Use of Latent Class Analysis to Predict Intensive Care Unit Admission and Mortality in Children with a Major Congenital Anomaly.

OBJECTIVE: To define major congenital anomaly (CA) subgroups and assess outcome variability based on defined subgroups. STUDY DESIGN: This population-based cohort study used registries in Denmark for children born with a major CA between January 1997 and December 2016, with follow-up until December 2018. We performed a latent class analysis (LCA) using child and family clinical and sociodemographic characteristics present at birth, incorporating additional variables occurring until age of 24 months. Cox proportional hazards regression models estimated hazard ratios (HRs) of pediatric mortality and intensive care unit (ICU) admissions for identified LCA classes. RESULTS: The study included 27 192 children born with a major CA. Twelve variables led to a 4-class solution (entropy = 0.74): (1) children born with higher income and fewer comorbidities (55.4%), (2) children born to young mothers with lower income (24.8%), (3) children born prematurely (10.0%), and (4) children with multiorgan involvement and developmental disability (9.8%). Compared with those in Class 1, mortality and ICU admissions were highest in Class 4 (HR = 8.9, 95% CI = 6.4-12.6 and HR = 4.1, 95% CI = 3.6-4.7, respectively). More modest increases were observed among the other classes for mortality and ICU admissions (Class 2: HR = 1.7, 95% CI = 1.1-2.5 and HR = 1.3, 95% CI = 1.1-1.4, respectively; Class 3: HR = 2.5, 95% CI = 1.5-4.2 and HR = 1.5, 95% CI = 1.3-1.9, respectively). CONCLUSIONS: Children with a major CA can be categorized into meaningful subgroups with good discriminative ability. These groupings may be useful for risk-stratification in outcome studies.

Patterns of multiple chronic conditions in pregnancy: Population-based study using latent class analysis.

BACKGROUND: Adults with multiple chronic conditions (MCC) are a heterogeneous population with elevated risk of future adverse health outcomes. Yet, despite the increasing prevalence of MCC globally, data about MCC in pregnancy are scarce. OBJECTIVES: To estimate the population prevalence of MCC in pregnancy and determine whether certain types of chronic conditions cluster together among pregnant women with MCC. METHODS: We conducted a population-based cohort study in Ontario, Canada, of all 15-55-year-old women with a recognised pregnancy, from 2007 to 2020. MCC was assessed from a list of 22 conditions, identified using validated algorithms. We estimated the prevalence of MCC. Next, we used latent class analysis to identify classes of co-occurring chronic conditions in women with MCC, with model selection based on parsimony, clinical interpretability and statistical fit. RESULTS: Among 2,014,508 pregnancies, 324,735 had MCC (161.2 per 1000, 95% confidence interval [CI] 160.6, 161.8). Latent class analysis resulted in a five-class solution. In four classes, mood and anxiety disorders were prominent and clustered with one additional condition, as follows: Class 1 (22.4% of women with MCC), osteoarthritis; Class 2 (23.7%), obesity; Class 3 (15.8%), substance use disorders; and Class 4 (22.1%), asthma. In Class 5 (16.1%), four physical conditions clustered together: obesity, asthma, chronic hypertension and diabetes mellitus. CONCLUSIONS: MCC is common in pregnancy, with sub-types dominated by co-occurring mental and physical health conditions. These data show the importance of preconception and perinatal interventions, particularly integrated care strategies, to optimise treatment and stabilisation of chronic conditions in women with MCC.

Miscarriage after SARS-CoV-2 vaccination: A population-based cohort study.

OBJECTIVE: To evaluate the risk of miscarriage following SARS-CoV-2 vaccination, while accounting for the competing risk of induced abortion. DESIGN: Population-based cohort study. SETTING: Ontario, Canada. PARTICIPANTS: Women aged 15-50 years with a confirmed pregnancy at ≤19 completed weeks' gestation. METHODS: Exposure to first SARS-CoV-2 vaccination, handled in a time-varying manner, was defined as (i) unvaccinated, (ii) remotely vaccinated >28 days before the estimated conception date or (iii) recently vaccinated ≤28 days before conception and up to 120 days after conception. MAIN OUTCOME MEASURES: The outcome was miscarriage, occurring between the estimated date of conception and up to 19 completed weeks of pregnancy. Fine-Grey hazard models, accounting for the competing risk of induced abortion, generated hazard ratios (aHR), adjusted for socio-demographic factors, comorbidities, and biweekly periods. RESULTS: Included were 246 259 pregnant women, of whom 34% received a first SARS-CoV-2 vaccination. Miscarriage occurred at a rate of 3.6 per 10 000 person-days among remotely vaccinated women and 3.2 per 10 000 person-days among those recently vaccinated, in contrast to a rate of 1.9 per 10 000 person-days among unvaccinated women, with corresponding aHR of 0.98 (95% confidence interval [CI] 0.91-1.07) and 1.00 (95% CI 0.93-1.08). CONCLUSIONS: SARS-CoV-2 vaccination was not associated with miscarriage while accounting for the competing risk of induced abortion. This study reiterates the importance of including pregnant women in new vaccine clinical trials and registries, and the rapid dissemination of vaccine safety data.

