Post-term birth is associated with greater risk of obesity in adolescent males

Prenatal and postnatal correlates of moderate-to-vigorous physical activity in midlife: evidence from the 1970 British Cohort Study

Background

It is hypothesised that lifelong physical activity behaviours are established in early life, however there is minimal, and contradictory, evidence examining prenatal and postnatal factors in relation to adulthood physical activity. We investigated associations between prospectively ascertained prenatal/postnatal factors and device-measured moderate-to-vigorous physical activity (MVPA) in midlife.

Methods

Analyses included 5011 participants from the 1970 British Cohort Study, a birth cohort study of individuals born within the same week. At birth, the following factors were ascertained: socioeconomic position (SEP), maternal age, number of previous pregnancies, maternal smoking, maternal diabetes, gestational age, birth weight, breastfeeding status and infant health concerns. MVPA was captured at age 46 with a thigh-worn accelerometer device following a 24-hour protocol over 7 days.

Results

In sex-adjusted models, lower SEP (−6.7 min/day (95% CI: −9.0 to –4.4) in those with a partly or unskilled paternal occupation), younger maternal age (0.4 min/day (0.2 to 0.5) per additional year of maternal age), maternal smoking during pregnancy (−2.5 min/day (−4.0 to –1.0)) and post-term gestational age (−7.4 min/day (−11.5 to –3.4); boys only) were associated with lower MVPA at age 46. In the mutually adjusted model, associations did not change but there was some evidence that birth weight may also be associated with MVPA levels.

Conclusions

SEP, maternal age, maternal smoking, post-term birth in boys and birth weight were associated with MVPA in midlife, indicating that midlife physical activity behaviours may be partially established at birth. Early interventions in disadvantaged environments may have a positive impact on physical activity throughout the life course.

Association between postterm pregnancy and adverse growth outcomes in preschool-age children

BACKGROUND

Postterm pregnancy has been associated with higher risk of perinatal mortality and morbidity, but its long-term health effects on offspring are poorly understood.

OBJECTIVES

The aim of the study was to investigate the prospective associations between maternal postterm pregnancy and adverse growth outcomes in children.

METHODS

The Jiaxing Birth Cohort is part of a large population-based health surveillance system in China and recruited pregnant females resident in the Jiaxing area between 1999 and 2013; newborns were followed up for a median duration of 5.8 y until they went to school. Mother-child pairs with maternal gestational information and offspring's anthropometric data at 4-7 y old were included. Postterm pregnancy was defined as maternal gestational age ≥42 and <47 wk, and its associations with offspring obesity, overweight/obesity, and thinness during childhood were determined by using Poisson regression models.

RESULTS

Of the 101,505 included mother-child pairs, 2369 (2.3%) children were born at postterm. Children born at postterm had significantly lower BMI-for-age z score, weight-for-age z score, and height-for-age z score than those born at term; the mean difference (95% CI) was -0.11 (-0.15, -0.06), -0.17 (-0.21, -0.13), and -0.16 (-0.20, -0.12), respectively. When comparing postterm with term pregnancy, the multivariable-adjusted RRs and 95% CIs among preschool-age children were 0.87 (0.68, 1.11) for obesity, 0.82 (0.72, 0.94) for overweight/obesity, and 1.18 (1.09, 1.28) for thinness, respectively. These risk estimates were robust in sensitivity analyses, but were attenuated in several subgroups stratified by age, sex, mode of delivery, and fetal distress.

CONCLUSIONS

Postterm pregnancy was associated with a higher risk of thinness, and a lower risk of overweight/obesity, as well as lower growth parameters in preschool-age children. These findings imply that postterm pregnancy may impede the long-term growth of offspring.

Body composition of children with different gestation time

OBJECTIVES

To examine the differences in body composition between prepubescent children, depending on the time of gestation.

METHODS

The study was conducted among children aged 3-10 years. The thickness of 5 (triceps, subscapular, suprailiac, abdominal, calf) skinfolds, mid-upper arm circumference, body height, weight and femur breadth was measured. Sum of 3 skinfolds, Body Mass Index (BMI) and muscle mass were calculated. Gestation time was obtained using a questionnaire.

RESULTS

Children in the short gestation time category were generally characterized by the greatest values of the analyzed characteristics, particularly above the ages of 6-8 years. Femur breadth and muscle mass were similar up to the mentioned age in all of the gestation time categories. BMI and all of the adiposity characteristics, below the age of 6 years, were the greatest in the long gestation time category.

