Cannabis use in pregnancy and maternal and infant outcomes: A Canadian cross-jurisdictional population-based cohort study.

BACKGROUND: With the recent legalization of cannabis in Canada, there is an urgent need to understand the effect of cannabis use in pregnancy. Our population-based study investigated the effects of prenatal cannabis use on maternal and newborn outcomes, and modification by infant sex. METHODS: The cohort included 1,280,447 singleton births from the British Columbia Perinatal Data Registry, the Better Outcomes Registry & Network Ontario, and the Perinatal Program Newfoundland Labrador from April 1st, 2012 to March 31st, 2019. Logistic regression determined the associations between prenatal cannabis use and low birth weight, small-for-gestational age, large-for-gestational age, spontaneous and medically indicated preterm birth, very preterm birth, stillbirth, major congenital anomalies, caesarean section, gestational diabetes and gestational hypertension. Models were adjusted for other substance use, socio-demographic and-economic characteristics, co-morbidities. Interaction terms were included to investigate modification by infant sex. RESULTS: The prevalence of cannabis use in our cohort was approximately 2%. Prenatal cannabis use is associated with increased risks of spontaneous and medically indicated preterm birth (1.80[1.68-1.93] and 1.94[1.77-2.12], respectively), very preterm birth (1.73[1.48-2.02]), low birth weight (1.90[1.79-2.03]), small-for-gestational age (1.21[1.16-1.27]) and large-for-gestational age (1.06[1.01-1.12]), any major congenital anomaly (1.71[1.49-1.97]), caesarean section (1.13[1.09-1.17]), and gestational diabetes (1.32[1.23-1.42]). No association was found for stillbirth or gestational hypertension. Only small-for-gestational age (p = 0.03) and spontaneous preterm birth (p = 0.04) showed evidence of modification by infant sex. CONCLUSIONS: Prenatal cannabis use increases the likelihood of preterm birth, low birth weight, small-for-gestational age and major congenital anomalies with prenatally exposed female infants showing evidence of increased susceptibility. Additional measures are needed to inform the public and providers of the inherent risks of cannabis exposure in pregnancy.

Timing of cesarean delivery in women with ≥2 previous cesarean deliveries.

BACKGROUND: The rate of cesarean delivery is continuously increasing with the leading indication being a previous cesarean delivery. For women with 1 previous cesarean delivery, it is generally agreed that the optimal timing of delivery by elective cesarean delivery is during the 39th week of gestation, whereas for women with ≥2 previous cesarean deliveries, the optimal delivery time remains debatable. OBJECTIVE: To assess the maternal and neonatal risks associated with elective delivery at different gestational ages ranging from 37 0/7 to 39 6/7 weeks' gestation and to compare it with expectant management among women with at least 2 previous cesarean deliveries. STUDY DESIGN: This was a retrospective, population-based cohort study of all women with at least 2 previous cesarean deliveries who delivered after 36 6/7 weeks of gestation in Ontario, Canada, between April 2012 and March 2019. Women with multifetal pregnancies or major fetal anomalies were excluded. For each completed gestational week, outcomes of women who had an elective repeat cesarean delivery at that week solely because of 2 previous cesarean deliveries were compared with the outcomes of those who were managed expectantly and delivered at a later gestational age. The primary outcome was a composite of maternal outcomes including mortality and severe maternal morbidity. Secondary outcomes were adverse neonatal outcomes. RESULTS: A total of 26,522 women met the inclusion criteria. The maternal risk was similar for elective delivery at 37 0/7 to 38 6/7 weeks of gestation compared with expectant management. However, elective delivery at 39 0/7 to 39 6/7 weeks' gestation was associated with a decreased risk for adverse outcomes when compared with expectant management (adjusted risk ratio, 0.51; 95% confidence interval, 0.29-0.91). For the neonate, elective delivery during the 37th week of gestation significantly increased the incidence of the composite adverse outcome than in an ongoing pregnancy (adjusted risk ratio, 1.68; 95% confidence interval, 1.39-2.01), but was comparable for elective delivery at 38 0/7 to 39 6/7 weeks' gestation and expectant management. The risk for an unplanned cesarean delivery increased from 6.5% before 38 weeks' gestation to 21.7% before 39 weeks' gestation and to 32.6% before 40 weeks' gestation. CONCLUSION: For women with ≥2 cesarean deliveries, elective delivery at 38 0/7 to 38 6/7 weeks' gestation likely represents the optimal balance between neonatal and maternal risk while decreasing the likelihood of an unplanned cesarean delivery.

