Social and economic factors, maternal behaviours in pregnancy and neonatal adiposity in the PANDORA cohort

BACKGROUND

Australian Indigenous women experience high rates of social disadvantage and type 2 diabetes (T2D) in pregnancy, but it is not known how social factors and maternal behaviours impact neonatal adiposity in offspring of women with hyperglycaemia in pregnancy.

METHODS

Participants were Indigenous (n = 404) and Europid (n = 240) women with gestational diabetes mellitus (GDM) or T2D in pregnancy and their offspring in the Pregnancy and Neonatal Diabetes Outcomes in Remote Australia (PANDORA) study. Social, economic factors, and maternal behaviours were measured in pregnancy and six neonatal anthropometric outcomes were examined after birth.

RESULTS

On univariate analysis, maternal education < 12 years (p = 0.03), unemployment (p = 0.001), welfare income vs no welfare income (p = 0.001), lower area based socio-economic score (p < 0.001), and fast food intake > 2 times/week (p = 0.002) were associated with increased sum of skinfolds (SSF) in offspring. Smoking was significantly associated with a reduction in anthropometric measures, except SSF. In multivariable models adjusted for ethnicity, BMI and hyperglycaemia, social and economic factors were no longer significant predictors of neonatal outcomes. Smoking was independently associated with a reduction in length, head circumference and fat free mass. Frequent fast food intake remained independently associated with SSF (β-coefficient 1.08 mm, p = 0.02).

CONCLUSION

In women with hyperglycaemia in pregnancy, social factors were associated with neonatal adiposity, particularly skinfold measures. Promoting smoking cessation and limited intake of energy-dense, nutrient-poor foods in pregnancy are important to improve neonatal adiposity and lean mass outcomes. Addressing inequities in social and economic factors are likely to be important, particularly for Indigenous women or women experiencing social disadvantage.

Cord blood metabolic markers are strong mediators of the effect of maternal adiposity on fetal growth in pregnancies across the glucose tolerance spectrum: the PANDORA study

AIMS/HYPOTHESIS

We aimed to assess associations between cord blood metabolic markers and fetal overgrowth, and whether cord markers mediated the impact of maternal adiposity on neonatal anthropometric outcomes among children born to Indigenous and Non-Indigenous Australian women with normal glucose tolerance (NGT), gestational diabetes mellitus (GDM) and pregestational type 2 diabetes mellitus.

METHODS

From the Pregnancy and Neonatal Outcomes in Remote Australia (PANDORA) study, an observational cohort of 1135 mother-baby pairs, venous cord blood was available for 645 singleton babies (49% Indigenous Australian) of women with NGT (n = 129), GDM (n = 419) and type 2 diabetes (n = 97). Cord glucose, triacylglycerol, HDL-cholesterol, C-reactive protein (CRP) and C-peptide were measured. Multivariable logistic and linear regression were used to assess the associations between cord blood metabolic markers and the outcomes of birthweight z score, sum of skinfold thickness (SSF), being large for gestational age (LGA) and percentage of body fat. Pathway analysis assessed whether cord markers mediated the associations between maternal and neonatal adiposity.

RESULTS

Elevated cord C-peptide was significantly associated with increasing birthweight z score (β 0.57 [95% CI 0.42, 0.71]), SSF (β 0.83 [95% CI 0.41, 1.25]), percentage of body fat (β 1.20 [95% CI 0.69, 1.71]) and risk for LGA [OR 3.14 [95% CI 2.11, 4.68]), after adjusting for age, ethnicity and diabetes type. Cord triacylglycerol was negatively associated with birthweight z score for Indigenous Australian women only. No associations between cord glucose, HDL-cholesterol and CRP >0.3 mg/l (2.9 nmol/l) with neonatal outcomes were observed. C-peptide mediated 18% (95% CI 13, 36) of the association of maternal BMI with LGA and 11% (95% CI 8, 17) of the association with per cent neonatal fat.

CONCLUSIONS/INTERPRETATION

Cord blood C-peptide is an important mediator of the association between maternal and infant adiposity, across the spectrum of maternal glucose tolerance.

Maternal dietary patterns during pregnancy derived by reduced-rank regression and birth weight in the Chinese population

Few studies have investigated the association between maternal dietary patterns (DP) during pregnancy, derived from reduced-rank regression (RRR), and fetal growth. This study aims to identify DP during pregnancy associated with macro- and micronutrient intakes, using the RRR method, and to examine their relationship with birth weight (BW). We used data of 7194 women from a large-scale cross-sectional survey in Northwest China. Dietary protein, carbohydrate, haem Fe density and the ratio of PUFA and MUFA:SFA were used as the intermediate variables in the RRR model to extract DP. Generalised estimating equation models were applied to evaluate the associations between DP and BW and related outcomes (including BW z-score, low birth weight (LBW) and small for gestational age (SGA)). Four DP during pregnancy were identified. Socio-demographically disadvantaged pregnant women were more likely to have lower BW and lower adherence to DP1 (high legumes, soyabean products, vegetables and animal-source foods, with relative low wheat and oils). Women with medium and high adherence to DP1 had significantly increased BW (medium 28·6 (95 % CI 7·1, 50·1); high 25·2 (95 % CI 2·7, 47·6)) and BW z-score and had significantly reduced risks of LBW and SGA. The associations were stronger among women with babies <3100 g. There is no association between other DP and outcomes. Higher adherence to the DP that was high in legumes, soyabean products, vegetables and animal-source foods was associated with improved BW in the Chinese pregnant women, particularly among those with disadvantageous socio-demographic conditions.

Use of smoking cessation pharmacotherapies during pregnancy is not associated with increased risk of adverse pregnancy outcomes: a population-based cohort study

BACKGROUND

Varenicline, bupropion and nicotine replacement therapy (NRT) are three effective pharmacotherapies for smoking cessation, but data about their safety in pregnancy are limited. We assessed the risk of adverse perinatal outcomes and major congenital anomalies associated with the use of these therapies in pregnancy in Australia.

METHODS

Perinatal data for 1,017,731 deliveries (2004 to 2012) in New South Wales and Western Australia were linked to pharmaceutical dispensing, hospital admission and death records. We identified 97,875 women who smoked during pregnancy; of those, 233, 330 and 1057 were exposed to bupropion, NRT and varenicline in pregnancy, respectively. Propensity scores were used to match exposed women to those who were unexposed to any smoking therapy (1:10 ratio). Propensity scores and gestational age at exposure were used to match varenicline-exposed to NRT-exposed women (1:1 ratio). Time-dependent Cox proportional hazards models estimated hazard ratios (HR) with 95% confidence intervals (95% CI) for any adverse perinatal event (a composite of 10 unfavourable maternal and neonatal outcomes) and any major congenital anomaly.

RESULTS

The risk of any adverse perinatal event was not significantly different between bupropion-exposed and unexposed women (39.2% versus 39.3%, HR 0.93, 95% CI 0.73-1.19) and between NRT-exposed and unexposed women (44.8% vs 46.3%, HR 1.02, 95% CI 0.84-1.23), but it was significantly lower in women exposed to varenicline (36.9% vs 40.1%, HR 0.86, 95% CI 0.77-0.97). Varenicline-exposed infants were less likely than unexposed infants to be born premature (6.5% vs 8.9%, HR 0.72, 95% CI 0.56-0.92), be small for gestational age (11.4% vs 15.4%, HR 0.68, 95% CI 0.56-0.83) and have severe neonatal complications (6.6% vs 8.2%, HR 0.74, 95% CI 0.57-0.96). Among infants exposed to varenicline in the first trimester, 2.9% had a major congenital anomaly (3.5% in unexposed infants, HR 0.91, 95% CI 0.72-1.15). Varenicline-exposed women were less likely than NRT-exposed women to have an adverse perinatal event (38.7% vs 51.4%, HR 0.58, 95% CI 0.33-1.05).

CONCLUSIONS

Pregnancy exposure to smoking cessation pharmacotherapies does not appear to be associated with an increased risk of adverse birth outcomes. Lower risk of adverse birth outcomes in varenicline-exposed pregnancies is inconsistent with recommendations that NRT be used in preference to varenicline.

Maternal and Neonatal Health Outcomes Associated with the Use of Gliclazide and Metformin for the Treatment of Diabetes in Pregnancy: A Record Linkage Study

Background: Gliclazide is commonly used in the treatment of diabetes mellitus; however, very little is known regarding the safety of its use in pregnancy. The aims of this study was to examine the rate of maternal hospitalizations, congenital anomalies, and adverse neonatal outcomes in pregnant women treated with gliclazide compared with pregnant women treated with metformin. Methods: Women who used gliclazide during pregnancy (n = 108) between 2003 and 2012 were identified by linking national medication dispensing data with the New South Wales perinatal data collection. A comparison group of women treated with only metformin during pregnancy (n = 108) were selected using propensity score matching. Data on hospital admissions, mortality, and congenital anomalies were extracted to examine the health of mothers and their children across groups. Results: Rates of maternal hospitalizations during pregnancy were not significantly different between women in the two groups (incident rate ratio: 1.10, 95% CI: 0.90-1.34, P = 0.339). There was no significant difference in average birth weight (3402 g compared with 3572 g, P = 0.072), incidence of neonatal hypoglycemia (<4.6% compared with <4.6%, P = 0.684), or congenital anomalies (7.4% compared with 5.6%, P = 0.582) in neonates exposed to gliclazide compared with metformin. Conclusions: The use of gliclazide during pregnancy was not associated with increased maternal hospitalization or neonatal adverse outcomes in comparison with the use of metformin in pregnancy; however, the limited number of exposed pregnancies is a key limitation.

