The aim of this study is to determine if there has been a true, absolute, or apparent relative increase in congenital diaphragmatic hernia (CDH) survival for the last 2 decades.
All neonatal Bochdalek CDH patients admitted to an Ontario pediatric surgical hospital during the period when significant improvements in CDH survival was reported (from January 1, 1992, to December 31, 1999) were analyzed. Patient characteristics were assessed for CDH population homogeneity and differences between institutional and vital statistics-based population survival outcomes. SAS 9.1 (SAS Institute, Cary, NC) was used for analysis.
Of 198 cohorts, demographic parameters including birth weight, gestational age, Apgar scores, sex, and associated congenital anomalies did not change significantly. Preoperative survival was 149 (75.2%) of 198, whereas postoperative survival was 133 (89.3%) of 149, and overall institutional survival was 133 (67.2%) of 198. Comparison of institution and population-based mortality (n = 65 vs 96) during the period yielded 32% of CDH deaths unaccounted for by institutions. Yearly analysis of hidden mortality consistently showed a significantly lower mortality in institution-based reporting than population.
A hidden mortality exists for institutionally reported CDH survival rates. Careful interpretation of research findings and more comprehensive population-based tools are needed for reliable counseling and evaluation of current and future treatments.
The purpose of this study was to investigate to what extent the Society of Obstetricians and Gynecologists of Canada (SOGC) guidelines on dystocia are being followed, and whether adherence to the guidelines is related to cesarean section rates. Data were extracted from a maternity database for nulliparous women with singleton, cephalic pregnancies at 37 or more completed weeks of gestation for a 4-year period. Patients delivered by elective cesarean section were excluded. Data were examined to determine whether those who had a cesarean section for dystocia in the first stage of labor fulfilled SOGC guidelines. In addition, the obstetricians were divided into two groups (high or low) according to their cesarean section rate for dystocia to determine whether a higher section rate was associated with an increased guideline violation rate. There were 239 nulliparous women who had a cesarean section for dystocia in the first stage of labor. The guidelines were followed in 47.7% of spontaneous labors and 77.5% of inductions. The mean section rate for dystocia in the first stage of labor was 10.8% in the high group and 6.6% in the low group, and the incidence of guideline violations in these groups was 48.0% and 39.6%, respectively ( P = 0.07). The study had a power of 0.88 to detect a 40% difference in guideline violation rates between the two groups. We conclude that many women have cesarean section for dystocia performed without fulfilling SOGC guidelines.
Few Canadian studies have examined the association between adolescent pregnancy and adverse pregnancy outcomes. The objective of this cohort study was to characterize the association between adolescent pregnancy and specific adverse maternal, obstetrical, and neonatal outcomes, as well as maternal health behaviours.
We conducted a retrospective population-based cohort study of all singleton births in Ontario between January 2006 and December 2010, using the Better Outcomes Registry and Network database. Outcomes for pregnant women
Customized birth weight percentiles are weight-for-gestational-age percentiles that account for the influence of maternal characteristics on fetal growth. Although intuitively appealing, the incremental value they provide in the identification of intrauterine growth restriction (IUGR) over conventional birth weight percentiles is controversial. The objective of this study was to assess the value of customized birth weight percentiles in a simulated cohort of 100,000 infants aged 37 weeks whose IUGR status was known. A cohort of infants with a range of healthy birth weights was first simulated on the basis of the distributions of maternal/fetal characteristics observed in births at the Royal Victoria Hospital in Montreal, Canada, between 2000 and 2006. The occurrence of IUGR was re-created by reducing the observed birth weights of a small percentage of these infants. The value of customized percentiles was assessed by calculating true and false positive rates. Customizing birth weight percentiles for maternal characteristics added very little information to the identification of IUGR beyond that obtained from conventional weight-for-gestational-age percentiles (true positive rates of 61.8% and 61.1%, respectively, and false positive rates of 7.9% and 8.5%, respectively). For the process of customization to be worthwhile, maternal characteristics in the customization model were shown through simulation to require an unrealistically strong association with birth weight.
There is concern that obstetric interventions (prelabor cesarean section and induced delivery) are drivers of late preterm (LP) birth. Our objective was to evaluate the independent association between obstetric interventions and LP birth and explore associated independent maternal and fetal risk factors for LP birth.