Diabetes mellitus in pregnancy across Canada.

BACKGROUND: Contemporary estimates of diabetes mellitus (DM) rates in pregnancy are lacking in Canada. Accordingly, this study examined trends in the rates of type 1 (T1DM), type 2 (T2DM) and gestational (GDM) DM in Canada over a 15-year period, and selected adverse pregnancy outcomes. METHODS: This study used repeated cross-sectional data from the Canadian Institute of Health Information (CIHI) hospitalization discharge abstract database (DAD). Maternal delivery records were linked to their respective birth records from 2006 to 2019. The prevalence of T1DM, T2DM and GDM were calculated, including relative changes over time, assessed by a Cochrane-Armitage test. Also assessed were differences between provinces and territories in the prevalence of DM. RESULTS: Over the 15-year study period, comprising 4,320,778 hospital deliveries in Canada, there was a statistically significant increase in the prevalence of GDM and T1DM and T2DM. Compared to pregnancies without DM, all pregnancies with any form of DM had higher rates of hypertension and Caesarian delivery, and also adverse infant outcomes, including major congenital anomalies, preterm birth and large-for-gestational age birthweight. CONCLUSION: Among 4.3 million pregnancies in Canada, there has been a rise in the prevalence of DM. T2DM and GDM are expected to increase further as more overweight women conceive in Canada.

Mental Illness in the 2 Years Prior to Pregnancy in a Population With Traumatic Brain Injury: A Cross-Sectional Study: La maladie mentale dans les deux ans précédant une grossesse dans une population souffrant de lésion cérébrale traumatique : une étude transversale.

OBJECTIVE: Existing studies, in mostly male samples such as veterans and athletes, show a strong association between traumatic brain injury (TBI) and mental illness. Yet, while an understanding of mental health before pregnancy is critical for informing preconception and perinatal supports, there are no data on the prevalence of active mental illness before pregnancy in females with TBI. We examined the prevalence of active mental illness ≤2 years before pregnancy (1) in a population with TBI, and (2) in subgroups defined by sociodemographic, health, and injury-related characteristics, all compared to those without TBI. METHOD: This population-based cross-sectional study was completed in Ontario, Canada, from 2012 to 2020. Modified Poisson regression generated adjusted prevalence ratios (aPRs) of active mental illness ≤2 years before pregnancy in 15,585 females with TBI versus 846,686 without TBI. We then used latent class analysis to identify subgroups with TBI according to sociodemographic, health, and injury-related characteristics and subsequently compared them to females without TBI on their outcome prevalence. RESULTS: Females with TBI had a higher prevalence of active mental illness ≤2 years before pregnancy than those without TBI (44.1% vs. 25.9%; aPR 1.46, 95% confidence interval, 1.43 to 1.49). There were 3 TBI subgroups, with Class 1 (low-income, past assault, recent TBI described as intentional and due to being struck by/against) having the highest outcome prevalence. CONCLUSIONS: Females with TBI, and especially those with a recent intentional TBI, have a high prevalence of mental illness before pregnancy. They may benefit from mental health screening and support in the post-injury, preconception, and perinatal periods. PLAIN LANGUAGE TITLE: Mental illness in the 2 years before pregnancy in a population with traumatic brain injury. PLAIN LANGUAGE SUMMARY: Research has shown a strong association between traumatic brain injury (TBI) and mental illness. Most previous studies have been conducted in primarily male samples, like veterans and professional athletes. Understanding mental health before pregnancy is important for deciding what supports people need before and during pregnancy. However, there are no studies on the frequency of mental illness in females with TBI before a pregnancy. We examined the frequency of mental illness 2 years before pregnancy in a population with TBI, and in subgroups defined by different social, health, and injury-related characteristics, compared to those without TBI. We undertook a population-wide study of all females with and without TBI in Ontario, Canada, with a birth in 2012-2020. We used statistical models to compare these groups on the presence of mental illness in the 2 years before pregnancy, before and after accounting for social and health characteristics. We also identified subgroups with TBI according to their social (e.g., poverty), health (e.g., chronic conditions), and injury-related characteristics (e.g., cause of injury) and subsequently compared them to females without TBI on their frequency of mental illness in the 2 years before pregnancy. Forty-four percent of females with TBI had mental illness in the 2 years before pregnancy compared to 25% of those without TBI. There were 3 TBI subgroups. Females with low-income, past assault, and injuries that were described as being intentional had the highest frequency of mental illness in the 2 years before pregnancy. Females with TBI may benefit from mental health screening and support post-injury and around the time of pregnancy.