Pregnancy And Neonatal Diabetes Outcomes in Remote Australia: the PANDORA study-an observational birth cohort

BACKGROUND

In Australia's Northern Territory, 33% of babies are born to Indigenous mothers, who experience high rates of hyperglycemia in pregnancy. We aimed to determine the extent to which pregnancy outcomes for Indigenous Australian women are explained by relative frequencies of diabetes type [type 2 diabetes (T2DM) and gestational diabetes (GDM)].

METHODS

This prospective birth cohort study examined participants recruited from a hyperglycemia in pregnancy register. Baseline data collected were antenatal and perinatal clinical information, cord blood and neonatal anthropometry. Of 1135 women (48% Indigenous), 900 had diabetes: 175 T2DM, 86 newly diagnosed diabetes in pregnancy (DIP) and 639 had GDM. A group of 235 women without hyperglycemia in pregnancy was also recruited.

RESULTS

Diabetes type differed for Indigenous and non-Indigenous women (T2DM, 36 vs 5%; DIP, 15 vs 7%; GDM, 49 vs 88%, p < 0.001). Within each diabetes type, Indigenous women were younger and had higher smoking rates. Among women with GDM/DIP, Indigenous women demonstrated poorer birth outcomes than non-Indigenous women: large for gestational age, 19 vs 11%, p = 0·002; neonatal fat 11.3 vs 10.2%, p < 0.001. In the full cohort, on multivariate regression, T2DM and DIP were independently associated (and Indigenous ethnicity was not) with pregnancy outcomes.

CONCLUSIONS

Higher rates of T2DM among Indigenous women predominantly contribute to absolute poorer pregnancy outcomes among Indigenous women with hyperglycemia. As with Indigenous and minority populations globally, prevention or delay of type 2 diabetes in younger women is vital to improve pregnancy outcomes and possibly to improve the long-term health of their offspring.

Modulation of Placental Gene Expression in Small-for-Gestational-Age Infants

Small-for-gestational-age (SGA) infants are fetuses that have not reached their genetically programmed growth potential. Low birth weight predisposes these infants to an increased risk of developing cardiovascular, metabolic and neurodevelopmental conditions in later life. However, our understanding of how this pathology occurs is currently incomplete. Previous research has focused on understanding the transcriptome, epigenome and bacterial signatures separately. However, we hypothesise that interactions between moderators of gene expression are critical to understanding fetal growth restriction. Through a review of the current literature, we identify that there is evidence of modulated expression/methylation of the placental genome and the presence of bacterial DNA in the placental tissue of SGA infants. We also identify that despite limited evidence of the interactions between the above results, there are promising suggestions of a relationship between bacterial signatures and placental function. This review aims to summarise the current literature concerning fetal growth from multiple avenues and propose a novel relationship between the placental transcriptome, methylome and bacterial signature that, if characterised, may be able to improve our current understanding of the placental response to stress and the aetiology of growth restriction.

Ultrasound Measurements of Intracranial Structures in Growth-Restricted Neonates with Fetal Blood Flow Redistribution: A Pilot Observational Study

BACKGROUND

Fetal growth restriction (FGR) is associated with neonatal and long-term neuro-morbidity. Preferential redistribution of blood flow to the brain is a common antenatal adaptation in FGR. The impact of this "brain sparing," which may signify severity of FGR, on the growth of brain structures has not been studied.

AIM

To compare corpus callosum (CC), cerebellar, and ventricular measurements of FGR neonates with evidence of fetal blood flow redistribution with those of gestation-matched appropriately grown (AGA) neonates.

METHODS

This was a pilot, prospective observational study conducted at a tertiary level neonatal unit in Melbourne, Australia. Cranial ultrasound was done between days 1 and 3 of life in FGR and AGA neonates.

RESULTS

Cranial ultrasound on 20 FGR, gestation (mean ± SD) 31.4 ± 3.1 weeks, weight 1,205 ± 463 g, and 20 AGA neonates, 31.1 ± 3.0 weeks, 1,668 ± 490 g, was performed. CC length was significantly decreased in FGR neonates as compared to AGA neonates (35.28 ± 3.47 vs. 38.83 ± 4.05 mm, p = 0.0002). CC was significantly thinner at genu (3.36 ± 0.66 vs. 4.04 ± 0.83 mm, p = 0.007), body (1.97 ± 0.36 vs. 2.27 ± 0.39 mm, p = 0.02), and splenium (4.07 ± 0.76 vs. 4.72 ± 0.75 mm, p = 0.003) in FGR vs. AGA neonates. CC-fastigium length was also significantly decreased (39.65 ± 3.87 vs. 41.96 ± 4.50 mm, p = 0.04). Similarly, FGR neonates showed decreased transverse cerebellar diameter (36.15 ± 5.51 vs. 38.81 ± 7.21 mm, p = 0.02), but ventricular measurements were comparable. In multivariate analysis, these differences were evident independent of the birth weight.

CONCLUSIONS

CC and cerebellar measurements are significantly smaller in FGR neonates with fetal blood flow redistribution, which warrants further study.

Does public reporting of the detection of fetal growth restriction improve clinical outcomes: a retrospective cohort study

OBJECTIVE

To assess the impact of publicly reporting a statewide fetal growth restriction (FGR) performance indicator.

DESIGN

Retrospective cohort study from 2000 to 2017.

SETTING

All maternity services in Victoria, Australia.

POPULATION

A total of 1 231 415 singleton births at ≥32 weeks of gestation.

METHODS

We performed an interrupted time-series analysis to assess the impact of publicly reporting an FGR performance indicator on the rate of detection for severe cases of small for gestational age (SGA). Rates of perinatal mortality and morbidity and obstetric intervention were assessed for severe SGA pregnancies and pregnancies delivered for suspected SGA.

MAIN OUTCOME MEASURES

Gestation at delivery, obstetric management and perinatal outcome.

RESULTS

The public reporting of a statewide FGR performance indicator was associated with a steeper reduction per quarter in the percentage of severe SGA undelivered by 40 weeks of gestation, from 0.13 to 0.51% (P = 0.001), and a decrease in the stillbirth rate by 3.3 per 1000 births among those babies (P = 0.01). Of babies delivered for suspected SGA, the percentage with birthweights ≥ 10th centile increased from 41.4% (n = 307) in 2000 to 53.3% (n = 1597) in 2017 (P < 0.001). Admissions to a neonatal intensive care unit for babies delivered for suspected SGA but with a birthweight ≥ 10th centile increased from 0.8 to 2.0% (P < 0.001).

CONCLUSIONS

The public reporting of an FGR performance indicator has been associated with the improved detection of severe SGA and a decrease in the rate of stillbirth among those babies, but with an increase in the rate of iatrogenic birth for babies with normal growth.

TWEETABLE ABSTRACT

The public reporting of hospital performance is associated with a reduction in stillbirth, but also with unintended interventions.

Trajectories of antipsychotic use before and during pregnancy and associated maternal and birth characteristics

OBJECTIVE

To identify distinct trajectories of antipsychotic use prior to and during pregnancy and describe the associated maternal and birth characteristics.

METHODS

We conducted a population-based cohort study of births (2005-2012) using linked administrative data in New South Wales, Australia. We used group-based trajectory modelling to classify trajectories of antipsychotic use in the 450 days prior to pregnancy and during pregnancy. We characterised women with different trajectories according to maternal sociodemographic characteristics, mental health diagnoses and hospitalisations, use of psychotropic medicines and birth outcomes.

RESULTS

Of 137,993 women who gave birth, 2741 (2.0%) were exposed to antipsychotics prior to or during pregnancy. We identified six trajectories of antipsychotic use: two involved short-term use of low daily doses prior to pregnancy (51.1%), while three involved long-term use of low (20.9%), moderate (11.0%) and high (2.0%) daily doses throughout pregnancy. One trajectory (15.0%) involved increasing use during pregnancy. Women with long-term use were more likely to have a schizophrenia or bipolar disorder diagnosis, to have used multiple psychotropics and to have a mental health hospitalisation during pregnancy. Overall, women using antipsychotics had elevated rates of adverse birth outcomes compared to unexposed women. Women with the greatest antipsychotic exposure had the highest rates of gestational diabetes and gestational hypertension.

CONCLUSION

Women using antipsychotics around pregnancy are heterogeneous, with varying patterns of use and associated birth outcomes, reflecting underlying differences in the indications for treatment and/or severity of illness. This diversity should be considered when developing clinical guidelines and designing safety studies.

Caesarean section and risk of type 1 diabetes: whole-of-population study

AIM

A hypothesized mechanism for increased type 1 diabetes risk among caesarean births is lack of exposure to the vaginal microbiota. Children born by prelabour caesarean are not exposed to the vaginal microbiota, whereas caesarean births during labour (intrapartum) may be exposed. The aim of this study was to estimate type 1 diabetes risk among children born by caesarean compared with normal vaginal delivery.

METHODS

This whole-of-population study linked routinely collected, de-identified administrative data from the South Australian Early Childhood Data Project for all births from 1999 to 2013. Type 1 diabetes cases were identified using inpatient hospitalizations from 2001 to 2014 (ICD-10-AM codes E10-E109). Type 1 diabetes risk for caesarean was assessed by Cox regression using two models: (i) caesarean vs. vaginal and (ii) prelabour or intrapartum caesarean vs. vaginal. Analyses were adjusted for confounding and multiple imputation was used to address missing data.

