Maternal mortality in the United States: are the high and rising rates due to changes in obstetrical factors, maternal medical conditions, or maternal mortality surveillance?

BACKGROUND

National Vital Statistics System reports show that maternal mortality rates in the United States have nearly doubled, from 17.4 in 2018 to 32.9 per 100,000 live births in 2021. However, these high and rising rates could reflect issues unrelated to obstetrical factors, such as changes in maternal medical conditions or maternal mortality surveillance (eg, due to introduction of the pregnancy checkbox).

OBJECTIVE

This study aimed to assess if the high and rising rates of maternal mortality in the United States reflect changes in obstetrical factors, maternal medical conditions, or maternal mortality surveillance.

STUDY DESIGN

The study was based on all deaths in the United States from 1999 to 2021. Maternal deaths were identified using the following 2 approaches: (1) per National Vital Statistics System methodology, as deaths in pregnancy or in the postpartum period, including deaths identified solely because of a positive pregnancy checkbox, and (2) under an alternative formulation, as deaths in pregnancy or in the postpartum period, with at least 1 mention of pregnancy among the multiple causes of death on the death certificate. The frequencies of major cause-of-death categories among deaths of female patients aged 15 to 44 years, maternal deaths, deaths due to obstetrical causes (ie, direct obstetrical deaths), and deaths due to maternal medical conditions aggravated by pregnancy or its management (ie, indirect obstetrical deaths) were quantified.

RESULTS

Maternal deaths, per National Vital Statistics System methodology, increased by 144% (95% confidence interval, 130-159) from 9.65 in 1999-2002 (n=1550) to 23.6 per 100,000 live births in 2018-2021 (n=3489), with increases occurring among all race and ethnicity groups. Direct obstetrical deaths increased from 8.41 in 1999-2002 to 14.1 per 100,000 live births in 2018-2021, whereas indirect obstetrical deaths increased from 1.24 to 9.41 per 100,000 live births: 38% of direct obstetrical deaths and 87% of indirect obstetrical deaths in 2018-2021 were identified because of a positive pregnancy checkbox. The pregnancy checkbox was associated with increases in less specific and incidental causes of death. For example, maternal deaths with malignant neoplasms listed as a multiple cause of death increased 46-fold from 0.03 in 1999-2002 to 1.42 per 100,000 live births in 2018-2021. Under the alternative formulation, the maternal mortality rate was 10.2 in 1999-2002 and 10.4 per 100,000 live births in 2018-2021; deaths from direct obstetrical causes decreased from 7.05 to 5.82 per 100,000 live births. Deaths due to preeclampsia, eclampsia, postpartum hemorrhage, puerperal sepsis, venous complications, and embolism decreased, whereas deaths due to adherent placenta, renal and unspecified causes, cardiomyopathy, and preexisting hypertension increased. Maternal mortality increased among non-Hispanic White women and decreased among non-Hispanic Black and Hispanic women. However, rates were disproportionately higher among non-Hispanic Black women, with large disparities evident in several causes of death (eg, cardiomyopathy).

CONCLUSION

The high and rising rates of maternal mortality in the United States are a consequence of changes in maternal mortality surveillance, with reliance on the pregnancy checkbox leading to an increase in misclassified maternal deaths. Identifying maternal deaths by requiring mention of pregnancy among the multiple causes of death shows lower, stable maternal mortality rates and declines in maternal deaths from direct obstetrical causes.

Association of Maternal Influenza Vaccination During Pregnancy With Early Childhood Health Outcomes

IMPORTANCE

Seasonal influenza vaccination in pregnancy can reduce influenza illness among pregnant women and newborns. Evidence is limited on whether seasonal influenza vaccination in pregnancy is associated with adverse childhood health outcomes.

OBJECTIVE

To assess the association between maternal influenza vaccination during pregnancy and early childhood health outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study, using a birth registry linked with health administrative data. All live births in Nova Scotia, Canada, between October 1, 2010, and March 31, 2014, were included, with follow-up until March 31, 2016. Adjusted hazard ratios (HRs) and incidence rate ratios (IRRs) with 95% confidence intervals were estimated while controlling for maternal medical history and other potential confounders using inverse probability of treatment weighting.