CONCLUSIONS

Results of the present study are important, as excess body mass and adiposity are associated with increased risk of cardiovascular and metabolic abnormalities later in life. Special emphasis should be placed on the prevention of overweight and obesity among premature babies and the education of their parents.

Associations of community, famliy and early individual factors with body mass index z-scores trajectories among Chinese children and adolescents

The prevalence of childhood overweight and obesity is increasing. This study aimed to examine trajectories of BMI z-scores among Chinese children and the potential determinants including early individual, family and community factors. Group-based trajectory modeling was employed to identify BMI z-scores trajectories of children aged 2-18 years using the five waves data (2010, 2012, 2014, 2016, and 2018) of the China Family Panel Studies (CFPS). Multivariate logistic regression was conducted to determine the association between early individual, family, community factors and BMI z-scores trajectories of children. We identified three trajectories for boys and girls, named Class 1 as "not-overweight", Class 2 as "persistent rapid descending but overweight during pre-school age", and Class 3 as "rapid rising up to school age and then become-overweight" class. Macrosomia (OR 1.772; 95% CI 1.188-2.644) and being a single child (OR 2.038; 95% CI 1.453-2.859) were more likely to belong in Class 3 among boys. Girls living in the advantaged communities (OR 1.539; 95% CI 1.052-2.252), rural-living (OR 1.558; 95% CI 1.133-2.142) and with none social integration (OR 1.496; 95% CI 1.07-2.091) were more likely to belong in Class 2. There are heterogeneous BMI z-scores trajectories of children aged 2-18, and pre-school age is a critical window that could predict the long-term growth patterns. BMI z-scores trends need to be monitored during pre-school age, focusing on those at higher risk of later overweight obesity status, and targeted interventions at the early individual, family, community levels are essential.

Concurrent Prebiotic Intake Reverses Insulin Resistance Induced by Early-Life Pulsed Antibiotic in Rats

Pulsed antibiotic treatment (PAT) early in life increases risk of obesity. Prebiotics can reduce fat mass and improve metabolic health. We examined if co-administering prebiotic with PAT reduces obesity risk in rat pups weaned onto a high fat/sucrose diet. Pups were randomized to (1) control [CTR], (2) antibiotic [ABT] (azithromycin), (3) prebiotic [PRE] (10% oligofructose (OFS)), (4) antibiotic + prebiotic [ABT + PRE]. Pulses of antibiotics/prebiotics were administered at d19-21, d28-30 and d37-39. Male and female rats given antibiotics (ABT) had higher body weight than all other groups at 10 wk of age. The PAT phenotype was stronger in ABT males than females, where increased fat mass, hyperinsulinemia and insulin resistance were present and all reversible with prebiotics. Reduced hypothalamic and hepatic expression of insulin receptor substrates and ileal tight junction proteins was seen in males only, explaining their greater insulin resistance. In females, insulin resistance was improved with prebiotics and normalized to lean control. ABT reduced Lactobacillaceae and increased Bacteroidaceae in both sexes. Using a therapeutic dose of an antibiotic commonly used for acute infection in children, PAT increased body weight and impaired insulin production and insulin sensitivity. The effects were reversed with prebiotic co-administration in a sex-specific manner.

Large-for-gestational-age phenotypes and obesity risk in adulthood: a study of 195,936 women

While there is evidence that being born large-for-gestational-age (LGA) is associated with an increased risk of obesity later in life, the data are conflicting. Thus, we aimed to examine the associations between proportionality at birth and later obesity risk in adulthood. This was a retrospective study using data recorded in the Swedish Birth Register. Anthropometry in adulthood was assessed in 195,936 pregnant women at 10-12 weeks of gestation. All women were born at term (37-41 weeks of gestation). LGA was defined as birth weight and/or length ≥2.0 SDS. Women were separated into four groups: appropriate-for-gestational-age according to both weight and length (AGA - reference group; n = 183,662), LGA by weight only (n = 4,026), LGA by length only (n = 5,465), and LGA by both weight and length (n = 2,783). Women born LGA based on length, weight, or both had BMI 0.12, 1.16, and 1.08 kg/m² greater than women born AGA, respectively. The adjusted relative risk (aRR) of obesity was 1.50 times higher for those born LGA by weight and 1.51 times for LGA by both weight and height. Length at birth was not associated with obesity risk. Similarly, women born LGA by ponderal index had BMI 1.0 kg/m² greater and an aRR of obesity 1.39 times higher than those born AGA. Swedish women born LGA by weight or ponderal index had an increased risk of obesity in adulthood, irrespective of their birth length. Thus, increased risk of adult obesity seems to be identifiable from birth weight and ignoring proportionality.

