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

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.

Preconception health among migrant women in England: A cross-sectional analysis of maternity services data 2018-2019

Background

Perinatal outcomes are poor among migrant women in vulnerable situations, but little is known about their health preconception. We investigated preconception health inequalities between migrant women in vulnerable situations and non-migrant women.

Methods

This national cross-sectional study used data from the NHS Maternity Services Data Set (MSDS) version 1.5, incorporating NHS maternity services in England. All 652,880 women with an antenatal booking appointment between 1/4/2018 and 31/3/2019 were included. Migration category data were available for 66.2 % (n = 432,022). Odds ratios were calculated comparing preconception indicators among probable migrants in vulnerable situations (English not their first language with complex social factors (CSF)), probable migrants not in vulnerable situations (English not their first language without CSF), probable non-migrants in vulnerable situations (English their first language with CSF) and probable non-migrants not in vulnerable situations (English their first language without CSF). CSF include recent migrants, asylum seekers, refugees, difficulty reading/speaking English; alcohol and/or drugs misuse; aged under 20; and/or experiencing domestic abuse.

Findings

We identified 3.8 % (25,070 women) of the study population as probable migrants in vulnerable situations, 10.2 % (66,783 women) as probable migrants not in vulnerable situations, 5.6 % (36,433 women) as probable non-migrants in vulnerable situations, 46.5 % (303,737 women) as probable non-migrants not in vulnerable situations, and 33.8 % as having missing migration category data. Probable migrants in vulnerable situations (n = 25,070) had over twice the odds of not taking folic acid preconception compared to probable non-migrants not in vulnerable situations (odds ratio 2.15, 95 % confidence interval 2.06-2.25). They had increased odds of previous obstetric complications and being underweight, but lower odds of physical and mental health conditions (apart from diabetes and hepatitis b), smoking and overweight or obesity.

Interpretation

Inequalities exist across many preconception indicators, highlighting opportunities to improve preconception health in this population to reduce health inequalities and improve perinatal and neonatal outcomes.

Funding

Medical Research Council.

Neurodevelopmental Programming of Adiposity: Contributions to Obesity Risk

This review analyzes the published evidence regarding maternal factors that influence the developmental programming of long-term adiposity in humans and animals via the central nervous system (CNS). We describe the physiological outcomes of perinatal underfeeding and overfeeding and explore potential mechanisms that may mediate the impact of such exposures on the development of feeding circuits within the CNS-including the influences of metabolic hormones and epigenetic changes. The perinatal environment, reflective of maternal nutritional status, contributes to the programming of offspring adiposity. The in utero and early postnatal periods represent critically sensitive developmental windows during which the hormonal and metabolic milieu affects the maturation of the hypothalamus. Maternal hyperglycemia is associated with increased transfer of glucose to the fetus driving fetal hyperinsulinemia. Elevated fetal insulin causes increased adiposity and consequently higher fetal circulating leptin concentration. Mechanistic studies in animal models indicate important roles of leptin and insulin in central and peripheral programming of adiposity, and suggest that optimal concentrations of these hormones are critical during early life. Additionally, the environmental milieu during development may be conveyed to progeny through epigenetic marks and these can potentially be vertically transmitted to subsequent generations. Thus, nutritional and metabolic/endocrine signals during perinatal development can have lifelong (and possibly multigenerational) impacts on offspring body weight regulation.

Thromboprophylaxis during pregnancy and the puerperium: a systematic review and economic evaluation to estimate the value of future research

Background

Pharmacological prophylaxis to prevent venous thromboembolism is currently recommended for women assessed as being at high risk of venous thromboembolism during pregnancy or in the 6 weeks after delivery (the puerperium). The decision to provide thromboprophylaxis involves weighing the benefits, harms and costs, which vary according to the individual's venous thromboembolism risk. It is unclear whether the United Kingdom's current risk stratification approach could be improved by further research.

Objectives

To quantify the current decision uncertainty associated with selecting women who are pregnant or in the puerperium for thromboprophylaxis and to estimate the value of one or more potential future studies that would reduce that uncertainty, while being feasible and acceptable to patients and clinicians.

Methods

A decision-analytic model was developed which was informed by a systematic review of risk assessment models to predict venous thromboembolism in women who are pregnant or in the puerperium. Expected value of perfect information analysis was used to determine which factors are associated with high decision uncertainty and should be the target of future research. To find out whether future studies would be acceptable and feasible, we held workshops with women who have experienced a blood clot or have been offered blood-thinning drugs and surveyed healthcare professionals. Expected value of sample information analysis was used to estimate the value of potential future research studies.