RESULTS

A total of 286 058 children born between 1999 and 2013 contributed to 2 200 252 person-years, of which 557 had type 1 diabetes. Of all births, 90 546 (31.7%) were caesarean, and of these 53.1% were prelabour and 46.9% intrapartum caesarean. Compared with vaginal delivery, the adjusted hazard ratio for type 1 diabetes was 1.05 [95% confidence interval (CI) 0.86-1.28) for caesarean, 1.02 (95% CI 0.79-1.32) for prelabour caesarean and 1.08 (95% CI 0.82-1.41) for intrapartum caesarean.

CONCLUSION

There may be a small increased type 1 diabetes risk following caesarean, but confidence intervals included the null. The lower estimate for prelabour compared with intrapartum caesarean, and the potential for unmeasured confounding suggest that neonatal vaginal microbiota might not be involved in type 1 diabetes.

Benefits of not smoking during pregnancy for Australian Aboriginal and Torres Strait Islander women and their babies: a retrospective cohort study using linked data

OBJECTIVES

To provide evidence for targeted smoking cessation policy, the aim of this study was to compare pregnancy outcomes of Aboriginal mothers who reported not smoking during pregnancy with Aboriginal mothers who reported smoking during pregnancy.

DESIGN

Population based retrospective cohort study using linked data.

SETTING

New South Wales, the most populous Australian state.

POPULATION

18 154 singleton babies born to 13 477 Aboriginal mothers between 2010 and 2014 were identified from routinely collected New South Wales datasets. Aboriginality was determined from birth records and from four linked datasets through an Enhanced Reporting of Aboriginality algorithm.

EXPOSURE

Not smoking at any time during pregnancy.

MAIN OUTCOME MEASURES

Unadjusted and adjusted relative risks (aRR) and 95% CIs from modified Poisson regression were used to examine associations between not smoking during pregnancy and maternal and perinatal outcomes including severe morbidity, inter-hospital transfer, perinatal death, preterm birth and small-for-gestational age. Population attributable fractions (PAFs) were calculated using adjusted relative risks.

RESULTS

Compared with babies born to mothers who smoked during pregnancy, babies born to non-smoking mothers had a lower risk of all adverse perinatal outcomes including perinatal death (aRR=0.58, 95% CI 0.44 to 0.76), preterm birth (aRR=0.58, 95% CI 0.53 to 0.64) and small-for-gestational age (aRR=0.35, 95% CI 0.32 to 0.39). PAFs (%) were 27% for perinatal death, 26% for preterm birth and 48% for small-for-gestational-age. Compared with women who smoked during pregnancy (n=8919), those who did not smoke (n=9235) had a lower risk of being transferred to another hospital (aRR=0.76, 95% CI 0.66 to 0.89).

CONCLUSIONS

Babies born to women who did not smoke during pregnancy had a lower risk of adverse perinatal outcomes. Rates of adverse outcomes among Aboriginal non-smokers were similar to those among the general population. These results quantify the proportion of adverse perinatal outcomes due to smoking and highlight why effective smoking cessation programme are urgently required for this population.

The association between haemoglobin levels in the first 20 weeks of pregnancy and pregnancy outcomes

BACKGROUND

Low haemoglobin has been linked to adverse pregnancy outcomes. Our study aimed to assess the association of haemoglobin (Hb) in the first 20 weeks of pregnancy, and restoration of low Hb levels, with pregnancy outcomes in Australia.

METHODS

Clinical data for singleton pregnancies from two tertiary public hospitals in New South Wales were extracted for 2011-2015. The relationship between the lowest Hb result in the first 20 weeks of pregnancy and adverse outcomes was determined using adjusted Poisson regression. Those with Hb <110 g/L were classified into 'restored' and 'not restored' based on Hb results from 21 weeks onwards, and risk of adverse outcomes explored with adjusted Poisson regression.

RESULTS

Of 31,906 singleton pregnancies, 4.0% had Hb <110 and 10.2% had ≥140 g/L at ≤20 weeks. Women with low Hb had significantly higher risks of postpartum haemorrhage, transfusion, preterm birth, very low birthweight, and having a baby transferred to higher care or stillbirth. High Hb was also associated with higher risks of preterm, very low birthweight, and transfer to higher care/stillbirth. Transfusion was the only outcome where risk decreased with increasing Hb. Risk of transfusion was significantly lower in the 'restored' group compared with the 'not restored' group (OR 0.39, 95% CI 0.22-0.70), but restoration of Hb did not significantly affect the other outcomes measured.

CONCLUSIONS

Women with both low and high Hb in the first 20 weeks of pregnancy had higher risks of adverse outcomes than those with normal Hb. Restoring Hb after 20 weeks did not improve most adverse outcome rates but did reduce risk of transfusion.

Disparities between Aboriginal and non-Aboriginal perinatal mortality rates in Western Australia from 1980 to 2015

BACKGROUND

Perinatal mortality rates are typically higher in Aboriginal than non-Aboriginal populations of Australia.

OBJECTIVES

This study aimed to examine the pattern of stillbirth and neonatal mortality rate disparities over time in Western Australia, including an evaluation of these disparities across gestational age groupings.

METHODS

All singleton births (≥20 weeks gestation) in Western Australia between 1980 and 2015 were included. Linked data were obtained from core population health datasets of Western Australia. Stillbirth and neonatal mortality rates and percentage changes in the rates over time were calculated by Aboriginal status and gestational age categories.

RESULTS

From 1980 to 2015, data were available for 930 926 births (925 715 livebirths, 5211 stillbirths and 2476 neonatal deaths). Over the study period, there was a substantial reduction in both the Aboriginal (19.6%) and non-Aboriginal (32.3%) stillbirth rates. These reductions were evident in most gestational age categories among non-Aboriginal births and in Aboriginal term births. Concomitantly, neonatal mortality rates decreased in all gestational age windows for both populations, ranging from 32.1% to 77.5%. The overall stillbirth and neonatal mortality rate differences between Aboriginal and non-Aboriginal birth decreased by 0.6 per 1000 births and 3.9 per 1000 livebirths, respectively, although the rate ratios (RR 2.51, 95% CI 2.14, 2.94) and (RR 2.94, 95% CI 2.24, 3.85), respectively reflect a persistent excess of Aboriginal perinatal mortality across the study period.

CONCLUSIONS

Despite steady improvements in perinatal mortality rates in Western Australia over 3½ decades, the gap between Aboriginal and non-Aboriginal rates remains unchanged in relative terms. There is a continuing, pressing need to address modifiable risk factors for preventable early mortality in Aboriginal populations.

Optic nerve sonography and ophthalmic artery Doppler velocimetry in healthy pregnant women: an Australian cohort study

PURPOSE

Maternal ocular sonography offers a window into cerebrovascular and intracranial pressure changes in pregnancy. This study aimed to determine the Doppler velocimetric variables of the ophthalmic artery, and the mean diameter of the optic nerve sheath (ONSD), in an Australian cohort of healthy pregnant women.

METHODS

A prospective observational cohort study of healthy women with uncomplicated singleton pregnancies in the third trimester was undertaken in a tertiary maternity service. A single prenatal ultrasonographic examination was performed on all participants, with a postnatal examination performed on a subgroup with uncomplicated deliveries.

RESULTS

Fifty women were examined at a mean gestation of 35 weeks. The mean ± SD Doppler variables in the ophthalmic artery were peak systolic velocity (PSV) 41.89 ± 13.13 cm/s, second peak velocity 20.63 ± 8.97 cm/s, end diastolic velocity 9.29 ± 5.13 cm/s, pulsatility index 1.97 ± 0.53, resistive index 0.78 ± 0.07, peak ratio (second peak velocity/PSV) 0.49 ± 0.12, while the mean ONSD was 4.34 ± 0.4 mm. None of these variables had a demonstrable relationship with gestation or mean arterial pressure (MAP), nor did the sheath diameter have a relationship with any of the Doppler variables.

CONCLUSIONS

The ocular sonographic variables observed in this population are similar to those reported in other cohorts. No clear relationship could be identified in this cohort between ophthalmic artery Doppler variables and the ONSD, and between each of these variables and gestation or MAP.

Adverse perinatal outcomes in immigrants: A ten-year population-based observational study and assessment of growth charts

BACKGROUND

Maternity populations are becoming increasingly multiethnic. Conflicting findings exist regarding the risk of adverse perinatal outcomes among immigrant mothers from different world regions and which growth charts are most appropriate for identifying the risk of adverse outcomes.

OBJECTIVE

To evaluate whether infant mortality and morbidity, and the categorisation of infants as small for gestational age or large for gestational age (SGA or LGA) vary by maternal country of birth, and to assess whether the choice of growth chart alters the risk of adverse outcomes in infants categorised as SGA and LGA.

METHODS

A population cohort of 601 299 singleton infants born in Australia to immigrant mothers was compared with 1.7 million infants born to Australian-born mothers, 2004-2013. Infants were categorised as SGA and LGA according to a descriptive Australian population-based birthweight chart (Australia-2012 reference) and the prescriptive INTERGROWTH-21st growth standard. Propensity score reweighting was used for the analysis.

RESULTS

Compared to Australian-born infants, infants of mothers from Africa, Philippines, India, other Asia countries, and the Middle East had between 15.4% and 48.1% elevated risk for stillbirth, preterm delivery, or low Apgar score. The association between SGA and LGA and perinatal mortality varied markedly by growth chart and country of birth. Notably, SGA infants from African-born mothers had a relative risk of perinatal mortality of 6.1 (95% CI 4.3, 6.7) and 17.3 (95% CI 12.0, 25.0) by the descriptive and prescriptive charts, respectively. LGA infants born to Australian-born mothers were associated with a 10% elevated risk of perinatal mortality by the descriptive chart compared to a 15% risk reduction by the prescriptive chart.

