Aim
Large for gestational age (LGA) babies have increased risks for short‐term outcomes such as shoulder dystocia, neonatal hypoglycaemia and longer hospital stay. Little is known of long‐term ...health, development and educational outcomes of LGA babies. The aim of this study was to determine the long‐term health, mortality, development and educational outcomes for infants born LGA at term.
Methods
A population‐based record linkage study of live singletons born at term (37–41 weeks of gestation) in New South Wales, Australia, from 2001 to 2006.
Results
This study compared 49 439 LGA (>90th percentile for birthweight, gestational age and sex) and 400 418 appropriate size for gestational age (AGA; 10th–90th percentile) infants. LGA infants had increased risk of birth and neonatal outcomes and hospitalisations, for brachial plexus injury after the neonatal period, and for all causes from 1 to 5 years of age. There were no differences in mortality up to 5 years of age or hospitalisations for type 1 diabetes in childhood. LGA infants had lower rates of developmental vulnerability (in kindergarten) and showed a significant trend (χ2 for trend <0.0001) to fewer low scores and more high scores in reading and numeracy (in Year 3) compared with AGA. After adjusting for potential confounders, only the relative risk for higher reading scores was statistically significant.
Conclusions
LGA infants show positive long‐term health, development and educational outcomes. Concerns for LGA infants still remain in the perinatal period as a result of birth trauma; however, these complications usually do not persist in postnatal and early childhood.
BACKGROUNDAdministrative or population health datasets (PHDS) are increasingly being used for research related to maternal and infant health. However, the accuracy and completeness of the information ...in the PHDS is important to ensure validity of the results of this research.
OBJECTIVETo compile and review studies that validate the reporting of conditions and procedures related to pregnancy, childbirth, and newborns and provide a tool of reference for researchers.
METHODSA systematic search was conducted of Medline and EMBASE databases to find studies that validated routinely collected datasets containing diagnoses and procedures related to pregnancy, childbirth, and newborns. To be included datasets had to be validated against a gold standard, such as review of medical records, maternal interview or survey, specialized register, or laboratory data. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and/or κ statistic for each diagnosis or procedure code were calculated.
RESULTSForty-three validation studies were included. Under-enumeration was common, with the level of ascertainment increasing as time from diagnosis/procedure to birth decreased. Most conditions and procedures had high specificities indicating few false positives, and procedures were more accurately reported than diagnoses. Hospital discharge data were generally more accurate than birth data, however identifying cases from more than 1 dataset further increased ascertainment.
CONCLUSIONSThis comprehensive collection of validation studies summarizing the quality of perinatal population data will be an invaluable resource to all researchers working with PHDS.
Background: Low serum 25-hydroxyvitamin D 25(OH)D concentrations during pregnancy have been associated with adverse pregnancy outcomes in a few studies but not in other studies.Objectives: We ...assessed the serum 25(OH)D concentration at 10–14 wk of pregnancy and its association with adverse pregnancy outcomes and examined the predictive accuracy.Design: In this nested case-control study, we measured serum 25(OH)D in 5109 women with singleton pregnancies who were attending first-trimester screening in New South Wales, Australia. Multivariate logistic regression was conducted to examine the association between low 25(OH)D concentrations and adverse pregnancy outcomes (small for gestational age, preterm birth, preeclampsia, gestational diabetes, miscarriage, and stillbirth). The predictive accuracy of models was assessed.Results: The median (IQR) 25(OH)D concentration for the total population was 56.4 nmol/L (43.3–69.8 nmol/L). Serum 25(OH)D concentrations showed significant variation by parity, smoking, weight, season of sampling, country of birth, and socioeconomic status. After adjustment for maternal and clinical risk factors, low 25(OH)D concentrations were not associated with most adverse pregnancy outcomes. The area under the receiver operating characteristic curve (AUC) and likelihood ratio for a composite of severe adverse pregnancy outcomes of 25(OH)D concentrations <25 nmol/L were 0.51 and 1.44, respectively, and, for risk factors alone, were 0.64 and 2.87, respectively. The addition of 25(OH)D information to maternal and clinical risk factors did not improve the ability to predict severe adverse pregnancy outcomes (AUC: 0.64; likelihood ratio: 2.32; P = 0.39).Conclusion: Low 25(OH)D serum concentrations in the first trimester of pregnancy are not associated with adverse pregnancy outcomes and do not predict complications any better than routinely assessed clinical and maternal risk-factor information.
Sleep apnea in pregnancy is known to adversely affect birth outcomes. Whether in utero exposure to maternal sleep apnea is associated with long-term childhood consequences is unclear.