Maternal deaths by suicide and drug overdose in two Canadian provinces; retrospective review.

OBJECTIVE: To identify and review factors associated with maternal deaths by suicide and drug overdose in the Canadian Coroner and Medical Examiners Database (CCMED), from 2017-2019. METHODS: We identified potential maternal deaths in Ontario and British Columbia by searching the CCMED narratives of deaths to females 10 to 60 years old for pregnancy-related terms. Identified narratives were then qualitatively reviewed in quadruplicate to determine if they were maternal deaths by suicide or drug overdose, and to extract information on maternal characteristics, the manner of death, and factors associated with each death. RESULTS: Of the 90 deaths identified in this study, 15 (16.7%) were due to suicide and 20 (22.2%) were due to a drug overdose. These deaths occurred to women of varying ages and across the pregnancy-postpartum period. Among the suicides, 10 were by hanging, and among the overdose-related deaths, 15 had fentanyl detected. Notably, 13 (37.1%) of the 35 deaths to suicide or drug overdose occurred beyond 42 days after pregnancy, 19 (54.3%) followed a miscarriage or induced abortion, and in 23 (65.7%) there was an established history of mental health illness. Substance use disorders were documented in 4 of the 15 suicides (26.7%), and 18 of the 20 overdose-related deaths (90.0%). CONCLUSION: Suicide and drug overdose may contribute more to maternal deaths in Canada than previously realized. Programs are needed to identify women at risk of these outcomes, and to intervene during pregnancy and beyond the conventional postpartum period.

Maternal Deaths Using Coroner's Data: A Latent Class Analysis.

OBJECTIVE: Knowledge regarding the antecedent clinical and social factors associated with maternal death around the time of pregnancy is limited. This study identified distinct subgroups of maternal deaths using population-based coroner's data, and that may inform ongoing preventative initiatives. METHODS: A detailed review of coroner's death files was performed for all of Ontario, Canada, where there is a single reporting mechanism for maternal deaths. Deaths in pregnancy, or within 365 days thereafter, were identified within the Office of the Chief Coroner for Ontario database, 2004-2020. Variables related to the social and clinical circumstances surrounding the deaths were abstracted in a standardized manner from each death file, including demographics, forensic information, nature and cause of death, and antecedent health and health care factors. These variables were then entered into a latent class analysis (LCA) to identify distinct types of deaths. RESULTS: Among 273 deaths identified in the study period, LCA optimally identified three distinct subgroups, namely, (1) in-hospital deaths arising during birth or soon thereafter (52.7% of the sample); (2) accidents and unforeseen obstetric complications also resulting in infant demise (26.3%); and (3) out-of-hospital suicides occurring postpartum (21.0%). Physical injury (22.0%) was the leading cause of death, followed by hemorrhage (16.8%) and overdose (13.3%). CONCLUSION: Peri-pregnancy maternal deaths can be classified into three distinct sub-types, with somewhat differing causes. These findings may enhance clinical and policy development aimed at reducing pregnancy mortality.

Short-Term Adverse Outcomes After Mifepristone-Misoprostol Versus Procedural Induced Abortion : A Population-Based Propensity-Weighted Study.

