Health Care Utilization in the First 7 Years in Children with Fetal Growth Abnormalities: A Retrospective Cohort Study.

OBJECTIVE: To investigate the relationship between birth weight for gestational age and health care utilization of term offspring from birth to 7 years. STUDY DESIGN: We used a population-based retrospective cohort study of infants (≥37 weeks' gestational age) born between 2003 and 2007 in the Canadian province of Nova Scotia (n = 42 050). Perinatal records were linked to provincial administrative health data from birth to age 7 years. The primary outcome was health care utilization (physician visits and hospital admissions) and costs. Birth weight was categorized as small for gestational age (SGA, <10th percentile), appropriate for gestational age (AGA), or large for gestational age (LGA, >90th percentile). Regression models adjusted for potential confounders were used to investigate the associations. RESULTS: Children born SGA had a higher number of specialist visits and hospital admissions, a longer length of stay for the birth admission, and, as a result, higher physician and hospital costs amounting to a cost differential of Can $1222 during the first 7 years of life compared with children born AGA. By contrast, health care use and costs did not differ between children born LGA and AGA. CONCLUSION: Former SGA term infants have a moderate increase in health care use and costs in early childhood compared with former AGA infants, and LGA birth at term is not associated with higher health care utilization.

The relationship between skin-to-skin contact and rates of exclusive breastfeeding at four months among a group of mothers in Nova Scotia: a retrospective cohort study.

OBJECTIVES: Exclusive breastfeeding is the ideal source of nutrition for the first 6 months of life. Although skin-to-skin contact (SSC) has been shown to be associated with greater rates of exclusive breastfeeding, the results are heterogeneous. SSC involves placing a naked infant on its mother's bare chest immediately after birth. We examined the association between SSC immediately after birth and exclusive breastfeeding at 4 months. METHODS: A retrospective cohort of healthy, term, singleton infants who were liveborn from 2008 to 2019 was constructed from the Nova Scotia Atlee Perinatal Database. Our main outcome was exclusive breastfeeding at 4 months, available for a subset of the cohort through linkage to a primary care database (n=256). Our secondary outcome was exclusive breastfeeding at hospital discharge, available for the broader cohort (n=56,459). Odds ratios (OR) for the association between SSC and exclusive breastfeeding at 4 months were estimated from logistic regression models. RESULTS: The odds of breastfeeding exclusively at 4 months were 4.14 (95% confidence interval (CI) 1.89-9.25) times greater among those who had SSC than among those who did not. The odds of breastfeeding exclusively at hospital discharge were 3.81 (95% CI 3.64-3.99) times greater among those who had SSC than among those who did not. The association between SSC and exclusive breastfeeding at hospital discharge was heterogeneous by birth year (OR 4.35, CI 4.07-4.65 in 2008-2011; OR 2.81, CI 2.57-3.07 in 2012-2015; OR 1.89, CI 1.63-2.10 in 2016-2019). CONCLUSION: Skin-to-skin contact appears to be associated with greater odds of exclusive breastfeeding at discharge and 4 months postpartum. Early SSC should continue to be supported for breastfeeding promotion.