...Population-based longitudinal study of singleton infants born during 2002-2012 was conducted using linked birth, hospital, death, developmental, and educational records from New South Wales, Australia. Maternal sleep apnea during pregnancy was identified from hospital records. Outcomes were mortality and hospitalizations up to age 6, developmental vulnerability in the first year of school (aged 5-6 years), and performance on standardized tests in the third year of school (aged 7-9 years). Cox proportional hazards and modified Poisson regression models were used to calculate hazard and risk ratios for outcomes in children exposed to maternal apnea compared with those not exposed.
Two hundred nine of 626188 singleton infants were exposed to maternal sleep apnea. Maternal apnea was not significantly associated with mortality (Fisher's exact p = .48), developmental vulnerability (adjusted RR 1.29; 95% CI 0.75-2.21), special needs status (1.58; 0.61-4.07), or low numeracy test scores (1.03; 0.63-1.67) but was associated with low reading test scores (1.55; 1.08-2.23). Maternal apnea significantly increased hospitalizations in the first year of life (adjusted HR 1.81; 95% CI 1.40-2.34) and between the first and sixth birthdays (1.41; 1.14-1.75). This is partly due to admissions for suspected pediatric sleep apnea.
Maternal sleep apnea during pregnancy is associated with poorer childhood health. Its impact on developmental and cognitive outcomes warrants further investigation.
Background Early-onset preeclampsia is associated with adverse maternal and perinatal outcomes. For women who consider another pregnancy after one complicated by early-onset preeclampsia, the ...likelihood of recurrence and the subsequent pregnancy outcome for themselves and their babies are pertinent considerations. Objectives The purpose of this study was to determine the subsequent pregnancy rate after a nulliparous pregnancy that was complicated by early-onset preeclampsia and among those who have a subsequent pregnancy, the risk of recurrence by gestational week, and adverse pregnancy outcomes. Study Design This was a population-based record linkage cohort study. The study population included nulliparous women with a singleton pregnancy and early-onset preeclampsia (<34 weeks gestation) who gave birth in New South Wales Australia from 2001–2010 (the index birth), with follow-up data for a subsequent birth through 2012. Early-onset in the index birth was further categorized as <28 vs 28–33 weeks gestation. Subsequent pregnancy outcomes that were assessed included the pregnancy rate, preeclampsia recurrence, and maternal and perinatal morbidity and mortality rates. The risk of preeclampsia necessitating delivery at each gestational week for women who were at risk was plotted, and the net gain or loss of gestational age when comparing the index with the subsequent pregnancy was calculated. Results Among 361,031 nulliparous women with singleton pregnancies, 1473 (0.4%) had early-onset preeclampsia. Women with early-onset preeclampsia in their first pregnancy had a lower subsequent pregnancy rate (59.7%) than women without preeclampsia (67.7%). Of the 758 women with a subsequent singleton birth, 256 (33.8%) experienced preeclampsia in the next pregnancy; 57 women (7.5%) with recurrent early-onset preeclampsia were included. Cumulative rates of preeclampsia in the subsequent pregnancy were higher at every gestation from 23 weeks gestation when the index birth was <28 weeks compared with 28–33 weeks gestation. The cumulative rate and gestation-specific risk of recurrent preeclampsia rose most steeply at 32–38 weeks gestation. Most women (94.6%) progressed to a later gestational age in their subsequent pregnancy. The median overall increase in gestational age at delivery was 6 weeks (interquartile range, 4–8); among women with recurrent preeclampsia, the median increase was 5 weeks (interquartile range, 2–7). Women with index birth <28 weeks gestation compared with 28–33 weeks gestation were more likely to deliver preterm (38.8% vs 28.7%; relative risk, 1.35; 95% confidence interval, 1.04–1.75) and have a perinatal death (4.3% vs 1.2%; relative risk, 3.46; 95% confidence interval, 1.15–10.39) at the subsequent birth, but live born infants had similar rates of severe morbidity (17.1% vs 15.0%; relative risk, 1.14; 95% confidence interval, 0.73–1.79). Conclusion Women with early-onset preeclampsia in a first pregnancy appear less likely than women without preeclampsia to have a subsequent pregnancy. Maternal and perinatal outcomes in the subsequent pregnancy are generally better than in the first; most women will not have recurrent preeclampsia, and those who do usually will give birth at a greater gestational age compared with their index birth.
Objective To identify the maternal and infant risk factors associated with hospital admission in the first year and estimate the associated costs of infant hospitalization. Study design Data from the ...Perinatal Data Collection for 599 753 liveborn infants born in New South Wales, Australia, 2001-2007 were linked to hospital admission data. Logistic regression models were used to investigate the association between maternal and infant characteristics and admission to hospital once, and more than once in the first year; and average costs for total hospital admissions were calculated. Results Almost 15% of infants were admitted to hospital once and 4.6% had multiple admissions. Gestational age <37 weeks was most strongly associated with admission to hospital once, and severe neonatal morbidity was most strongly associated with multiple admissions (aOR 2.60; 95% CI 2.47-2.75). Infants born <39 weeks gestational age, to adolescent mothers, mothers who smoke, are not married, or had a planned delivery also have an increased risk of multiple admissions. Infants with severe neonatal morbidity contributed 27% of total infant hospital costs. With each increasing week of gestational age the mean annual cost decreased on average 10% and 27% for infants with and without neonatal morbidity respectively. Conclusions Infants born with severe neonatal morbidity have increased hospitalizations in the first year; however, the majority of burden on health system is by infants without severe neonatal morbidity. Hospitalizations, and associated costs, increased with decreasing gestational age, even for infants born at 37-38 weeks. Targeted public health strategies may reduce the burden of infant hospitalizations.