Results

The systematic review included 17 studies, comprising 19 unique externally validated risk assessment models and 1 internally validated model. Estimates of sensitivity and specificity were highly variable ranging from 0% to 100% and 5% to 100%, respectively. Most studies had unclear or high risk of bias and applicability concerns. The decision analysis found that there is substantial decision uncertainty regarding the use of risk assessment models to select high-risk women for antepartum prophylaxis and obese postpartum women for postpartum prophylaxis. The main source of decision uncertainty was uncertainty around the effectiveness of thromboprophylaxis for preventing venous thromboembolism in women who are pregnant or in the puerperium. We found that a randomised controlled trial of thromboprophylaxis in obese postpartum women is likely to have substantial value and is more likely to be acceptable and feasible than a trial recruiting women who have had a previous venous thromboembolism. In unselected postpartum women and women following caesarean section, the poor performance of risk assessment models meant that offering prophylaxis based on these models had less favourable cost effectiveness with lower decision uncertainty.

Limitations

The performance of the risk assessment model for obese postpartum women has not been externally validated.

Conclusions

Future research should focus on estimating the efficacy of pharmacological thromboprophylaxis in pregnancy and the puerperium, and clinical trials would be more acceptable in women who have not had a previous venous thromboembolism.

Study registration

This study is registered as PROSPERO CRD42020221094.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR131021) and is published in full in Health Technology Assessment; Vol. 28, No. 9. See the NIHR Funding and Awards website for further award information.

Childhood obesity and adverse cardiometabolic risk in large for gestational age infants and potential early preventive strategies: a narrative review

Accumulating evidence indicates that obesity and cardiometabolic risks become established early in life due to developmental programming and infants born as large for gestational age (LGA) are particularly at risk. This review summarizes the recent literature connecting LGA infants and early childhood obesity and cardiometabolic risk and explores potential preventive interventions in early infancy. With the rising obesity rates in women of childbearing age, the LGA birth rate is about 10%. Recent literature continues to support the higher rates of obesity in LGA infants. However, there is a knowledge gap for their lifetime risk for adverse cardiometabolic outcomes. Potential factors that may modify the risk in early infancy include catch-down early postnatal growth, reduction in body fat growth trajectory, longer breastfeeding duration, and presence of a healthy gut microbiome. The early postnatal period may be a critical window of opportunity for active interventions to mitigate or prevent obesity and potential adverse metabolic consequences in later life. A variety of promising candidate biomarkers for the early identification of metabolic alterations in LGA infants is also discussed. IMPACT: LGA infants are the greatest risk category for future obesity, especially if they experience rapid postnatal growth during infancy. Potential risk modifying secondary prevention strategies in early infancy in LGA infants include catch-down early postnatal growth, reduction in body fat growth trajectory, longer breastfeeding duration, and presence of a healthy gut microbiome. LGA infants may be potential low-hanging fruit targets for early preventive interventions in the fight against childhood obesity.

Birthweight z-score and fat-free mass at birth predict body composition at 3 years in Danish children born from obese mothers

Aim

We investigated associations between newborn body composition and anthropometry and body composition at 3 years in Danish children born from obese mothers.

Methods

Analyses are based on data from the observational cohort study SKOT II (SKOT; small children's diet and well‐being (Danish)). Body composition at birth and at 3 years was assessed by dual‐energy X‐ray absorptiometry (DXA) scans and bioelectrical impedance analysis (BIA), respectively. Multiple linear regression models were applied to determine associations between newborn body composition and anthropometry and body composition at 3 years.

Results

Birthweight z‐score (BWZ) was positively associated with fat‐free mass (FFM), height, fat‐free mass index (FFMI), fat mass (FM) and fat mass index (FMI) at 3 years. Newborn FFM was positively associated with FFM, height, FFMI and FM at 3 years, and positive trends were seen between newborn FM and FM and FMI at 3 years.

Conclusion

We showed that infants born with a higher BWZ go on to be taller at 3 years. They also grow to be heavier, to which FM and FFM both contribute, independently of linear growth. Additionally, it seems that FFM tracks into early childhood, thus supporting intrauterine programming of later health.

