewcastleOttawa Quality Assessment Scale.

RESULTS

Thirty-seven observational studies were included. Interpregnancy weight loss or gain were associated with large for gestational age (OR: 0.89; 95 % CI: 0.84-0.94; I2 = 83.6 % and OR: 1.33; 95 % CI:1.26-1.40; I2 = 98.9 %), and stillbirth risk (OR: 1.10; 95 % CI: 1.01-1.18; I2 = 0.0 % and OR: 1.21; 95 % CI: 1.09-1.33; I2 = 60.2 %,).

CONCLUSIONS

Findings highlight the importance of managing weight between interpregnancy periods, although these findings should be interpreted cautiously because of the possible influence of social determinants of health and other factors.

The Fit After Baby randomized controlled trial: An mHealth postpartum lifestyle intervention for women with elevated cardiometabolic risk

BACKGROUND

Postpartum women with overweight/obesity and a history of adverse pregnancy outcomes are at elevated risk for cardiometabolic disease. Postpartum weight loss and lifestyle changes can decrease these risks, yet traditional face-to-face interventions often fail. We adapted the Diabetes Prevention Program into a theory-based mobile health (mHealth) program called Fit After Baby (FAB) and tested FAB in a randomized controlled trial.

METHODS

The FAB program provided 12 weeks of daily evidence-based content, facilitated tracking of weight, diet, and activity, and included weekly coaching and gamification with points and rewards. We randomized women at 6 weeks postpartum 2:1 to FAB or to the publicly available Text4baby (T4B) app (active control). We measured weight and administered behavioral questionnaires at 6 weeks, and 6 and 12 months postpartum, and collected app user data.

RESULTS

81 eligible women participated (77% White, 2% Asian, 15% Black, with 23% Hispanic), mean baseline BMI 32±5 kg/m2 and age 31±5 years. FAB participants logged into the app a median of 51/84 (IQR 25,71) days, wore activity trackers 66/84 (IQR 43,84) days, logged weight 17 times (IQR 11,24), and did coach check-ins 5.5/12 (IQR 4,9) weeks. The COVID-19 pandemic interrupted data collection for the primary 12-month endpoint, and impacted diet, physical activity, and body weight for many participants. At 12 months postpartum women in the FAB group lost 2.8 kg [95% CI -4.2,-1.4] from baseline compared to a loss of 1.8 kg [95% CI -3.8,+0.3] in the T4B group (p = 0.42 for the difference between groups). In 60 women who reached 12 months postpartum before the onset of the COVID-19 pandemic, women randomized to FAB lost 4.3 kg [95% CI -6.0,-2.6] compared to loss in the control group of 1.3 kg [95% CI -3.7,+1.1] (p = 0.0451 for the difference between groups).

CONCLUSIONS

There were no significant differences between groups for postpartum weight loss for the entire study population. Among those unaffected by the COVID pandemic, women randomized to the FAB program lost significantly more weight than those randomized to the T4B program. The mHealth FAB program demonstrated a substantial level of engagement. Given the scalability and potential public health impact of the FAB program, the efficacy for decreasing cardiometabolic risk by increasing postpartum weight loss should be tested in a larger trial.

Distribution and association of interpregnancy weight change with subsequent pregnancy outcomes in Asian women

The extent of interpregnancy weight change and its association with subsequent pregnancy outcomes among Asians remain unclear. We examined changes in maternal body mass index (BMI) between the first two deliveries and outcomes in the second delivery. Medical records of women with their first two consecutive deliveries between 2015 and 2020 at KK Women's and Children's Hospital, Singapore were retrieved. Gestational-age-adjusted BMI was determined by standardising to 12 weeks gestation and interpregnancy BMI change was calculated as the difference between both pregnancies. Pregnancy outcomes were analysed using modified Poisson regression models. Of 6264 included women with a median interpregnancy interval of 1.44 years, 40.7% had a stable BMI change within ± 1 kg/m², 10.3% lost > 1 kg/m², 34.3% gained 1-3 kg/m² and 14.8% gained ≥ 3 kg/m². Compared to women with stable BMI change, those with > 1 kg/m² loss had higher risk of low birthweight (adjusted risk ratio [RR] 1.36; 95% confidence interval 1.02-1.80), while those with 1-3 kg/m² gain had higher risks of large-for-gestational-age birth (1.16; 1.03-1.31), gestational diabetes (1.25; 1.06-1.49) and emergency Caesarean delivery (1.16; 1.03-1.31); these risks were higher in those with ≥ 3 kg/m² gain. Our study strengthens the case for interpregnancy weight management to improve subsequent pregnancy outcomes.

Obesity in Pregnancy: A Comprehensive Review of Influential Guidelines

Importance

Obesity is one of the most common clinical entities complicating pregnancies and is associated with short- and long-term consequences for both the mother and the offspring.

Objective

The aim of this study were to review and compare the most recently published influential guidelines on the management of maternal obesity in the preconceptional, antenatal, intrapartum, and postpartum period.

Evidence Acquisition

A descriptive review of guidelines from the American College of Obstetricians and Gynecologists, the International Federation of Gynecology and Obstetrics, the Society of Obstetricians and Gynecologists of Canada, the Royal College of Obstetricians and Gynecologists, and the Royal Australian and New Zealand College of Obstetricians and Gynecologists on obesity in pregnancy was carried out.

Results

There is an overall agreement among the reviewed guidelines regarding the importance of prepregnancy weight loss with behavioral modification, optimization of gestational weight gain, and screening for comorbidities in improving pregnancy outcomes of obese women. Women with previous bariatric surgery should be screened for nutritional deficiencies and have a closer antenatal surveillance, according to all guidelines. In addition, folic acid supplementation is recommended for 1 to 3 months before conception and during the first trimester, but several discrepancies were identified with regard to other vitamins, iodine, calcium, and iron supplementation. All medical societies recommend early screening for gestational diabetes mellitus and early anesthetic assessment in obese women and suggest the use of aspirin for the prevention of preeclampsia when additional risk factors are present, although the optimal dosage is controversial. The International Federation of Gynecology and Obstetrics, Society of Obstetricians and Gynecologists of Canada, Royal College of Obstetricians and Gynecologists, and Royal Australian and New Zealand College of Obstetricians and Gynecologists point out that specific equipment and adequate resources must be readily available in all health care facilities managing obese pregnant women. Moreover, thromboprophylaxis and prophylactic antibiotics are indicated in case of cesarean delivery, and intrapartum fetal monitoring is justified during active labor in obese patients. However, there are no consistent protocols regarding the fetal surveillance, the monitoring of multiple gestations, the timing and mode of delivery, and the postpartum follow-up, although weight loss and breastfeeding are unanimously supported.