EXPOSURES

Seasonal influenza vaccination during pregnancy.

MAIN OUTCOMES AND MEASURES

Childhood outcomes studied were immune-related (eg, asthma, infections), non-immune-related (eg, neoplasms, sensory impairment), and nonspecific (eg, urgent or inpatient health care utilization), measured from emergency department and hospitalization databases.

RESULTS

Among 28 255 children (49% female, 92% born at ≥37 weeks' gestation), 10 227 (36.2%) were born to women who received seasonal influenza vaccination during pregnancy. During a mean follow-up of 3.6 years, there was no significant association between maternal influenza vaccination and childhood asthma (incidence rate, 3.0 vs 2.5 per 1000 person-years; difference, 0.53 per 1000 person-years [95% CI, -0.15 to 1.21]; adjusted HR, 1.22 [95% CI, 0.94 to 1.59]), neoplasms (0.32 vs 0.26 per 1000 person-years; difference, 0.06 per 1000 person-years [95% CI, -0.16 to 0.28]; adjusted HR, 1.26 [95% CI, 0.57 to 2.78]), or sensory impairment (0.80 vs 0.97 per 1000 person-years; difference, -0.17 per 1000 person-years [95% CI, -0.54 to 0.21]; adjusted HR, 0.82 [95% CI, 0.49 to 1.37]). Maternal influenza vaccination in pregnancy was not significantly associated with infections in early childhood (incidence rate, 184.6 vs 179.1 per 1000 person-years; difference, 5.44 per 1000 person-years [95% CI, 0.01 to 10.9]; adjusted IRR, 1.07 [95% CI, 0.99 to 1.15]) or with urgent and inpatient health services utilization (511.7 vs 477.8 per 1000 person-years; difference, 33.9 per 1000 person-years [95% CI, 24.9 to 42.9]; adjusted IRR, 1.05 [95% CI, 0.99 to 1.16]).

CONCLUSIONS AND RELEVANCE

In this population-based cohort study with mean follow-up duration of 3.6 years, maternal influenza vaccination during pregnancy was not significantly associated with an increased risk of adverse early childhood health outcomes.

Neonatal Abstinence Syndrome and Associated Neonatal and Maternal Mortality and Morbidity

OBJECTIVES

We examined demographic characteristics and birth outcomes of infants with neonatal abstinence syndrome (NAS) and their mothers in Canada.

METHODS

This retrospective, population-based, descriptive cross-sectional study of mother-infant dyads included all singleton live births in Canada (excluding Quebec), from 2005-2006 to 2015-2016 (N = 2 881 789). Demographic characteristics, NAS, and neonatal and maternal morbidities were identified from delivery hospitalization data (including diagnostic codes). The main composite outcomes were maternal and neonatal mortality and/or severe morbidity, including death and potentially life-threatening conditions in the mother and the infant, respectively. Logistic regression yielded adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

RESULTS

The study included 10 027 mother-infant dyads with NAS. The incidence of NAS increased from 0.20% to 0.51%. Maternal mortality was 1.99 vs 0.31 per 10 000 women in the NAS group versus the comparison group (aOR = 6.53; 95% CI: 1.59 to 26.74), and maternal mortality and/or severe morbidity rates were 3.10% vs 1.35% (aOR = 2.21; 95% CI: 1.97 to 2.49). Neonatal mortality was 0.12% vs 0.19% (aOR = 0.28; 95% CI: 0.15 to 0.53), and neonatal mortality and/or severe morbidity rates were 6.36% vs 1.73% (aOR = 2.27; 95% CI: 2.06 to 2.50) among infants with NAS versus without NAS.

CONCLUSIONS

NAS incidence increased notably in Canada between 2005-2006 and 2015-2016. Infants with NAS had elevated severe morbidity, and their mothers had elevated mortality and severe morbidity. These results highlight the importance of implementing integrated care services to support the mother-infant dyad during childbirth and in the postpartum period.