Body composition of New Zealand-born term babies differs by ethnicity, gestational age and sex

BACKGROUND

Body composition provides important information on nutrition and future metabolic risk. New Zealand has a diverse ethnic population for which there are no newborn body composition data.

AIM

To determine body composition in a cohort of New Zealand-born term babies.

STUDY DESIGN

Observational study.

SUBJECTS

Healthy, term infants between 37⁺⁰ and 41⁺⁶ weeks' gestation in two hospitals in Auckland, New Zealand.

OUTCOME MEASURES

Body composition by air displacement plethysmography and anthropometry measured within 5 days of birth. Parent-identified ethnicity was prioritised according to Ministry of Health criteria. Data were analysed using t-test, ANOVA with Tukey post-hoc tests, quantile regression and are mean(SD).

RESULTS

440 babies (54% male) were included. Pacific Island/Māori (PI/M) were heavier at birth than Asian/Middle Eastern/Latin American/African (Asian+) babies (3403(506) vs 3181(485) g, p < .05). PI/M and European (E) babies were longer with larger head and waist circumferences than Asian+ babies (all p < .05). Absolute fat mass (FM) was not different amongst ethnicities (E, 365(156), PI/M, 347(183), Asian+, 357(188) g) but PI/M babies had significantly lower FM% than Asian+ (9.8(4.3) vs 10.9(4.5) %, p < .05). Fat-free mass (FFM) was greater in PI/M (3056(400) g) than E (2952(345) g (p < .05) and both PI/M and E had greater FFM than Asian+ (2824(363) g, p < .05). Early term babies had less FFM than term and late-term babies (2732(370), 3012(352), 3173(302)g, p < .001) respectively.

CONCLUSIONS

Asian+ babies were the smallest babies with the least FFM yet had similar FM and the highest FM%, indicative of a thin, fat phenotype from birth.

Exercise capacity and cardiac function in adolescents born post-term

There is some evidence that children born post-term (≥42 weeks of gestation) have metabolic abnormalities that may be associated with an increased risk of adverse health outcomes in adulthood. However, there are no data as to whether adolescents born post-term display alterations in aerobic capacity or cardiovascular function. We studied 48 adolescents (56% males) in Auckland (New Zealand) with a mean age of 14.3 years (SD = 1.7): 25 born post-term and 23 born at term (37-41 weeks of gestation). Assessments included metabolic markers in blood, whole body DXA scans, 24-hour ambulatory blood pressure monitoring, maximal exercise capacity, as well as cardiac MRI scan at rest and during submaximal exercise. Exercise capacity was lower in the post-term than in control participants (44.5 vs 47.8 ml/kgffm/min; p = 0.04). There were no differences in left ventricular volumes at rest and during exercise between groups. The 24-hour ambulatory blood pressure monitoring also showed no differences between the two groups. Being born post-term was associated with reduced exercise capacity, but with no observed differences in central cardiac function. We speculate that the reduction in exercise capacity may be due to changes in the peripheral vascular system.

Gestational age at birth and academic performance: population-based cohort study

Background

Numerous studies suggest pre-term birth is associated with cognitive deficit. However, less is known about cognitive outcomes following post-term birth, or the influence of weight variations within term or post-term populations. We examined associations between gestational age (GA) and school performance, by weight-for-GA, focusing on extremely pre- and post-term births.

Method

Record linkage study of Swedish children born 1973-94 ( n =  2 008 102) with a nested sibling comparison ( n =  439 629). We used restricted cubic regression splines to examine associations between GA and the grade achieved on leaving secondary education, comparing siblings to allow stronger causal inference with regard to associations between GA and school performance.

Results

Grade averages of both pre- and post-term children were below those of full-term counterparts and lower for those born small-for-GA. The adjusted grades of extremely pre-term children (at 24 completed weeks), while improving in later study periods, were lower by 0.43 standard deviations (95% confidence interval 0.38-0.49), corresponding with a 21-point reduction (19 to 24) on a 240-point scale. Reductions for extremely post-term children (at 45 completed weeks) were lesser [-0.15 standard deviation (-0.17 to -0.13) or -8 points (-9 to -7)]. Among matched siblings, we observed weaker residual effects of pre-term and post-term GA on school performance.

Conclusions

There may be independent effects of fetal maturation and fetal growth on school performance. Associations among matched siblings, although attenuated, remained consistent with causal effects of pre- and post-term birth on school performance.