Changes in rate of preterm birth and adverse pregnancy outcomes attributed to preeclampsia after introduction of a refined definition of preeclampsia: A population-based study.

INTRODUCTION: Since 2013, various guidelines for hypertension in pregnancy have been refined, no longer requiring proteinuria as a requisite criterion for preeclampsia. We aimed to evaluate the impact of the new definition on preterm birth (PTB) and adverse pregnancy outcomes. MATERIAL AND METHODS: Women delivering in Ontario between April 2012 and November 2016 were included. Delivery <24+0/7 weeks, major fetal anomalies or preexisting renal disease were excluded. The primary outcome was livebirth <37, <34 or <32 weeks. Rates, adjusted rate ratios (aRR) and ratio of the rate ratio (RRR) were used to compare outcomes in the 2 years after the new Society of Obstetricians and Gynaecologists of Canada (SOGC) guideline (December 2014-November 2016; period 2) vs the 2 years before (April 2012-March 2014; period 1), among women with and without preeclampsia. RESULTS: In all, 268 543 and 267 964 births in periods 1 & 2, respectively, were included. Respective preeclampsia rates increased significantly from 3.9% to 4.4% (p < 0.001), with no change in maternal morbidity rates. In preeclamptic women, respective rates of PTB <37 weeks were 21.0% and 20.7% (aRR 1.01, 95% confidence interval [CI] 1.00-1.02), with significant aRR for PTB <34 (0.86, 95% CI 0.77-0.96) and <32 weeks (0.79, 95% CI 0.67-0.94). A similar aRR was observed in women without preeclampsia. In preeclamptic women, composite severe neonatal morbidity decreased after guideline change (aRR 0.95, 95% CI 0.91-0.99), a finding not observed in women without preeclampsia (RRR 0.95, 95% CI 0.91-0.99). CONCLUSIONS: The new definition of preeclampsia was associated with increased disease rates, a modest reduction in adverse neonatal outcomes and no change in maternal outcomes.

Gastroschisis in Ontario, Canada: 2012-2018.

BACKGROUND: Gastroschisis is a congenital anomaly of the abdomen in which the intestines are found outside of the body at birth. While no clear causative factors have been identified, it is strongly associated with young maternal age. Other reported associations include low maternal socioeconomic status, low maternal body mass index (BMI), and smoking. METHODS: This is a retrospective review of epidemiologic data relating to cases of gastroschisis in Ontario from 2012-2018 in the Better Outcomes Registry & Network (BORN) Ontario database, which is the province's prescribed maternal-newborn registry. We describe the epidemiology of gastroschisis in Ontario with respect to birth prevalence, maternal age, health, exposures, and geography. RESULTS: The birth prevalence of gastroschisis is 2.31 cases/10,000 births. There was no apparent change in birth prevalence over the study period and there was no difference between male and female infants. Gastroschisis was associated with younger maternal ages and was inversely correlated with maternal BMI. Gastroschisis was associated with first completed pregnancy. Maternal diabetes was associated with a lower birth prevalence of gastroschisis than average. Mothers of babies with gastroschsis were more likely to report use of tobacco, alcohol, and drugs during pregnancy than those without gastroschisis, with marijuana use showing the largest increase in birth prevalence of gastroschisis. Mothers living in rural areas were more likely to have a baby with gastroschisis than those in urban centers, even after controlling for maternal age. CONCLUSIONS: This Ontario registry study reveals that mothers with babies with gastroschisis are more likely to be young and thin, live in rural areas, and report prenatal smoking, alcohol use, and drug use than women whose pregnancies do not have gastroschsis.

The relationship between maternal body mass index and pregnancy outcomes in twin compared with singleton pregnancies.