Interpregnancy weight gain and childhood obesity: analysis of a UK population-based cohort

BACKGROUND

Maternal obesity increases the risk of adverse long-term health outcomes in mother and child including childhood obesity. We aimed to investigate the association between interpregnancy weight gain between first and second pregnancies and risk of overweight and obesity in the second child.

METHODS

We analysed the healthcare records of 4789 women in Hampshire, UK with their first two singleton live births within a population-based anonymised linked cohort of routine antenatal records (August 2004 and August 2014) with birth/early life data for their children. Measured maternal weight and reported height were recorded at the first antenatal appointment of each pregnancy. Measured child height and weight at 4-5 years were converted to age- and sex-adjusted body mass index (BMI z-score). Log-binomial regression was used to examine the association between maternal interpregnancy weight gain and risk of childhood overweight and obesity in the second child. This was analysed first in the whole sample and then stratified by baseline maternal BMI category.

RESULTS

The prevalence of overweight/obesity in the second child was 19.1% in women who remained weight stable, compared with 28.3% in women with ≥3 kg/m2 weight gain. Interpregnancy gain of ≥3 kg/m2 was associated with increased risk of childhood overweight/obesity (adjusted relative risk (95% CI) 1.17 (1.02-1.34)), with attenuation on adjusting for birthweight of the second child (1.08 (0.94-1.24)). In women within the normal weight range at first pregnancy, the risks of childhood obesity (≥95th centile) were increased with gains of 1-3 kg/m2 (1.74 (1.07-2.83)) and ≥3 kg/m2 (1.87 (1.18-3.01)).

CONCLUSION

Children of mothers within the normal weight range in their first pregnancy who started their second pregnancy with a considerably higher weight were more likely to have obesity at 4-5 years. Supporting return to pre-pregnancy weight and limiting weight gain between pregnancies may achieve better long-term maternal and offspring 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.

Does interpregnancy BMI change affect the risk of complications in the second pregnancy? Analysis of pooled data from Aberdeen, Finland and Malta

Objective

Weight management interventions during pregnancy have had limited success in reducing the risk of pregnancy complications. Focus has now shifted to pre-pregnancy counselling to optimise body weight before subsequent conception. We aimed to assess the effect of interpregnancy body mass index (BMI) change on the risk of perinatal complications in the second pregnancy.

Methods

A cohort study was performed using pooled maternity data from Aberdeen, Finland and Malta. Women with a BMI change of ±2 kg/m² between their first and second pregnancies were compared with those who were BMI stable (remained within ±2 kg/m²). Outcomes assessed included pre-eclampsia (PE), intrauterine growth restriction (IUGR), preterm birth, birth weight, and stillbirth in the second pregnancy. We also assessed the effect of unit change in BMI for PE and IUGR. Logistic regression was used to calculate odds ratios with 95% confidence intervals.

Results

An increase of ≥2 kg/m² between the first two pregnancies increased the risk of PE (1.66 (1.49–1.86)) and high birthweight (>4000 g) (1.06 (1.03–1.10)). A reduction of ≥2 kg/m² increased the chance of IUGR (1.15 (1.01–1.31)) and preterm birth (1.14 (1.01–1.30)), while reducing the risk of instrumental delivery (0.75 (0.68–0.85)) and high birthweight (0.93 (0.87–0.98)). Reducing BMI did not significantly decrease PE risk in women with obesity or those with previous PE. A history of PE or IUGR in the first pregnancy was the strongest predictor of recurrence independent of interpregnancy BMI change (5.75 (5.30–6.24) and (7.44 (6.71–8.25), respectively).

Conclusion

Changes in interpregnancy BMI have a modest impact on the risk of high birthweight, PE and IUGR in contrasting directions. However, a prior history of PE and IUGR is the dominant predictor of recurrence at second pregnancy.

Factors associated with birthweight decline in Japan (1980-2004)

BACKGROUND

Birthweight has been declining consistently for more than 30 years in Japan. This rapid rise in low birthweight is one of the worst among the countries of the Organization for Economic Co-operation and Development. We examined potential determinants of birthweight decline in Japan.

METHODS

We used population-based birth certificate data from vital statistics records and retrieved 40,968,266 birth certificates of neonates born between 1980 and 2004. We analyzed time trends using linear regression analysis in examining whether the decline in birthweight could be explained by obstetrical variables such as gestational age and multiple gestations.