CONCLUSIONS

Country-of-birth-specific variations are becoming increasingly important for providing ethnically appropriate and safe maternity care. Our findings highlight significant variations in risk of adverse perinatal outcomes in immigrant subgroups, and demonstrate how the choice of growth chart alters the quantification of risk associated with being born SGA or LGA.

Birth outcomes in women with gestational diabetes managed by lifestyle modification alone: The PANDORA study

AIMS

To assess outcomes of women in the Pregnancy and Neonatal Diabetes Outcomes in Remote Australia (PANDORA) cohort with gestational diabetes mellitus (GDM) managed by lifestyle modification compared with women without hyperglycaemia in pregnancy.

METHODS

Indigenous (n = 97) and Europid (n = 113) women managed by lifestyle modification were compared to women without hyperglycaemia (n = 235). Multivariate linear and logistic regressions assessed whether GDM-lifestyle women had poorer outcomes compared to women without hyperglycaemia.

RESULTS

Women with GDM-lifestyle had higher body mass index and lower gestational weight gain than women without hyperglycaemia. On univariate analysis, gestational age at delivery was lower and induction rates were higher in women with GDM-lifestyle than without hyperglycaemia. On multivariable regression, GDM-lifestyle was associated with lower gestational age at delivery (by 0.73 weeks), lower birthweight z-score (by 0.26, p = 0.007), lower likelihood of large for gestational age (LGA) [OR (95% CI): 0.55 (0.28, 1.02), p = 0.059], and greater likelihood of labour induction [2.34 (1.49, 3.66), p < 0.001] than women without hyperglycaemia.

CONCLUSION

Women with GDM managed by lifestyle modification had higher induction rates and their offspring had lower birthweight z-scores, with a trend to lower LGA than those without hyperglycaemia in pregnancy. Further studies are indicated to explore reasons for higher induction rates.

Ethnic differences in prevalence, risk factors, and perinatal outcomes of gestational diabetes mellitus: A comparison between immigrant ethnic Chinese women and Australian-born Caucasian women in Australia

BACKGROUND

The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. Ethnic differences in risk factors and perinatal outcomes are clinically important. Chinese women constitute approximately 10% of the world's population, and are an increasing migrant population, yet prevalence, risk factors, and outcomes of GDM in this population are insufficiently explored.

METHODS

A retrospective study of a large pregnancy dataset comparing GDM prevalence, risk factors, and perinatal outcomes between immigrant ethnic Chinese women and Australian-born Caucasian women was conducted using logistic regression.

RESULTS

Overall, 73 517 births were extracted from the pregnancy databases of two of Australia's largest maternity services. Chinese women (n = 3419) had a 4-fold higher risk of GDM than Caucasians (n = 28 594) after adjusting for risk factors of GDM. A past history of GDM (adjusted odds ratio [aOR] 5.24; 95% confidence interval [95% CI] 2.91-9.42] was the main GDM risk factor in both groups. Other GDM risk factors varied between groups. Perinatal outcomes in Chinese women with and without GDM were similar, except for neonatal hypoglycemia (aOR 2.01; 95% CI 1.14-3.56]. Caucasian women with GDM had more adverse perinatal outcomes than women without GDM. After adjusting for confounders, Chinese women with GDM had a lower risk of labor induction, large-for-gestational-age babies, neonatal hypoglycemia, respiratory distress, and low Apgar scores than Caucasian women with GDM.

CONCLUSIONS

Differences in prevalence, risk profile, and adverse outcomes in GDM were evident between ethnic Chinese and Caucasian women. A precision medicine approach to GDM may be warranted considering ethnicity and individual risk profiles rather than a one-size-fits-all approach.

Identification of the optimal growth charts for use in a preterm population: An Australian state-wide retrospective cohort study

BACKGROUND

Preterm infants are a group at high risk of having experienced placental insufficiency. It is unclear which growth charts perform best in identifying infants at increased risk of stillbirth and other adverse perinatal outcomes. We compared 2 birthweight charts (population centiles and INTERGROWTH-21st birthweight centiles) and 3 fetal growth charts (INTERGROWTH-21st fetal growth charts, World Health Organization fetal growth charts, and Gestation Related Optimal Weight [GROW] customised growth charts) to identify which chart performed best in identifying infants at increased risk of adverse perinatal outcome in a preterm population.

METHODS AND FINDINGS

We conducted a retrospective cohort study of all preterm infants born at 24.0 to 36.9 weeks gestation in Victoria, Australia, from 2005 to 2015 (28,968 records available for analysis). All above growth charts were applied to the population. Proportions classified as <5th centile and <10th centile by each chart were compared, as were proportions of stillborn infants considered small for gestational age (SGA, <10th centile) by each chart. We then compared the relative performance of non-overlapping SGA cohorts by each chart to our low-risk reference population (infants born appropriate size for gestational age [>10th and <90th centile] by all intrauterine charts [AGAall]) for the following perinatal outcomes: stillbirth, perinatal mortality (stillbirth or neonatal death), Apgar <4 or <7 at 5 minutes, neonatal intensive care unit admissions, suspicion of poor fetal growth leading to expedited delivery, and cesarean section. All intrauterine charts classified a greater proportion of infants as <5th or <10th centile than birthweight charts. The magnitude of the difference between birthweight and fetal charts was greater at more preterm gestations. Of the fetal charts, GROW customised charts classified the greatest number of infants as SGA (22.3%) and the greatest number of stillborn infants as SGA (57%). INTERGROWTH classified almost no additional infants as SGA that were not already considered SGA on GROW or WHO charts; however, those infants classified as SGA by INTERGROWTH had the greatest risk of both stillbirth and total perinatal mortality. GROW customised charts classified a larger proportion of infants as SGA, and these infants were still at increased risk of mortality and adverse perinatal outcomes compared to the AGAall population. Consistent with similar studies in this field, our study was limited in comparing growth charts by the degree of overlap, with many infants classified as SGA by multiple charts. We attempted to overcome this by examining and comparing sub-populations classified as SGA by only 1 growth chart.

CONCLUSIONS

In this study, fetal charts classified greater proportions of preterm and stillborn infants as SGA, which more accurately reflected true fetal growth restriction. Of the intrauterine charts, INTERGROWTH classified the smallest number of preterm infants as SGA, although it identified a particularly high-risk cohort, and GROW customised charts classified the greatest number at increased risk of perinatal mortality.

Caesarean section improves neonatal outcomes only from 24 + 0 weeks for periviable breech but not for cephalic infants

Background: Although caesarean delivery at periviable gestations may minimize birth trauma, it may not necessarily improve perinatal outcomes. The aim of this study was to assess the impact of mode of birth on outcomes for breech versus cephalic presentation at 22 + 0-25 + 6 weeks.Methods: Retrospective cohort study of single, nonanomalous infants at 22 + 0-25 + 6 weeks gestation born at a tertiary center in Australia. Neonatal outcomes were analyzed comparing both breech and cephalic presentation and mode of delivery.Results: Six hundred and eighty eight women fulfilled the inclusion criteria with 39.7% (273/688) breech and 60.3% (415/688) cephalic infants. Survival was 31.5% (86/273) and 38.1% (158/415) in the breech and cephalic cohorts respectively. Vaginal breech infants had reduced odds of survival compared to the vaginal cephalic group (aOR 0.37, 95% CI 0.17-0.75, p < .01) with no difference in survival if delivery occurred by caesarean section. Vaginal breech birth had higher odds of very low Apgar scores, stillbirth, and neonatal death. At 22 + 0-22 + 6 weeks, outcomes were universally fatal. At 24 + 0-24 + 6 and 25 + 0-25 + 6 weeks, vaginal breech birth had lower odds of survival (aOR 0.33, 95% CI 0.13-0.84, p < .05 and aOR 0.10, 95% CI 0.03-0.34, p < .001 respectively) compared to caesarean breech births.Conclusions: Caesarean section improves perinatal outcomes for periviable breech infants > 24 + 0 weeks.

Pregnancy outcomes among women with type 1 diabetes mellitus using continuous subcutaneous insulin infusion versus multiple daily injections: A retrospective cohort study

Background

Insulin delivery options for pregnant women with type 1 diabetes mellitus are either continuous subcutaneous insulin infusion or multiple daily injections. The aim of this paper is to compare pregnancy outcomes in women with type 1 diabetes mellitus using continuous subcutaneous insulin infusion or multiple daily injections in pregnancy.

Methods

Retrospective single-centre cohort study of 298 pregnancies booked between 2006 and 2016. Descriptive analysis was performed for HbA1c values. Logistic regression models were created to compare selected maternal and neonatal outcomes.

Results

Continuous subcutaneous insulin infusion was associated with increased risk of large-for-gestational age (aOR 2.00, 95% CI 1.20-3.34) and preterm neonates (aOR 1.80, 95% CI 1.04-3.03). Continuous subcutaneous insulin infusion had no association with increased risk of adverse pregnancy outcomes. No difference in HbA1c values existed between groups.

Conclusion

Using continuous subcutaneous insulin infusion for type 1 diabetes mellitus through pregnancy is associated with increased risk of large-for-gestational age and preterm neonates, without increased risk of associated adverse maternal or neonatal outcomes.

Real-world experience of metformin use in pregnancy: Observational data from the Northern Territory Diabetes in Pregnancy Clinical Register

BACKGROUND

In Australia's Northern Territory, Indigenous mothers account for 33% of births and have high rates of hyperglycemia in pregnancy. The prevalence of type 2 diabetes (T2D) in pregnancy is up to 10-fold higher in Indigenous than non-Indigenous Australian mothers, and the use of metformin is common. We assessed birth outcomes in relation to metformin use during pregnancy from a clinical register.