Conclusions

Obesity in pregnancy is a significant contributor to maternal and perinatal morbidity with a constantly rising global prevalence among reproductive-aged women. Thus, the development of uniform international protocols for the effective management of obese women is of paramount importance to safely guide clinical practice and subsequently improve pregnancy outcomes.

Does prepregnancy weight change have an effect on subsequent pregnancy health outcomes? A systematic review and meta-analysis

International guidelines recommend women with an overweight or obese body mass index (BMI) aim to reduce their body weight prior to conception to minimize the risk of adverse perinatal outcomes. Recent systematic reviews have demonstrated that interpregnancy weight gain increases women's risk of developing adverse pregnancy outcomes in their subsequent pregnancy. Interpregnancy weight change studies exclude nulliparous women. This systematic review and meta-analysis was conducted following MOOSE guidelines and summarizes the evidence of the impact of preconception and interpregnancy weight change on perinatal outcomes for women regardless of parity. Sixty one studies met the inclusion criteria for this review and reported 34 different outcomes. We identified a significantly increased risk of gestational diabetes (OR 1.88, 95% CI 1.66, 2.14, I²  = 87.8%), hypertensive disorders (OR 1.46 95% CI 1.12, 1.91, I²  = 94.9%), preeclampsia (OR 1.92 95% CI 1.55, 2.37, I²  = 93.6%), and large-for-gestational-age (OR 1.36, 95% CI 1.25, 1.49, I²  = 92.2%) with preconception and interpregnancy weight gain. Interpregnancy weight loss only was significantly associated with increased risk for small-for-gestational-age (OR 1.29 95% CI 1.11, 1.50, I²  = 89.9%) and preterm birth (OR 1.06 95% CI 1.00, 1.13, I²  = 22.4%). Our findings illustrate the need for effective preconception and interpregnancy weight management support to improve pregnancy outcomes in subsequent pregnancies.

Preconceptional maternal weight loss and hypertensive disorders in pregnancy: a systematic review and meta-analysis

BACKGROUND

Hypertensive disorders of pregnancy (HDP), including pregnancy-induced hypertension (PIH), Preeclampsia (PE), Hemolysis Elevated Liver enzymes and Low Platelets (HELLP) and chronic hypertension, are leading causes of maternal and perinatal morbidity and mortality. Although the pathophysiology of HDP is complex, preconceptional weight reduction in obese women might reduce these complications. We conducted a systematic review and meta-analysis to investigate the effectiveness of preconceptional weight loss by lifestyle intervention or bariatric surgery in overweight and obese women and the reduction of the risk of HDP.

METHODS AND RESULTS

Databases are searched until September 2019 resulting in 2547 articles: 110 full-text analysis and 29 detailed analysis. Reduced risks were shown for HDP in seven articles (n = 4381) of weight loss after lifestyle intervention or bariatric surgery (OR range 0.10-0.64), for PIH in four articles (n = 46,976) (OR range 0.14-0.79), and for PE in seven articles (n = 169,734) (OR range 0.14-0.84). The stratified analysis of weight loss after lifestyle intervention and bariatric surgery shows comparable results. The meta-analysis of 20 studies of the effectiveness of lifestyle intervention and bariatric surgery revealed reduced risks of HDP (OR 0.45 (95% CI 0.32-0.63)), PIH (OR 0.61 (95%CI 0.44-0.85)) and PE (OR 0.67 (95%CI 0.51-0.88)).

CONCLUSIONS

Preconceptional weight loss after lifestyle intervention or bariatric surgery is effective in reducing risks of HDP, PIH and PE, and emphasizes the need to optimize weight in overweight and obese women with a child wish. More research is recommended to investigate short-term and long-term beneficial and harmful side-effects of these interventions on maternal and offspring health.

Pregnancy Outcomes after Preeclampsia: The Effects of Interpregnancy Weight Change

OBJECTIVE

This study aimed to examine the effects of interpregnancy weight change on pregnancy outcomes, including recurrent preeclampsia, preterm birth, small-for-gestational age (SGA), large-for-gestational age (LGA), and cesarean delivery, among women with a history of preeclampsia. We also evaluated whether these associations were modified by prepregnancy body mass index (BMI) category in the first pregnancy (BMI < 25 vs. ≥25 kg/m²) and if associations were present among women who maintained a healthy BMI category in both pregnancies.

STUDY DESIGN

We conducted a population-based retrospective cohort study including 15,108 women who delivered their first two nonanomalous singleton live births in Missouri (1989-2005) and experienced preeclampsia in the first pregnancy. We performed Poisson regression with robust error variance to estimate relative risks and 95% confidence intervals for outcomes of interest after controlling for potential confounders.

RESULTS

Interpregnancy weight gain was associated with increased risk of recurrent preeclampsia, LGA, and cesarean delivery. These risks increased in a "dose-response" manner with increasing magnitude of interpregnancy weight gain and were generally more pronounced among women who were underweight or normal weight in the first pregnancy. Interpregnancy weight loss exceeding 1 BMI unit was associated with increased risk of SGA among underweight and normal weight women, while interpregnancy weight loss exceeding 2 BMI units was associated with reduced risk of recurrent preeclampsia among overweight and obese women.

CONCLUSION

Even small changes in interpregnancy weight may significantly affect pregnancy outcomes among formerly preeclamptic women. Appropriate weight management between pregnancies has the potential to attenuate such risks.

KEY POINTS

· Interpregnancy weight change among formerly preeclamptic women significantly affects pregnancy outcomes.. · Interpregnancy weight gain is associated with increased risk of recurrent preeclampsia, large-for-gestational-age and cesarean delivery.. · Interpregnancy weight loss is associated with increased risk of small-for-gestational age and recurrent preeclampsia..

Relationship between weight retention at 6 weeks postpartum and the risk of large-for-gestational age birth in a second pregnancy in China: a retrospective cohort study

OBJECTIVE

We aimed to investigate the association between weight retention at 6 weeks postpartum after the first pregnancy and large-for-gestational age (LGA) risk in a subsequent pregnancy.

STUDY DESIGN

A retrospective cohort study.

SETTING

A tertiary hospital of China.

PARTICIPANTS

5950 Chinese singleton pregnancies that delivered their second singletons between 28 and 42 weeks of gestation.

OUTCOMES MEASURES

We calculated the weight retention at 6 weeks postpartum after the first pregnancy (the body mass index (BMI) at 6 weeks after the first birth minus the prepregnant BMI of the first pregnancy) and the gestational weight gain in the second pregnancy. We used the logistic regression to obtain adjusted OR. We determined the relationship between maternal BMI change at 6 weeks after the first pregnancy and LGA risk in the second pregnancy.