RéSUMé: OBJECTIFS: L'allaitement exclusif est la source de nutrition idéale pour les six premiers mois de la vie. Bien qu'il ait été démontré que le contact peau à peau (SSC) est associé à des taux plus élevés d'allaitement exclusif, les résultats sont hétérogènes. La SSC consiste à placer un enfant nu sur la poitrine nue de sa mère immédiatement après la naissance. Nous avons examiné l'association entre la SSC immédiatement après la naissance et l'allaitement exclusif à quatre mois. MéTHODES: Une cohorte rétrospective de nourrissons seuls à terme en bonne santé de 2008 à 2019 a été construite à partir de la Nova Scotia Atlee Perinatal Database. Notre critère de jugement principal était l'allaitement exclusif à quatre mois, disponible pour un sous-ensemble de la cohorte grâce à un couplage à une base de données de soins primaires (n = 256). Notre critère de jugement secondaire était l'allaitement exclusif à la sortie de l'hôpital, disponible pour la cohorte plus large (n = 56 459). Les rapports de cotes (OR) pour l'association entre la SSC et l'allaitement exclusif à quatre mois ont été estimés à partir de modèles de régression logistique. RéSULTATS: Les chances d'allaiter exclusivement à quatre mois étaient 4,14 (intervalle de confiance (IC) à 95 % 1,89-9,25) fois plus élevées chez celles qui avaient le SSC que chez celles qui n'en avaient pas. Les chances d'allaiter exclusivement à la sortie de l'hôpital étaient 3,81 (IC à 95 % 3,64 à 3,99) fois plus élevées chez celles qui avaient la SSC que chez celles qui n'en avaient pas. L'association entre la CSS et l'allaitement exclusif à la sortie de l'hôpital était hétérogène selon l'année de naissance (OR 4,35, IC 4,07-4,65 en 2008-2011; OR 2,81, IC 2,57-3,07 en 2012-2015; et OR 1,89, IC 1,63-2,10 en 2016-2019). CONCLUSION: Le contact peau à peau semble être associé à une plus grande probabilité d'allaitement exclusif à la sortie de l'hôpital et à quatre mois après l'accouchement. La SSC tôt avec les nouveau-nés doit continuer à être soutenue en tant qu'aspect des pratiques de promotion de l'allaitement.

Association between second stage of labour length and risk of obstetrical anal sphincter injury in nulliparous women: a population-based retrospective cohort study.

INTRODUCTION AND HYPOTHESIS: Obstetrical anal sphincter injury (OASIS) is a common consequence of vaginal delivery in nulliparas and carries the risk of short- and long-term morbidity. The objective of this study was to estimate the association between the duration of the second stage of labour and OASIS risk. METHODS: A population-based, retrospective cohort of nulliparas delivering singleton, vertex, non-anomalous fetuses at term in Nova Scotia, Canada, from 2005 to 2019, were identified using the Nova Scotia Atlee Perinatal Database. Poisson regression models were used to estimate risk ratios (RR) with robust 95% confidence intervals (CI) adjusting for confounding variables to investigate the association between the length of the second stage and OASIS in the entire cohort and in operative vaginal deliveries. RESULTS: Of 36,662 participants, 7.6% sustained an OASIS (6.8% third-degree, 0.8% fourth-degree tear). The proportion of participants who sustained an OASIS increased over the study period. For each 30-min increase in the length of second stage, the OASIS risk increased by 11% (RR 1.11, 95% CI 1.10-1.12). When stratified by mode of delivery, second stage length ≥ 90 min was associated with an increased OASIS risk in spontaneous (RR 1.35, 95% CI 1.15-1.58) and vacuum-assisted vaginal deliveries (RR 1.42, 95% CI 1.11-1.81). In forceps-assisted vaginal deliveries, OASIS risk was increased, with shorter and longer durations of the second stage. CONCLUSION: Increasing length of the second stage of labour was associated with increasing risk of OASIS overall, but the association was heterogeneous between modes of delivery. Length of the second stage should be considered in counseling about OASIS risk.

Classification of Individual Pain Response Trajectories Following Medically Indicated Heel Lances in Preterm Infants During Their NICU Admission.

