Maternal pre-pregnancy body mass index and risk of preterm birth: a collaboration using large routine health datasets.

BACKGROUND: Preterm birth (PTB) is a leading cause of child morbidity and mortality. Evidence suggests an increased risk with both maternal underweight and obesity, with some studies suggesting underweight might be a greater factor in spontaneous PTB (SPTB) and that the relationship might vary by parity. Previous studies have largely explored established body mass index (BMI) categories. Our aim was to compare associations of maternal pre-pregnancy BMI with any PTB, SPTB and medically indicated PTB (MPTB) among nulliparous and parous women across populations with differing characteristics, and to identify the optimal BMI with lowest risk for these outcomes. METHODS: We used three UK datasets, two USA datasets and one each from South Australia, Norway and Denmark, together including just under 29 million pregnancies resulting in a live birth or stillbirth after 24 completed weeks gestation. Fractional polynomial multivariable logistic regression was used to examine the relationship of maternal BMI with any PTB, SPTB and MPTB, among nulliparous and parous women separately. The results were combined using a random effects meta-analysis. The estimated BMI at which risk was lowest was calculated via differentiation and a 95% confidence interval (CI) obtained using bootstrapping. RESULTS: We found non-linear associations between BMI and all three outcomes, across all datasets. The adjusted risk of any PTB and MPTB was elevated at both low and high BMIs, whereas the risk of SPTB was increased at lower levels of BMI but remained low or increased only slightly with higher BMI. In the meta-analysed data, the lowest risk of any PTB was at a BMI of 22.5 kg/m2 (95% CI 21.5, 23.5) among nulliparous women and 25.9 kg/m2 (95% CI 24.1, 31.7) among multiparous women, with values of 20.4 kg/m2 (20.0, 21.1) and 22.2 kg/m2 (21.1, 24.3), respectively, for MPTB; for SPTB, the risk remained roughly largely constant above a BMI of around 25-30 kg/m2 regardless of parity. CONCLUSIONS: Consistency of findings across different populations, despite differences between them in terms of the time period covered, the BMI distribution, missing data and control for key confounders, suggests that severe under- and overweight may play a role in PTB risk.

Elective labor induction vs expectant management of pregnant women at term and children's educational outcomes at 8 years of age.

OBJECTIVE: To estimate the effect of elective induction of labor at 39 weeks' gestation on children's educational outcomes as measured using the Australian National Assessment Program-Literacy and Numeracy (NAPLAN) tests in school year 3 (∼8 years of age), compared with expectant management. METHODS: We merged perinatal data on all infants born in South Australia from 1999 to 2008 with children's school assessment data from NAPLAN. The study population included all singleton infants born without a malformation at 39-42 weeks in vertex presentation. Children who had undertaken the NAPLAN test in school year 3 were included. We excluded births to women who had a contraindication to vaginal delivery and those with a condition possibly justifying elective delivery before 39 weeks. The outcome of interest was children's educational outcome as measured using NAPLAN, which includes five learning domains (reading, writing, spelling, grammar and numeracy). Each domain was categorized according to performance at or below vs above the national minimum standard (NMS). Average treatment effects (ATEs) of elective induction of labor at 39 weeks compared with expectant management on the proportion of children performing at/below the NMS for each domain were estimated using the augmented inverse-propensity-weighted estimator, accounting for potential confounders. RESULTS: Of 53 843 children born at 39-42 weeks in vertex presentation from 1999 to 2008 and who were expected to participate in the year-3 NAPLAN from 2008 to 2015, a total of 31 120 had at least one year-3 NAPLAN domain. Of these, 1353 children were delivered after elective induction of labor at 39 weeks while 29 767 children were born following expectant management. The ATEs (mean differences) of elective induction of labor at 39 weeks compared with expectant management on the proportion of children scoring at/below the NMS on each domain were 0.01 (95% CI, -0.02 to 0.03) for reading, 0.02 (95% CI, 0.00-0.04) for writing, 0.01 (95% CI, -0.01 to 0.04) for spelling, 0.02 (95% CI, -0.01 to 0.04) for grammar and 0.03 (95% CI, 0.00-0.05) for numeracy. CONCLUSION: Elective induction of labor at 39 weeks did not affect children's standardized literacy and numeracy testing outcomes at 8 years of age when compared with expectant management. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Effects of racism on the socio-emotional wellbeing of Aboriginal Australian children.