In this population-based cross-sectional study, the BORN Information System was used to identify all infants born between 34 and 40 completed weeks of gestation between 2005 and 2012 in Ontario, Canada. The association between obstetric interventions (preterm cesarean section and induced delivery) and LP birth (34 to 36 completed weeks' gestation vs 37 to 40 completed weeks' gestation) was assessed using generalized estimating equation regression.
Of 917,013 births between 34 and 40 weeks, 49,157 were LP (5.4%). In the adjusted analysis, "any obstetric intervention" (risk ratio [RR], 0.65; 95% confidence interval [CI], 0.57-0.74), induction (RR, 0.71; 95% CI, 0.61-0.82) and prelabor cesarean section (RR, 0.66; 95% CI, 0.59-0.74) were all associated with a lower likelihood of LP vs term birth. Several independent potentially modifiable risk factors for LP birth were identified including previous cesarean section (RR, 1.28; 95% CI, 1.16-1.40), smoking during pregnancy (RR, 1.28; 95% CI, 1.21-1.36) and high material (RR, 1.1; 95% CI, 1.03-1.18) and social (RR, 1.09; 95% CI, 1.02-1.16) deprivation indices.
After accounting for differences in maternal and fetal risk, LP births had a 35% lower likelihood of obstetric interventions than term births. Obstetric care providers may be preferentially avoiding induction and prelabor cesarean section between 34 and 37 weeks' gestation.
To explore the relationship between overweight and obesity and breastfeeding behaviors, a cohort study was conducted among 22,131 women who delivered in Ontario hospitals between April 1 2008 and March 31 2010.
Data regarding maternal characteristics, maternal body mass index (BMI), infant characteristics, and breastfeeding practices were obtained through the Better Outcomes Registry & Network birth records Database. Multivariate linear regression analysis was used to determine the rates of three outcome measures - intention to breastfeed, exclusive breastfeeding in hospital, and exclusive breastfeeding upon discharge from hospital - between non-obese, overweight and obese patients.
While overweight mothers have similar intentions to breastfeed compared to non-overweight mothers (OR 1.03 (0.87-1.21), obese mothers were less likely to intend to breastfeed (OR 0.84 (0.70-0.99). Overweight and obese mothers were less likely to exclusively breastfeed in hospital compared to non-overweight mothers (aOR 0.67 (0.60-0.75) and 0.67 (0.60-0.75), respectively), and overweight and obese mothers were less likely to exclusively breastfeed on discharge (aOR 0.68 (0.61-0.76) and 0.68 (0.61-0.76), respectively).
This study highlights that while overweight and obese women may benefit more from exclusive breastfeeding compared to non-overweight women, they are less likely to exclusively breastfeed in the immediate post-partum period.
The Canadian Perinatal Network (CPN) maintains an ongoing national database focused on threatened very preterm birth. The objective of the network is to facilitate between-hospital comparisons and other research that will lead to reductions in the burden of illness associated with very preterm birth.
Women were included in the database if they were admitted to a participating tertiary perinatal unit at 22+0 to 28+6 weeks' gestation with one or more conditions most commonly responsible for very preterm birth, including spontaneous preterm labour with contractions, incompetent cervix, prolapsing membranes, preterm prelabour rupture of membranes, gestational hypertension, intrauterine growth restriction, or antepartum hemorrhage. Data were collected by review of maternal and infant charts, entered directly into standardized electronic data forms and uploaded to the CPN via a secure network.
Between 2005 and 2009, the CPN enrolled 2524 women from 14 hospitals including those with preterm labour and contractions (27.4%), short cervix without contractions (16.3%), prolapsing membranes (9.4%), antepartum hemorrhage (26.1%), and preterm prelabour rupture of membranes (23.0%). The mean gestational age at enrolment was 25.9 ± 1.9 weeks and the mean gestation age at delivery was 29.9 ± 5.1 weeks; 57.0% delivered at
The objective of this randomized simulation study was to determine whether use of the King laryngeal tube (KLT) airway resulted in differences in chest compression fraction (CCF) during simulated cardiac arrest managed by primary care paramedics (PCPs), as compared with basic airway management (bag-mask ventilation [BMV]).