OBJECTIVES: Infants born preterm are exposed to repeated painful procedures during neonatal intensive care unit admission. Particularly in preterm infants, trajectories of pain response are not well understood. The aim of this study was to classify pain response trajectories over 2 minute following medically indicated heel lances in preterm infants. MATERIALS AND METHODS: This study used existing clinical trial data (NCT01561547) that evaluated the efficacy of kangaroo care and sucrose for infant pain control. Pain was measured using the Premature Infant Pain Profile at 30, 60, 90, and 120 seconds following a heel lance. Group-based trajectory modeling was used to classify pain response in this 2 minute period. RESULTS: A total of 236 infants with median gestational age of 33 weeks contributed 610 procedures. A model with 5 trajectory classes best fit the data. Three trajectories were stable over time at different levels of intensity from low-mild to low-moderate pain. One trajectory reflected a linear reduction from high-moderate to low-moderate pain. The final trajectory showed variable moderate-high pain. At all times points, 3 classes were at least 1-point different from the overall sample mean pain score. Only 21 (9%) infants maintained the same class for all 3 procedures. DISCUSSION: In this sample of preterm infants receiving pain relief, most pain trajectories reflected mild to low-moderate pain that was stable over 2 minute after heel lance initiation. Trajectories were not consistent over multiple procedures within infants, and an overall mean pain score for the sample may misrepresent subgroups of pain response.

Revisiting Risk and Benefit in Early Oncology Trials in the Era of Precision Medicine: A Systematic Review and Meta-Analysis of Phase I Trials of Targeted Single-Agent Anticancer Therapies.

PURPOSE: Phase I trials are a crucial step in the evaluation of new cancer therapies. Historically, low rates of response (5%) and comparably high rates of death from toxicities (0.5%) have contributed to debates on the ethics and orientation of these trials. With the introduction of novel targeted therapies, a contemporary estimate is needed. METHODS: We systematically searched PubMed, Embase, and ClinicalTrials.gov for reports of phase I oncology trials of single-agent targeted immunomodulators, molecularly targeted therapies, and antiangiogenic agents, published between January 2015 and July 2018. Adult and pediatric trials of solid and hematological malignancies were eligible. Treatment-related adverse events (grades 3, 4, and 5) and response rates (objective, complete, and partial) were extracted and analyzed. RESULTS: One hundred and fifty-eight trial reports, covering 6,707 patients, were included. The rate of treatment-related deaths was 0.0% (95% CI, 0.0 to 0.1), while 13.2% of patients (9.5 to 17.3) experienced a grade 3 or 4 treatment-related toxicity. The combined objective response rate was 6.4% (4.6 to 8.5). Among trials using tumor biomarkers as eligibility criteria, the objective response rate was higher (12.0% [7.3 to 17.6] compared to 4.9% [2.5 to 5.7], P value < .01). The same was true of trials focusing on a single tumor type (13.4% [8.2 to 19.4]) compared to multiple tumor types (3.8% [2.5 to 5.3], P value < .01). CONCLUSION: Reduced grade 5 risk and improved benefit appears to exist in modern phase I oncology trials, particularly in trials that target single tumor types and integrate biomarkers as eligibility criteria. These findings provide information to support informed consent discussions, highlight the need for improved reporting of phase I oncology trials, and provide direction for optimizing their design.

The Relationship Between Pre-Pregnancy Attempts to Lose Weight and Gestational Weight Gain: An Exploratory Primary Care Prospective Cohort Study.

OBJECTIVE: The primary objective of this study was to explore the association between weight cycling in the 6 months prior to pregnancy and gestational weight gain concordance with the 2009 Institute of Medicine guidelines for weight gain in pregnancy. METHODS: This was a prospective cohort study. Participants were women aged 18 years or older with a singleton pregnancy who had a prenatal appointment between April 1 and August 31, 2019. Eligible women completed a questionnaire that assessed their pre-pregnancy attempts to lose weight, measured with a modified version of the Weight Cycling subscale within the Revised Restraint Scale. After delivery, participants' last recorded gestational weight before delivery, and corresponding gestational ages were obtained from prenatal records. RESULTS: One hundred and ninety-five pregnant women consented to participate in the study (a 95.6% response rate). Of them, 5 were excluded; therefore, 190 participants were included in the analysis. One-third of participants had attempted to lose weight in the 6 months before pregnancy. Logistic regression showed that for every one-unit increase in Weight Cycling score, the odds of excess gestational weight gain increased by a factor of 1.32. CONCLUSION: Women's pre-conceptual efforts to enter pregnancy at a lower BMI should be approached in a manner that avoids pre-pregnancy weight cycling.