BACKGROUND: Racism is a pervasive experience in the life of Aboriginal Australians that begins in childhood. As a psychosocial stressor, racism compromises wellbeing and impacts developmental trajectories. The purpose of the present study was to estimate the effect of racism on indicators of Australian Aboriginal child socio-emotional wellbeing (SEWB) at one to two years after exposure. Age-related differences in the onset of symptoms were explored. METHODS: Data from the B- and K-cohorts of the Longitudinal Study of Indigenous Children were used (aged 6 to 12 years). Racism, confounding variables, and the Strengths and Difficulties Questionnaire (a measure of SEWB) were collected by questionnaires and guided interviews with each child's main caregiver. Adjusted Poisson regression was used to estimate the relative risk (RRa) effects of racism on SEWB for both cohorts separately. RRa were pooled in a random effects meta-analysis. RESULTS: Exposure to racism was associated with an adjusted point estimate indicating a 41% increased risk for total emotional and behavioural difficulties, although the confidence intervals were wide (pooled RRa 1.41, 95% CI 0.75, 2.07). Analyses by cohort showed younger children had higher RRa for total difficulties (RRa 1.72, 95% CI 1.16, 2.54), whilst older children had higher RRa for hyperactive behaviour (RRa 1.66, 95% CI 1.01, 2.73). CONCLUSIONS: The effects observed contributes to our understanding of the impact of racism on Aboriginal Australian children. Support for emotional and behavioural difficulties, and hyperactive behaviour, for Aboriginal children might help counteract the effects of racism. Future longitudinal research and policies aimed at reducing racism in Australian society are necessary.

Metabolic syndrome and time to pregnancy: a retrospective study of nulliparous women.

OBJECTIVE: To determine: (1) the association between metabolic syndrome (MetS), time to pregnancy (TTP), and infertility; (2) associations between individual and an increasing number of MetS components, TTP, and infertility; and (3) whether these relationships differ by body mass index (BMI < 30 kg/m2 versus BMI ≥ 30 kg/m2 ). DESIGN: Retrospective cohort study. SETTING: Multiple centres (in Australia, Ireland, New Zealand, and the UK). POPULATION: Five thousand five hundred and nineteen low-risk nulliparous pregnant women. METHODS: Data on retrospectively reported TTP (number of months to conceive) and a blood sample to assess metabolic health were collected between 14 and 16 weeks of gestation. MetS was defined according to the International Diabetes Federation criteria. Accelerated failure time models with log-normal distribution were conducted to estimate time ratios (TRs) and 95% CIs. Differences in MetS on infertility (TTP > 12 months) were compared using a generalised linear model (Poisson distribution) with robust variance estimates (relative risks, RRs; 95% CIs). All analyses (entire cohort and split by BMI) were controlled for a range of maternal and paternal confounding factors. MAIN OUTCOME MEASURES: Time to pregnancy and infertility. RESULTS: Of the 5519 women included, 12.4% (n = 684) had MetS. Compared with women without MetS, women with MetS had a longer TTP (adjusted TR 1.30; 95% CI 1.15-1.46), which was similar in women who were obese and in women who were not obese. Marginal estimates for median TTP in women with MetS versus without MetS was 3.1 months (3.0-3.3 months) versus 4.1 months (3.6-4.5 months), respectively. Women with MetS were at a 62% greater risk for infertility and were at a greater risk for infertility whether they were obese (adjusted RR 1.62; 95% CI 1.15-2.29) or not (adjusted RR 1.73; 95% CI 1.33-2.23). Reduced high-density lipoprotein cholesterol (HDL-C) and raised triglycerides (TGs) were the main individual components associated with risk for infertility. CONCLUSION: Metabolic syndrome is associated with longer TTP and infertility, independent of obesity. Additional studies, before pregnancy, are required to support our findings and to determine the applicability of which combinations of metabolic abnormalities pose the greatest risk to delayed fertility, or whether individual components are amenable to modification. TWEETABLE ABSTRACT: Metabolic syndrome is associated with longer time to pregnancy and infertility, independent of obesity.