Antibiotics, gut microbiome and obesity

Antibiotics have been hailed by many as "miracle drugs" that have been effectively treating infectious diseases for over a century, leading to a marked reduction in morbidity and mortality. However, with the increasing use of antibiotics, we are now faced not only with the increasing threat of antibiotic resistance, but also with a rising concern about potential long-term effects of antibiotics on human health, including the development of obesity. The obesity pandemic continues to increase, a problem that affects both adults and children alike. Disruptions to the gut microbiome have been linked to a multitude of adverse conditions, including obesity, type 2 diabetes, inflammatory bowel diseases, anxiety, autism, allergies, and autoimmune diseases. This review focuses on the association between antibiotics and obesity, and the role of the gut microbiome. There is strong evidence supporting the role of antibiotics in the development of obesity in well-controlled animal models. However, evidence for this link in humans is still inconclusive, and we need further well-designed clinical trials to clarify this association.

GWAS on prolonged gestation (post-term birth): analysis of successive Finnish birth cohorts

Background

Gestation is a crucial timepoint in human development. Deviation from a term gestational age correlates with both acute and long-term adverse health effects for the child. Both being born preterm and post-term, that is, having short and long gestational ages, are heritable and influenced by the prenatal and perinatal environment. Despite the obvious heritable component, specific genetic influences underlying differences in gestational age are poorly understood.

Methods

We investigated the genetic architecture of gestational age in 9141 individuals, including 1167 born post-term, across two Northern Finland cohorts born in 1966 or 1986.

Results

Here we identify one globally significant intronic genetic variant within the ADAMTS13 gene that is associated with prolonged gestation (p=4.85×10−8). Additional variants that reached suggestive levels of significance were identified within introns at the ARGHAP42 and TKT genes, and in the upstream (5’) intergenic regions of the B3GALT5 and SSBP2 genes. The variants near the ADAMTS13, B3GALT5, SSBP2 and TKT loci are linked to alterations in gene expression levels (cis-eQTLs). Luciferase assays confirmed the allele specific enhancer activity for the BGALT5 and TKT loci.

Conclusions

Our findings provide the first evidence of a specific genetic influence associated with prolonged gestation. This study forms a foundation for a better understanding of the genetic and long-term health risks faced by induced and post-term individuals. The long-term risks for induced individuals who have a previously overlooked post-term potential may be a major issue for current health providers.

Being in limbo: Women's lived experiences of pregnancy at 41 weeks of gestation and beyond - A phenomenological study

BACKGROUND

Globally, the prevalence of post term pregnancy (PTP) is about 5-10%, but the rate varies considerably between and within countries. PTP is defined as a pregnancy ≥294 days, but the definition is arbitrary. Many studies focusing on the prevalence, risks and management of PTP include pregnancies ≥41 gestational weeks (GW). However, qualitative interview studies concerning women's experiences of PTP are lacking. Therefore, the aim of this study was to describe women's lived experiences of a pregnancy ≥41 GW.

METHOD

The study has a lifeworld research approach. Individual in-depth interviews were conducted from August 2013 to September 2014 with 10 healthy women with an expected normal pregnancy at GW 41 + 1-6 days in Gothenburg, Sweden. Interviews were conducted at the antenatal clinic or in the woman's home, depending on her preference. Data were analysed with a phenomenological reflective lifeworld approach.

RESULT

The essence of women's experiences of a pregnancy at GW ≥ 41 was described as being in limbo, a void characterised by contradictions related to time, giving birth and the condition. Exceeding the estimated date of childbirth implied a period of up to 2 weeks that was not expected. The contradictory aspect was the notion that time passed both slowly and quickly. Negative feelings dominated and increased over time. The women experienced difficulty due to not being in complete control, while at the same time finding it a beneficial experience. Health care professionals focused solely on the due date, while the women felt neither seen nor acknowledged. Lack of information led to searches in social media. Previously, they had trusted the body's ability to give birth, but this trust diminished after GW 41 + 0. In this state of limbo, the women became more easily influenced by people around them, while in turn influencing others.

CONCLUSIONS

Being in limbo represents a contradictory state related to time and process of giving birth, when women need to be listened to by healthcare professionals. An understanding of the importance of different information sources, such as family and friends, is necessary. It is vital that women are seen and acknowledged by midwives at the antenatal clinics. In addition, they should be asked how they experience waiting for the birth in order to create a sense of trust and confidence in the process.