Domperidone for insufficient lactation in England 2002-2015: A drug utilization study with interrupted time series analysis

PURPOSE

Our aim was to describe trends in the prescription of domperidone for insufficient lactation in England, the characteristics of women prescribed it postpartum, and the impact of a 2014 European Medicines Agency (EMA) recommendation to restrict its use due to a potential increased risk of sudden cardiac death associated with its use.

METHODS

We conducted a population-based cohort study with interrupted time series analysis using data from the Clinical Practice Research Datalink linked to Hospital Episode Statistics. We identified women with live births from 2002 to 2015, excluding those with nonlactation indications for domperidone (n = 247 349). We evaluated trends in the prescription rate of domperidone in the 6 months postpartum and differences in this rate before and after the EMA recommendation.

RESULTS

Domperidone was prescribed among 1438 deliveries at a rate of 1.24 per 100 person-years. This rate increased from 0.56 to 2.1 per 100 person-years between 2002-2004 and 2011-2013 (rate ratio: 3.8; 95% confidence interval [CI], 3.2-4.6). Prescribing decreased in level by 0.35 (95% CI, -0.86 to 0.16) per 100 person-years immediately following the recommendation with little change in trend (0.003; 95% CI, -0.059 to 0.065 per 100 person-years). Following the recommendation, prescription of doses >30 mg and coprescription of drugs with a risk of torsade de pointes decreased. No arrhythmic events were observed among domperidone users.

CONCLUSIONS

Although we observed an important increase in prescribing during the study period, domperidone remains infrequently prescribed postpartum in England. While overall prescribing changed little, some prescribing practices became more restricted following the EMA's recommendation.

Factors Underlying the Temporal Increase in Maternal Mortality in the United States

OBJECTIVE

To identify the factors underlying the recent increase in maternal mortality ratios (maternal deaths per 100,000 live births) in the United States.

METHODS

We carried out a retrospective study with data on maternal deaths and live births in the United States from 1993 to 2014 obtained from the birth and death files of the Centers for Disease Control and Prevention. Underlying causes of death were examined between 1999 and 2014 using International Classification of Diseases, 10th Revision (ICD-10) codes. Poisson regression was used to estimate maternal mortality rate ratios (RRs) and 95% confidence intervals (CIs) after adjusting for the introduction of a separate pregnancy question and the standard pregnancy checkbox on death certificates and adoption of ICD-10.

RESULTS

Maternal mortality ratios increased from 7.55 in 1993, to 9.88 in 1999, and to 21.5 per 100,000 live births in 2014 (RR 2014 compared with 1993 2.84, 95% CI 2.49-3.24; RR 2014 compared with 1999 2.17, 95% CI 1.93-2.45). The increase in maternal deaths from 1999 to 2014 was mainly the result of increases in maternal deaths associated with two new ICD-10 codes (O26.8, ie, primarily renal disease; and O99, ie, other maternal diseases classifiable elsewhere); exclusion of such deaths abolished the increase in mortality (RR 1.09, 95% CI 0.94-1.27). Regression adjustment for improvements in surveillance also abolished the temporal increase in maternal mortality ratios (adjusted maternal mortality ratios 7.55 in 1993, 8.00 per 100,000 live births in 2013; adjusted RR 2013 compared with 1993 1.06, 95% CI 0.90-1.25).

CONCLUSION

Recent increases in maternal mortality ratios in the United States are likely an artifact of improvements in surveillance and highlight past underestimation of maternal death. Complete ascertainment of maternal death in populations remains a challenge even in countries with good systems for civil registration and vital statistics.

Heterogeneity of respiratory distress syndrome: risk factors and morbidity associated with early and late gestation disease

BACKGROUND

Although respiratory distress syndrome (RDS) is considered a disease of prematurity, there is evidence to suggest heterogeneity between early and late gestation RDS. We examined the epidemiologic features of RDS occurring at early and late gestation.

METHODS

We conducted a retrospective cohort study including live births in the United States in 2005-06, with information obtained from the National Center for Health Statistics. Early (<32 weeks) and late gestation RDS (≥39 weeks) were contrasted in terms of risk factors and associations with pregnancy complications, obstetric intervention and co-morbidity. Logistic regression was used to quantify the effects of risk factors, while other associations were quantified descriptively.