Incidence, Intrapartum Risk Factors, and Prognosis of Neonatal Hypoxic-Ischemic Encephalopathy Among Infants Born at 35 Weeks Gestation or More.

INTRODUCTION: Neonatal hypoxic-ischemic encephalopathy (HIE) is associated with neonatal mortality, acute neurological injury, and long-term neurodevelopmental disabilities; however, the association between intrapartum factors and HIE remains unclear. METHODS: This population-based cohort study used linked obstetrical and newborn data derived from the Nova Scotia Atlee Perinatal Database (NSAPD, 1988-2015) and the AC Allen Perinatal Follow-Up Program Database (2006-2015) for all pregnancies with live, non-anomalous newborns ≥35 weeks gestation, not delivered by pre-labour cesarean section. Temporal trends in HIE incidence were described, and logistic regression estimated odds ratios (OR) with 95% confidence intervals (CI) for the association of intrapartum factors with HIE. RESULTS: The NSAPD identified 227 HIE cases in the population of 226 711 deliveries from 1988 to 2015. Women with clinical chorioamnionitis in labour (OR 8.0; 95% CI 3.9-16), emergency cesarean delivery (OR 10; 95% CI 7.6-14), shoulder dystocia (OR 3.5; 95% CI 2.1-5.7), placental abruption (OR 18; 95% CI 11-29), and cord prolapse (OR 30; 95% CI 15-61) were more likely to have newborns with HIE. Two-thirds of newborns with HIE had an abnormal intrapartum fetal heart rate tracing. The mortality rate among infants with HIE was 27% by 3 years of age. Neurodevelopmental outcomes in the surviving infants were normal in 43% and showed severe developmental delay in 40%. CONCLUSION: Overall, the rate of HIE was low in infants born at ≥35 weeks gestation. The identification of associated intrapartum factors should promote increased surveillance in these clinical situations and emphasize the importance of careful management to optimize newborn outcomes.

Birth by Caesarean section and otitis media in childhood: a retrospective cohort study.

The objective of the present study was to examine the association between birth by Caesarean section (CS) and otitis media (OM) in childhood. We assembled a retrospective cohort of children born between 2003 and 2007 in Nova Scotia and followed them through to 2014. The cohort was derived through a linkage of the Nova Scotia Atlee Perinatal Database with provincial administrative health data. Cox proportional hazards, negative binomial regression and logistic regression were used to examine the association between CS and OM. Among the 36,318 children, 27% were born by CS, and 78% had at least one OM episode (median 2 episodes). Children born by CS were at a slightly higher risk of OM (hazard ratio 1.06, 95% confidence interval (CI) 1.03, 1.09), had more OM episodes in the first 7 years of life (incidence rate ratio 1.04, 95% CI 1.01, 1.07), and were more likely to be above the 95th percentile for OM episodes than children born vaginally (odds ratio 1.10, 95% CI 0.99, 1.23). Our study shows that birth by CS is weakly associated with OM in childhood, but the clinical and public health impact of these findings is small.

The 3G Multigenerational Cohort of Nova Scotian women and their mothers and offspring.