BACKGROUND: Prior studies comparing first-trimester pharmaceutical induced abortion (IA) with procedural IA were prone to selection bias, were underpowered to assess serious adverse events (SAEs), and did not account for confounding by indication. Starting in 2017, mifepristone-misoprostol was dispensed at no cost in outpatient pharmacies across Ontario, Canada. OBJECTIVE: To compare short-term risk for adverse outcomes after early IA by mifepristone-misoprostol versus by procedural IA. DESIGN: Population-based cohort study. SETTING: Ontario, Canada. PATIENTS: All women who had first-trimester IA. MEASUREMENTS: A total of 39 856 women dispensed mifepristone-misoprostol as outpatients were compared with 65 176 women undergoing procedural IA at 14 weeks' gestation or earlier within nonhospital outpatient clinics (comparison 1). A total of 39 856 women prescribed mifepristone-misoprostol were compared with 8861 women undergoing ambulatory hospital-based procedural IA at an estimated 9 weeks' gestation or less (comparison 2). The primary composite outcome was any SAE within 42 days after IA, including severe maternal morbidity, end-organ damage, intensive care unit admission, or death. A coprimary broader outcome comprised any SAE, hemorrhage, retained products of conception, infection, or transfusion. Stabilized inverse probability of treatment weighting accounted for confounding between exposure groups. RESULTS: Mean age at IA was about 29 years (SD, 7); 33% were primigravidae. Six percent resided in rural areas, and 25% resided in low-income neighborhoods. In comparison 1, SAEs occurred among 133 women after mifepristone-misoprostol IA (3.3 per 1000) versus 114 after procedural IA (1.8 per 1000) (relative risk [RR], 1.87 [95% CI, 1.44 to 2.43]; absolute risk difference [ARD], 1.5 per 1000 [CI, 0.9 to 2.2]). The respective rates of any adverse event were 28.9 versus 12.4 per 1000 (RR, 2.33 [CI, 2.11 to 2.57]; ARD, 16.5 per 1000 [CI, 14.5 to 18.4]). In comparison 2, SAEs occurred among 133 (3.4 per 1000) and 27 (3.3 per 1000) women, respectively (RR, 1.04 [CI, 0.61 to 1.78]). The respective rates of any adverse event were 31.2 versus 24.9 per 1000 (RR, 1.25 [CI, 1.04 to 1.51]). LIMITATION: A woman prescribed mifepristone-misoprostol may not have taken the medication, and the exact gestational age at IA was not always known. CONCLUSION: Although rare, short-term adverse events are more likely after mifepristone-misoprostol IA than procedural IA, especially for less serious adverse outcomes. PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research.

The association between offspring birthweight and future risk of maternal diabetes: A population-based study.

AIMS: As an indicator of maternal cardiometabolic health, newborn birthweight may be an important predictor of maternal type 2 diabetes mellitus (diabetes). We evaluated the relation between offspring birthweight and onset of maternal diabetes after pregnancy. METHODS: This retrospective cohort study used linked population-based health databases from Ontario, Canada. We included women aged 16-50 years without pre-pregnancy diabetes, and who had a live birth between 2006 and 2014. We used Cox proportional hazard regression to evaluate the association between age- and sex-standardized offspring birthweight percentile categories and incident maternal diabetes, while adjusting for maternal age, parity, year, ethnicity, gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP). Results were further stratified by the presence of GDM in the index pregnancy. RESULTS: Of 893,777 eligible participants, 14,329 (1.6%) women were diagnosed with diabetes over a median (IQR) of 4.4 (1.5-7.4) years of follow-up. There was a continuous positive relation between newborn birthweight above the 75th percentile and maternal diabetes. Relative to a birthweight between the 50th and 74.9th percentiles, women whose newborn had a birthweight between the 97th and 100th percentiles had an adjusted hazards ratio (aHR) of diabetes of 2.30 (95% CI 2.16-2.46), including an aHR of 2.01 (95% CI 1.83-2.21) among those with GDM, and 2.59 (2.36-2.84) in those without GDM. CONCLUSIONS: A higher offspring birthweight signals an increased risk of maternal diabetes, offering another potentially useful way to identify women especially predisposed to diabetes.

The association between immigration status and the development of type 2 diabetes in women with a prior diagnosis of gestational diabetes: A population-based study.

AIMS: The aim of this study was to examine the influence of immigration status and region of origin on the risk of type 2 diabetes in women with prior gestational diabetes (GDM). METHODS: This retrospective population-based cohort study included women with gestational diabetes (GDM) aged 16 to 50 years in Ontario, Canada, who gave birth between 2006 and 2014. We compared the incidence of type 2 diabetes after delivery between long-term residents and immigrants-overall, by time since immigration and by region of-using Cox regression adjusted for age, year, neighbourhood income, rurality, infant birth weight and presence of hypertensive disorders of pregnancy (HDP). RESULTS: Among 38,515 women with prior GDM (42% immigrants), immigrants had a significantly higher risk of type 2 diabetes compared with long-term residents (adjusted hazard ratio [HR] 1.19, 95% confidence interval [CI] 1.13-1.26), with no meaningful difference based on time since immigration. The highest adjusted relative risks of type 2 diabetes compared with long-term residents were found for immigrants from Sub-Saharan Africa (HR 1.63, 95% CI 1.40-1.90), Latin America/Caribbean (HR 1.44, 95% CI 1.28-1.62) and South Asia (HR 1.34, 95% CI 1.25-1.44). CONCLUSIONS: Immigration is associated with a significantly higher risk of type 2 diabetes after GDM, particularly for women from certain low- and middle-income countries. Diabetes prevention strategies will need to consider the unique needs of immigrants from these regions.

Risk of recurrent severe maternal morbidity: a population-based study.