RESULTS

Relative to other categories of BMI change at 6 weeks postpartum, women who gained ≥3 kg/m² compared with the prepregnancy BMI were at increased LGA risk. The stratified analysis showed that LGA risk was increased in the second pregnancy in underweight and normal weight women who gained ≥3 kg/m² when using remain stable women as the reference group (OR=3.35, 95% CI 1.11 to 10.12 for underweight women; OR=2.23, 95% CI 1.43 to 3.45 for normal weight women) at 6 weeks postpartum. For the women who gained ≥3 kg/m² at 6 weeks postpartum, LGA risk was increased in normal weight women with an adequate (OR=3.21, 95% CI 1.10 to 9.33) and excessive (OR=2.62, 95% CI 1.02 to 6.76) gestational weight in the second pregnancy when using obese women as the reference.

CONCLUSION

Postpartum weight retention at 6 weeks after the first pregnancy provides us a new early window to identify LGA risk in a subsequent pregnancy and allows us to implement primary preventative strategies.

The relation between maternal obesity and placenta accreta spectrum: A multinational database study

INTRODUCTION

It has been suggested that women with obesity have increased risk of developing placenta accreta spectrum (PAS). It is unclear if this is independent of the increased risk of cesarean delivery seen with obesity itself. The aim of this study was to explore the association between maternal obesity and PAS, particularly severe PAS (percreta).

MATERIAL AND METHODS

This is a cohort study based on cases recorded in the International Society for Placenta Accreta Spectrum (IS-PAS) database between April 2008 and May 2019. Multivariable logistic regression was used to explore the effect of maternal obesity on severity of PAS; this model was adjusted for other known risk factors including previous cesarean deliveries, maternal age, and placenta previa. The estimated rate of obesity in a hypothetical cohort with similar characteristics (previous cesarean delivery and same parity) was calculated and compared with the observed rate of obesity in the women of the PAS cohort (one sample test of proportions).

RESULTS

Of the 386 included women with PAS, 227 (58.8%) had severe disease (percreta). In univariable analysis, maternal obesity initially appeared to be associated with increased odds of developing the most severe type of PAS, percreta (odds ratio [OR] 1.87; 95% CI 1.14-3.09); however, this association was lost after adjustment for other risk factors including previous cesarean delivery (OR 1.44; 95% CI 0.85-2.44). There was no difference in the observed rate of obesity and the rate estimated based on the risk of cesarean delivery from obesity alone (31.3% vs 36.8%, respectively; P = .07).

CONCLUSIONS

Obesity does not seem to be an independent risk factor for PAS or severity for PAS. These findings are relevant for clinicians to provide accurate counseling to women with obesity regarding increased risks related to pregnancy.

Barriers to a healthy postpartum lifestyle and the possibilities of an information technology-based intervention: A qualitative study

BACKGROUND

Being overweight or obese is associated with higher risk of adverse maternal and fetal outcomes, including gestational diabetes and childhood obesity. Many women exceed the gestational weight gain recommendations. Thus, it is important to focus on the women's lifestyle between their pregnancies to lower the risk of weight retention before the next pregnancy as well as in a life course perspective.

OBJECTIVE

The objective of this study was to explore barriers postpartum women experience with respect to a healthy lifestyle during the postpartum period, and to assess whether an IT-based intervention might be a supportive tool to assist and motivate postpartum women to healthy lifestyle.

METHOD

A systematic text condensation was applied to semi-structured focus groups. Five focus group interviews were carried out with a total of 17 postpartum women and two interviews with a total of six health professionals. Participants were recruited through the municipality in Svendborg, Denmark, and at Odense University Hospital in Odense, Denmark, during a four-month period in early 2018. The results were analysed within the frame of the capability, opportunity, motivation and behaviour model (COM-B).

RESULTS

From the women's perspective, better assistance is needed from the health professionals to obtain or maintain a healthy lifestyle. The women need tools that inform and help them understand and prioritize own health related risks, and to motivate them to plan and take care of their own health. There is room for engaging the partner more in the communication related to the baby and family's lifestyle. Lastly, the women already use audiobooks and podcasts to obtain information.

CONCLUSION

Postpartum women need tools that inform and motivate for a healthy lifestyle postpartum. The tools should allow access to high quality information from health care professionals when the information is needed and also allow engagement from the partner. An IT-based intervention could be a way to support and motivate postpartum women for a healthy lifestyle.

Interpregnancy Weight Change and Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aimed to synthesize evidence regarding the association between interpregnancy weight change (IPWC) and gestational diabetes mellitus (GDM) in the subsequent pregnancy.

METHODS

MEDLINE, EMBASE, Cochrane Library, and Web of Science were searched from inception to May 10, 2020. This review included studies that reported the association between IPWC and GDM in the subsequent pregnancy without restriction on study design, IPWC classification, or parity. The "no weight change" interpregnancy category was defined by each study, and data were synthesized to analyze the risk of GDM according to weight change.

RESULTS

Thirteen observational studies were included. A higher risk of GDM in the subsequent pregnancy when there was interpregnancy weight gain (odds ratio [OR] = 1.56; 95% CI: 1.30-1.83; I²  = 82.30%) was found. However, interpregnancy weight loss was associated with lower risk of GDM in the subsequent pregnancy (OR = 0.83; 95% CI: 0.68-0.98; I²  = 58.10%), but the decrease in the risk of GDM in the subsequent pregnancy was greater among women with pregestational BMI higher than 25 kg/m² (OR = 0.58; 95% CI: 0.39-0.77; I²  = 0.00%).

CONCLUSIONS

The risk of GDM in the subsequent pregnancy increases with interpregnancy weight gain, whereas it decreases with interpregnancy weight loss.

Reappraisal of Gestational Weight Gain Recommendations in Obese Pregnant Women: A Population-Based Study of 337,590 Births

BACKGROUND AND OBJECTIVE

Maternal obesity is an epidemic health problem that is aggravated by excessive gestational weight gain (GWG) and postpartum weight retention. Current US Institute of Medicine (now US National Academy of Medicine) guidelines (2009) for GWG need to be evaluated against the current rise in obesity in the general and pregnant population. We wanted to study the relation between GWG and pregnancy and birth outcomes and to relate this to the current recommendations for GWG.