RESULTS

There were 27,971 RDS cases, yielding an incidence of 6.4 per 1000 live births. Early and late gestation RDS differed in terms of risk factors, with factors such as multi-fetal gestation more strongly associated with early (adjusted odds ratio [aOR] 11.6, 95 % confidence interval 11.0-12.2) compared with late gestation RDS (aOR 3.66, 95 % confidence interval 2.68-4.98). The morbidity correlates of early and late gestation RDS also differed substantially; neonatal seizures were less strongly associated with early (OR 5.90, 95 % confidence interval 3.67-9.47) compared with late gestation RDS (OR 33.1, 95 % confidence interval 27.2-40.2), while meconium aspiration syndrome was not significantly associated with early gestation RDS (OR 1.87, 95 % confidence interval 0.94-3.72) and very strongly associated with late gestation RDS (OR 39.8, 95 % confidence interval 34.7-45.6).

CONCLUSIONS

Differences in risk factors and morbidity correlates of early and late gestation RDS suggest that these entities represent two distinct diseases.

Atonic Postpartum Hemorrhage: Blood Loss, Risk Factors, and Third Stage Management

OBJECTIVE

Atonic postpartum hemorrhage rates have increased in many industrialized countries in recent years. We examined the blood loss, risk factors, and management of the third stage of labour associated with atonic postpartum hemorrhage.

METHODS

We carried out a case-control study of patients in eight tertiary care hospitals in Canada between January 2011 and December 2013. Cases were defined as women with a diagnosis of atonic postpartum hemorrhage, and controls (without postpartum hemorrhage) were matched with cases by hospital and date of delivery. Estimated blood loss, risk factors, and management of the third stage labour were compared between cases and controls. Conditional logistic regression was used to adjust for confounding.

RESULTS

The study included 383 cases and 383 controls. Cases had significantly higher mean estimated blood loss than controls. However, 16.7% of cases who delivered vaginally and 34.1% of cases who delivered by Caesarean section (CS) had a blood loss of < 500 mL and < 1000 mL, respectively; 8.2% of controls who delivered vaginally and 6.7% of controls who delivered by CS had blood loss consistent with a diagnosis of postpartum hemorrhage. Factors associated with atonic postpartum hemorrhage included known protective factors (e.g., delivery by CS) and risk factors (e.g., nulliparity, vaginal birth after CS). Uterotonic use was more common in cases than in controls (97.6% vs. 92.9%, P < 0.001). Delayed cord clamping was only used among those who delivered vaginally (7.7% cases vs. 14.6% controls, P = 0.06).

CONCLUSION

There is substantial misclassification in the diagnosis of atonic postpartum hemorrhage, and this could potentially explain the observed temporal increase in postpartum hemorrhage rates.

Contribution of placenta accreta to the incidence of postpartum hemorrhage and severe postpartum hemorrhage

OBJECTIVE

To quantify the contribution of placenta accreta to the rate of postpartum hemorrhage and severe postpartum hemorrhage.

METHODS

All hospital deliveries in Canada (excluding Quebec) for the years 2009 and 2010 (N=570,637) were included in a retrospective cohort study using data from the Canadian Institute for Health Information. Placenta accreta included placental adhesion to the uterine wall, musculature, and surrounding organs (accreta, increta, or percreta). Severe postpartum hemorrhage included postpartum hemorrhage with blood transfusion, hysterectomy, or other procedures to control bleeding (including uterine suturing and ligation or embolization of pelvic arteries). Rates, rate ratios, population-attributable fractions (ie, incidence of postpartum hemorrhage attributable to placenta accreta), and 95% confidence intervals (CIs) were estimated. Logistic regression was used to quantify associations between placenta accreta and risk factors.