The KLT was introduced to all providers in our system at the time of study initiation. All participants received the same training, and were not aware that the primary outcome of the study was CCF. Standard airway management by PCPs prior to this was BMV. Pairs of PCPs were randomized to use KLT or BMV during a scripted 6-minute cardiac arrest scenario. The scenarios were videotaped, and data were abstracted by a single investigator. The CCF was calculated (fraction of time chest compressions were done/total scenario time). The CCF, number of seconds to first ventilation, and number of seconds to first compression were compared using the Mann-Whitney U test.
Sixty-seven pairs of PCPs participated: 30 in the KLT arm and 37 in the BMV arm. Demographics were similar in each group: KLT 68.3% males, BMV 55.4% males; KLT mean age 33.52 years (standard deviation [SD]: 11.95), BMV mean age 32.07 years (SD: 8.78); and KLT mean years of experience 9.03 (SD: 9.86), BMV mean years of experience 6.59 (SD: 6.58). The CCF was higher in the KLT group: median 0.82 (interquartile range [IQR] 0.71-0.88) compared with the BMV group: median 0.70 (IQR 0.66-0.73), p
The developing foetus is thought to be at increased risk from exposure to environmental contaminants; however, developmental exposure data is notably lacking for many contaminants. Moreover, potential regional differences or effect of place of birth on residue levels measured in pregnant women is also unknown. Therefore, as part of a multinational biomonitoring study, 125 primiparous pregnant Canadian women were recruited from five Canadian centres (Vancouver, Calgary, Hamilton, Ottawa, and Halifax). Metals in whole blood and persistent organic pollutants (POPs) in plasma were measured by inductively coupled plasma mass spectrometry (ICPMS) and gas chromatography-mass spectrometry (GCMS), respectively. Of the 125 women recruited to this study, complete data sets were available for 123 of which 103 were Canadian born. Data were analysed by analysis of covariance and linear mixed models using age and body mass index as covariates. The metals cadmium (Cd), cobalt (Co), lead (Pb), nickel (Ni), selenium (Se), and total mercury (Hg) were detected in more than 93% of the samples tested. ß-Hexachlorohexane (ß-HCH), oxychlordane, trans-nonachlor, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), polybrominated diphenyl ether (PBDE) congeners (PBDE-153, PBDE-47), polychlorinated biphenyl (PCB) congeners (PCB-138, -153, and -180), and the dioxin-like PCB congener PCB-118 were quantified in greater than 70% of the samples tested. Significant differences in the concentrations of Cd, Ni, PCB-153, and p,p'-DDE were found between the centres studied. Furthermore, foreign-born pregnant women had significantly higher concentrations of Cd, ß-HCH, PBDE-47, PCB-138, -153, -180, and p,p'-DDE compared to Canadian born pregnant women. Taken together, the data suggest that there are potential regional differences in contaminant body burden and place of birth may also contribute to differences in maternal residue concentrations.
The Maternal-Infant Research on Environmental Chemicals (MIREC) Study was established to obtain Canadian biomonitoring data for pregnant women and their infants, and to examine potential adverse health effects of prenatal exposure to priority environmental chemicals on pregnancy and infant health.
Women were recruited during the first trimester from 10 sites across Canada and were followed through delivery. Questionnaires were administered during pregnancy and post-delivery to collect information on demographics, occupation, life style, medical history, environmental exposures and diet. Information on the pregnancy and the infant was abstracted from medical charts. Maternal blood, urine, hair and breast milk, as well as cord blood and infant meconium, were collected and analysed for an extensive list of environmental biomarkers and nutrients. Additional biospecimens were stored in the study's Biobank. The MIREC Research Platform encompasses the main cohort study, the Biobank and follow-up studies.
Of the 8716 women approached at early prenatal clinics, 5108 were eligible and 2001 agreed to participate (39%). MIREC participants tended to smoke less (5.9% vs. 10.5%), be older (mean 32.2 vs. 29.4 years) and have a higher education (62.3% vs. 35.1% with a university degree) than women giving birth in Canada.
The MIREC Study, while smaller in number of participants than several of the international cohort studies, has one of the most comprehensive datasets on prenatal exposure to multiple environmental chemicals. The biomonitoring data and biological specimen bank will make this research platform a significant resource for examining potential adverse health effects of prenatal exposure to environmental chemicals.