METHODS

Population-based study. We performed an epidemiological analysis in a cohort of Belgian pregnant women with singleton live births at term (≥37 weeks) between 2009 and 2014 (n = 337,590). Logistic regression was used to determine the optimal GWG in relation to relevant pregnancy and birth outcomes.

RESULTS

The prevalence of maternal obesity significantly increased from 10.3% in 2009 to 11.4% in 2014. The mean (SD) body mass index at the start of the pregnancy significantly increased from 23.9 (4.5) in 2009 to 24.2 (4.6) in 2014. Excessive GWG was frequent, especially in overweight (56.8%) and obese (52.9%) pregnant women. In the logistic regression model, the amount of GWG associated with the lowest incidence of both large-for-gestational-age and small-for-gestational-age infants was 21 kg in underweight women, 14 kg in normal weight, 8 kg in overweight, 0 kg in obese class I, -4 kg in obese class II and -5 kg in obese class III.

CONCLUSION

The prevalence of maternal obesity has risen in Belgium between 2009 and 2014. Current GWG guidelines, based on historic observational data, are probably too liberal for class II and III obese women in which better outcomes are being predicted for lower weight gain than recommended.

Interpregnancy weight change and recurrence of gestational diabetes mellitus: a population-based cohort study

OBJECTIVE

To estimate recurrence risk of gestational diabetes mellitus (GDM) by interpregnancy weight change.

DESIGN

Population-based cohort study.

SETTING AND POPULATION

Data from the Swedish (1992-2010) and the Norwegian (2006-2014) Medical Birth Registries on 2763 women with GDM in first pregnancy, registered with their first two singleton births and available information on height and weight.

METHODS

Interpregnancy weight change (BMI in second pregnancy minus BMI in first pregnancy) was categorised in six groups by BMI units. Relative risks (RRs) of GDM recurrence were obtained by general linear models for the binary family and adjusted for confounders. Analyses were stratified by BMI in first pregnancy (<25 and ≥25 kg/m² ).

MAIN OUTCOME MEASURE

GDM in second pregnancy.

RESULTS

Among overweight/obese women (BMI ≥25), recurrence risk of GDM decreased in women who reduced their BMI by 1-2 units (relative risk [RR] 0.80, 95% CI 0.65-0.99) and >2 units (RR 0.72, 95% CI 0.59-0.89) and increased if BMI increased by ≥4 units (RR 1.26, 95% CI 1.05-1.51) compared wth women with stable BMI (-1 to 1 units). In normal weight women (BMI <25), risk of GDM recurrence increased if BMI increased by 2-4 units (RR 1.32, 95% CI 1.08-1.60) and ≥4 units (RR 1.61, 95% CI 1.28-2.02) compared with women with stable BMI.

CONCLUSION

Interpregnancy weight loss reduced risk of GDM recurrence in overweight/obese women. Weight gain between pregnancies increased recurrence risk for GDM in both normal and overweight/obese women. Our findings highlight the importance of weight management in the interconception window in women with a history of GDM.

TWEETABLE ABSTRACT

Interpregnancy weight loss reduces recurrence of gestational diabetes mellitus in overweight/obese women.

Maternal weight change between successive pregnancies: an opportunity for lifecourse obesity prevention

Maternal obesity is a major risk factor for adverse health outcomes for both the mother and the child, including the serious public health problem of childhood obesity which is globally on the rise. Given the relatively intensive contact with health/care professionals following birth, the interpregnancy period provides a golden opportunity to focus on preconception and family health, and to introduce interventions that support mothers to achieve or maintain a healthy weight in preparation for their next pregnancy. In this review, we summarise the evidence on the association between interpregnancy weight gain with birth and obesity outcomes in the offspring. Gaining weight between pregnancies is associated with an increased risk of large-for-gestational age (LGA) birth, a predictor of childhood obesity, and weight loss between pregnancies in women with overweight or obesity seems protective against recurrent LGA. Interpregnancy weight loss seems to be negatively associated with birthweight. There is some suggestion that interpregnancy weight change may be associated with preterm birth, but the mechanisms are unclear and the direction depends if it is spontaneous or indicated. There is limited evidence on the direct positive link between maternal interpregnancy weight gain with gestational diabetes, pre-eclampsia, gestational hypertension and obesity or overweight in childhood, with no studies using adult offspring adiposity outcomes. Improving preconception health and optimising weight before pregnancy could contribute to tackling the rise in childhood obesity. Research testing the feasibility, acceptability and effectiveness of interventions to optimise maternal weight and health during this period is needed, particularly in high-risk and disadvantaged groups.

Weight gain in early, mid, and late pregnancy and hypertensive disorders of pregnancy

OBJECTIVE

To examine the relationship of weight change during early, mid, and late pregnancy with the development of a hypertensive disorder of pregnancy (HDP).

STUDY DESIGN

These data are from a prospective cohort study of nulliparous women with live singleton pregnancies. "Early" weight change was defined as the difference between self-reported pre-pregnancy weight and weight at the first visit (between 6 and 13 weeks' gestation); "mid" weight change was defined as the weight change between the first and second visits (between 16 and 21 weeks' gestation); "late" weight change was defined as the weight change between the second and third visits (between 22 and 29 weeks' gestation). Weight change in each time period was further characterized as inadequate, adequate, or excessive based on the Institute of Medicine's (IOM's) trimester-specific weekly weight gain goals based on pre-pregnancy body mass index. Multivariable Poisson regression was performed to adjust for potential confounders.

MAIN OUTCOME MEASURE

Development of any hypertensive disorder of pregnancy.

RESULTS

Of 8296 women, 1564 (18.9%) developed a HDP. Weight gain in excess of the IOM recommendations during the latter two time periods was significantly associated with HDP. Specifically, trimester-specific excessive weight gain in the mid period (aIRR 1.16, 95% CI 1.01-1.35) as well as in the late period (aIRR = 1.19, 95% CI = 1.02-1.40) was associated with increased risk of developing HDP. The weight gain preceded the onset of clinically apparent disease.

CONCLUSIONS

Excessive weight gain as early as the early second trimester was associated with increased risks of development of HDP.

Text messaging to help women with overweight or obesity lose weight after childbirth: the intervention adaptation and SMS feasibility RCT

Background

There is a need to develop weight management interventions that fit seamlessly into the busy lives of women during the postpartum period.

Objective

The objective was to develop and pilot-test an evidence- and theory-based intervention, delivered by short message service, which supported weight loss and weight loss maintenance in the postpartum period.

Design

Stage 1 involved the development of a library of short message service messages to support weight loss and weight loss maintenance, with personal and public involvement, focusing on diet and physical activity with embedded behaviour change techniques, and the programming of a short message service platform to allow fully automated intervention delivery. Stage 2 comprised a 12-month, single-centre, two-arm, pilot, randomised controlled trial with an active control.