RESULTS

The incidence of placenta accreta was 14.4 (95% CI 13.4-15.4) per 10,000 deliveries (819 cases among 570,637 deliveries), whereas the incidence of placenta accreta with postpartum hemorrhage was 7.2 (95% CI 6.5-8.0) per 10,000 deliveries. Postpartum hemorrhage among women with placenta accreta was predominantly third-stage hemorrhage (41% of all cases). Although placenta accreta was strongly associated with postpartum hemorrhage (rate ratio 8.3, 95% CI 7.7-8.9), its low frequency resulted in a small population-attributable fraction (1.0%, 95% CI 0.93-1.16). However, the strong association between placenta accreta and postpartum hemorrhage with hysterectomy (rate ratio 286, 95% CI 226-361) resulted in a population-attributable fraction of 29.0% (95% CI 24.3-34.3).

CONCLUSION

Placenta accreta is too infrequent to account for the recent temporal increase in postpartum hemorrhage but contributes substantially to the proportion of postpartum hemorrhage with hysterectomy.

Can drug effects explain the recent temporal increase in atonic postpartum haemorrhage?

BACKGROUND

Rates of postpartum haemorrhage and atonic postpartum haemorrhage have increased in several high-income countries. We carried out a study to examine if drug use in pregnancy, or drug and other interactions, explained this increase in postpartum haemorrhage.

METHODS

The linked administrative and hospital databases of the Québec Pregnancy Cohort were used to define a cohort of pregnant women in Québec, Canada, from 1998 to 2009 (n = 138,704). Case-control studies on any postpartum haemorrhage and atonic postpartum haemorrhage were carried out within this population, with up to five controls randomly selected for each case after matching on index date and hospital of delivery (incidence density sampling). Conditional logistic regression was used to estimate the effects of drug use on postpartum haemorrhage and atonic postpartum haemorrhage.

RESULTS

There was an unexpected non-linear, declining temporal pattern in postpartum haemorrhage and atonic postpartum haemorrhage between 1998 and 2009. Use of antidepressants (mainly selective serotonin reuptake inhibitors) was associated with higher rates of postpartum haemorrhage [adjusted rate ratio (aRR) 1.48, 95% confidence interval (CI) 1.23, 1.77] and atonic postpartum haemorrhage [aRR 1.40, 95% CI 1.13, 1.74]. Thrombocytopenia was also associated with higher rates of postpartum haemorrhage [aRR 1.52, 95% CI 1.16, 2.00]. There were no statistically significant drug interactions. Adjustment for maternal factors and drug use had little effect on temporal trends in postpartum haemorrhage and atonic postpartum haemorrhage.

CONCLUSIONS

Although antidepressant use and thrombocytopenia were associated with higher rates of atonic postpartum haemorrhage, antidepressant and other drug use did not explain temporal trends in postpartum haemorrhage.

Hypertensive disorders of pregnancy and the recent increase in obstetric acute renal failure in Canada: population based retrospective cohort study

OBJECTIVE

To examine whether changes in postpartum haemorrhage, hypertensive disorders of pregnancy, or other risk factors explain the increase in obstetric acute renal failure in Canada.

DESIGN

Retrospective cohort study.

SETTING

Canada (excluding the province of Quebec).

PARTICIPANTS

All hospital deliveries from 2003 to 2010 (n=2,193,425).

MAIN OUTCOME MEASURES

Obstetric acute renal failure identified by ICD-10 diagnostic codes.

METHODS

Information on all hospital deliveries in Canada (excluding Quebec) between 2003 and 2010 (n=2,193,425) was obtained from the Canadian Institute for Health Information. Temporal trends in obstetric acute renal failure were assessed among women with and without postpartum haemorrhage, hypertensive disorders of pregnancy, or other risk factors. Logistic regression was used to determine if changes in risk factors explained the temporal increase in obstetric acute renal failure.

RESULTS

Rates of obstetric acute renal failure rose from 1.66 to 2.68 per 10,000 deliveries between 2003-04 and 2009-10 (61% increase, 95% confidence interval 24% to 110%). Adjustment for postpartum haemorrhage, hypertensive disorders, and other factors did not attenuate the increase. The temporal increase in acute renal failure was restricted to deliveries with hypertensive disorders (adjusted increase 95%, 95% confidence interval 38% to 176%), and was especially pronounced among women with gestational hypertension with significant proteinuria (adjusted increase 171%, 71% to 329%). No significant increase occurred among women without hypertensive disorders (adjusted increase 12%, -28 to 72%).