BACKGROUND: Severe maternal morbidity is a composite indicator of maternal health and obstetrical care. Little is known about the risk of recurrent severe maternal morbidity in a subsequent delivery. OBJECTIVE: This study aimed to estimate the risk of recurrent severe maternal morbidity in the next delivery after a complicated first delivery. STUDY DESIGN: We analyzed a population-based cohort study of women with at least 2 singleton hospital deliveries between 1989 and 2021 in Quebec, Canada. The exposure was severe maternal morbidity in the first hospital-recorded delivery. The study outcome was severe maternal morbidity at the second delivery. Log-binomial regression models adjusted for maternal and pregnancy characteristics were used to generate relative risks and 95% confidence intervals comparing women with and without severe maternal morbidity at first delivery. RESULTS: Among 819,375 women, 43,501 (3.2%) experienced severe maternal morbidity in the first delivery. The rate of severe maternal morbidity recurrence at second delivery was 65.2 vs 20.3 per 1000 in women with and without previous severe maternal morbidity (adjusted relative risk, 3.11; 95% confidence interval, 2.96-3.27). The adjusted relative risk for recurrence of severe maternal morbidity was greatest among women who had ≥3 different types of severe maternal morbidity at their first delivery, relative to those with none (adjusted relative risk, 5.50; 95% confidence interval, 4.26-7.10). Women with cardiac complication at first delivery had the highest risk of severe maternal morbidity in the next delivery. CONCLUSION: Women who experience severe maternal morbidity have a relatively high risk of recurrent morbidity in the subsequent pregnancy. In women with severe maternal morbidity, these study findings have implications for prepregnancy counseling and maternity care in the next pregnancy.

Pre-phototherapy total serum bilirubin levels in extremely preterm infants.

BACKGROUND: Extremely preterm infants are prone to hyperbilirubinemia and its sequelae. Currently recommended thresholds for initiating phototherapy in these newborns are consensus-based (CB). METHODS: A multi-site retrospective cohort study of 642 infants born at 240/7 to 286/7 weeks' gestation, between January 2013 and June 2017, was conducted at three NICUs in Canada. Pre-phototherapy TSB percentile levels at 24 h of age were generated and contrasted with published CB thresholds. RESULTS: Among infants born 240/7 to 256/7 weeks' gestation, the differences between our TSB percentiles vs. the CB threshold of 85.0 µmol/L were 10.0 µmol/L (95% CI, 6.0-16.0) at the 75th percentile and 35.3 µmol/L (95% CI, 26.1-42.8) at the 95th percentile. Respectively, among infants born at 260/7 to 276/7 weeks, differences were 19.4 µmol/L (95% CI, 16.8-23.4) and 43.3 µmol/L (95% CI, 34.7-46.9). Born at 280/7 to 286/7 weeks' gestation, differences between our 75th and 95th TSB percentiles and the CB threshold of 103 µmol/L were 6.9 µmol/L (95% CI, 3.2-12.0) and 36.0 µmol/L (95% CI, 31.0-44.3), respectively. CONCLUSIONS: We provide statistically derived pre-phototherapy TSB levels that may clarify patterns of pre-phototherapy TSB levels in extremely preterm infants. IMPACT: We present statistically derived pre-phototherapy total serum bilirubin levels in a cohort of extremely preterm infants. Most of these preterm infants received phototherapy-some at below currently published thresholds. There are notable differences between our statistically derived pre-phototherapy TSB levels and currently published lower limit TSB thresholds for phototherapy. Our study results assist in the understanding of pre-phototherapy TSB levels in extremely preterm infants.

Receipt of adequate prenatal care for privately sponsored versus government-assisted refugees in Ontario, Canada: a population-based cohort study.

BACKGROUND: Canada has 2 main streams of resettlement: government-assisted refugees and privately sponsored refugees, whereby citizens can privately sponsor refugees and provide resettlement services, including health care navigation. Our objective was to compare receipt of adequate prenatal care among privately sponsored and government-assisted refugees. METHODS: This population-based study used linked health administrative and demographic databases. We included all resettled refugees classified as female who landed in Ontario, Canada, between April 2002 and May 2017, and who had a live birth or stillbirth conceived at least 365 days after their landing date. Our primary outcome - adequacy of prenatal care - was a composite that comprised receipt of a first-trimester prenatal visit, the number of prenatal care visits recommended by the Society of Obstetricians and Gynaecologists of Canada and a prenatal fetal anatomy ultrasound. We accounted for potential confounding with inverse probability of treatment weighting, using a propensity score. RESULTS: We included 2775 government-assisted and 2374 privately sponsored refugees. Compared with privately sponsored refugees (62.3% v. 69.3%), government-assisted refugees received adequate prenatal care less often, with a weighted relative risk of 0.93 (95% confidence interval 0.88-0.95). INTERPRETATION: Among refugees resettled to Canada, a government-assisted resettlement model was associated with receiving less adequate prenatal care than a private sponsorship model. Government-assisted refugees may benefit from additional support in navigating health care beyond the first year after arrival.