Setting

This study was set in Northern Ireland; women were recruited via community-based approaches.

Participants

A total of 100 women with overweight or obesity who had given birth in the previous 24 months were recruited.

Interventions

The intervention group received an automated short message service intervention about weight loss and weight loss maintenance for 12 months. The active control group received automated short message service messages about child health and development for 12 months.

Main outcome measures

The main outcomes measured were the feasibility of recruitment and retention, acceptability of the intervention and trial procedures, and evidence of positive indicative effects on weight. Weight, waist circumference and blood pressure were measured by the researchers; participants completed a questionnaire booklet and wore a sealed pedometer for 7 days at baseline, 3, 6, 9 and 12 months. Outcome assessments were collected during home visits and women received a voucher on completion of each of the assessments. Qualitative interviews were conducted with women at 3 and 12 months, to gather feedback on the intervention and active control and the study procedures. Quantitative and qualitative data were used to inform the process evaluation and to assess fidelity, acceptability, dose, reach, recruitment, retention, contamination and context.

Results

The recruitment target of 100 participants was achieved (intervention, n = 51; control, n = 49); the mean age was 32.5 years (standard deviation 4.3 years); 28 (28%) participants had a household income of < £29,999 per annum. Fifteen women became pregnant during the follow-up (intervention, n = 9; control, n = 6) and withdrew from the study for this reason. At the end of the 12-month study, the majority of women remained in the study [85.7% (36/42) in the intervention group and 90.7% (39/43) in the active control group]. The research procedures were well accepted by women. Both groups indicated a high level of satisfaction with the short message service intervention that they were receiving. There was evidence to suggest that the intervention may have a positive effect on weight loss and prevention of weight gain during the postpartum period.

Limitations

The interviews at 3 and 12 months were conducted by the same researchers who collected other outcome data.

Conclusions

An evidence- and theory-based intervention delivered by short message service was successfully developed in conjunction with postpartum women with overweight and obesity. The intervention was acceptable to women and was feasible to implement in the 12-month pilot randomised controlled trial. The progression criteria for a full randomised controlled trial to examine effectiveness and cost-effectiveness were met.

Future work

Some minor refinements need to be made to the intervention and trial procedures based on the findings of the pilot trial in preparation for conducting a full randomised controlled trial.

Trial registration

Current Controlled Trial ISRCTN90393571.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 8, No. 4. See the NIHR Journals Library website for further project information. The intervention costs were provided by the Public Health Agency, Northern Ireland.

The impact of interpregnancy weight change on perinatal outcomes in women and their children: A systematic review and meta-analysis

Prepregnancy overweight and obesity are associated with higher risk of perinatal complications. However, the effect of weight change prior to pregnancy on perinatal outcome is largely unknown. Therefore, it is aimed to examine the impact on perinatal outcomes of interpregnancy BMI change in women of different BMI categories. The MEDLINE, EMBASE, LILACS, and CINAHL databases were searched (1990-August 2019). Observational studies on interpregnancy BMI change were selected. Outcomes evaluated were gestational diabetes mellitus (GDM), preeclampsia, gestational hypertension (GH), cesarean section, preterm birth, and newborns being large (LGA) or small (SGA) for gestational age. Meta-analyses and meta-regression analyses were executed. Thirty studies were included (n > 1 million). Interpregnancy BMI gain was associated with a higher risk of GDM (for BMI gain ≥3 kg/m² : OR 2.21; [95%CI 1.53-3.19]), preeclampsia (1.77 [1.53-2.04]), GH (1.78 [1.61-1.97]), cesarean section (1.32 [1.24-1.39]), and LGA (1.54 [1.28-1.86]). The effects of BMI gain were most pronounced in women with BMI <25 kg/m² before the first pregnancy regarding GDM, GH, and cesarean section. Except for LGA, interpregnancy BMI loss did not result in a decreased risk of perinatal complications. In this study, women of normal weight who gain weight before pregnancy were identified as a high-risk population for perinatal complications. This emphasizes that weight management is important for women of all BMI categories and a pregnancy wish.

Development and Field Evaluation of the INTER-ACT App, a Pregnancy and Interpregnancy Coaching App to Reduce Maternal Overweight and Obesity: Mixed Methods Design

Background

The interpregnancy and pregnancy periods are important windows of opportunity to prevent excessive gestational weight retention. Despite an overwhelming number of existing health apps, validated apps to support a healthy lifestyle between and during pregnancies are lacking.

Objective

To describe the development and evaluation of the INTER-ACT app, which is part of an interpregnancy and pregnancy lifestyle coaching module, to prevent excessive weight gain in pregnancy and enhance optimal weight and a healthy lifestyle in the interpregnancy period.

Methods

A mixed methods design was used to identify the needs of health care providers and end users, according to 15 semistructured interviews, two focus groups, and two surveys. The user interface was evaluated in a pilot study (N=9).

Results

Health care providers indicated that a mobile app can enhance a healthy lifestyle in pregnant and postpartum women. Pregnant women preferred graphic displays in the app, weekly notifications, and support messages according to their own goals. Both mothers and health care providers reported increased awareness and valued the combination of the app with face-to-face coaching.

Conclusions

The INTER-ACT app was valued by its end users because it was offered in combination with face-to-face contact with a caregiver.

Change in prepregnancy body mass index and gastroschisis

PURPOSE

Maternal body mass index (BMI) is inversely associated with gastroschisis, but a causal relationship has not been established. As data demonstrating that a change in exposure status is related to a change in the frequency of the outcome can add to the evidence for causality, we conducted a case-control study of change in maternal BMI, assessed using interpregnancy change in BMI (IPC-BMI), and gastroschisis.

METHODS

Data for 258 gastroschisis cases and 2561 controls were obtained from the Texas Birth Defects Registry and vital records (2006-2012). Logistic regression was used to estimate the adjusted association between IPC-BMI and gastroschisis.

RESULTS

The continuous IPC-BMI variable was inversely associated with gastroschisis (adjusted odds ratio [aOR] = 0.90, 95% confidence interval [CI]: 0.86, 0.95). When assessed as a six-level categorical variable, with weight stable women as the referent, the odds of gastroschisis were higher following a BMI decrease of greater than 1 unit (aOR = 1.37, 95% CI: 0.91, 2.06) and lower after a BMI increase of ≥3 units (aOR = 0.62, 95% CI: 0.42, 0.94).