Domperidone for increasing breast milk volume in mothers expressing breast milk for their preterm infants: a systematic review and meta-analysis.

BACKGROUND: Mothers of preterm infants often struggle to produce enough breast milk to meet the nutritional needs of their infant. Galactagogues such as domperidone are often prescribed to increase breast milk supply but evidence supporting their role in clinical practice is uncertain. OBJECTIVE: To evaluate the efficacy and safety of domperidone for increasing breast milk volume in mothers expressing breast milk for their preterm infants. SEARCH STRATEGY: MEDLINE, Embase and Web of Science were searched without language restrictions from first publication until January 2017. Bibliographies of articles and reviews were hand-searched for additional reports. SELECTION CRITERIA: Randomised controlled trials that compared domperidone with placebo in mothers of preterm infants (<37 weeks' gestation) experiencing insufficient milk supply. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion, extracted data and evaluated study quality. Differences in breast milk volume and adverse events were combined using fixed effects meta-analysis. MAIN RESULTS: The pooled analysis of five trials consisting of 194 women demonstrated a moderate increase in daily breast milk volume of 88.3 ml/day (95% CI 56.8-119.8) with the use of domperidone compared with placebo. No difference was evident with respect to maternal adverse events (odds ratio 1.05, 95% CI 0.65-1.71), with no reported cases of prolonged QTc syndrome or sudden cardiac death. Sensitivity analyses showed no important differences in the estimates of effects. CONCLUSIONS: Domperidone is well tolerated and results in a moderate short-term increase in expressed breast milk volume among mothers of preterm infants previously identified as having insufficient breast milk supply. TWEETABLE ABSTRACT: Domperidone leads to short-term improvements in breast milk volume in mothers of preterm infants.

Cesarean birth is not associated with early childhood body mass index.

Cesarean birth leads to a markedly different microbiome compared to vaginal birth, and the microbiome has been implicated in childhood obesity. Among mothers who had a previous cesarean, we compared anthropometry of 3- to 6-year-old children who were subsequently born by cesarean section versus vaginal birth. This large population-based study involved linking de-identified administrative perinatal and anthropometric data. Children's weight and height were collected at community-based clinics and converted to age- and sex-adjusted z-scores of height-for-age (HFAz), weight-for-age (WFAz) and BMI-for-age (BMIz). The average treatment effect (ATE) of cesarean versus vaginal birth was calculated from augmented inverse probability weighted analyses accounting for a wide range of confounding variables. There was little evidence of an effect of cesarean birth on HFAz (ATE = 0.26 95%CI -0.35, 0.87, n = 3993), WFAz (ATE = 0.35, 95%CI -0.19, 0.89, n = 4817) or BMIz (ATE = 0.11, 95%CI -0.25, 0.46, n = 3909). Cesarean section was not associated with anthropometry among children aged 3-6 years.

A whole-of-population study of term and post-term gestational age at birth and children's development.

OBJECTIVE: To examine the risk of poor child development according to week of gestation at birth, among children born ≥ 37 weeks' gestation. DESIGN: Population-based study using linked data (n = 12,601). SETTING: South Australia. POPULATION: All births ≥ 37 weeks' gestation. METHODS: Relative risks of developmental vulnerability for each week of gestation were calculated with adjustment for confounders and addressing missing information. MAIN OUTCOME MEASURES: Child development was documented by teachers during a national census of children attending their first year of school in 2009, using the Australian Early Development Index (AEDI). Children scoring in the lowest 10% of the AEDI were categorised as developmentally vulnerable. RESULTS: The percentage of children vulnerable on one or more AEDI domains for the following gestational ages 37, 38, 39, 40, 41, 42-45 weeks was 24.8, 22.3, 20.6, 20.0, 20.4 and 24.2, respectively. Compared with children born at 40 weeks, the adjusted relative risks [(95% confidence interval (CI)] for vulnerability on ≥ 1 AEDI domain were; 37 weeks 1.13 (0.99-1.28), 38 weeks 1.05 (0.96-1.15), 39 weeks 1.02 (0.94-1.12), 41 weeks 1.00 (0.90-1.11) and 42-45 weeks 1.20 (0.84-1.72). CONCLUSIONS: Children born at 40-41 weeks' gestation may have the lowest risk of developmental vulnerability at school entry, reinforcing the importance of term birth in perinatal care. Early term or post-term gestational age at birth can help clinicians, teachers and parents recognise children with potential developmental vulnerabilities at school entry.

