To estimate the effect of maternal age on survival free of major morbidity among preterm newborns younger than 33 weeks of gestation at birth.
Data from a retrospective cohort of preterm newborns younger than 33 weeks of gestation admitted to Canadian neonatal intensive care units between 2003 and 2008 were analyzed. The primary outcome was survival without major morbidity (defined as bronchopulmonary dysplasia, intraventricular hemorrhage grade 3 or 4, periventricular leukomalacia, retinopathy of prematurity stage 3, 4 or 5, or necrotizing enterocolitis stage 2 or 3). Trends in outcomes in relation to maternal age groups were examined using a multivariable analysis that controlled for confounders.
Baseline comparison for the 12,326 eligible newborns revealed no differences in sex, small-for-gestational-age status, and chorioamnionitis among different maternal age groups. Higher rates of cesarean delivery, use of prenatal steroids, maternal hypertension, and diabetes were noted as maternal age increased (P
Advanced maternal age at birth is considered a major risk factor for birth outcomes. It is unclear to what extent this association is confounded by maternal characteristics. To test whether advanced maternal age at birth independently increases the risk of low birth weight (
To investigate whether advanced maternal age is associated with preterm birth, irrespective of parity.
Population-based registry study.
Swedish Medical Birth Register.
First, second, and third live singleton births to women aged 20 years or older in Sweden, from 1990 to 2011 (n = 2 009 068).
Logistic regression analysis was used in each parity group to estimate risks of very and moderately preterm births to women at 20-24, 25-29, 30-34, 35-39, and 40 years or older, using 25-29 years as the reference group. Odds ratios (ORs) were adjusted for year of birth, education, country of birth, smoking, body mass index, and history of preterm birth. Age-related risks of spontaneous and medically indicated preterm births were also investigated.
Very preterm (22-31 weeks of gestation) and moderately preterm (32-36 weeks) births.
Risks of very preterm birth increased with maternal age, irrespective of parity: adjusted ORs in first, second, and third births ranged from 1.18 to 1.28 at 30-34 years, from 1.59 to 1.70 at 35-39 years, and from 1.97 to 2.40 at =40 years. In moderately preterm births, age-related associations were weaker, but were statistically significant from 35-39 years in all parity groups. Advanced maternal age increased the risks of both spontaneous and medically indicated preterm births.
Advanced maternal age is associated with an increased risk of preterm birth, irrespective of parity, especially very preterm birth. Women aged 35 years and older, expecting their first, second, or third births, should be regarded as a risk group for very preterm birth.
Women aged 35 years and older should be regarded as a risk group for very preterm birth, irrespective of parity.
Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disease in the world, but little is known about its potential association with pregnancy outcomes. We aimed to investigate pregnancy outcomes in NAFLD.
The Swedish Medical Birth Register (MBR) was used to identify births between 1992 and 2011 (N = 1 960 416). By linkage with the National Patient Register, we identified women with a diagnosis of NAFLD. The MBR was then used to identify outcomes: gestational diabetes, pre-eclampsia, Caesarean section, Apgar score
This study aimed to assess whether adolescents have an increased risk of adverse pregnancy outcomes (APO) compared to adult women. We used data on 43,327 births from the population-based Arkhangelsk County Birth Registry, Northwest Russia, for 2012-2014. The perinatal outcomes included stillbirth, preterm birth (
Department of Women's and Children's Health, Division of Reproductive and Perinatal Health Care, and the Department of Clinical Science and Education, Södersjukhuset (KI SÖS), Karolinska Institutet, Stockholm, and the Centre for Clinical Research, Dalarna, Falun, Sweden; and the Center for Evidence Based Practice, Faculty of Health Sciences, Bergen University College, and the Department of Clinical Science, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway.
To investigate the association between advanced maternal age and adverse pregnancy outcomes and to compare the risks related to advanced maternal age with those related to smoking and being overweight or obese.
A population-based register study including all nulliparous women aged 25 years and older with singleton pregnancies at 22 weeks of gestation or greater who gave birth in Sweden and Norway from 1990 to 2010; 955,804 women were analyzed. In each national sample, adjusted odds ratios (ORs) of very preterm birth, moderately preterm birth, small for gestational age, low Apgar score, fetal death, and neonatal death in women aged 30-34 years (n=319,057), 35-39 years (n=94,789), and 40 years or older (n=15,413) were compared with those of women aged 25-29 years (n=526,545). In the Swedish sample, the number of additional cases of each outcome associated with maternal age 30 years or older, smoking, and overweight or obesity, respectively, was estimated in relation to a low-risk group of nonsmokers of normal weight and aged 25-29 years.
The adjusted OR of all outcomes increased by maternal age in a similar way in Sweden and Norway; and the risk of fetal death was increased even in the 30- to 34-year-old age group (Sweden n=826, adjusted OR 1.24, 95% confidence interval [CI] 1.13-1.37; Norway n=472, adjusted OR 1.26, 95% CI 1.12-1.41). Maternal age 30 years or older was associated with the same number of additional cases of fetal deaths (n=251) as overweight or obesity (n=251).
