Mode of delivery after a previous cesarean birth, and associated maternal and neonatal morbidity.

BACKGROUND: The mode of delivery for women with a previous cesarean delivery remains contentious. We conducted a study comparing maternal and infant outcomes after attempted vaginal birth after cesarean delivery versus elective repeat cesarean delivery. METHODS: We used data from the Discharge Abstract Database that includes all hospital deliveries in Canada (excluding Quebec). In our analysis, we included singleton deliveries to women between 37 and 43 weeks gestation who had a single prior cesarean delivery between April 2003 and March 2015. The primary outcomes were severe maternal morbidity and mortality, and serious neonatal morbidity and mortality. We used logistic regression to estimate adjusted rate ratios (RRs) and 95% confidence intervals (CIs). RESULTS: Absolute rates of severe maternal morbidity and mortality were low but significantly higher after attempted vaginal birth after cesarean delivery compared with elective repeat cesarean delivery (10.7 v. 5.65 per 1000 deliveries, respectively; adjusted RR 1.96, 95% CI 1.76 to 2.19). Adjusted rate differences in severe maternal morbidity and mortality, and serious neonatal morbidity and mortality were small (5.42 and 7.09 per 1000 deliveries, respectively; number needed to treat 184 and 141, respectively). The association between vaginal birth after cesarean delivery, and serious neonatal morbidity and mortality showed a temporal worsening (adjusted RR 0.94, 95% CI 0.77 to 1.15 in 2003-2005; adjusted RR 2.07, 95% CI 1.83 to 2.35 in 2012-2014). INTERPRETATION: Although absolute rates of adverse outcomes are low, attempted vaginal birth after cesarean delivery continues to be associated with higher relative rates of severe morbidity and mortality in mothers and infants. Temporal worsening of infant outcomes after attempted vaginal birth after cesarean delivery highlights the need for greater care in selecting candidates, and more careful monitoring of labour and delivery.

Fetal, Infant and Maternal Outcomes among Women with Prolapsed Membranes Admitted before 29 Weeks Gestation.

BACKGROUND: Few studies have examined fetal, infant and maternal mortality and morbidity among pregnant women at very early gestation with an open cervix and prolapsed membranes. We carried out a study describing the outcomes of women hospitalized with prolapsed membranes at 22-28 weeks' gestation. METHODS: We prospectively recruited women with singleton pregnancies admitted at 22-28 weeks' gestation to tertiary hospitals of the Canadian Perinatal Network between 2005 and 2009. Time-to-delivery, perinatal death, neonatal intensive care unit (NICU) admission, severe neonatal morbidity and severe maternal morbidity were compared between women admitted at 22-25 vs. 26-28 weeks gestation. Logistic regression was used to estimate adjusted odds ratios (AOR) and 95% confidence intervals. RESULTS: 129 women at 22-25 weeks gestation and 65 women at 26-28 weeks gestation were admitted to hospital and the median time-to-delivery was 4 days in both groups. Stillbirth rates were 12.4% vs 4.6% among women admitted at earlier vs later gestation (AOR 2.8, 95% CI 0.5-14.8), while perinatal death rates were 38.0% vs 6.1% (AOR 14.1, 95% CI 3.5-59.0), respectively. There were no significant differences in NICU admission and severe morbidity among live-born infants; 89.4% and 82.3% died or were admitted to NICU, (P value 0.18), and 53.9% vs 44.0% of NICU infants had severe neonatal morbidity (P value 0.28). Antibiotics, tocolysis and cerclage did not have a significant effect on perinatal death. Maternal death or severe maternal morbidity occurred in 8.5% and 6.2% of women admitted at 22-25 vs 26-28 weeks (AOR 1.2, 95% CI 0.4-4.2). CONCLUSION: Perinatal mortality among women with prolapsed membranes at very early gestation is high, although significantly lower among those admitted at a relatively later gestational age. Rates of adverse maternal outcomes are also high. This information can be used to counsel women with prolapsed membranes at 22 to 28 weeks gestation.

Magnesium sulphate for fetal neuroprotection: benefits and challenges of a systematic knowledge translation project in Canada.