Prenatal determinants of physical activity and cardiorespiratory fitness in adolescence - Northern Finland Birth Cohort 1986 study

BACKGROUND

Lower levels of physical activity and cardiorespiratory fitness are key risk factors of chronic adult diseases. Physical activity and cardiorespiratory fitness are predicted by birth weight, but the underlying parental and pregnancy-related factors remain largely unknown. We examined how prenatal determinants are associated with physical activity and cardiorespiratory fitness in adolescence.

METHODS

Of the 16-year-old members of the population-based Northern Finland Birth Cohort 1986 (NFBC 1986), 6682 singletons with no major physical disability reported their amount of physical activity outside school hours, and 4706 completed a submaximal cycle ergometer test assessing cardiorespiratory fitness. Physical activity was expressed as metabolic equivalent hours per week (METh/week) and cardiorespiratory fitness as peak oxygen uptake (ml·kg-1·min-1). Prenatal determinants included birth weight, length of gestation, mother's and father's body mass index (BMI), maternal gestational diabetes mellitus (GDM), and maternal hypertension and smoking during pregnancy. Data were analyzed by multiple linear regression.

RESULTS

A higher birth weight and longer length of gestation predicted lower levels of physical activity and cardiorespiratory fitness at 16 years, although the association between length of gestation and physical activity was inverse U-shaped. Mother's or father's overweight or obesity before pregnancy were associated with lower levels of their offspring's physical activity and fitness in adolescence. Adjusting for maternal pregnancy disorders and the adolescent's own BMI attenuated the associations with the mother's but not the father's overweight/obesity. Furthermore, maternal GDM predicted lower cardiorespiratory fitness.

CONCLUSIONS

A high birth weight and parental overweight/obesity are associated with lower levels of both physical activity and cardiorespiratory fitness in adolescence, while maternal GDM and longer length of gestation are associated with lower cardiorespiratory fitness. Both long and short lengths of gestation predict low physical activity.

Pre-term and post-term births: predictors and implications on neonatal mortality in Northern Ethiopia

BACKGROUND

Pre-term and post-term births are major determinants of neonatal mortality, including short- and long-term morbidity. In developing countries, where pre-term and post-term births are disproportionately common, the magnitude and underlying causes are not well understood, and evidence is required to design appropriate interventions. This study measured the incidence and identified risk factors of pre-term birth and post-term births in Ethiopia. In addition, it examined the effects of pre-term and post-term birth on neonatal mortality.

METHOD

This study is a portion of prospective cohort study conducted on 1152 live births born between April and July 2014 in seven hospitals in Tigray region, Northern Ethiopia. Neonatal mortality and birth outcomes were considered as dependent variables. Data were collected using a structured questionnaire and weekly neonatal follow up directed at midwives. Data were described using frequency, percentage, ratio of relative risk (RRR), and 95 % confidence interval (CI). We used multinomial and binary logistic regression to identify independent predictors of birth outcome and neonatal mortality respectively.

RESULT

The prevalence of pre-term and post term births was 8.1 % and 6.0 % respectively. Underweight maternal body mass index (RRR: 0.47, CI: 0.22-0.99), medium reported income (RRR: 0.26, CI: 0.12-0.5), length of neonate (RRR: 0.05, CI: 0.01-0.41), and multiple births (RRR: 2.86, CI: 1.4-5.650) were associated with pre-term birth. Predictors for post-term birth were overweight maternal body mass index (RRR: 3.88, CI: 1.01-15.05), high reported income mothers (RRR: 2.17, CI:1.1-4.3), as well as unmarried, widowed and divorced marital status (RRR:2.43, CI:1.02-5.80). With regards to binary logistic regression, pre-term birth (RR: 2.45, CI: 1.45-4.04) was an independent predictor for neonatal mortality, but this was not true for post-term births (RR: 0.45, CI: 0.07-2.96).

CONCLUSION

Socioeconomic and proximate factors are important predictors for pre-term and post-term births. Empowering women in terms of income status and controlling body mass index within the normal range are recommended. In addition, early detection and close antenatal follow-ups for mothers, who are at risk before and during pregnancy, are necessary to prevent both pre-term and post-term births.

Body Mass Index, Overweight, and Obesity in Swedish Women Born Post-term

BACKGROUND

There is increasing evidence that post-term birth (≥42 weeks of gestation) is associated with adverse long-term outcomes. We assessed whether women born post-term displayed increased risk of overweight and obesity in adulthood.