CONCLUSIONS

The increase in obstetric acute renal failure in Canada between 2003 and 2010 was restricted to women with hypertensive disorders and was especially pronounced among women with pre-eclampsia. Further study is required to determine the cause of the increase among women with pre-eclampsia.

Incidence, risk factors, and temporal trends in severe postpartum hemorrhage

OBJECTIVE

Because the diagnosis of postpartum hemorrhage (PPH) depends on the accoucheur's subjective estimate of blood loss and varies according to mode of delivery, we examined temporal trends in severe PPH, defined as PPH plus receipt of a blood transfusion, hysterectomy, and/or surgical repair of the uterus.

STUDY DESIGN

We analyzed 8.5 million hospital deliveries in the US Nationwide Inpatient Sample from 1999 to 2008 for temporal trends in, and risk factors for, severe PPH, based on International Classification of Diseases, 9th revision, clinical modification diagnosis and procedure codes. Sequential logistic regression models that account for the stratified random sampling design were used to assess the extent to which changes in risk factors explain the trend in severe PPH.

RESULTS

Of the total 8,571,209 deliveries, 25,906 (3.0 per 1000) were complicated by severe PPH. The rate rose from 1.9 to 4.2 per 1000 from 1999 to 2008 (P for yearly trend < .0001), with increases in severe atonic and nonatonic PPH, due especially to PPH with transfusion, but also PPH with hysterectomy. Significant risk factors included maternal age ≥35 years (adjusted odds ratio [aOR], 1.5; 95% confidence interval [CI], 1.5-1.6), multiple pregnancy (aOR, 2.8; 95% CI, 2.6-3.0), fibroids (aOR, 2.0; 95% CI, 1.8-2.2), preeclampsia (aOR, 3.1; 95% CI, 2.9-3.3), amnionitis (aOR, 2.9; 95% CI, 2.5-3.4), placenta previa or abruption (aOR, 7.0; 95% CI, 6.6-7.3), cervical laceration (aOR, 94.0; 95% CI, 87.3-101.2), uterine rupture (aOR, 11.6; 95% CI, 9.7-13.8), instrumental vaginal delivery (aOR, 1.5; 95% CI, 1.4-1.6), and cesarean delivery (aOR, 1.4; 95% CI, 1.3-1.5). Changes in risk factors, however, accounted for only 5.6% of the increase in severe PPH.

CONCLUSION

A doubling in incidence of severe PPH over 10 years was not explained by contemporaneous changes in studied risk factors.

Epidemiological investigation of a temporal increase in atonic postpartum haemorrhage: a population-based retrospective cohort study

OBJECTIVE

Increases in atonic postpartum haemorrhage (PPH) have been reported from several countries in recent years. We attempted to determine the potential cause of the increase in atonic and severe atonic PPH.

DESIGN

Population-based retrospective cohort study.

SETTING

British Columbia, Canada, 2001-2009.

POPULATION

All women with live births or stillbirths.

METHODS

Detailed clinical information was obtained for 371 193 women from the British Columbia Perinatal Data Registry. Outcomes of interest were atonic PPH and severe atonic PPH (atonic PPH with blood transfusion ≥1 unit; atonic PPH with blood transfusion ≥3 units or procedures to control bleeding), whereas determinants studied included maternal characteristics (e.g. age, parity, and body mass index) and obstetrics practice factors (e.g. labour induction, augmentation, and caesarean delivery). Year-specific unadjusted and adjusted odds ratios for the outcomes were compared using logistic regression.

MAIN OUTCOME MEASURES

Atonic PPH and severe atonic PPH.