Associations between dietary patterns at 6 and 15 months of age and sociodemographic factors.

BACKGROUND/OBJECTIVES: Data from the Avon Longitudinal Study of Parents and Children (ALSPAC) have previously shown that dietary patterns are observable by 3 years. However, it is not clear when dietary patterns emerge. We aimed to describe dietary patterns in early life and their associations with maternal and infant sociodemographic characteristics. SUBJECTS/METHODS: Principal component analysis was applied to diet questionnaires of ALSPAC participants at 6 months (n = 7052) and 15 months (n = 5610) to extract dietary patterns. The sociodemographic factors associated with dietary patterns were investigated using regression analyses. RESULTS: Four dietary patterns were extracted at both 6 and 15 months. A traditional-style pattern characterized by home-prepared meats, vegetables and desserts, a second pattern characterized by ready-prepared baby foods and a third pattern characterized by discretionary foods such as biscuits, sweets and crisps were identified at both ages. At 6 months, the fourth pattern was characterized predominantly by breastfeeding and at 15 months, by contemporary-style foods including herbs, legumes, nuts, raw fruit and vegetables. Higher maternal age and education, number of siblings and lower body mass index (BMI) was associated with higher scores on the breastfeeding or meat, vegetables and desserts patterns, whereas higher discretionary food pattern scores were associated with younger maternal age, lower education, higher BMI and more siblings. Associations between sociodemographic factors and the ready-prepared baby food pattern scores were inconsistent across ages. CONCLUSIONS: Dietary patterns emerge from infancy and are associated with sociodemographic characteristics.

Human milk fatty acids from lactating mothers of preterm infants: a study revealing wide intra- and inter-individual variation.

Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important nutrients in the preterm diet and fixed ratios have been proposed for formula. We evaluated the intra- and inter-individual variation in milk fatty acids from mothers of preterm infants involved in a randomised trial of tuna oil or placebo supplementation. Milk samples were collected every 2 weeks while infants were hospitalised and fatty acids analysed by capillary gas chromatography. DHA was higher in milk of supplemented mothers than control (% total fatty acids, mean+/-SD, treatment 0.9+/-0.4, control 0.3+/-0.1, p<0.0005) and ranged between 0.3-2.5% and 0.1-1.1%, respectively. AA did not differ between groups and ranged between 0.2-0.9% and 0.3-0.9%, respectively. Control mothers milk had wider AA:DHA ratio than treatment mothers (0.4-3.2 versus 0.2-2.1). Due to the wide variation in milk AA and DHA, statements recommending infant formula based on a fixed AA:DHA ratio should be re-examined.

Effect of two doses of docosahexaenoic acid (DHA) in the diet of preterm infants on infant fatty acid status: results from the DINO trial.

Formula supplemented with docosahexaenoic acid (DHA) improves retinal function of preterm infants but the optimal dose is unknown. In a randomized controlled trial we examined the effect of increasing the DHA concentration of human milk and formula on circulating fatty acids of preterm infants. Infants born <33 weeks gestation were fed high-DHA milk (1% total fat as DHA) or standard-DHA milk (0.2-0.3% DHA) until reaching their estimated due date (EDD). Milk arachidonic acid (AA) concentration was approximately 0.5% for both groups. At EDD, erythrocyte membrane phospholipid DHA was elevated in the high-DHA group compared with standard-DHA (mean+/-SD, high-DHA 6.8+/-1.2, standard-DHA 5.2+/-0.7, p<0.0005) but AA was lower (high-DHA 14.9+/-1.3, standard-DHA 16.0+/-1.2, p<0.0005). Feeding preterm infants human milk and formula with 1% DHA raises but does not saturate erythrocyte phospholipids with DHA. Milk exceeding 1% DHA may be required to increase DHA status to levels seen in term infants.