RESULTS

From 1980 to 2004, we observed a decline in mean birthweight with a yearly effect of - 8.07 g, which became steeper after 1985, persisted until 1999, and plateaued thereafter. After adjusting for gestational age, gender, birth order, multiple gestations, and fathers' age, the yearly effect between 1980 and 2004 persisted at - 5.13 g.

CONCLUSION

Recent decreases in birthweight among Japanese neonates were not fully explained by trends in gestational age, gender, birth order, multiple gestations, and fathers' age. Thus, additional factors such as pre-pregnancy maternal body mass index (BMI) and maternal diet should be considered. Reducing the rate of induced deliveries and improving the BMI or diet of young women should be a public health priority.

Factors associated with small- and large-for-gestational-age in socioeconomically vulnerable individuals in the 100 Million Brazilian Cohort

BACKGROUND

Evidence points to diverse risk factors associated with small- (SGA) and large-for-gestational-age (LGA) births. A more comprehensive understanding of these factors is imperative, especially in vulnerable populations.

OBJECTIVES

To estimate the occurrence of and sociodemographic factors associated with SGA and LGA births in poor and extremely poor populations of Brazil.

METHODS

The study population consisted of women of reproductive age (14-49 y), whose last child was born between 2012 and 2015. INTERGROWTH 21st consortium criteria were used to classify weight for gestational age according to sex. Multinomial logistic regression modeling was performed to investigate associations of interest.

RESULTS

Of 5,521,517 live births analyzed, SGA and LGA corresponded to 7.8% and 17.1%, respectively. Multivariate analysis revealed greater odds of SGA in children born to women who self-reported as black (OR: 1.21; 95% CI: 1.19, 1.22), mixed-race (parda) (OR: 1.08; 95% CI: 1.07, 1.09), or indigenous (OR: 1.11; 95% CI: 1.06, 1.15), were unmarried (OR: 1.08; 95% CI: 1.07, 1.08), illiterate (OR: 1.47; 95% CI: 1.42, 1.52), did not receive prenatal care (OR: 1.57; 95% CI: 1.53, 1.60), or were aged 14-20 y (OR: 1.21; 95% CI: 1.20, 1.22) or 35-49 y (OR: 1.12; 95% CI: 1.10, 1.13). Considering LGA children, higher odds were found in infants born to women living in households with ≥3 inadequate housing conditions (OR: 1.11; 95% CI: 1.10, 1.12), in indigenous women (OR: 1.22; 95% CI: 1.19, 1.25), those who had 1-3 y of schooling (OR: 1.18; 95% CI: 1.17, 1.19), 1-3 prenatal visits (OR: 1.16; CI 95%: 1.14, 1.17), or were older (OR: 1.26; 95% CI: 1.25, 1.27).

CONCLUSIONS

In poorer Brazilian populations, socioeconomic, racial, and maternal characteristics are consistently associated with the occurrence of SGA births, but remain less clearly linked to the occurrence of LGA births.

Change in modifiable maternal characteristics and behaviours between consecutive pregnancies and offspring adiposity: A systematic review

Causal evidence links modifiable maternal exposures during the periconceptional period with offspring obesity. The interconception period may be an important time to intervene. We systematically identified studies examining change in modifiable maternal exposures between pregnancies and offspring adiposity. We searched for longitudinal studies published between 1990 and 2019, which included measurements taken on at least two occasions in the period from 1 year prior to the conception of the first birth to the time of the second birth, and which included a measure of adiposity in second, or higher order, siblings. Age, ethnicity and genetics were not considered modifiable; all other factors including length of the interpregnancy interval were. Eleven studies satisfied the inclusion criteria. Higher interpregnancy weight gain or loss, maternal smoking inception, mothers smoking in their first pregnancy and quitting, increasing the number of cigarettes smoked and longer interpregnancy intervals were positively associated with adiposity in second or higher order children. Vaginal birth after caesarean delivery was protective. Further research is needed to ascertain whether the risk of adiposity is fixed based on first pregnancy exposures or if interpregnancy change alters the risk for a subsequent child. This can inform the type and effectiveness of interventions for mothers prior to a subsequent pregnancy.

Risk factors and time trends for isolated craniosynostosis

BACKGROUND

We sought to investigate associations between maternal/infant characteristics and isolated craniosynostosis as well as its subtypes sagittal, metopic, and coronal synostosis, and assess trends in the prevalence of these conditions.