RESULTS

Atonic PPH increased from 4.8% in 2001 to 6.3% in 2009, atonic PPH with blood transfusion ≥1 unit increased from 16.6 in 2001 to 25.5 per 10 000 deliveries in 2009, and atonic PPH with blood transfusion ≥3 units or procedures to control bleeding increased from 11.9 to 17.6 per 10 000 deliveries. The crude 34% (95% CI 26-42%) increase in atonic PPH between 2001 and 2009 remained unchanged (42% increase, 95% CI 34-51%) after adjustment for determinants of PPH. Similarly, adjustment did not explain the increase in severe atonic PPH.

CONCLUSIONS

Changes in maternal characteristics and obstetric practice do not explain the recent increase in atonic and severe atonic PPH.

Determinants of increases in stillbirth rates from 2000 to 2010

BACKGROUND

After decades of decline, stillbirth rates have increased in several industrialized countries in recent years. We examined data from the province of British Columbia, Canada, in an attempt to explain this unexpected phenomenon.

METHODS

We carried out a retrospective population-based cohort study of all births in British Columbia from 2000 to 2010. Outcomes of interest included overall stillbirth rates, birth weight-and gestational age-specific stillbirth rates, rates of spontaneous stillbirths (excluding pregnancy terminations that satisfied the definition of stillbirth [fetal death with a birth weight ≥ 500 g or gestational age at delivery ≥ 20 wk], hereafter referred to as "pregnancy terminations") and rates of congenital anomalies among live-born infants. We used logistic regression to adjust for changes in maternal age, parity, weight before pregnancy and multiple births.

RESULTS

Overall, stillbirth rates increased by 31% (95% confidence interval [CI] 13% to 50%), from 8.08 per 1000 total births in 2000 to 10.55 per 1000 in 2010. The rate of stillbirths with a birth weight of less than 500 g increased significantly (p(trend) = 0.03), whereas the rate of stillbirths with a birth weight of 1000 g or more decreased significantly (p(trend) = 0.009). The rate of spontaneous stillbirths decreased nonsignificantly by 16%, from 5.7 per 1000 total births in 2000 to 4.8 per 1000 in 2010. There was a significant decline of 30% (95% CI 6% to 47%) in the rate of spontaneous stillbirth with a birth weight of 1000 g or more between 2000 and 2010; adjustment for maternal factors did not appreciably change this temporal effect. The prevalence of congenital anomalies among live-born infants decreased significantly, from 5.21 per 100 live births during the first 3 years (2000-02) to 4.77 per 100 during the final 3 years (2008-10).

INTERPRETATION

Increases in pregnancy terminations were responsible for the increases observed in stillbirth rates and were associated with declines in the prevalence of congenital anomalies among live-born infants.

Trends in postpartum hemorrhage from 2000 to 2009: a population-based study

Background

Postpartum hemorrhage, a major cause of maternal death and severe maternal morbidity, increased in frequency in Canada between 1991 and 2004. We carried out a study to describe the epidemiology of postpartum hemorrhage in British Columbia, Canada, between 2000 and 2009.

Methods

The study population included all women residents of British Columbia who delivered between 2000 and 2009. Data on postpartum hemorrhage by subtypes and severity were obtained from the British Columbia Perinatal Data Registry. Among women with postpartum hemorrhage, severe cases were identified by the use of blood transfusions or procedures to control bleeding. Rates of postpartum hemorrhage and changes over time were assessed using rates, rate ratios and 95% confidence intervals (CI).

Results

The rate of postpartum hemorrhage increased by 27% (95% CI 21-34%) between 2000 and 2009 (from 6.3% to 8.0%), while atonic postpartum hemorrhage rates increased by 33% (95% CI 26-41%) from 4.8% to 6.4%. Atonic postpartum hemorrhage with blood transfusion increased from 17.8 to 25.5 per 10,000 deliveries from 2000 to 2009 and atonic postpartum hemorrhage with either suturing of the uterus, ligation of pelvic vessels or embolization increased from 1.8 to 5.6 per 10,000 deliveries from 2001 to 2009. The increase in atonic postpartum hemorrhage was most evident between 2006 and 2009 and occurred across regions, hospitals and various maternal, fetal and obstetric characteristics.

Conclusions

Atonic postpartum hemorrhage and severe atonic postpartum hemorrhage increased in British Columbia between 2000 and 2009. Further research is required to identify the cause of the increase.