METHODS

The study included women with gestational diabetes (GDM), newly diagnosed diabetes in pregnancy (DIP), or pre-existing T2D from 2012 to 2016. Data were analyzed for metformin use in the third trimester. Regression models were adjusted for maternal age, body mass index, parity, and insulin use.

RESULTS

Of 1649 pregnancies, 814 (49.4%) were to Indigenous women, of whom 234 (28.7%) had T2D (vs 4.6% non-Indigenous women; P < 0.001). Metformin use was high in Indigenous women (84%-90% T2D, 42%-48% GDM/DIP) and increased over time in non-Indigenous women (43%-100% T2D, 14%-35% GDM/DIP). Among Indigenous women with GDM/DIP, there were no significant differences between groups with and without metformin in cesarean section (51% vs 39%; adjusted odds ratio [aOR] 1.25, 95% confidence interval [CI] 0.87-1.81), large for gestational age (24% vs 13%; aOR 1.5, 95% CI 0.9-2.5), or serious neonatal adverse events (9.4% vs 5.9%; aOR 1.32, 95% CI 0.68-2.57). Metformin use was independently associated with earlier gestational age (37.7 vs 38.5 weeks), but the risk did not remain independently higher after exclusion of women managed with medical nutrition therapy alone, and the increase in births <37 weeks was not significant on multivariate analysis.

CONCLUSIONS

We found no clear evidence of any adverse outcomes related to the use of metformin for the treatment of hyperglycemia in pregnancy.

Reference centiles for maternal placental growth factor levels at term from a low-risk population

INTRODUCTION

Placental growth factor (PLGF) is a biomarker of placental function. The aim of this study was to define reference ranges for maternal PLGF levels in a normotensive cohort ≥36 + 0 weeks.

METHOD

Prospective observational data from Mater Mothers' Hospital, Brisbane. PLGF levels were measured in women at ≥36 + 0 weeks with singleton, non-anomalous pregnancies. Women with hypertension and fetal growth restriction were excluded. PLGF (pg/mL) was assayed using DELFIA® Xpress (PerkinElmer Inc). The Generalised Additive Model for Location, Shape and Scale (GAMLSS) method was used for the calculation of gestational age-adjusted centiles. Data analysis was performed with Stata 13 (StataCorp, LLC) and R software (R Foundation for Statistical Computing, Vienna, Austria). In all women, PLGF was measured within 2 weeks of delivery.

RESULTS

The study cohort comprised of 845 women (36 weeks n = 73, 37 weeks n = 230, 38 weeks n = 214, 39 weeks n = 172, 40 weeks n = 115, 41weeks n = 41). PLGF levels were negatively correlated with gestational age (r = -0.20, p < 0.001). Median PLGF levels dropped significantly from 36 weeks to 41 weeks (169.0 pg/mL to 96.6 pg/mL, p < 0.001). Gestational age specific maternal PLGF centiles were reported using fractional polynomial additive term and Box-Cox t distribution. PLGF did not perform adequately as a predictive test for adverse perinatal outcomes (AUC <0.6).

DISCUSSION

We have created gestational centile reference ranges for maternal PLGF from a normotensive cohort. These novel data suggest maternal PLGF levels decline ≥36 + 0 weeks. The utility of PLGF as a predictor of adverse perinatal outcomes at term, should be further investigated with clinical trials.

Comparison of iodine status pre- and post-mandatory iodine fortification of bread in South Australia: a population study using newborn thyroid-stimulating hormone concentration as a marker

Objective:

The present study aimed to evaluate the effect of mandatory iodine fortification of bread on the iodine status of South Australian populations using newborn thyroid-stimulating hormone (TSH) concentration as a marker.

Design:

The study used an interrupted time-series design.

Setting:

TSH data collected between 2005 and 2016 (n 211 033) were extracted from the routine newborn screening programme in South Australia for analysis. Iodine deficiency is indicated when more than 3 % of newborns have TSH > 5 mIU/l.

Participants:

Newborns were classified into three groups: the pre-fortification group (those born before October 2009); the transition group (born between October 2009 and June 2010); and the post-fortification group (born after June 2010).

Results:

The percentage of newborns with TSH > 5 mIU/l was 5·1, 6·2 and 4·6 % in the pre-fortification, transition and post-fortification groups, respectively. Based on a segmented regression model, newborns in the post-fortification period had a 10 % lower risk of having TSH > 5 mIU/l than newborns in the pre-fortification group (incidence rate ratio (IRR) = 0·90; 95 % CI 0·87, 0·94), while newborns in the transitional period had a 22 % higher risk of having TSH > 5 mIU/l compared with newborns in the pre-fortification period (IRR = 1·22; 95 % CI 1·13, 1·31).

Conclusions:

Using TSH as a marker, South Australia would be classified as mild iodine deficiency post-fortification in contrast to iodine sufficiency using median urinary iodine concentration as a population marker. Re-evaluation of the current TSH criteria to define iodine status in populations is warranted in this context.

Associations of dietetic management with maternal and neonatal health outcomes in women diagnosed with gestational diabetes: a retrospective cohort study

BACKGROUND

In 2010, the recommended diagnostic thresholds for gestational diabetes mellitus (GDM) were amended, which has increased GDM diagnoses, as well as pressure on the services involved in GDM management, specifically impacting dietetic workloads. The present study examined the associations between dietetic intervention in women with GDM and maternal and neonatal health outcomes.

METHODS

The present study involved 1233 adult women with GDM who delivered at The Royal Women's Hospital (RWH), Melbourne, Australia, between July 2015 and May 2017. Retrospective data assessing GDM-care (therapy type, diagnosis time and model of care, maternal and neonatal health outcomes, and outpatient dietetic consultations) were retrieved from patient medical records. Unadjusted and adjusted linear and logistic regression were used to assess associations of GDM care dietetic intervention and GDM care and dietetic intervention with maternal and neonatal health outcomes.

RESULTS

Women receiving dietetic intervention had a decreased likelihood of infant admission to the neonatal intensive care unit or special care nursery than women who not receiving dietetic intervention [adjusted odds ratio (OR) = 0.41, 95% confidence interval (CI) = 0.22-0.75; P = 0.004). Women requiring pharmacotherapy were more likely to experience maternal complications (adjusted OR = 3.13, 95% CI = 2.23-4.41; P < 0.001) and had a greater number of dietetic consultations (β-coefficient = 0.28, 95% CI = 0.17-0.39; P < 0.001) compared to women managed through diet.

CONCLUSIONS

Dietetic intervention plays a key role in optimising maternal and neonatal health outcomes for women with GDM. Exploring further the impact of dietetic intervention in women diagnosed with GDM is key with respect to understanding the optimal delivery of care for these women. The type and number of consultations included in a dietetic intervention should be investigated further.

Short-term health outcomes of newborn infants of substance-using mothers in Australia and New Zealand: A systematic review

AIM

Substance use is not unusual among women of childbearing age. Pregnant women who use a substance and the consequent impacts on a newborn vary across studies and settings. We reviewed New Zealand and Australian literature to examine the short-term health outcomes of newborn of substance-using mothers and their demographic characteristics.

METHODS

Five medical/nursing databases and google scholar were searched in April 2017. Studies were considered eligible if they described outcomes of newborn of substance-using mothers. Mixed Methods Appraisal Tool was used for quality assessment of candidate studies. Relevant data were extracted and analyzed using narrative synthesis. Based on data availability, a subset of studies was included in meta-analysis.

RESULTS

Although findings of individual studies vary, there are some evidence that the infants born to substance-using mothers were likely to have preterm birth, low birthweight, small-for-gestational age, low Apgar score, and admission to neo-natal intensive care unit. The likelihood of adverse health outcomes was much higher for newborns of polysubstance-using mothers, than newborns of mothers using a single substance. Pregnant women who use illicit substance are predominantly socially disadvantaged, in their twenties and or of Aboriginal descent.

CONCLUSION

Infants of substance-using mothers suffer a range of adverse health outcomes. Multidisciplinary and integrated approach of services that ensure supportive social determinants of health may result in a better outcome for newborn and positive behavioral change among mothers.

Inter-agency indicators of out-of-home-care placement by age 13-14 years: A population record linkage study

BACKGROUND

Cross-agency administrative data can improve cost-effective triage systems for child protection and other human service delivery.

OBJECTIVE

To determine the minimum set of cross-agency indicators that could accurately classify placement in out-of-home-care (OOHC) before age 13-14 years.

PARTICIPANTS AND SETTING

Participants were 72,079 Australian children (mean age = 13.16 years; SD = 0.37; 51.4% male) and their parents, for whom linked administrative records spanning the years 1994-2016 were available for analysis within the 'New South Wales Child Development Study'.

METHODS

First, a series of logistic regression analyses were conducted to examine associations between cross-agency (health, justice, education) risk indicators and membership of the sub-cohort of 1239 children who had an OOHC placement prior to age 13-14 years, relative to (1) the sub-cohort of 55,473 children who had no previous contact with child protection services, and (2) the sub-cohort of 15,367 children who had been reported to child protection services but had no record of OOHC placement. We then explored the classification characteristics associated with a smaller combination of risk factors, and the utility of specific familial risk factors, for classifying membership of the OOHC subgroup.

RESULTS

A combination of six risk indicators evident before OOHC placement can classify children placed in OOHC with approximately 95% accuracy, and the presence of at least four of these risk indicators provides excellent specificity (99.6%).

CONCLUSIONS

A combination of risk factors observable in administrative datasets held by multiple government agencies may be used to target support services to prevent entry into OOHC for children from vulnerable families.