CONCLUSIONS

Our findings suggest that maternal change in BMI is associated with gastroschisis and, thus, add to the epidemiological evidence that can be used to inform our understanding of the relationship between BMI and gastroschisis.

Maternal interpregnancy weight change and premature birth: Findings from an English population-based cohort study

Background

The relationship between maternal weight change between pregnancies and premature birth is unclear. This study aimed to investigate whether interpregnancy weight change between first and second, or second and third pregnancy is associated with premature birth.

Methods

Routinely collected data from 2003 to 2018 from one English maternity centre was used to produce two cohorts. The primary cohort (n = 14,961 women) consisted of first and second live-birth pregnancies. The secondary cohort (n = 5,108 women) consisted of second and third live-birth pregnancies. Logistic regression models were used to examine associations between interpregnancy BMI change and premature births adjusted for confounders. Subgroup analyses were carried out, stratifying by initial pregnancy BMI groups and analysing spontaneous and indicated premature births separately.

Results

In the primary cohort, 3.4% (n = 514) of births were premature compared to 4.2% (n = 212) in the secondary cohort, with fewer indicated than spontaneous premature births in both cohorts.

Primary cohort

Weight loss (>3kg/m²) was associated with increased odds of premature birth (adjusted odds ratio (aOR):3.50, 95% CI: 1.78–6.88), and spontaneous premature birth (aOR: 3.34, 95%CI: 1.60–6.98), in women who were normal weight (BMI 18.5-25kg/m²) at first pregnancy. Weight gain >1kg/m² was not associated with premature birth regardless of starting BMI.

Secondary cohort

Losing >3kg/m² was associated with increased odds of premature birth (aOR: 2.01, 95%CI: 1.05–3.87), when analysing the whole sample, but not when restricting the analysis to women who were overweight or obese at second pregnancy.

Conclusions

Normal-weight women who lose significant weight (>3kg/m²) between their first and second live pregnancies have greater odds of premature birth compared to normal-weight women who remain weight stable in the interpregnancy period. There was no evidence of association between weight change in women who were overweight or obese at the start of their first pregnancy and premature birth.

Effect of interpregnancy weight change on perinatal outcomes: systematic review and meta-analysis

Background

Although obesity is a well-known risk factor for adverse pregnancy outcomes, evidence is sparse about the effects of interpregnancy weight change on the risk of adverse perinatal complications in a subsequent pregnancy. The current study aims to assess the effect of interpregnancy weight change on the risk of developing gestational diabetes, pre-eclampsia, pregnancy induced hypertension, preterm birth, or delivering a large- or small-for-gestational age neonate.

Methods

Pubmed, Ovid Embase, ClinicalTrial.gov and the Cochrane library were systematically searched up until July 24th, 2019. Interpregnancy weight change was defined as the difference between pre-pregnancy weight of an index pregnancy and a consecutive pregnancy. Inclusion criteria included full text original articles reporting quantitative data about interpregnancy weight change in multiparous women with any time interval between consecutive births and the risk of any perinatal complication of interest. Studies reporting adjusted odds ratios and a reference group of − 1 to + 1 BMI unit change between pregnancies were harmonised by meta-analysis.

Results

Twenty-three cohort studies identified a total of 671,906 women with two or more consecutive pregnancies. Seven of these studies were included in the meta-analysis (280,672 women). Interpregnancy weight gain was consistently associated with a higher risk of gestational diabetes, pre-eclampsia, pregnancy induced hypertension and large-for-gestational age births. In contrast, interpregnancy weight loss was associated with a lower risk of delivering a large-for-gestational age neonate. The effect magnitude (relative risk) of interpregnancy weight gain on pregnancy induced hypertension or delivering a large-for-gestational age neonate was greater among women with a normal BMI in the index pregnancy compared to women with a starting BMI ≥25 kg/m².

Conclusion

These findings confirm that interpregnancy weight change impacts the risk of developing perinatal complications in a subsequent pregnancy. This provides evidence in support of guidelines encouraging women to achieve post-partum weight loss, as their risk of perinatal complications might be minimised if they return to their pre-pregnancy weight before conceiving again.

Prospectively registered with PROSPERO (CRD42017067326).

The Risks Associated With Obesity in Pregnancy

BACKGROUND

Approximately one-third of all women of childbearing age are overweight or obese. For these women, pregnancy is associated with increased risks for both mother and child.

METHODS

This review is based on pertinent publications retrieved by a selective search of PubMed, with special attention to current population-based cohort studies, systematic reviews, meta-analyses, and controlled trials.

RESULTS

Obesity in pregnancy is associated with unfavorable clinical outcomes for both mother and child. Many of the risks have been found to depend linearly on the body-mass index (BMI). The probability of conception declines linearly, starting from a BMI of 29 kg/m2, by 4% for each additional 1 kg/m2 of BMI (hazard ratio 0.96, 95% confidence interval: [0.91; 0.99]). A 10% increase of pregravid BMI increases the relative risk of gestational diabetes and that of preeclampsia by approximately 10% each. A 5 kg/m2 increase of BMI elevates the relative risk of intrauterine death to 1.24 [1.18; 1.30]. An estimated 11% of all neonatal deaths can be attributed to the consequences of maternal overweight and obesity. Nonetheless, in most randomized controlled trials, nutritional and lifestyle interventions did not bring about any clinically relevant reduction in the incidence of gestational diabetes and fetal macrosomia.

CONCLUSION

The risks associated with obesity in pregnancy cannot necessarily be influenced by intervention. Preventive measures aimed at normalizing body weight before a woman becomes pregnant are, therefore, all the more important.

Delivery-to-Delivery Weight Gain and Risk of Hypertensive Disorders in a Subsequent Pregnancy

OBJECTIVE

To estimate whether weight gain between deliveries is associated with an increased risk of hypertensive disorders in a subsequent pregnancy.

METHODS

This is a case-control study of women who had two live singleton births of at least 24 weeks of gestation at a single maternity hospital from January 1, 2005, to December 31, 2015, with no hypertensive disorder documented in the index pregnancy. Maternal weight gain between deliveries was measured as the change in body mass index (BMI) at delivery. Women who were diagnosed with any hypertensive disorder in the subsequent pregnancy were compared with those who experienced no hypertensive disorder in the subsequent pregnancy using χ statistics for categorical variables and t tests for continuous variables. Logistic regression was used to determine whether weight gain remained independently associated with hypertensive disorders after adjusting for potential confounders.