For the individual woman, the absolute risk for each of the outcomes was small, but for society, it may be significant as a result of the large number of women who give birth after the age of 30 years.
The role of administrative databases for research on drug safety during pregnancy can be limited by their inaccurate assessment of the timing of exposure, as the gestational age at birth is typically unavailable. Therefore, we sought to develop and validate algorithms to estimate the gestational age at birth using information available in these databases.
Using a population-based cohort of 286,432 mother-child pairs in British Columbia (1998-2007), we validated an ICD-9/10-based preterm-status indicator and developed algorithms to estimate the gestational age at birth on the basis of this indicator, maternal age, singleton/multiple status, and claims for routine prenatal care tests. We assessed the accuracy of the algorithm-based estimates relative to the gold standard of the clinical gestational age at birth recorded in the delivery discharge record.
The preterm-status indicator had specificity and sensitivity of 98% and 91%, respectively. Estimates from an algorithm that assigned 35?weeks of gestational age at birth to deliveries with the preterm-status indicator and 39?weeks to those without them were within 2?weeks of the clinical gestational age at birth in 75% of preterm and 99% of term deliveries.
Subtracting 35?weeks (245?days) from the date of birth in deliveries with codes for preterm birth and 39?weeks (273?days) in those without them provided the optimal estimate of the beginning of pregnancy among the algorithms studied.
Preterm birth is the leading cause of perinatal morbidity and mortality. Risk factors for preterm birth include a personal or familial history of preterm delivery, ethnicity and low socioeconomic status yet the ability to predict preterm delivery before the onset of preterm labour evades clinical practice. Evidence suggests that genetics may play a role in the multi-factorial pathophysiology of preterm birth. The All Our Babies Study is an on-going community based longitudinal cohort study that was designed to establish a cohort of women to investigate how a women's genetics and environment contribute to the pathophysiology of preterm birth. Specifically this study will examine the predictive potential of maternal leukocytes for predicting preterm birth in non-labouring women through the examination of gene expression profiles and gene-environment interactions.
Collaborations have been established between clinical lab services, the provincial health service provider and researchers to create an interdisciplinary study design for the All Our Babies Study. A birth cohort of 2000 women has been established to address this research question. Women provide informed consent for blood sample collection, linkage to medical records and complete questionnaires related to prenatal health, service utilization, social support, emotional and physical health, demographics, and breast and infant feeding. Maternal blood samples are collected in PAXgene™ RNA tubes between 18-22 and 28-32 weeks gestation for transcriptomic analyses.
The All Our Babies Study is an example of how investment in clinical-academic-community partnerships can improve research efficiency and accelerate the recruitment and data collection phases of a study. Establishing these partnerships during the study design phase and maintaining these relationships through the duration of the study provides the unique opportunity to investigate the multi-causal factors of preterm birth. The overall All Our Babies Study results can potentially lead to healthier pregnancies, mothers, infants and children.
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To assess the risk factors for preterm birth in twin pregnancies, particularly monochorionicity.
A cohort study of 767 sets of twins, each twin weighing more than 500 g, born between January 1, 1992, and December 31, 2001, at St. Joseph's Health Care in London, Ontario. Statistical analysis was performed using forward stepwise logistic regression models, with gestational age at birth less than 28 or 32 weeks as the outcome.
Polyhydramnios and chorioamnionitis were significant risk factors for preterm birth prior to 28 or 32 weeks' gestation. Monochorionicity was a risk factor for preterm birth prior to 32 weeks' gestation. Past term birth and maternal age over 30 years were associated with reduced risk for preterm birth.
Monochorionic placentation is a significant risk factor for preterm twin birth.
This study was designed to test the hypothesis that fetal exposure to corticosteroids in the antenatal period is an independent risk factor for the development of asthma in childhood.
A population-based cohort study was conducted of all pregnant women who resided in Nova Scotia, Canada, and gave birth to a singleton fetus between January 1989 and December 1998 and lived to discharge. After exclusions, 79,395 infants were available for analysis. Using linked health care utilization records, incident asthma cases between 36 to 72 months of age were identified. Generalized Estimating Equations were used to estimate the odds ratio of the association between exposure to corticosteroids and asthma while controlling for confounders.
Over the 10 years of the study corticosteroid therapy increased by threefold. Exposure to corticosteroids during pregnancy was associated with a risk of asthma in childhood: adjusted odds ratio of 1.23 (95% confidence interval: 1.06, 1.44).
Antenatal steroid therapy appears to be an independent risk factor for the development of asthma between 36 and 72 months of age. Further research into the smallest possible steroid dose required to achieve the desired post-natal effect is needed to reduce the risk of developing childhood asthma.