Risk of interpersonal violence during and after pregnancy among people with schizophrenia: a population-based cohort study.

BACKGROUND: Schizophrenia is associated with increased risk of experiencing interpersonal violence. Little is known about risk specifically around the time of pregnancy. METHODS: This population-based cohort study included all individuals (aged 15-49 yr) listed as female on their health cards who had a singleton birth in Ontario, Canada, between 2004 and 2018. We compared those with and without schizophrenia on their risk of an emergency department (ED) visit for interpersonal violence in pregnancy or within 1 year postpartum. We adjusted relative risks (RRs) for demographics, prepregnancy history of substance use disorder and history of interpersonal violence. In a subcohort analysis, we used linked clinical registry data to evaluate interpersonal violence screening and self-reported interpersonal violence during pregnancy. RESULTS: We included 1 802 645 pregnant people, 4470 of whom had a diagnosis of schizophrenia. Overall, 137 (3.1%) of those with schizophrenia had a perinatal ED visit for interpersonal violence, compared with 7598 (0.4%) of those without schizophrenia, for an RR of 6.88 (95% confidence interval [CI] 5.66-8.37) and an adjusted RR of 3.44 (95% CI 2.86-4.15). Results were similar when calculated separately for the pregnancy (adjusted RR 3.47, 95% CI 2.68-4.51) period and the first year postpartum (adjusted RR 3.45, 95% CI 2.75-4.33). Pregnant people with schizophrenia were equally likely to be screened for interpersonal violence (74.3% v. 73.8%; adjusted RR 0.99, 95% CI 0.95-1.04), but more likely to self-report it (10.2% v. 2.4%; adjusted RR 3.38, 95% CI 2.61-4.38), compared with those without schizophrenia. Among patients who did not self-report interpersonal violence, schizophrenia was associated with an increased risk for a perinatal ED visit for interpersonal violence (4.0% v. 0.4%; adjusted RR 6.28, 95% CI 3.94-10.00). INTERPRETATION: Pregnancy and postpartum are periods of higher risk for interpersonal violence among people with schizophrenia compared with those without schizophrenia. Pregnancy is a key period for implementing violence prevention strategies in this population.

Prescription of oxycodone versus codeine after childbirth and risk of persistent opioid use: a population-based cohort study.

BACKGROUND: Oxycodone is increasingly prescribed for postpartum analgesia in lieu of codeine owing to concerns regarding the neonatal safety of codeine during lactation. We examined whether initiation of oxycodone after delivery was associated with an increased risk of persistent opioid use relative to initiation of codeine. METHODS: We conducted a population-based cohort study of people who filled a prescription for either codeine or oxycodone within 7 days of discharge from hospital after delivery between Sept. 1, 2012, and June 30, 2020. The primary outcome was persistent opioid use, defined as 1 or more additional prescriptions for an opioid within 90 days of the first postpartum prescription and 1 or more additional prescriptions in the 91 to 365 days thereafter. We used inverse probability of treatment weighting to assess the risk of persistent postpartum opioid use, comparing people who initiated oxycodone with those who initiated codeine. RESULTS: Over the 8-year study period, we identified 70 607 people who filled an opioid prescription within 7 days of discharge from hospital: 21 308 (30.2%) received codeine and 49 299 (69.8%) oxycodone. Compared with people who filled a prescription for codeine, receipt of oxycodone was not associated with persistent opioid use (relative risk [RR] 1.04, 95% confidence interval [CI] 0.91-1.20). We found an association between a prescription for oxycodone and persistent use after vaginal delivery (RR 1.63, 95% CI 1.31-2.03), but not after cesarean delivery (RR 0.85, 95% CI 0.73-1.00). INTERPRETATION: Initiation of oxycodone (v. codeine) was not associated with an increased risk of persistent opioid use, except after vaginal delivery.

Morbidity and mortality of newborns born to immigrant and nonimmigrant females residing in low-income neighbourhoods.