METHODS

Data were collected at first antenatal visit (~10-12 weeks of gestation) on singleton Swedish women aged ≥18 years in 1991-2009 (mean age 26.1 years), who were born post-term (n = 27 153) or at term (37-41 weeks of gestation; n = 184 245). Study outcomes were evaluated for continuous associations with gestational age. Stratified analyses were carried out comparing women born post-term or at term. Analyses were also run with a 2-week buffer between groups to account for possible errors in gestational age estimation, comparing women born very post-term (≥43 weeks of gestation; n = 5761) to those born within a narrower term window (38-40 weeks of gestation; n = 130 110).

RESULTS

Increasing gestational age was associated with greater adult weight and body mass index (BMI). Stratified analyses showed that women born post-term were 0.5 kg heavier and had BMI 0.2 kg/m(2) greater than those born at term. Differences were more marked between women born very post-term (≥43 weeks) vs. a narrower term group (38-40 weeks): 1.0 kg and 0.3 kg/m(2) . The adjusted relative risks of overweight/obesity and obesity in women born very post-term were 1.13 and 1.12 times higher, respectively, than in those born at term.

CONCLUSIONS

Post-term birth is associated with greater BMI and increased risk of overweight and obesity in adulthood, particularly among women born ≥43 weeks of gestation.

Risk Factors for Childhood Obesity in the First 1,000 Days: A Systematic Review

CONTEXT

Mounting evidence suggests that the origins of childhood obesity and related disparities can be found as early as the "first 1,000 days"-the period from conception to age 2 years. The main goal of this study is to systematically review existing evidence for modifiable childhood obesity risk factors present from conception to age 2 years.

EVIDENCE ACQUISITION

PubMed, Embase, and Web of Science were searched for studies published between January 1, 1980, and December 12, 2014, of childhood obesity risk factors present during the first 1,000 days. Prospective, original human subject, English-language research with exposure occurrence during the first 1,000 days and with the outcome of childhood overweight or obesity (BMI ≥85th percentile for age and sex) collected between age 6 months and 18 years were analyzed between December 13, 2014, and March 15, 2015.

EVIDENCE SYNTHESIS

Of 5,952 identified citations, 282 studies met inclusion criteria. Several risk factors during the first 1,000 days were consistently associated with later childhood obesity. These included higher maternal pre-pregnancy BMI, prenatal tobacco exposure, maternal excess gestational weight gain, high infant birth weight, and accelerated infant weight gain. Fewer studies also supported gestational diabetes, child care attendance, low strength of maternal-infant relationship, low SES, curtailed infant sleep, inappropriate bottle use, introduction of solid food intake before age 4 months, and infant antibiotic exposure as risk factors for childhood obesity.

CONCLUSIONS

Modifiable risk factors in the first 1,000 days can inform future research and policy priorities and intervention efforts to prevent childhood obesity.

Study protocol of SWEPIS a Swedish multicentre register based randomised controlled trial to compare induction of labour at 41 completed gestational weeks versus expectant management and induction at 42 completed gestational weeks

Background

Observational data shows that postterm pregnancy (≥42 gestational weeks, GW) and late term pregnancy (≥41 GW), as compared to term pregnancy, is associated with an increased risk for adverse outcome for the mother and infant. Standard care in many countries is induction of labour at 42 GW. There is insufficient scientific support that induction of labour at 41 GW, as compared with expectant management and induction at 42 GW will reduce perinatal mortality and morbidity without an increase in operative deliveries, negative delivery experiences or higher costs. Large randomised studies are needed since important outcomes; such as perinatal mortality and hypoxic ischaemic encephalopathy are rare events.

Methods/Design

A total of 10 038 healthy women ≥18 years old with a normal live singleton pregnancy in cephalic presentation at 41 GW estimated with a first or second trimester ultrasound, who is able to understand oral and written information will be randomised to labour induction at 41 GW (early induction) or expectant management and induction at 42 GW (late induction). Women will be recruited at university clinics and county hospitals in Sweden comprising more than 65 000 deliveries per year. Primary outcome will be a composite of stillbirth, neonatal mortality and severe neonatal morbidity. Secondary outcomes will be other adverse neonatal and maternal outcomes, mode of delivery, women’s experience, cost effectiveness and infant morbidity up to 3 months of age. Data on background variables, obstetric and neonatal outcomes will be obtained from the Swedish Pregnancy Register and the Swedish Neonatal Quality Register. Data on women’s experiences will be collected by questionnaires after randomisation and 3 months after delivery. Primary analysis will be intention to treat. The statistician will be blinded to group and intervention.