BACKGROUND: Administration of magnesium sulphate (MgSO4) to women with imminent preterm birth at <34 weeks is an evidence-based antenatal neuroprotective strategy to prevent cerebral palsy. Although a Society of Obstetricians and Gynaecologists of Canada (SOGC) national guideline with practice recommendations based on relevant clinical evidence exists, ongoing controversies about aspects of this treatment remain. Given this, we anticipated managed knowledge translation (KT) would be needed to facilitate uptake of the guidelines into practice. As part of the Canadian Institutes of Health Research (CIHR)-funded MAG-CP (MAGnesium sulphate to prevent Cerebral Palsy) project, we aimed to compare three KT methods designed to impact both individual health care providers and the organizational systems in which they work. METHODS: The KT methods undertaken were an interactive online e-learning module available to all SOGC members, and at MAG-CP participating sites, on-site educational rounds and focus group discussions, and circulation of an anonymous 'Barriers and Facilitators' survey for the systematic identification of facilitators and barriers for uptake of practice change. We compared these strategies according to: (i) breadth of respondents reached; (ii) rates and richness of identified barriers, facilitators, and knowledge needed; and (iii) cost. RESULTS: No individual KT method was superior to the others by all criteria, and in combination, they provided richer information than any individual method. The e-learning module reached the most diverse audience of health care providers, the site visits provided opportunity for iterative dialogue, and the survey was the least expensive. Although the site visits provided the most detailed information around individual and organizational barriers, the 'Barriers and Facilitators' survey provided more detail regarding social-level barriers. The facilitators identified varied by KT method. The type of knowledge needed was further defined by the e-learning module and surveys. CONCLUSIONS: Our findings suggest that a multifaceted approach to KT is optimal for translating national obstetric guidelines into clinical practice. As audit and feedback are essential parts of the process by which evidence to practice gaps are closed, MAG-CP is continuing the iterative KT process described in this paper concurrent with tracking of MgSO4 use for fetal neuroprotection and maternal and child outcomes until September 2015; results are anticipated in 2016.

Magnesium Sulphate for Eclampsia and Fetal Neuroprotection: A Comparative Analysis of Protocols Across Canadian Tertiary Perinatal Centres.

BACKGROUND: Magnesium sulphate (MgSO4) has been recommended for fetal neuroprotection to prevent cerebral palsy, with national societies adopting new guidelines for its use. A knowledge translation project to implement Canadian guidelines is ongoing. Discussion about MgSO4 for fetal neuroprotection could not occur distinct from MgSO4 for eclampsia prophylaxis and treatment. Thus, in order to explore standardization of MgSO4 use in Canada, we sought to compare local protocols for eclampsia and fetal neuroprotection across tertiary perinatal centres. METHODS: Twenty-five Canadian tertiary perinatal centres were asked to submit their protocols for use of MgSO4 for eclampsia prophylaxis/treatment and fetal neuroprotection. Information abstracted included date of protocol, definitions of indications for treatment, details of MgSO4 administration, maternal and fetal monitoring, antidote for toxicity, and abnormal signs requiring physician attention. Descriptive analyses were used to compare site protocols with known definitions of preeclampsia. Data from the Canadian Perinatal Network (CPN) were used to verify what was done in clinical practice. RESULTS: Twenty-two of the 25 centres submitted protocols for eclampsia prevention/treatment. Eleven of these provided a definition of preeclampsia that warranted treatment; five of the 22 advised treatment of severe preeclampsia only. Criteria for treatment and monitoring procedures varied across centres. Sixteen of the 22 sites with protocols had data from the CPN. Of 635 women with pre-eclampsia, 422 (66.5%) received MgSO4. Twenty of 25 centres provided protocols for fetal neuroprotection. Definitions of indications were consistent across sites, except for gestational age cut-off. CONCLUSION: This study suggests that local protocols are often inconsistent with published evidence. While this may be related to local institutional practices, relevant processes must be put in place to maximize uniformity of practice and improve patient care.