Birth outcomes in Aboriginal mother-infant pairs from the Northern Territory, Australia, who received 23-valent polysaccharide pneumococcal vaccination during pregnancy, 2006-2011: The PneuMum randomised controlled trial

BACKGROUND

Pregnant women and infants <6 months old have a high baseline risk for pneumococcal disease compared to the general population, particularly among Indigenous populations living in poverty and low-resource settings. Efficacy trials of pneumococcal vaccination in pregnancy examining adverse birth outcomes are lacking.

AIMS

We report adverse birth events as secondary outcomes from the 'PneuMum' randomised controlled trial of 23-valent pneumococcal polysaccharide vaccination (23vPPV) in pregnancy (August 2006-January 2011).

MATERIALS AND METHODS

Australian Aboriginal women aged 17-39 years with singleton uncomplicated pregnancies were randomised (1:2 ratio) to receive 23vPPV or no 23vPPV in pregnancy at 30-36 weeks gestation. We compared risks of stillbirth, preterm birth, low birthweight (LBW), and small for gestational age (SGA) between vaccinated and unvaccinated pregnant women. Cox proportional hazard ratios (HRs) were calculated on an intention-to-treat basis.

RESULTS

Among 227 enrolled participants, 75 (33%) received 23vPPV in pregnancy. Risk differences in adverse birth outcomes between 23vPPV vaccinated and unvaccinated pregnant women were; preterm birth 9% vs 4% (HR 2.79; 95% CI 0.94-8.32) P = 0.07; LBW 9% vs 5% (HR 2.09; 95% CI 0.76-5.78) P = 0.15; and SGA 15% vs 17% (HR 1.02; 95% CI 0.50-2.06) P = 0.96. There were no stillbirths.

CONCLUSIONS

We found a numerically higher rate of preterm births among women who received 23vPPV in pregnancy compared to unvaccinated pregnant women. Although further investigation with larger participant numbers is needed to better evaluate this safety signal, the contribution of safety results from smaller studies using appropriate data analysis methodologies is critical, particularly as more clinical trials in pneumococcal vaccination in pregnancy are progressing.

Maternal exposure to fine particulate matter from a coal mine fire and birth outcomes in Victoria, Australia

INTRODUCTION

The Hazelwood coal mine fire was an unprecedented event in Australian history that resulted in the surrounding towns in regional Victoria being covered in plumes of smoke and ash for six weeks in 2014. Evidence concerning adverse reproductive impacts associated with maternal exposure to ambient air pollution is expanding. Gaps remain regarding the relative impact of acute changes in outdoor air quality lasting days to months, such as that resulting from coal mine fires.

METHODS

Routinely collected perinatal data was used to define a complete cohort of singleton babies born within the affected region. Maternal average, and peak, fine particulate matter (PM_2.5) was assigned to residential address at time of delivery using a chemical transport model. Maternal, infant, meteorological and temporal variables were adjusted for in final linear and log-binomial regression models.

RESULTS

There were a total of 3591 singleton livebirths during the study period; 763 of which were in utero during the coal mine fire. Average PM_2.5 exposure was 4.4 μg/m³ (median 1.9; IQR 2.1 μg/m³) and peak was 45.0 μg/m³ (median 30.4; IQR 35.1 μg/m³). There was no association between coal mine fire-attributable PM_2.5 and fetal growth or gestational maturity outcomes. However, there was weak evidence that gestational diabetes mellitus was an effect modifier in the relationship between maternal PM_2.5 exposure and birth weight. Babies born to exposed gestational diabetic mothers were 97 g heavier per 10 μg/m³ increase in average PM_2.5 exposure (95%CI 74, 120 g). No association was observed among mothers without gestational diabetes.

CONCLUSION

Maternal exposure to fine particulate matter resulting from the 2014 Hazelwood coal mine fire did not appear to adversely effect fetal maturity. However, there was weak evidence of a trophic response among babies born to exposed mothers with gestational diabetes, a possible susceptibility that requires further exploration.

Serum podocalyxin at 11-13 weeks of gestation in the prediction of small for gestational age neonates

OBJECTIVE

To investigate a potential new marker for the prediction of small for gestational age (SGA) infants.

STUDY DESIGN

Nested case-control study involving 280 uncomplicated pregnancies and 70 cases of SGA without pre-eclampsia. Serum podocalyxin was measured at 11-13 weeks of gestation and results were expressed in multiples of the median (MoM). The performance of screening by a combination of maternal history and podocalyxin levels was assessed with ROC curves.

RESULTS

SGA was predicted by maternal age, height, South Asian ethnicity, and previous delivery without pre-eclampsia. Median podocalyxin levels were higher in affected than uncomplicated pregnancies (1.303 versus 0.994 MoM, p < 0.001). At a 10% false-positive rate, maternal history identified 40.0% of the cases (AUC = 0.74, 95%CI 0.671-0.809). The addition of podocalyxin increased the detection to 54.3% (AUC = 0.78, 95%CI 0.771-0.842, p = 0.027 for the difference in ROC curves).

CONCLUSION

First-trimester podocalyxin may be useful in screening for SGA infants.

Prenatal alcohol exposure and infant gross motor development: a prospective cohort study

BACKGROUND

Maternal alcohol consumption in pregnancy may have adverse effects on child gross motor (GM) development. There have been few human studies on this topic, particularly ones examining low exposure. This study examined the association between prenatal alcohol exposure (PAE) and infant GM development at 12-months of age.

METHODS

Participants were 1324 women recruited from antenatal clinics in Sydney and Perth, Australia. Maternal and paternal alcohol use was assessed in pregnancy via interview; offspring GM development was measured at 12-months with the Bayley Scales of Infant Development (BSID-III).

RESULTS

Any alcohol use in pregnancy was common: 56.1%, of pregnant women drank early in Trimester one (0-6 weeks), however this reduced to 27.9% on average thereafter and at predominantly low levels. However, infant BSID GM scale scores were not found to differ significantly as a function of PAE in the first 6-weeks (low, moderate, binge or heavy PAE), nor with low PAE across pregnancy.

CONCLUSIONS

We found no evidence to suggest that low PAE is associated with measurable impairment in infant GM development at 12-months. Further research is needed to examine potential PAE impacts on GM development in heavier exposure groups and through the childhood years when subtle GM deficits may be more detectable.

Thrombocytopenia in well small for gestational age neonates

: Thrombocytopenia has been closely associated with small-for-gestational-age neonates (SGA; birthweight less than tenth percentile) admitted to the special care nursery or neonatal ICU. It is unclear if 'well' SGA neonates experience the same incidence of thrombocytopenia in the SGA population as compared to sick neonates. We conducted a retrospective cohort study from a health network in Melbourne, Australia, between 2012 and 2015 to identify SGA neonates (≥ 35 weeks' gestation at birth) that were otherwise well. Neonates with at least one platelet count within 7 days of life were matched to appropriate-for-gestational-age (AGA) neonates from the same birth centre, with the same sex, and closest gestational age and birth date, who were also considered otherwise well. 16.7% of matched neonates had thrombocytopenia (303/1814) and of these, a larger proportion of SGA neonates were thrombocytopenic, 21.7% (197/907), than AGA neonates, 11.7% (106/907, P < 0.01). The incidence of thrombocytopenia was greater in the SGA cohort regardless of admission destination (special care nursery/neonatal ICU 26.8 vs. 13.9%, P < 0.01; Postnatal Ward 16.5 vs. 9.4%, P < 0.01). Thrombocytopenia is more prevalent amongst constitutionally well SGA neonates than AGA neonates. SGA alone increases the risk of thrombocytopenia.

A large proportion of poor birth outcomes among Aboriginal Western Australians are attributable to smoking, alcohol and substance misuse, and assault

Background

Aboriginal infants have poorer birth outcomes than non-Aboriginal infants. Harmful use of tobacco, alcohol, and other substances is higher among Aboriginal women, as is violence, due to factors such as intergenerational trauma and poverty. We estimated the proportion of small for gestational age (SGA) births, preterm births, and perinatal deaths that could be attributed to these risks.

Methods

Birth, hospital, mental health, and death records for Aboriginal singleton infants born in Western Australia from 1998 to 2010 and their parents were linked. Using logistic regression with a generalized estimating equation approach, associations with birth outcomes and population attributable fractions were estimated after adjusting for demographic factors and maternal health during pregnancy.

Results

Of 28,119 births, 16% of infants were SGA, 13% were preterm, and 2% died perinatally. 51% of infants were exposed in utero to at least one of the risk factors and the fractions attributable to them were 37% (SGA), 16% (preterm) and 20% (perinatal death).

Conclusions

A large proportion of adverse outcomes were attributable to the modifiable risk factors of substance use and assault. Significant improvements in Aboriginal perinatal health are likely to follow reductions in these risk factors. These results highlight the importance of identifying and implementing risk reduction measures which are effective in, and supported by, Aboriginal women, families, and communities.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2252-4) contains supplementary material, which is available to authorized users.

Trends and predictors of extreme preterm birth: Western Australian population-based cohort study

Background

The preterm birth rate is rising in high-income countries and is associated with increased mortality and morbidity. Although the risks increase with greater prematurity and risk factors have been found to vary with gestational age and labour onset, few studies have focused on the myriad pathways to extreme preterm birth (20–27 weeks’ gestation). The current study investigated trends in extreme preterm birth by labour onset type and examined the antecedent risks to further our understanding around the identification of high-risk pregnancies.