Discussion

It is important to investigate if an intervention at 41 GW is superior to standard care in order to reduce death and lifelong disability for the children. The pregnant population, >41 GW, constitutes 15–20 % of all pregnancies and the results of the study will thus have a great impact. The use of registries for randomisation and collection of outcome data represents a unique and new study design.

Trial registration

The study was registered in Current Controlled Trials, ISRCTN26113652 the 30^th of March 2015 (DOI 10.1186/ISRCTN26113652).

Preterm and postterm birth in immigrant- and Swedish-born parents: a population register-based study

Ethnic minorities/immigrant groups tend to have increased risk for preterm birth. Less is known about this risk in diverse immigrant groups, couples of mixed ethnic-origin and in relation to duration of residence. Data from the Swedish Medical Birth Register on 1,028,303 mothers who gave birth to 1,766,026 singleton live born infants (1982-2002), was linked to the Education and Total Population Registers. Immigrant parents were identified by country of birth. Risk of early preterm, late preterm and postterm birth was analyzed using multinomial logistic regression. Polish, Yugoslavian, Iranian, South Asian, East Asian and Sub-Saharan African parents, Swedish mothers who had children with non-Swedish fathers, and parents from two different immigrant groups had higher risk of early preterm birth [adjusted relative risk (RR) (95% CI) 1.76 (1.24-2.50), 1.57 (1.31-1.87), 1.67 (1.30-2.14), 1.52 (1.07-2.16), 1.51 (1.08-2.10), 2.03 (1.32-3.12), 1.56 (1.45-1.67), and 1.55 (1.35-1.77) respectively] compared to Swedish-born parents. South Asian, Sub-Saharan African, and East Asian immigrants had a higher risk of late preterm birth compared to Swedish-born parents. North African and Middle Eastern, Somali, and Ethiopian/Eritrean groups had increased risk of postterm birth [adjusted RR 1.31 (1.16-1.47), 2.57 (2.31-2.86), 1.85 (1.67-2.04) respectively]. Adjustment for covariates did not substantially change associations. Immigrant mothers resident <3 years had higher risk for early preterm and postterm birth compared to residents >10 years [adjusted RR 1.46 (1.24-1.71) and 1.16 (1.11-1.23) respectively]. In addition to higher risk of preterm birth in select immigrant groups, some immigrant groups are also at higher risk of postterm birth. Shorter duration of residence is associated with higher risk of non-term deliveries.

Genes and post-term birth: late for delivery

Background

Recent evidence suggests that prolonged pregnancies beyond 42 weeks of gestation (post-term births) are associated with long-term adverse health outcomes in the offspring.

Discussion

There is evidence that post-term birth has not only environmental causes, but also significant heritability, suggesting genetic and/or epigenetic influences interact with environmental cues to affect gestational length.

Summary

As prolonged gestation is associated with adverse short- and long-term outcomes in the offspring, further research into the underlying genetic and epigenetic causes of post-term birth could be of importance for improving obstetric management.

Early developmental conditioning of later health and disease: physiology or pathophysiology?

Extensive experimental animal studies and epidemiological observations have shown that environmental influences during early development affect the risk of later pathophysiological processes associated with chronic, especially noncommunicable, disease (NCD). This field is recognized as the developmental origins of health and disease (DOHaD). We discuss the extent to which DOHaD represents the result of the physiological processes of developmental plasticity, which may have potential adverse consequences in terms of NCD risk later, or whether it is the manifestation of pathophysiological processes acting in early life but only becoming apparent as disease later. We argue that the evidence suggests the former, through the operation of conditioning processes induced across the normal range of developmental environments, and we summarize current knowledge of the physiological processes involved. The adaptive pathway to later risk accords with current concepts in evolutionary developmental biology, especially those concerning parental effects. Outside the normal range, effects on development can result in nonadaptive processes, and we review their underlying mechanisms and consequences. New concepts concerning the underlying epigenetic and other mechanisms involved in both disruptive and nondisruptive pathways to disease are reviewed, including the evidence for transgenerational passage of risk from both maternal and paternal lines. These concepts have wider implications for understanding the causes and possible prevention of NCDs such as type 2 diabetes and cardiovascular disease, for broader social policy and for the increasing attention paid in public health to the lifecourse approach to NCD prevention.

Does low birth weight predict hypertension and obesity in schoolchildren?