Gender differences in HIV and hepatitis C related vulnerabilities among aboriginal young people who use street drugs in two Canadian cities

OBJECTIVES

Vulnerability to HIV and Hepatitis C virus (HCV) infection for indigenous populations worldwide must be contextualized in experiences of current and past trauma. Aboriginal women entrenched in poverty face further gender-specific harms which place them at increased risk for HIV infection.

METHODS

This study was cross-sectional and based on a community-based sample of Aboriginal young people (Metis, Aboriginal, First Nations, Inuit, and non-status Indians) between the ages of 14 and 30 years who used injection or non-injection non-cannabis illegal drugs (street drugs) in the previous month. Between October 2003 and July 2005, 543 participants living in either Vancouver or Prince George, Canada, were recruited by word of mouth, posters, and street outreach. Young people in the study completed a questionnaire administered by Aboriginal interviewers. Female participants (n = 262) were compared to male participants (n = 281) with respect to sociodemographics, trauma, sexual risk variables, and drug use patterns. Trained nurses drew blood samples for HIV and HCV antibodies and provided pre- and post-test counseling.

RESULTS

Proportions positive for HIV and HCV were significantly higher among young women. HIV was 13.1% [9.5, 17.7] in women compared to 4.3% [2.5, 7.4] in men, and HCV was 43.6% [37.6, 49.8] in women as compared to 25.4% [20.5, 30.9] in men. When the analysis was restricted to young people who reported injection drug use, the proportions positive for HIV and HCV remained significantly higher among young women. Experiences of forced sex were reported by 70% of young women compared to 29% of young men, p < 0.001, while the median age of first forced sex was 6-years-old for both men and women.

DISCUSSION

The results of the final model indicated that HIV had been associated with residing in Vancouver, having injected for longer, and sexual abuse, but not being female. However, this gendered analysis demonstrated that a greater proportion of young women were experiencing sexual abuse, and sexual abuse was associated with HIV positive status. Harm reduction and drug treatment programs are urgently required that target women at a young age and address complex traumatic experiences associated with childhood sexual abuse.

The Cedar Project: a comparison of HIV-related vulnerabilities amongst young Aboriginal women surviving drug use and sex work in two Canadian cities

BACKGROUND

In Canada, Aboriginal women and youth continue to be overrepresented amongst new cases of HIV, and are considered at increased risk for sex and drug-related harm. Young women involved in sex work are particularly vulnerable. The purpose of this study is to determine HIV-related vulnerabilities associated with sex work amongst young Aboriginal women in two Canadian cities.

METHODS

This study is based on a community-based cohort of Aboriginal young people (status and non-status First Nations, Inuit and Métis) between the ages of 14 and 30 who used injection or non-injection illegal drugs (street drugs) in the previous month. Participants lived in Vancouver, Canada, or Prince George, a remote, northern Canadian city. Between October 2003 and July 2005, 543 participants were recruited by word of mouth, posters, and street outreach. A baseline questionnaire was administered by Aboriginal interviewers, and trained nurses drew blood samples for HIV and HCV antibodies and provided pre- and post-test counselling. This study included 262 young women who participated at baseline. Analyses were conducted to compare socio-demographics, drug use patterns, injection practices, sexual experiences, and HIV and HCV prevalence between young women who reported being involved in sex work in the last 6 months (n=154) versus young women who did not (n=108). Logistic regression was used to identify factors independently associated with recent sex work involvement.

RESULTS

Both sexual violence and drug using patterns were found to be markedly different for women having recently been involved in sex work. Multivariate analysis revealed daily injection of cocaine (AOR=4.4; 95% CI: 1.9, 10.1 and smoking crack (AOR=2.9; 95% CI: 1.6, 5.2) in the previous 6 months, and lifetime sexual abuse (AOR=2.5; 95% CI: 1.4, 4.4) to be independently associated with sex work.

INTERPRETATION

Harm reduction and treatment programs that address historical and lifetime trauma amongst Aboriginal people and prioritize emotional and physical safety for young Aboriginal women involved in sex work are required.