METHODS

We identified cases in the Texas Birth Defects Registry from 1999 to 2014. We used Poisson regression to identify associations between maternal/infant characteristics and craniosynostosis. We used joinpoint regression and unadjusted Poisson regression to evaluate temporal trends. Finally, we computed adjusted Poisson models to evaluate whether temporal trends were evident after accounting for changes in the population distributions of maternal/infant characteristics over time.

RESULTS

Relative to all live births in the general population, cases were more frequently male or preterm. Mothers of cases were more frequently non-Hispanic white and more frequently obese. Non-Hispanic black or Hispanic maternal race/ethnicity was associated with a lower prevalence of all craniosynostosis subtypes. Previous live births were associated with sagittal synostosis; residence on the U.S.-Mexico border was associated with sagittal and coronal synostosis. The prevalence of any isolated craniosynostosis increased (average annual percent change estimated from joinpoint regression [AAPC]: 2.9%), as did the prevalences of sagittal (AAPC: 3.3%) and metopic synostosis (AAPC: 5.4%). In crude Poisson models, the same temporal trends were observed, however these were attenuated after adjusting for maternal/infant characteristics.

CONCLUSIONS

Prevalence of isolated craniosynostosis increased from 1999 to 2014. The largest AAPC was observed for metopic synostosis. Changes in the population distribution of associated maternal/infant characteristics may explain these trends.

The Enigmatic Role of Serum & Glucocorticoid Inducible Kinase 1 in the Endometrium

The serum- and glucocorticoid-inducible kinase 1 (SGK1) is subject to genetic up-regulation by diverse stimulators including glucocorticoids, mineralocorticoids, dehydration, ischemia, radiation and hyperosmotic shock. To become active, the expressed kinase requires phosphorylation, which is accomplished by PI3K/PDK1 and mTOR dependent signaling. SGK1 enhances the expression/activity of various transport proteins including Na+/K+-ATPase as well as ion-, glucose-, and amino acid- carriers in the plasma membrane. SGK1 can further up-regulate diverse ion channels, such as Na+-, Ca2+-, K+- and Cl- channels. SGK1 regulates expression/activity of a wide variety of transcription factors (such as FKHRL1/Foxo3a, β-catenin, NFκB and p53). SGK1 thus contributes to the regulation of transport, glycolysis, angiogenesis, cell survival, immune regulation, cell migration, tissue fibrosis and tissue calcification. In this review we summarized the current findings that SGK1 plays a crucial function in the regulation of endometrial function. Specifically, it plays a dual role in the regulation of endometrial receptivity necessary for implantation and, subsequently in pregnancy maintenance. Furthermore, fetal programming of blood pressure regulation requires maternal SGK1. Underlying mechanisms are, however, still ill-defined and there is a substantial need for additional information to fully understand the role of SGK1 in the orchestration of embryo implantation, embryo survival and fetal programming.

Large for Gestational Age and Risk for Academic Delays and Learning Disabilities: Assessing Modification by Maternal Obesity and Diabetes

The objective of this study was to examine academic delays for children born large for gestational age (LGA) and assess effect modification by maternal obesity and diabetes and then to characterize risks for LGA for those with a mediating condition. Cohort data were obtained from the New York City Longitudinal Study of Early Development, linking birth and educational records (n = 125,542). Logistic regression was used to compare children born LGA (>90th percentile) to those born appropriate weight (5-89th percentile) for risk of not meeting proficiency on assessments in the third grade and being referred to special education. Among children of women with gestational diabetes, children born LGA had an increased risk of underperforming in mathematics (ARR: 1.18 (95% CI: 1.07-1.31)) and for being referred for special education (ARR: 1.18 (95% CI: 1.02-1.37)). Children born LGA but of women who did not have gestational diabetes had a slightly decreased risk of academic underperformance (mathematics-ARR: 0.94 (95% CI: 0.90-0.97); Language arts-ARR: 0.96 (95% CI: 0.94-0.99)). Children born to women with gestational diabetes with an inadequate number of prenatal care visits were at increased risk of being born LGA, compared to those receiving extensive care (ARR: 1.67 (95% CI: 1.20-2.33)). Children born LGA of women with diabetes were at increased risk of delays; greater utilization of prenatal care among these diabetic women may decrease the incidence of LGA births.

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.

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.

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).