RESULTS

Of 1,033 women, 188 (18.2%) were diagnosed with a hypertensive disorder in the subsequent pregnancy. Of these, 166 (88.3%) had a hypertensive disorder specific to pregnancy (gestational hypertension; preeclampsia; superimposed preeclampsia; or hemolysis, elevated liver enzymes, and low platelet count syndrome), and 22 (11.7%) had chronic hypertension only. Greater weight gain between deliveries was significantly associated with a higher frequency of hypertensive disorders, which remained significant for a BMI increase of at least 2 kg/m in multivariable analyses (adjusted odds ratio [OR] 1.76, 95% CI 1.14-2.74 for 2 to less than 4 kg/m, adjusted OR 3.19, 95% CI 1.86-5.47 for 4 kg/m or more). Conversely, weight loss of 2 kg/m or more was associated with a decreased risk of a hypertensive disorder (adjusted OR 0.41, 95% CI 0.21-0.81).

CONCLUSION

Among women with no hypertensive disorder noted in an index pregnancy, an increase in BMI of at least 2 kg/m between deliveries was independently associated with an increased risk of a hypertensive disorder in a subsequent pregnancy.

Is maternal weight gain between pregnancies associated with risk of large-for-gestational age birth? Analysis of a UK population-based cohort

OBJECTIVE

Maternal overweight and obesity during pregnancy increases the risk of large-for-gestational age (LGA) birth and childhood obesity. We aimed to investigate the association between maternal weight change between subsequent pregnancies and risk of having a LGA birth.

DESIGN

Population-based cohort.

SETTING

Routinely collected antenatal healthcare data between January 2003 and September 2017 at University Hospital Southampton, England.

PARTICIPANTS

Health records of women with their first two consecutive singleton live-birth pregnancies were analysed (n=15 940).

PRIMARY OUTCOME MEASURE

Risk of LGA, recurrent LGA and new LGA births in the second pregnancy.

RESULTS

Of the 15 940 women, 16.0% lost and 47.7% gained weight (≥1 kg/m²) between pregnancies. A lower proportion of babies born to women who lost ≥1 kg/m² (12.4%) and remained weight stable between -1 and 1 kg/m² (11.9%) between pregnancies were LGA compared with 13.5% and 15.9% in women who gained 1-3 and ≥3 kg/m², respectively. The highest proportion was in obese women who gained ≥3 kg/m² (21.2%). Overweight women had a reduced risk of recurrent LGA in the second pregnancy if they lost ≥1 kg/m² (adjusted relative risk (aRR) 0.69, 95% CI 0.48 to 0.97) whereas overweight women who gained ≥3 kg/m² were at increased risk of new LGA after having a non-LGA birth in their first pregnancy (aRR 1.35, 95% CI 1.05 to 1.75). Normal-weight women who gained weight were also at increased risk of new LGA in the second pregnancy (aRR 1.26, 95% CI 1.06 to 1.50 with gain of 1-3 kg/m² and aRR 1.34, 95% CI 1.09 to 1.65 with gain of ≥3 kg/m²).

CONCLUSIONS

Losing weight after an LGA birth was associated with a reduced LGA risk in the next pregnancy in overweight women, while interpregnancy weight gain was associated with an increased new LGA risk. Preventing weight gain between pregnancies is an important measure to achieve better maternal and offspring outcomes.

Effect of Maternal Obesity and Preconceptional Weight Loss on Male and Female Offspring Metabolism and Olfactory Performance in Mice

According to the “developmental origins of health and disease” (DOHaD) concept, maternal obesity predisposes the offspring to non-communicable diseases in adulthood. While a preconceptional weight loss (WL) is recommended for obese women, its benefits on the offspring have been poorly addressed. We evaluated whether preconceptional WL was able to reverse the adverse effects of maternal obesity in a mouse model, exhibiting a modification of foetal growth and of the expression of genes encoding epigenetic modifiers in liver and placenta. We tracked metabolic and olfactory behavioural trajectories of offspring born to control, obese or WL mothers. After weaning, the offspring were either put on a control diet (CD) or a high-fat (HFD). After only few weeks of HFD, the offspring developed obesity, metabolic alterations and olfactory impairments, independently of maternal context. However, male offspring born to obese mother gained even more weight under HFD than their counterparts born to lean mothers. Preconceptional WL normalized the offspring metabolic phenotypes but had unexpected effects on olfactory performance: a reduction in olfactory sensitivity, along with a lack of fasting-induced, olfactory-based motivation. Our results confirm the benefits of maternal preconceptional WL for male offspring metabolic health but highlight some possible adverse outcomes on olfactory-based behaviours.

Interpregnancy change in body mass index and infant outcomes in Texas: a population-based study

Background

Maternal prepregnancy body mass index (BMI) is associated with several infant outcomes, but it is unclear whether these associations reflect causal relationships. We conducted a study of interpregnancy change in BMI (IPC-BMI) to improve understanding of the associations between BMI and large for gestational age (LGA), small for gestational age (SGA), and preterm birth (PTB).

Methods

Birth certificate data from 2481 linked sibling pairs (Texas, 2005–2012) were used to estimate IPC-BMI and evaluate its association with LGA, SGA, and PTB in the younger sibling of the pair. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) using data from the full sample and within strata defined by prepregnancy BMI for the older sibling.

Results

On average, women gained 1.1 BMI units between pregnancies. In the full sample, interpregnancy BMI decreases were associated with reduced odds of LGA and increased odds of SGA and PTB (IPC-BMI < -1 versus 0 to < 1: LGA aOR 0.7, 95% CI 0.4, 1.1; SGA aOR 1.6, 95% CI 1.0, 2.7; PTB aOR 1.9, 95% CI 1.3, 2.8). In stratified analyses, similar associations were observed in some, but not all, strata. Findings for interpregnancy BMI increases were less consistent, with little evidence for associations between these outcomes and the most extreme IPC-BMI increases.

Conclusions

There is growing evidence that interpregnancy BMI decreases are associated with LGA, SGA, and PTB. However, taken as a whole, the literature provides insufficient evidence to establish causal links between maternal BMI and these outcomes.

Interpregnancy Body Mass Index Changes: Distribution and Impact on Adverse Pregnancy Outcomes in the Subsequent Pregnancy

OBJECTIVE

To examine the change in body mass index (BMI) categories between pregnancies and its effect on adverse pregnancy outcomes.

STUDY DESIGN

We performed a retrospective cohort study of women with two consecutive deliveries from 2005 to 2010. Analysis was limited to women with BMI recorded at <24 weeks for both pregnancies. Standard BMI categories were used. Adverse pregnancy outcomes included preterm birth at <37 weeks, intrauterine growth restriction (IUGR), pregnancy-related hypertension, and gestational diabetes mellitus (GDM). Women with increased BMI category between pregnancies were compared with those who remained in the same BMI category.