BACKGROUND: The negative impact of exposures such as maternal obesity, excessive gestational weight gain, and hypertension in pregnancy on the health of the next generation has been well studied. Evidence from animal studies suggests that the effects of in utero exposures may persist into the second generation, but the epidemiological literature on the influence of pregnancy-related exposures across three generations in humans is sparse. OBJECTIVES: This cohort was established to investigate associations between antenatal and perinatal exposures and health outcomes in women and their offspring. POPULATION: The cohort includes women who were born and subsequently had their own pregnancies in the Canadian province of Nova Scotia from 1980 onward. DESIGN: Intergenerational linkage of data in the Nova Scotia Atlee Perinatal Database was used to establish a population-based dynamic retrospective cohort. METHODS: The cohort has prospectively collected information on sociodemographics, maternal health and health behaviours, pregnancy health and complications, and obstetrical and neonatal outcomes for two generations of women and their offspring. PRELIMINARY RESULTS: As of October 2018, the 3G cohort included 14 978 grandmothers (born 1939-1986), 16 766 mothers or cohort women (born 1981-2003), and 28 638 children (born 1996-2018). The cohort women were generally younger than Nova Scotian women born after 1980, and as a result, characteristics associated with pregnancy at a younger age were more frequently seen in the cohort women; sampling weights will be created to account for this design effect. The cohort will be updated annually to capture future deliveries to women who are already in the cohort and women who become eligible for inclusion when they deliver their first child. CONCLUSIONS: The 3G Multigenerational Cohort is a population-based cohort of women and their mothers and offspring, spanning a time period of 38 years, and provides the opportunity to study inter- and transgenerational associations across the maternal line.

Optimal Timing of Prenatal Ultrasound in Predicting Birth Weight in Diabetic Pregnancies.

OBJECTIVE: This study sought to determine the optimal timing of ultrasound in the third trimester to predict birth weight accurately in diabetic women with a singleton pregnancy. METHODS: A retrospective cohort study of all diabetic women with a singleton pregnancy treated in Halifax, Nova Scotia, was performed. Estimated fetal weight was derived from ultrasound measures using the Hadlock2 equation. The Mongelli equation was used to predict birth weight. The association between gestational age at ultrasound and accuracy of predicted birth weight was assessed, with accuracy as a continuous variable representing the difference between predicted and actual birth weight and as a categorical variable (with four gestational age categories) representing whether predicted birth weight was within, over, or under 250 g of actual birth weight RESULTS: The cohort of 943 women comprised 121 (12.8%) with type 1 diabetes, 111 (11.7%) with type 2 diabetes, and 711 (75.4%) with gestational diabetes. Ultrasound scans performed at term were the most accurate in predicting birth weight. At this gestational age, the mean difference between predicted and actual birth weight was -30 g (95% confidence interval -109 to -48). After adjusting for maternal body mass index, age, smoking, type of diabetes, and interval between ultrasound examination and delivery, accuracy improved as gestational age at ultrasound increased (P = 0.005). The odds of underpredicting or overpredicting birth weight were not significantly affected by the timing of the ultrasound examination. CONCLUSION: Because the predictive accuracy of ultrasound prediction of birth weight improves with gestational age, fetal growth assessment at term is recommended to aid with delivery planning in women with diabetes.

Cesarean Delivery and Healthcare Utilization and Costs in the Offspring: A Retrospective Cohort Study.

OBJECTIVE: To examine the association between cesarean delivery and healthcare utilization and costs in offspring from birth until age 7 years. STUDY DESIGN: A retrospective cohort study of singleton term births in the Canadian province of Nova Scotia between 2003 and 2007 followed until age 7 years was conducted using data from the Nova Scotia Atlee Perinatal Database and administrative health data. The main exposure was mode of delivery (cesarean delivery vs vaginal birth); the outcome was healthcare utilization and costs during the first 7 years of life. Associations were modeled using multiple regression adjusting for maternal prepregnancy weight and sociodemographic factors. RESULTS: In total, 32 464 births were included in the analysis. Compared with children born by vaginal birth, children born by cesarean delivery had more physician visits (incidence rate ratio 1.06, 95% CI 1.05-1.08) and longer hospital stays (incidence rate ratio 1.12, 95% CI 1.03-1.21) and were more likely to be high utilizers of physician visits (OR 1.23, 95% CI 1.10-1.37). Physician and hospital costs were $775 higher for children born by cesarean delivery compared with vaginal birth. CONCLUSIONS: Cesarean delivery compared with vaginal birth is associated with small but statistically significant increases in healthcare utilization and costs during the first 7 years of life.

Barriers Preventing Medical Students From Performing Pelvic Examinations During Obstetrics and Gynaecology Clinical Clerkship Rotations.