Methods

Retrospective cohort study including all singleton extreme preterm births in Western Australia between 1986 and 2010. De-identified data from six core population health datasets were linked and used to ascertain extreme preterm births (excluding medical terminations and birth defects) after spontaneous onset of labour, preterm pre-labour rupture of membranes, and medically indicated labour onset. Trends over time in extreme preterm birth were analysed using linear regression. Multivariable regression techniques were used to assess the relative risks associated with each salient, independent risk factor and to calculate Population Attributable Risks (PARs).

Results

The extreme preterm birth rate including medical terminations and birth defects significantly increased over time whereas the extreme preterm birth rate excluding medical terminations and birth defects did not change. After medical terminations and birth defects were excluded, the rate of medically indicated extreme preterm births significantly increased over time whereas the rate of preterm pre-labour rupture of membranes extreme preterm births significantly reduced, and the rate of spontaneous extreme preterm births did not significantly change. In the multivariate analyses, factors associated with placental dysfunction accounted for >10% of the population attributable risk within each labour onset type.

Conclusions

First study to show that the increase in extreme preterm birth in high-income jurisdiction is no longer evident after medical terminations and birth defects are excluded. Interventions that identify and target women at risk of placental dysfunction presents the greatest opportunity to reduce extreme preterm births.

Human placental androgen receptor variants: Potential regulators of male fetal growth

INTRODUCTION

Numerous studies show that males have increased intrauterine growth compared to females, and that pregnancy complications may further these growth differences, but the regulatory mechanisms underlying these differences remain unknown. We propose that these growth outcomes may be due to sex-specific differences in androgen sensitivity - giving rise to altered growth signalling pathways - mediated by the differential expression of placental androgen receptor (AR) variants.

METHODS

Placental protein and mRNA were used to identify AR protein variant levels and AR-downstream target gene expression, and were then analysed against neonatal measurements. Dihydrotestosterone (DHT)-induced AR protein variant expression and downstream growth factors were examined in vitro.

RESULTS

Four known AR variants (AR-FL, AR-V1, AR-V7, and AR-45), and three unknown proteins (120, 90 and 55 kDa) immunoreactive to the anti-AR antibody were identified in human placentae. Male placentae from controlled asthmatic pregnancies had increased AR-45 and decreased AR-V1 and AR-V7 nuclear expression. Increased nuclear AR-45 expression was associated with increased insulin-like growth factor 1 (IGF-1), IGF-1 receptor (IGF-1R), and IGF-binding protein 5 (IGFBP-5) mRNA expression and normal male growth. AR-45 mRNA and protein did not change in the presence of uncontrolled maternal asthma and associated with an increase in small for gestational (SGA) male fetuses. In vitro DHT stimulation increased AR-45 protein and IGF-1R and IGFBP-5 mRNA expression.

CONCLUSIONS

Collectively, our data shows altered AR protein expression and downstream signalling targets may contribute to sex-specific fetal growth outcomes in response to an adverse environment, and that AR-45 appears central in mediating these changes.

Maternal fetal programming of birthweight among Australian Aboriginal infants: a population-based data linkage study

BACKGROUND

Low birthweight, which is common among Australian Aboriginal infants, has been found to persist across generations because of shared genetic and environmental factors and possibly fetal programming. Fetal programming refers to the response of a fetus to hostile uterine conditions with lifelong effects and possibly, in turn, providing a poorer uterine environment for future offspring. Fetal programming might have a greater effect in populations that have undergone rapid lifestyle transitions-for example, Indigenous populations. Disentangling causal effects is difficult, but family-based approaches could provide insights. We explored whether poor maternal fetal growth caused low birthweight in Aboriginal infants.

METHODS

In this data linkage study, we used linked administrative health records of 12 865 singleton Aboriginal infants born in Western Australia between 1980 and 2010 and their relatives (including siblings born in 2011). Electronic birth records included all births since 1980 with at least 20 weeks completed gestation or a birthweight of 400 g. We compared parental-offspring birthweight associations using three approaches-a regression analysis of the complete sample, adjusting for confounding variables; a comparison of the maternal-offspring and paternal-offspring associations; and a within-cousin group comparison. We used binary and continuous measures of birthweight. We categorised infants and their parents as small for gestational age (SGA) if their birthweight was below the first decile of birthweights for all singleton livebirths of the same sex and gestational age in Australia between 1998 and 2007.

FINDINGS

The relative risk (RR) of SGA birth was higher for infants with SGA mothers than for those with non-SGA mothers (RR 1·65, 95% CI 1·49 to 1·83), after adjusting for grandmaternal parity. After additional adjustment for maternal height, the risk remained higher for those with non-SGA mothers (RR 1·51, 1·36 to 1·68). The maternal birthweight Z score coefficient was 0·17 (95% CI 0·14 to 0·20), compared with 0·13 (0·10 to 0·16) for paternal birthweight, a difference of 0·03 (-0·01 to 0·08). In the cousin analysis, the maternal-offspring association was fully attenuated (0·00, 95% CI -0·05 to 0·06). Conditions in the current pregnancy were strongly associated with offspring birthweight Z score. Smoking was associated with a mean decrease of 0·39 (95% CI -0·45 to -0·34) in offspring birthweight Z score, drug misuse with a decrease of 0·31 (-0·43 to -0·20), and diabetes with an increase of 0·58 (0·39 to 0·77).

INTERPRETATION

We found little support for maternal fetal programming causing low offspring birthweight. The similar maternal and paternal influence on birthweight and our cousin analysis suggested transmission of genetic and environmental factors could explain much of the maternal-offspring birthweight association. Compared with other risk factors in the current pregnancy, fetal programming appears to have little or no role in the high numbers of infants with low birthweight among Aboriginal populations.

FUNDING

National Health and Medical Research Council of Australia and Bellberry Ltd.

Health outcomes for Australian Aboriginal and Torres Strait Islander children born preterm, low birthweight or small for gestational age: A nationwide cohort study

Objective

To examine health outcomes in Australian Aboriginal and Torres Strait Islander children experiencing perinatal risk and identify protective factors in the antenatal period.

Methods

Baby/Child cohorts of the Longitudinal Study of Indigenous Children, born 2001–2008, across four annual surveys (aged 0–8 years, N = 1483). Children with ‘mild’ and ‘moderate-to-high’ perinatal risk were compared to children born normal weight at term for maternal-rated global health and disability, and body-mass-index measured by the interviewer.

Results

Almost one third of children had experienced mild (22%) or moderate-to-high perinatal risk (8%). Perinatal risk was associated with lower body-mass-index z-scores (regression coefficients adjusted for pregnancy and environment factors: mild = -0.21, 95% CI = -0.34, -0.07; moderate-to-high = -0.42, 95% CI = -0.63, -0.21). Moderate-to-high perinatal risk was associated with poorer global health, with associations becoming less evident in models adjusted for pregnancy and environment factors; but not evident for disability. A range of protective factors, including cultural-based resilience and smoking cessation, were associated with lower risk of adverse outcomes.

Conclusions

Perinatal risks are associated with Australian Aboriginal and Torres Strait children experiencing adverse health particularly lower body weight. Cultural-based resilience and smoking cessation may be two modifiable pathways to ameliorating health problems associated with perinatal risk.

Can the gap in Aboriginal outcomes be explained by DOHaD

In Australia, there are two distinct populations, each with vastly disparate health outcomes: Aboriginal and Torres Strait Islander People and non-Aboriginal Australians. Aboriginal Australians have significantly higher rates of health and socioeconomic disadvantage, and Aboriginal babies are also more likely to be born low birth weight or growth restricted. The Developmental Origins of Health and Disease (DOHaD) hypothesis advocates that a sub-optimal intrauterine environment, often manifested as diminished foetal growth, during critical periods of foetal development has the potential to alter the risk of non-communicable disease in the offspring. A better understanding of the role of the intrauterine environment and subsequent developmental programming, in response to both transgenerational and immediate stimuli, in Aboriginal Australians remains a relatively unexplored field and may provide insights into the prevailing health disparities between Aboriginal and non-Aboriginal children. This narrative review explores the role of DOHaD in explaining the ongoing disadvantage experienced by Aboriginal People in today's society through a detailed discussion of the literature on the association between foetal growth, as a proxy for the quality of the intrauterine environment, and outcomes in the offspring including perinatal health, early life development and childhood education. The literature largely supports this hypothesis and this review therefore has potential implications for policy makers not only in Australia but also in other countries that have minority and Indigenous populations who suffer disproportionate disadvantage such as the United States, Canada and New Zealand.

Impact of different glycaemic treatment targets on pregnancy outcomes in gestational diabetes

AIM

With no current randomized trials, we explored the impact of tight compared with standard treatment targets on pregnancy outcomes in gestational diabetes mellitus (GDM).

METHODS

This cohort study of singleton births ≥ 28 weeks' gestation was conducted at two major Australian maternity services (2009-2013). Standardized maternal, neonatal and birth outcomes were examined using routine healthcare data and compared for women with GDM at Service One (n = 2885) and Service Two (n = 1887). Services applied different treatment targets: Service One (standard targets, reference group) fasting < 5.5 mmol/l, 2-h postprandial < 7.0 mmol/l; Service Two (tight targets) fasting < 5.0 mmol/l, 2-h postprandial < 6.7 mmol/l. Multivariable regression with propensity score adjustment was used to examine associations between targets and outcomes.

RESULTS

GDM prevalence and insulin use were 7.9% and 31% at Service One, and 5.7% and 46% at Service Two. There were no differences in primary outcomes: birthweight > 90th centile [adjusted odds ratio (OR) 1.06, 95% confidence interval (CI) 0.87-1.30] and < 10th centile (OR 0.84, 95% CI 0.70-1.01), or secondary outcomes gestational hypertension, pre-eclampsia, shoulder dystocia or a perinatal composite. Service Two with tight targets had increased induction of labour (OR 3.63, 95% CI 3.17-4.16), elective Caesarean section (OR 1.75, 95% CI 1.37-2.23) and Apgar scores < 7 at 5 min (OR 1.54, 95% CI 1.05-2.25), decreased hypoglycaemia (OR 0.76, 95% CI 0.61-0.94]), jaundice (OR 0.47, 95% CI 0.35-0.63) and respiratory distress (OR 0.68, 95% CI 0.47-0.98).