BACKGROUND: Living in low-income neighbourhoods and being an immigrant are each independently associated with adverse neonatal outcomes, but it is unknown if disparities exist in the neonatal period for children of immigrant and nonimmigrant females living in low-income areas. We sought to compare the risk of severe neonatal morbidity and mortality (SNMM) between newborns of immigrant and nonimmigrant mothers who resided in low-income neighbourhoods. METHODS: This population-based cohort study used administrative data for females residing in low-income urban neighbourhoods in Ontario, who had an in-hospital, singleton live birth at 20-42 weeks' gestation, from 2002 to 2019. We defined immigrant status as nonrefugee immigrant or nonimmigrant, further detailed by country of birth and duration of residence in Ontario. The primary outcome was a SNMM composite (with 16 diagnoses, including neonatal death and 7 neonatal procedures as indicators), arising within 0-27 days after birth. We estimated relative risks (RRs) and 95% confidence intervals (CIs) using modified Poisson regression with generalized estimating equations. RESULTS: Our cohort included 148 050 and 266 191 live births among immigrant and nonimmigrant mothers, respectively. Compared with newborns of non-immigrant females, SNMM was less frequent among newborns of immigrant females (49.7 v. 65.6 per 1000 live births), with an adjusted RR of 0.76 (95% CI 0.74 to 0.79). The most frequent SNMM indicator was receipt of ventilatory support. Relative to neonates of nonimmigrant females, the risk of SNMM was highest among those of immigrants from Jamaica (adjusted RR 1.14, 95% CI 1.05 to 1.23) and Ghana (adjusted RR 1.20, 95% CI 1.05 to 1.38), and lowest among those of immigrants from China (adjusted RR 0.44, 95% CI 0.40 to 0.48). Among immigrants, the risk of SNMM declined with shorter duration of residence before the index birth. INTERPRETATION: Within low-income urban areas, newborns of immigrant females had an overall lower risk of SNMM than those of nonimmigrant females, with considerable variation by maternal birthplace and duration of residence. Initiatives should focus on improving preconception health and perinatal care within subgroups of females residing in low-income neighbourhoods.

Accuracy of aspirin prophylaxis for preeclampsia prevention documentation within a large administrative dataset.

BACKGROUND: Low-dose aspirin prophylaxis is recommended for women at risk of preeclampsia. Capturing aspirin prophylaxis within administrative databases can be challenging since it is an over-the-counter medication. The Better Outcome Registry and Network (BORN) database, a perinatal health registry in Ontario, Canada, includes a formal variable that captures aspirin prophylaxis for preeclampsia. This variable has not been formally validated. OBJECTIVES: To assess the accuracy of the aspirin prophylaxis variable in the BORN database against an electronic medical record (EMR). METHODS: This validation study comprised 200 randomly selected women who had a livebirth at St. Michael's Hospital (SMH) in Toronto, Ontario, from January 2018 to July 2022. Recorded aspirin prophylaxis in pregnancy and maternal sociodemographic characteristics were independently extracted by two abstractors. Accuracy of aspirin prophylaxis use in the BORN database was compared to that in the SMH EMR, expressed as sensitivity, specificity, positive (PPV) and negative predictive values (NPV), Cohen's kappa (κ), and overall percent agreement, with 95% confidence intervals (CI). Sensitivity analyses were performed to account for missing or unclear aspirin prophylaxis use. RESULTS: Among 200 women, 24 (12.0%) received aspirin prophylaxis - 12.5% within the SMH EMR and 8.0% in the BORN database. Women using aspirin were older (37.0 vs 33.0 years) and had higher median gravidity (3 vs. 2). Sensitivity and specificity of the BORN aspirin prophylaxis variable were 62.5% (95% CI 40.6, 81.2) and 100.0% (95% CI 97.3, 100.0), respectively. The corresponding positive and negative predictive values were 100.0% (95% CI 78.2, 100.0), and 93.8% (95% CI 88.6, 97.1), respectively. Cohen's κ was 0.74 (95% CI 0.58, 0.90), and overall percent agreement was 94.4% (95% CI 87.1, 100.0). CONCLUSIONS: Aspirin use within the BORN database, based on a standard variable field, appears accurate enough for the potential use in epidemiological studies of aspirin prophylaxis for preeclampsia or as a covariate in related studies.

ABO and Rh blood groups and risk of infection: systematic review and meta-analysis.