BACKGROUND

Birth weight appears to play a role in determining high blood pressure (BP) and obesity during childhood. The purpose of this study is to investigate the association between birth weight and later obesity and hypertension among 10- to 13-year-old schoolchildren.

METHODS

A total of 1,184 primary school students were selected from 20 randomized schools between 2011 and 2012 in Iran. Height, weight, waist circumference and BP were measured using standard instruments. Data were analyzed using stepwise regression and logistic regression models.

RESULTS

13.5% of children had a history of low birth weight. First-degree family history of obesity, excessive gestational weight gain and birth weight were significantly correlated with overweight/obesity and abdominal obesity (p = 0.001), whereas only birth weight was associated with high BP (p = 0.001). An inverse correlation was found between waist circumference and systolic/diastolic BP. The duration of breastfeeding in children with low birth weight was inversely correlated with obesity/overweight, abdominal obesity and hypertension.

CONCLUSION

The results suggests that birth weight is inversely associated with BP and more so with obesity and abdominal obesity. The duration of having been breastfed could have an influence on later hypertension, obesity and abdominal obesity. Further results are needed to test these correlations as well as diagnosing early life factors to prevent young adult overweight/obesity or hypertension.

Pre-pubertal children born post-term have reduced insulin sensitivity and other markers of the metabolic syndrome

BACKGROUND

There are no data on the metabolic consequences of post-term birth (≥42 weeks gestation). We hypothesized that post-term birth would adversely affect insulin sensitivity, as well as other metabolic parameters and body composition in childhood.

METHODS

77 healthy pre-pubertal children, born appropriate-for-gestational-age were studied in Auckland, New Zealand: 36 born post-term (18 boys) and 41 (27 boys) born at term (38-40 weeks gestation). Primary outcome was insulin sensitivity measured using intravenous glucose tolerance tests and Bergman's minimal model. Other assessments included fasting hormone concentrations and lipid profiles, body composition from whole-body dual-energy X-ray absorptiometry, 24-hour ambulatory blood pressure monitoring, and inflammatory markers.

RESULTS

Insulin sensitivity was 34% lower in post-term than in term children (7.7 vs. 11.6 x10⁻⁴·min⁻¹·(mU/l); p<0.0001). There was a compensatory increase in acute insulin response among post-term children (418 vs 304 mU/l; p=0.037), who also displayed lower glucose effectiveness than those born at term (2.25 vs 3.11 x10⁻²·min⁻¹; p=0.047). Post-term children not only had more body fat (p=0.014) and less fat-free mass (p=0.014), but also had increased central adiposity with more truncal fat (p=0.017) and greater android to gynoid fat ratio (p=0.007) compared to term controls. Further, post-term children displayed other markers of the metabolic syndrome: lower normal nocturnal systolic blood pressure dipping (p=0.027), lower adiponectin concentrations (p=0.005), as well as higher leptin (p=0.008) and uric acid (p=0.033) concentrations. Post-term boys (but not girls) also displayed a less favourable lipid profile, with higher total cholesterol (p=0.018) and LDL-C (p=0.006) concentrations, and total cholesterol to HDL-C ratio (p=0.048).

CONCLUSIONS

Post-term children have reduced insulin sensitivity and display a number of early markers of the metabolic syndrome. These findings could have important implications for the management of prolonged pregnancies. Future studies need to examine potential impacts later in life, as well as possible underlying mechanisms.

Early life nutritional programming of obesity: mother-child cohort studies

BACKGROUND

The obesity epidemic has resulted in more overweight/obese women before and during pregnancy. Their offspring tend to have higher birth weights and more body fat, and carry an increased risk of obesity later in life. These effects may partly be related to the heightened risk of gestational diabetes, occurring in at least 16% of all pregnancies irrespective of current body weight.

METHODS

An ILSI Europe workshop reviewed the key contributors leading to adverse outcomes in pregnancy and childhood, including gestational weight gain and nutrition. New research opportunities from prospective mother-child cohort studies were explored.

RESULTS

Simple measures of gestational weight gain provide insufficient detail of the underlying physiological and metabolic adaptations occurring in pregnancy, and should be complemented by measures of body composition, metabolic and endocrine responses. Recordings of maternal dietary intake and nutrient status are often limited and potential correlations with gestational weight gain have been poorly studied. Many pregnancies in overweight/obese women are uncomplicated and result in offspring of normal weight, leaving the main determinants of later adverse outcomes to be clarified.

CONCLUSIONS

The workshop provided insights of primary measurements for the characterization of sustainable nutritional intervention strategies in the mother, infant and child for preventing obesity in later life.