CONCLUSIONS

Tight GDM treatment targets were associated with greater insulin use and no difference in primary birthweight outcomes. The service with tight targets had higher obstetric intervention, lower rates of reported hypoglycaemia, jaundice, respiratory distress and lower Apgar scores. High-quality interventional data are required before tight treatment targets can be implemented.

Increased α-Linolenic Acid Intake during Pregnancy is Associated with Higher Offspring Birth Weight

BACKGROUND

The amount and type of fat in the maternal diet during pregnancy are important contributors to fetal growth. The importance of plant-based omega-3 fatty acid (α-linolenic acid, ALA) intake in fetal growth has not been previously examined.

OBJECTIVE

We sought to determine the association of maternal ALA intake during pregnancy with birth weight and body composition of the offspring.

METHODS

Mothers and their newborn infants (n = 224) were recruited from the Royal Prince Alfred Hospital, Australia. Maternal diet during pregnancy was assessed using a validated food frequency questionnaire. Plasma fatty acid composition was analyzed in a subset of mothers (n = 41). Newborn body composition was assessed using air-displacement plethysmography. All analyses were adjusted for gestational age, sex, physical activity, and total energy intake.

RESULTS

Dietary fatty acid intakes were positively associated with plasma phospholipid fatty acids for total omega-3 fatty acids (β = 0.452, P = 0.003), ALA (β = 0.339, P = 0.03), linoleic acid (β = 0.353, P = 0.03), eicosapentaenoic acid (β = 0.407, P = 0.009), and docosahexaenoic acid (β = 0.388, P = 0.01). Higher maternal intake of ALA (% total fat) was associated with higher offspring birth weight [189.7-g increase per 1% higher ALA (95% CI: 14, 365 g); P = .04], although individually neither newborn fat mass nor fat-free mass was significant. Birth weight increased across tertiles of maternal ALA intake (P ANOVA = 0.05), with birth weight being 221 g (95% CI: 12, 429 g) higher in those with the highest maternal ALA intake compared with those with the lowest intake (P = 0.04). Mothers of infants born small for gestational age (n = 32) had a lower ALA intake than those born appropriate for gestational age (n = 162) or large for gestational age [(n = 21); P = 0.05].

CONCLUSIONS

In otherwise healthy women giving birth at a major tertiary hospital in Australia, intake of ALA during pregnancy is associated with higher offspring birth weight. This may have implications for dietary strategies aimed at optimizing fetal growth via modification of maternal diet.

Implications of the introduction of new criteria for the diagnosis of gestational diabetes: a health outcome and cost of care analysis

OBJECTIVE

To identify effects on health outcomes from implementing new criteria diagnosing gestational diabetes mellitus(GDM) and to analyse costs-of-care associated with this change.

DESIGN

Quasi-experimental study comparing data from the calendar year before (2014) and after (2016) the change.

SETTING

Single, tertiary-level, university-affiliated, maternity hospital.

PARTICIPANTS

All women giving birth in the hospital, excluding those with pre-existing diabetes or multiple pregnancy.

MAIN OUTCOME MEASURES

Primary outcomes were caesarean section, birth weight >90th percentile for gestation, hypertensive disorder of pregnancy and preterm birth less than 37 weeks. A number of secondary outcomes reported to be associated with GDM were also analysed.Care packages were derived for those without GDM, diet-controlled GDM and GDM requiring insulin. The institutional Business Reporting Unit data for average occasions of service, pharmacy schedule for the costs of consumables and medications, and Medicare Benefits Schedule ultrasound services were used for costing each package. All costs were estimated in figures from the end of 2016 negating the need to adjust for Consumer Price Index increases.

RESULTS

There was an increase in annual incidence of GDM of 74% without overall improvements in primary health outcomes. This incurred a net cost increase of AUD$560 093. Babies of women with GDM had lower rates of neonatal hypoglycaemia and special care nursery admissions after the change, suggesting a milder spectrum of disease.

CONCLUSION

New criteria for the diagnosis of GDM have increased the incidence of GDM and the overall cost of GDM care. Without obvious changes in short-term outcomes, validation over other systems of diagnosis may require longer term studies in cohorts using universal screening and treatment under these criteria.

Baseline incidence of adverse birth outcomes and infant influenza and pertussis hospitalisations prior to the introduction of influenza and pertussis vaccination in pregnancy: a data linkage study of 78 382 mother-infant pairs, Northern Territory, Australia, 1994-2015

We conducted probabilistic data linkage of three population datasets for the Northern Territory (NT), Australia, to describe the incidence of preterm births, stillbirths, low birthweight and small for gestational age (SGA) per 1000 NT births; and influenza and pertussis hospitalisations per 1 00 000 NT births in infants <7 months of age, in a pre-maternal vaccination era. The Perinatal Trends dataset (1994-2014) formed the cohort of 78 382 births. Aboriginal mother-infant pairs (37%) had disproportionately higher average annual rates (AR) for all adverse birth outcomes compared to their non-Aboriginal counterparts; rate ratios: preterm births 2.2 (AR 142.4 vs. 64.7); stillbirths 2.3 (AR 10.8 vs. 4.6); low birthweight 2.9 (AR 54 vs. 19); and SGA 1.7 (AR 187 vs. 111). Hospitalisation (2000-2015) and Immunisation Register datasets (1994-2015), showed that influenza hospitalisations (n = 53) and rates were 42.3 times higher in Aboriginal infants (AR 254 vs. 6); and that pertussis hospitalisations (n = 37) were 7.1 times higher in Aboriginal infants (AR 142.5 vs. 20.2) compared to non-Aboriginal infants. These baseline data are essential to assess the safety and effectiveness of influenza and pertussis vaccinations in pregnant women from the NT. Remote living Aboriginal women and infants stand to benefit the most from these vaccines.

Fertility and Neonatal Outcomes of Freeze-All vs. Fresh Embryo Transfer in Women With Advanced Endometriosis

Background: Eutopic endometrium from women with endometriosis has functional changes in several aspects, which may largely account for the decrease in the quality of endometrial receptivity. It is of utmost importance to know whether freeze-all strategy can restore optimal receptivity in endometriotic women leading to the better ART outcomes. Methods: Retrospective study involved patients with advanced endometriosis undergoing first embryo transfer cycles during the period from March 2006 to March 2017 at a tertiary care center. After propensity score matching, there were 506 women in the freeze-all group and 255 women in fresh group. Our main outcomes included the rates of implantation, clinical pregnancy, and live birth. Subgroup analyses were performed after stratification by the number of oocytes retrieved and fertilization method. Neonatal outcomes included gestational age and birth weight z-score for singletons and multiple births. Results: In our matched cohort, the implantation, clinical pregnancy and live birth rates were statistically significantly higher in the freeze-all group compared with fresh transfer groups (34.4 vs. 25.5%, 51.8 vs. 38.8%, and 45.3 vs. 31.8%, all P < 0.001, respectively). A more beneficial effect of freeze-all cycles was found in patients who got more than 15 oocytes. Additionally, when ICSI insemination techniques were used to achieve fertilization, the advantage of freeze-all strategy was not obvious. Assessment of 382 babies showed no statistically significant difference in the mode of delivery, sex of live-born, gestational age, unadjusted median birth weight, and z-score between two study groups. Conclusion: Freeze-all strategy is an attractive option to improve the outcomes of ART for women with advanced endometriosis.

Childhood health and education outcomes following early term induction for large-for-gestational age: A population-based record linkage study

INTRODUCTION

There is debate about optimal management of pregnancies with a large-for-gestational age baby. A recent randomized controlled trial reported that early term induction of labor reduced cesarean section rates and infant morbidity. However, long term childhood outcomes have not been assessed. The aim of this study was to assess maternal, neonatal and child health and education outcomes for large-for-gestational age babies induced at 37-38 weeks' gestation.

MATERIAL AND METHODS

Population-based record linkage study of term (37+ weeks), cephalic-presenting singleton pregnancies with a large-for-gestational age baby in New South Wales, Australia, 2002-2006. Linked birth, hospital, mortality and education data were used with at least 9 years follow up from birth. Exposure was induction of labor at 37-38 weeks, compared to expectant management (spontaneous birth at ≥37 weeks and planned births at ≥39 weeks). Relative risks and 95% confidence intervals were estimated using Modified Poisson regression with robust variance.

RESULTS

Among 10 174 eligible pregnancies, 412 (4.0%) had an induction at 37-38 weeks. Women in the induction group were less likely to have a cesarean section (RR: 0.65, 95% CI: 0.51-0.82). Infants had higher rates of: low Apgar scores, birth trauma, neonatal jaundice and phototherapy use, and admission to special care nursery or neonatal intensive care than their expectantly managed counterparts. As children, they had higher rates of hospital admission (RR: 1.16, 95% CI: 1.04-1.30) and special needs (RR: 1.98, 95% CI: 1.12-3.50). However, by age 8 there was no difference in overall literacy and numeracy achievement.

CONCLUSIONS

Although women who had an early term labor induction with large-for-gestational age were less likely to have a cesarean section, the increased risk of neonatal morbidities and additional healthcare utilization suggests the need for caution in early induction of large-for-gestational age babies before 39 weeks' gestation.