OBJECIVE: Women with twins have an a priori increased risk for many of the complications associated with maternal obesity. Thus, the impact of maternal obesity in twins may differ from that reported in singletons. In addition, given the increased metabolic demands in twin pregnancies, the impact of maternal underweight may be greater in twin compared with singleton gestations. Our objective was to test the hypothesis that the relationship between maternal pre-pregnancy body mass index (BMI) and adverse pregnancy outcomes differ between twin and singleton gestations. METHODS: This was a retrospective population-based study of all women who had a singleton or twin hospital birth in Ontario, Canada, between April 2012 and March 2016. Data were obtained from the Better Outcomes Registry & Network (BORN) Ontario. The relationship between maternal BMI category and pregnancy complications was assessed separately in twin and singleton gestations. The primary outcome was a composite variable that included any of the following complications: preeclampsia, gestational diabetes, or preterm birth before 320/7 weeks. Relative risk (aRR) and 95% confidence intervals (CI) for adverse outcomes for each BMI category as defined by WHO (using normal weight category as reference) were generated using modified Poisson regression, adjusting for maternal age, nulliparity, smoking, previous preterm birth, and fetal sex. RESULTS: A total of 487,870 women with singleton (n = 480,010) and twin (n = 7860) pregnancies met the inclusion criteria. The risk of the composite primary outcome, preeclampsia, gestational diabetes, and cesarean delivery increased with high maternal BMI in both singleton and twin gestations, but these associations were weaker in twin compared with singleton gestations (association of BMI ≥ 40.0 kg/m2 with primary outcome: aRR = 3.10, 95%-CI 2.96-3.24 in singletons compared with aRR = 1.74, 95%-CI 1.37-2.20 in twins). In singleton pregnancies the risk of preterm birth at < 320/7 weeks increased with maternal BMI, mainly due to an increased risk of provider-initiated preterm birth. In twin gestations, however, underweight (but not overweight or obesity) was associated with the greatest risk of preterm birth at < 32 weeks (aRR 1.67, 95%-CI 1.17-2.37), mainly due to an increased risk of spontaneous preterm birth (aRR 2.10, 95%-CI 1.44-3.08). CONCLUSION: In healthy women with twin pregnancies, underweight is associated with the greatest risk for preterm birth, while the association of maternal obesity with adverse pregnancy outcomes is weaker than that observed in singletons.

Gestational diabetes mellitus is associated with adverse outcomes in twin pregnancies.

BACKGROUND: Among singleton pregnancies, gestational diabetes mellitus is associated with adverse outcomes. In twin pregnancies, this association may be attenuated, given the higher rate of prematurity and the a priori increased risk of some of these complications. OBJECTIVE: Our aim was to test the hypothesis that gestational diabetes mellitus is less likely to be associated with adverse pregnancy outcomes in twin compared with singleton gestations. METHODS: This retrospective cohort study comprised all twin and singleton live births in Ontario, Canada, 2012-2016. Pregnancy outcomes were compared between women with vs without gestational diabetes mellitus, analyzed separately for twin and singleton births. Adjusted risk ratios and 95% confidence intervals were generated using modified Poisson regression, adjusting for maternal age, nulliparity, smoking, race, body mass index, preexisting hypertension, and assisted reproductive technology. RESULTS: A total of 270,843 women with singleton (n = 266,942) and twin (n = 3901) pregnancies met the inclusion criteria. In both the twin and singleton groups, gestational diabetes mellitus was associated with (adjusted risk ratio, [95% confidence interval]) cesarean delivery (1.11 [1.02-1.21] and 1.20 [1.17-1.23], respectively) and preterm birth at <370/7 weeks (1.21 [1.08-1.37] and 1.48 [1.39-1.57]) and at <340/7 weeks (1.45 [1.03-2.04] and 1.25 [1.06-1.47]). In singletons, but not twins, gestational diabetes mellitus was associated with gestational hypertension (1.66 [1.55-1.77]) and preeclampsia. With respect to neonatal outcomes, gestational diabetes mellitus was associated with birthweight greater than the 90th percentile in both twins and singletons, with the risk being 2-fold higher in twins (2.53 [1.52-4.23] vs 1.18 [1.13-1.23], respectively, P = .004). Gestational diabetes mellitus was associated with jaundice in both twins (1.56 [1.10-2.21]) and singletons (1.49 [1.37-1.62) but was associated with the following complications only in singletons: neonatal intensive care unit admission (1.44 [1.38-1.50]), respiratory morbidity (1.09 [1.02-1.16]), and neonatal hypoglycemia (3.20 [3.01-3.40]). CONCLUSION: In contrast to singleton pregnancies, gestational diabetes mellitus in twins was not associated with hypertensive complications and certain neonatal morbidities. Still, the current study highlights that gestational diabetes mellitus is associated with some adverse pregnancy outcomes including accelerated fetal growth also in twin pregnancies.

Timing of Delivery in Women With Chronic Hypertension.