BACKGROUND: Persons with non-O and Rh-positive blood types are purported to be more susceptible to infection, including SARS-CoV-2, but there remains uncertainty about the degree to which this is so for both non-viral and viral infections. METHODS: We systematically reviewed Embase and PubMed from January 1st 1960 to May 31st 2022. English-language publications were selected that separately investigated the relation between ABO and/or Rh blood group and risk of SARS-CoV-2 and non-SARS-CoV-2 infection. Pooled odds ratios (ORp) and 95% confidence intervals (CI) were then generated for each. RESULTS: Non-O blood groups had a higher ORp for SARS-CoV-2 than O blood groups, both within 22 case-control studies (2.13, 95% CI 1.49- 3.04) and 15 cohort studies (1.89, 95% CI 1.56- 2.29). For non-SARS-CoV-2 viral infections, the respective ORp were 1.98 (95% CI 1.49-2.65; 4 case-control studies) and 1.87 (95% CI 1.53-2.29; 12 cohort studies). For non-viral infections, the ORp were 1.56 (95% CI 0.98-2.46; 13 case-control studies) and 2.11 (95% CI 1.67-6.67; 4 cohort studies). Rh-positive status had a higher ORp for SARS-CoV-2 infection within 6 case-control studies (13.83, 95% CI 6.18-30.96) and 6 cohort studies (19.04, 95% CI 11.63-31.17), compared to Rh-negative persons. For Rh status, non-SARS-CoV-2 infections, the ORp were 23.45 (95% CI 16.28-33.76) among 7 case-control studies, and 9.25 (95% CI 2.72-31.48) within 4 cohort studies. High measures of heterogeneity were notably observed for all analyses. CONCLUSIONS: Non-O and Rh-positive blood status are each associated with a higher risk of SARS-CoV-2 infection, in addition to other viral and non-viral infections.

Predicting adverse outcomes in pregnant patients positive for SARS-CoV-2: a machine learning approach- a retrospective cohort study.

BACKGROUND: Pregnant people are particularly vulnerable to SARS-CoV-2 infection and to ensuing severe illness. Predicting adverse maternal and perinatal outcomes could aid clinicians in deciding on hospital admission and early initiation of treatment in affected individuals, streamlining the triaging processes. METHODS: An international repository of 1501 SARS-CoV-2-positive cases in pregnancy was created, consisting of demographic variables, patient comorbidities, laboratory markers, respiratory parameters, and COVID-19-related symptoms. Data were filtered, preprocessed, and feature selection methods were used to obtain the optimal feature subset for training a variety of machine learning models to predict maternal or fetal/neonatal death or critical illness. RESULTS: The Random Forest model demonstrated the best performance among the trained models, correctly identifying 83.3% of the high-risk patients and 92.5% of the low-risk patients, with an overall accuracy of 89.0%, an AUC of 0.90 (95% Confidence Interval 0.83 to 0.95), and a recall, precision, and F1 score of 0.85, 0.94, and 0.89, respectively. This was achieved using a feature subset of 25 features containing patient characteristics, symptoms, clinical signs, and laboratory markers. These included maternal BMI, gravidity, parity, existence of pre-existing conditions, nicotine exposure, anti-hypertensive medication administration, fetal malformations, antenatal corticosteroid administration, presence of dyspnea, sore throat, fever, fatigue, duration of symptom phase, existence of COVID-19-related pneumonia, need for maternal oxygen administration, disease-related inpatient treatment, and lab markers including sFLT-1/PlGF ratio, platelet count, and LDH. CONCLUSIONS: We present the first COVID-19 prognostication pipeline specifically for pregnant patients while utilizing a large SARS-CoV-2 in pregnancy data repository. Our model accurately identifies those at risk of severe illness or clinical deterioration, presenting a promising tool for advancing personalized medicine in pregnant patients with COVID-19.

Twin pregnancy and severe maternal mental illness: a Canadian population-based cohort study.

Twin pregnancy is a risk factor for postpartum depression and anxiety. Whether this translates into a higher risk of severe maternal mental illness in the short-term or long-term is unknown. This study was a population-based retrospective cohort study, using linked health administrative databases for the entire province of Ontario, Canada. Included were primiparas aged 15-50 years with a twin vs. singleton hospital livebirth, between January 1, 2003, and March 31, 2019. Propensity-score inverse probability of treatment weights accounted for potential confounding. The primary outcome of severe mental illness comprised a composite of an emergency department visit or hospitalization for mental illness or self-injury, or death by suicide, assessed in the first year after birth, and in long-term follow-up, up to 17 years thereafter. Fifteen thousand twenty-four twin and 796,804 (15,022 weighted) singleton births were included, with a mean (IQR) duration of follow-up of 9 (5-13) years. After weighting, the mean (SD) maternal age was 31.3 (5.5) years. In the first 365 days postpartum, severe mental illness occurred at rates of 10.5 and 8.7 per 1000 person-years in twin and singleton mothers, respectively, corresponding to a hazard ratio (HR) of 1.21 (95% CI 1.07-1.47). From 366 days onward, the corresponding figures were 5.9 and 6.1 per 1000 person-years (HR 0.96, 95% CI 0.89-1.04). Individuals with a twin birth appear to experience an increased risk for severe mental illness in the first year postpartum, but not thereafter. This suggests a potential need for targeted counselling and mental health services for mothers within the first year after birth.