OBJECTIVE: This study sought to identify barriers that prevent medical students from performing pelvic examinations in their obstetrics and gynaecology (Ob/Gyn) clinical clerkship rotations and to compare the perspectives of faculty, residents, nurses, and students regarding perceived barriers. METHODS: An electronic survey was distributed to third-year Dalhousie University (Halifax, NS) medical students on completion of their Ob/Gyn clerkship rotations in the 2015-2016 academic year and to Ob/Gyn nursing staff, faculty, and residents (Canadian Task Force Classification III). RESULTS: There were 82 responses, giving an overall response rate of 28%. Students reported performing an average of 9.2 speculum examinations, 3.8 cervical checks, and 2.8 bimanual examinations during their 6-week rotations. They reported being declined the opportunity to perform an examination an average of 7.1 times. Students perceived themselves to be more competent performing these examinations compared with staff perception of student competency. Students perceived resident interest in teaching, resident and staff time constraints, and patient willingness to have a medical student involved in their examination as frequent barriers. Faculty, residents, and nurses perceived student gender, patient willingness, difficulty of examination, and resident time constraints to be significant barriers. CONCLUSION: This study is the first to examine multidisciplinary perspectives on perceived barriers to medical students performing pelvic examinations. Staff and students have different perceptions of a student's competence performing these examinations. Existing barriers are likely multifactorial.

Birth weight for gestational age and the risk of asthma in childhood and adolescence: a retrospective cohort study.

OBJECTIVE: To examine the association between birth weight for gestational age and asthma in childhood and adolescence while controlling for potential confounders and considering smoking as an effect modifier. METHODS: A retrospective cohort of all singleton term births in Nova Scotia, Canada, between 1989 and 1993 was identified in the provincial perinatal database and followed through 2014 by linking with administrative health data. The outcome, asthma, was defined as having one hospitalisation or two physician visits with an International Classification of Diseases code for asthma in a 2-year period. Birth weight was categorised as small (SGA), large (LGA) or appropriate (AGA) for gestational age. Multivariable-adjusted Cox proportional hazards models were used to examine the association between the birth weight for gestational age and asthma and to test for effect modification by maternal smoking in pregnancy. RESULTS: Of the 40 724 cohort children, 10.5% and 11.7% were born SGA and LGA, respectively, and the risk of developing asthma to age 18 years was 30.2%. The adjusted HRs for SGA and LGA (relative to AGA) and asthma were 1.07 (95% CI 1.02 to 1.14) and 0.96 (95% CI 0.91 to 1.02), respectively. Relative to AGA children born to non-smoking mothers, SGA children were not at increased risk of asthma (HR 1.02), whereas both AGA and SGA children born to smoking mothers were at significantly increased risk (HR 1.14 and 1.29, respectively). CONCLUSIONS: Our findings suggest that SGA in term infants is not associated with asthma in childhood in the absence of smoking in pregnancy.

Maternal pre-pregnancy obesity and health care utilization and costs in the offspring.

BACKGROUND/OBJECTIVE: The association between maternal pre-pregnancy obesity and adverse child health outcomes is well described, but there are few data on the relationship with offspring health service use. We examined the influence of maternal pre-pregnancy obesity on offspring health care utilization and costs over the first 18 years of life. METHODS: This was a population-based retrospective cohort study of children (n = 35,090) born between 1989 and 1993 and their mothers, who were identified using the Nova Scotia Atlee Perinatal Database and linked to provincial administrative health data from birth through 2014. The primary outcome was health care utilization as determined by the number and cost of physician visits, hospital admissions and days, and high utilizer status (>95th percentile of physician visits). The secondary outcome was health care utilization by ICD chapter. Maternal pre-pregnancy weight was categorized as normal weight, overweight, or obese. Multivariable-adjusted regression models were used to examine the association between maternal weight status and offspring health care use. RESULTS: Children of mothers with pre-pregnancy obesity had more physician visits (10%), hospital admissions (16%), and hospital days (10%) than children from mothers of normal weight over the first 18 years of life. Offspring of mothers with obesity had C$356 higher physician costs and C$1415 hospital costs over 18 years than offspring of normal weight mothers. Children of mothers with obesity were 1.74 times more likely to be a high utilizer of health care and had higher rates of physician visits and hospital stays for nervous system and sense organ disorders, respiratory disorders, and gastrointestinal disorders compared to children of normal weight mothers. CONCLUSION: Our findings suggest that maternal pre-pregnancy overweight and obesity are associated with slightly higher offspring health care utilization and costs in the first 18 years of life.