OBJECTIVE: To assess whether routine induction of labor at 38 or 39 weeks in women with chronic hypertension is associated with the risk of superimposed preeclampsia or cesarean delivery. METHODS: We conducted a retrospective population-based study of women with chronic hypertension who had a singleton hospital birth at 38 0/7 weeks of gestation of gestation in Ontario, Canada, between 2012 and 2016. Women who underwent induction of labor at 38 0/7 to 38 6/7 weeks of gestation for chronic hypertension (n=281) were compared with those who were managed expectantly during that week and remained undelivered at 39 0/7 weeks of gestation (n=1,606). Separately, women who underwent induction of labor at 39 0/7 to 39 6/7 weeks of gestation for chronic hypertension (n=259) were compared with women who remained undelivered at 40 0/7 weeks of gestation (n=801). RESULTS: Of 534,529 women gave birth during the study period, 6,054 (1.1%) had chronic hypertension and 2,420 met the inclusion criteria. Women managed expectantly at 38 or 39 weeks of gestation were at risk of new-onset superimposed preeclampsia (19.2% [308/1,606] and 19.0% [152/801], respectively) and eclampsia (0.6% [10/1,606] and 0.7% [6/801], respectively), and more than half underwent induction of labor later in gestation (56.8% and 57.8%, respectively). The risk of cesarean delivery in the induction groups was lower (38 weeks of gestation) or similar (39 weeks of gestation) to that observed in women managed expectantly at the corresponding weeks (38 weeks of gestation: 17.1% vs 24.0%, adjusted relative risk 0.74 [95% CI 0.57-0.95]; 39 weeks of gestation: 20.1% vs 26.0%, adjusted relative risk 0.90 [95% CI 0.69-1.17]). CONCLUSION: Our findings suggest that in women with isolated chronic hypertension, induction of labor at 38 or 39 weeks of gestation may prevent severe hypertensive complications without increasing the risk of cesarean delivery.

Incidence and risk factors for gestational diabetes mellitus in twin versus singleton pregnancies.

OBJECTIVE: To compare the incidence and risk factors for gestational diabetes mellitus (GDM) between women with twin and singleton pregnancies. METHODS: Retrospective study of all women who had a twin or singleton birth in Ontario (2012-2016). Risk ratios (RR) and 95% CIs for GDM (stratified by type of treatment) were adjusted for relevant confounding variables. Multivariable Poisson regression analysis was used to identify risk factors for GDM in twin and singleton gestations. RESULTS: Of 270,843 women who met inclusion criteria, 266,942 (98.6%) and 3901 (1.4%) had a singleton and a twin pregnancy, respectively. Women with twins had a significantly higher risk for overall GDM (aRR = 1.13, 95% CI 1.01-1.28) and diet-treated GDM (aRR = 1.20, 95% CI 1.01-1.42) while the association with insulin-treated GDM was not significant (aRR = 1.07, 95% CI 0.89-1.28). Maternal age ≥ 35 years, non-Caucasian ethnicity and BMI > 30 kg/m2 were independent risk factors for GDM among women with twins and singletons, and the magnitude of the association of these factors with GDM was similar. CONCLUSIONS: Women with twins are at increased risk of GDM, mainly due to a higher rate of diet-treated GDM. Despite higher baseline risk of GDM in women with twins, the effect of known risk factors for GDM is similar to that observed in singletons.

Disease management for depression in an MS clinic.

OBJECTIVE: Evidence-based treatments for depression in multiple sclerosis (MS) are available, but their implementation can be challenging. We explored the feasibility and effectiveness of implementing a disease management program for depression in an MS clinic. METHODS: A non-randomized "before-after" design was used. The University of Calgary MS Clinic performs routine screening for depression using the Center for Epidemiologic Studies Depression Rating Scale (CES-D). During a six month baseline period, the screen results were not systematically acted upon. During a subsequent nine-month study period, a case manager was routinely notified of positive screens. These patients were offered disease management. Major depression was assessed six months later with a blind administration of the Mini Neuropsychiatric Interview (MINI). Quality of life (EQ-5D) and functional status (WHO DAS II) were also measured. RESULTS: Eighty-three patients were enrolled in the study; 54 were in the disease management group and 29 received treatment as usual. There was a lower frequency of major depression in the intervention group six months post-screening. No differences in quality of life or functional status were seen. CONCLUSIONS: Disease management approaches for depression were developed in primary care environments and have been adapted for geriatric and diabetic populations. These strategies may require modification for application in MS clinics. While an intervention for depression was effective in those who received it, its impact on the targeted clinical population was reduced by lower than expected rates of participation and higher than expected rates of treatment at baseline.