RESULTS

In total, 537 women were included, of whom 125 (23%) increased BMI category. There was no association between increase in BMI category and risk of preterm birth, IUGR, or pregnancy-related hypertension. Women who increased BMI category had an increased odds of GDM compared with women who remained in the same BMI category (6.4 vs. 2.2%; p = 0.018). The increased risk remained after controlling for age, history of GDM, and starting BMI (adjusted odds ratio: 8.2; 95% confidence interval: 2.1-32.7; p = 0.003).

CONCLUSION

Almost one-quarter of women increased BMI categories between pregnancies. This modifiable risk factor has a significant impact on the risk of GDM.

Weight loss after pregnancy: challenges and opportunities

It is important to pay attention to weight management before and between pregnancies, as women have an increased risk of weight gain during the reproductive years. Having a baby is a life-changing event for women and the challenge of weight management amidst this period of major physiological, psychological and social change should not be underestimated. However, the postpartum period offers an opportune time for lifestyle interventions, as women may have heightened awareness of their own and their wider families' health. Systematic reviews indicate that interventions including both diet and physical activity along with individualised support and self-monitoring are more likely to be successful in promoting postpartum weight loss. However, high levels of attrition and poor engagement have been an issue in previous trials in this area. Since postpartum women are difficult to reach and retain, future research must consider how to make weight-management interventions an attractive and attainable proposition for women who are juggling multiple, competing demands on their time. Ideally, intervention approaches need to be flexible and allow sustained contact with women, to facilitate a focus on maintenance of weight loss, as well as opportunities for re-engagement after life events that may disrupt weight-management progress. Using technology to deliver or support interventions holds promise but trials are needed to generate a range of appealing, effective and scalable options for postpartum women. What works at other life stages may not necessarily work here owing to specific barriers to weight management encountered in the postpartum period.

The Emerging Role of Biomarkers in the Diagnosis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common complication of pregnancy; its rising incidence is a result of increased maternal obesity and older maternal age together with altered diagnostic criteria identifying a greater proportion of pregnant women with GDM. Its consequences are far-reaching, associated with poorer maternal and neonatal outcomes compared to non-GDM pregnancies, and GDM has implications for metabolic health in both mother and offspring. Objective markers to identify women at high risk for the development of GDM are useful to target therapy and potentially prevent its development. Established clinical risk factors for GDM include overweight/obesity, age, ethnicity, and family history of diabetes, though they lack specificity for its development. The addition of biomarkers to predictive models of GDM may improve the ability to identify women at risk of GDM prior to its development. These biomarkers reflect the pathophysiologic mechanisms of GDM involving insulin resistance, chronic inflammation, and altered placental function. In addition, the role of epigenetic changes in GDM pathogenesis highlights the complex interplay between genetic and environmental factors, potentially offering further refinement of the prediction of GDM risk. In this review, we will discuss the clinical challenges associated with the diagnosis of GDM and its current pathophysiologic basis, giving rise to potential biomarkers that may aid in its identification. While not yet validated for clinical use, we explore the possible clinical role of biomarkers in the future. We also explore novel diagnostic tools, including high throughput methodologies, that may have potential future application in the identification of women with GDM.

How common is substantial weight gain after pregnancy?

BACKGROUND

Although population-based studies indicate that on average, women gain 1-2kg between pregnancies, women with obesity often attribute its development to childbearing. There is little contemporary data available regarding how commonly this occurs, particularly in women of different body mass index (BMI) categories. The aim of this study was to examine inter-pregnancy weight changes among women at a tertiary obstetric hospital in Melbourne, Australia.

METHODS

This was a retrospective review of data from the Birthing Outcomes System electronic record of 19,617 women aged 20 years or older, who delivered at least two consecutive singleton infants at ≥37 weeks' gestation at Mercy Hospital for Women between December 1994 and December 2015. A logistic regression model was used to assess the relationship between gain of ≥4kg/m² between pregnancies and maternal BMI category in the first pregnancy, adjusting for covariates of maternal age, inter-pregnancy interval, and socioeconomic status.

RESULTS

Gain of ≥4kg/m² between the first two pregnancies occurred in 7.5% of normal weight women, 10.5% of overweight women, and 13.4% of women with obesity. One in five women who were normal weight in their first pregnancy increased to overweight or obese BMI categories in their second pregnancy.

CONCLUSIONS

Substantial weight gain in relation to pregnancy affects a considerable proportion of women. Since inter-pregnancy weight gain is associated with several complications in the next pregnancy and longer term, avoiding excessive weight gain during and between pregnancies may prevent adverse health consequences in mothers and offspring.

Gestational diabetes mellitus and interpregnancy weight change: A population-based cohort study

BACKGROUND

Being overweight is an important risk factor for Gestational Diabetes Mellitus (GDM), but the underlying mechanisms are not understood. Weight change between pregnancies has been suggested to be an independent mechanism behind GDM. We assessed the risk for GDM in second pregnancy by change in Body Mass Index (BMI) from first to second pregnancy and whether BMI and gestational weight gain modified the risk.

METHODS AND FINDINGS

In this observational cohort, we included 24,198 mothers and their 2 first pregnancies in data from the Medical Birth Registry of Norway (2006-2014). Weight change, defined as prepregnant BMI in second pregnancy minus prepregnant BMI in first pregnancy, was divided into 6 categories by units BMI (kilo/square meter). Relative risk (RR) estimates were obtained by general linear models for the binary family and adjusted for maternal age at second delivery, country of birth, education, smoking in pregnancy, interpregnancy interval, and year of second birth. Analyses were stratified by BMI (first pregnancy) and gestational weight gain (second pregnancy). Compared to women with stable BMI (-1 to 1), women who gained weight between pregnancies had higher risk of GDM-gaining 1 to 2 units: adjusted RR 2.0 (95% CI 1.5 to 2.7), 2 to 4 units: RR 2.6 (2.0 to 3.5), and ≥4 units: RR 5.4 (4.0 to 7.4). Risk increased significantly both for women with BMI below and above 25 at first pregnancy, although it increased more for the former group. A limitation in our study was the limited data on BMI in 2 pregnancies.

CONCLUSIONS

The risk of GDM increased with increasing weight gain from first to second pregnancy, and more strongly among women with BMI < 25 in first pregnancy. Our results suggest weight change as a metabolic mechanism behind the increased risk of GDM, thus weight change should be acknowledged as an independent factor for screening GDM in clinical guidelines. Promoting healthy weight from preconception through the postpartum period should be a target.