Characteristics and Outcomes of Adolescent Births in Nova Scotia: A Retrospective Cohort Study.

OBJECTIVE: This study sought to examine the maternal characteristics and outcomes of adolescent births in Nova Scotia. METHODS: The investigators conducted a retrospective population-based cohort study using the Nova Scotia Atlee Perinatal Database. Maternal characteristics and maternal and neonatal outcomes of singleton live births between 2006 and 2015 were compared between adolescent (aged 12 to 19) and adult (aged 20 to 35) women. Associations were examined using log-binomial regression models. RESULTS: Of the 35 111 births that occurred during the study period, 11% were to adolescent mothers. Compared with adult women, adolescents had higher rates of smoking and substance abuse and were of lower socioeconomic status. Adolescent mothers were more than twice as likely as women aged 20 to 35 to smoke during pregnancy. Adolescent women were significantly less likely to have gestational diabetes, need induction of labour, have an assisted vaginal delivery, require a Caesarean section, have a large-for-gestational age infant, or breastfeed at discharge compared with the 20 to 35 age group. Birth of a small-for-gestational age infant and other adverse neonatal outcomes were more frequently seen in adolescents compared with adult women in the unadjusted models, but this difference vanished in models adjusted for sociodemographic factors and smoking. CONCLUSION: This study highlights disparities in socioeconomic characteristics and health behaviours between births in adolescent and adult mothers and suggests that a targeted multidisciplinary approach would be valuable for the pregnant adolescent. The role of antenatal support for pregnant adolescents is reinforced because sociodemographic factors and smoking accounted for differences in neonatal outcomes relative to adult women.

Interprovincial variation in pre-pregnancy body mass index and gestational weight gain and their impact on neonatal birth weight with respect to small and large for gestational age.

OBJECTIVES: To explore provincial variation in both excess and inadequate pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) and their impact on small- and large-for-gestational-age (SGA, LGA) infants. METHODS: Four provinces with a perinatal database capturing the required exposures participated: British Columbia (BC), Ontario (ON), Nova Scotia (NS), and Newfoundland and Labrador (NL). In multiple, concurrent retrospective studies, we included women ≥ 19 years, who gave birth from 22+0 to 42+6 weeks' gestation, to a live singleton from April 2013-March 2014. From adjusted odds ratios, we calculated population attributable fractions (PAF) of SGA and LGA for BMI and GWG. RESULTS: The proportion of overweight and obese women increased from western to eastern Canada. In BC, ON, NS, and NL, the proportions of women who were overweight were 21.1%, 24.0%, 23.7%, and 25.4%, while obesity proportions were 14.2%, 18.1%, 24.2%, and 29.8%, respectively. Excess GWG affected 53.9%, 49.9%, 57.6%, and 65.6% of women, respectively. Excess GWG contributed to 29.5-42.5% of LGA, compared with the PAFs for overweight (6.8-12.0%) and obesity (13.2-20.6%). Inadequate GWG's contribution to SGA (4.8-12.3%) was higher than underweight BMI's (2.9-6.2%). CONCLUSION: In this interprovincial study, high and increasing proportions of women from west to east had excess pre-pregnancy BMI, and between half to two thirds had excess GWG. The contributions of GWG outside of recommendations to SGA and LGA were greater than that of low or high BMI. GWG is a potentially modifiable determinant of SGA and LGA across Canada.