Unexplained variation in induction of labour (IOL) rates exist between hospitals, even after accounting for casemix and hospital differences. We aimed to explore factors that influence clinical ...decision-making for IOL that may be contributing to the variation in IOL rates between hospitals.
We undertook a qualitative study involving semi-structured, audio-recorded interviews with obstetricians and midwives. Using purposive sampling, participants known to have diverse opinions on IOL were selected from ten Australian maternity hospitals (based on differences in hospital IOL rate, size, location and case-mix complexities). Transcripts were indexed, coded, and analysed using the Framework Approach to identify main themes and subthemes.
Forty-five participants were interviewed (21 midwives, 24 obstetric medical staff). Variations in decision-making for IOL were based on the obstetrician's perception of medical risk in the pregnancy (influenced by the obstetrician's personality and knowledge), their care relationship with the woman, how they involved the woman in decision-making, and resource availability. The role of a 'gatekeeper' in the procedural aspects of arranging an IOL also influenced decision-making. There was wide variation in the clinical decision-making practices of obstetricians and less accountability for decision-making in hospitals with a high IOL rate, with the converse occurring in hospitals with low IOL rates.
Improved communication, standardised risk assessment and accountability for IOL offer potential for reducing variation in hospital IOL rates.
Objective We undertook a systematic review to assess normative levels of vitamin D in early pregnancy and association with subsequent pregnancy outcomes. Study Design Medline and Embase databases and ...reference lists were searched. Inclusion criteria were pregnant populations, blood sample taken during the first trimester, and serum hydroxyvitamin D levels assessed. Results Eighteen studies reported vitamin D levels in first trimester (n = 11-3730), and 5 examined pregnancy outcomes. Mean vitamin D concentrations differed when stratified by ethnicity: white (mean SD: 29.4 11.7 to 73.1 27.1 nmol/L) and nonwhite (15.2 12.1 to 43 12 nmol/L). Most studies used general population cut points to define deficiency and found a large proportion of women deficient. Two articles examined risk of preeclampsia and reported differing findings, whereas 2 of 3 found low levels associated with increased risk of small-for-gestational age births. Conclusion There is no clear definition of vitamin D deficiency in pregnancy and insufficient evidence to suggest low vitamin D levels in early pregnancy are associated with adverse pregnancy outcomes.
With the increasing use of probabilistically linked administrative data in health research, it is important to understand whether systematic differences occur between the populations with linked and ...unlinked records. While probabilistic linkage involves combining records for individuals, population perinatal health research requires a combination of information from both the mother and her infant(s). The aims of this study were to (i) describe probabilistic linkage for perinatal records in New South Wales (NSW) Australia, (ii) determine linkage proportions for these perinatal records, and (iii) assess records with linked mother and infant hospital-birth record, and unlinked records for systematic differences.
This is a population-based study of probabilistically linked statutory birth and hospital records from New South Wales, Australia, 2001-2008. Linkage groups were created where the birth record had complete linkage with hospital admission records for both the mother and infant(s), partial linkage (the mother only or the infant(s) only) or neither. Unlinked hospital records for mothers and infants were also examined. Rates of linkage as a percentage of birth records and descriptive statistics for maternal and infant characteristics by linkage groups were determined.
Complete linkage (mother hospital record - birth record - infant hospital record) was available for 95.9% of birth records, partial linkage for 3.6%, and 0.5% with no linked hospital records (unlinked). Among live born singletons (complete linkage = 96.5%) the mothers without linked infant records (1.6%) had slightly higher proportions of young, non-Australian born, socially disadvantaged women with adverse pregnancy outcomes. The unlinked birth records (0.4%) had slightly higher proportions of nulliparous, older, Australian born women giving birth in private hospitals by caesarean section. Stillbirths had the highest rate of unlinked records (3-4%).
This study shows that probabilistic linkage of perinatal records can achieve high, representative levels of complete linkage. Records for mother's that did not link to infant records and unlinked records had slightly different characteristics to fully linked records. However, these groups were small and unlikely to bias results and conclusions in a substantive way. Stillbirths present additional challenges to the linkage process due to lower rates of linkage for lower gestational ages, where most stillbirths occur.
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