Contexte : L'utilisation de sulfate de magnésium (MgSO4) a été recommandée à des fins de neuroprotection fœtale dans le but de prévenir l'infirmité motrice cérébrale; des sociétés nationales adoptent d'ailleurs de nouvelles lignes directrices quant à son utilisation. Un projet de transfert des connaissances visant la mise en œuvre des lignes directrices canadiennes est en cours. Le rôle du MgSO4 en ce qui concerne la neuroprotection fœtale ne peut être abordé sans que l'on mentionne son utilisation dans le cadre de la prophylaxie et de la prise en charge de l'éclampsie. Ainsi, pour explorer la standardisation de l'utilisation de MgSO4 au Canada, nous avons cherché à comparer les protocoles locaux qui en régissent l'utilisation en matière d'éclampsie et de neuroprotection fœtale dans les centres périnataux tertiaires. Méthodes : Nous avons demandé à 25 centres périnataux tertiaires canadiens de nous soumettre leurs protocoles quant à l'utilisation du MgSO4 aux fins de la neuroprotection fœtale et de la prophylaxie / prise en charge de l'éclampsie. Les renseignements que nous avons tirés de ces protocoles comprenaient la date du protocole, les définitions des indications de traitement, les détails de l'administration du MgSO4, le monitorage maternel et fœtal, l'antidote pour contrer la toxicité et les symptômes anormaux nécessitant l'offre de soins médicaux. Des analyses descriptives ont été utilisées pour comparer les protocoles de ces centres aux définitions connues de la prééclampsie. Des données issues du Réseau périnatal canadien (RPC) ont été utilisées pour vérifier ce qui se faisait dans le cadre de la pratique clinique. Résultats : Vingt-deux des 25 centres nous ont soumis leurs protocoles de prévention / prise en charge de l'éclampsie. Onze de ces centres nous ont fourni une définition de ce qui était considéré comme une prééclampsie justifiant une prise en charge; cinq des 22 centres ne préconisaient que la prise en charge de la prééclampsie grave. Les critères des interventions de traitement et de monitorage variaient d'un centre à l'autre. Seize des 22 sites comptant des protocoles présentaient des données issues du RPC. Au sein d'un groupe de 635 femmes connaissant une prééclampsie, 422 (66,5 %) ont reçu du MgSO4. Vingt des 25 centres nous ont fourni leurs protocoles de neuroprotection fœtale. Les définitions des indications étaient uniformes d'un site à l'autre, sauf en ce qui concerne le seuil en matière d'âge gestationnel. Conclusion : Cette étude avance que les protocoles locaux ne concordent souvent pas avec les données probantes publiées. Bien que cela puisse être attribuable aux pratiques institutionnelles locales, des processus pertinents doivent être mis en place pour maximiser l'uniformité de la pratique et améliorer les soins offerts aux patientes.

Delivery of breech presentation at term gestation in Canada, 2003-2011.

OBJECTIVE: To examine neonatal mortality and morbidity rates by mode of delivery among women with breech presentation at term gestation. METHODS: We carried out a population-based cohort study examining neonatal outcomes among term, nonanomalous singletons in breech presentation among all hospital deliveries in Canada (excluding Quebec) between 2003 and 2011. Mode of delivery was categorized into vaginal delivery, cesarean delivery in labor, and cesarean delivery without labor. Composite neonatal mortality and morbidity (death, assisted ventilation, convulsions, or specific birth injury) was the primary outcome. Logistic regression was used to estimate the independent effects of mode of delivery. RESULTS: The study population included 52,671 breech deliveries; vaginal deliveries increased from 2.7% in 2003 to 3.9% in 2011, and cesarean deliveries in labor increased from 8.7% to 9.8%. Composite neonatal mortality and morbidity rates at 37 weeks of gestation or greater after vaginal delivery were significantly higher than those after cesarean without labor (adjusted rate ratio 3.60, 95% confidence interval [CI] 2.50-5.15; adjusted rate difference 15.8/1,000 deliveries, 95% CI 9.2-25.2). Among women at 40 weeks of gestation or greater, neonatal mortality and morbidity rates after vaginal delivery were significantly higher than those after cesarean delivery without labor (adjusted rate ratio 5.39, 95% CI 2.68-10.8; adjusted rate difference 24.1/1,000 deliveries, 95% CI 9.2-53.8). Neonatal mortality and morbidity rates were also higher after caesarean delivery in labor. CONCLUSION: Among term, nonanomalous singletons in breech presentation at term, composite neonatal mortality and morbidity rates were significantly higher after vaginal delivery and cesarean delivery in labor compared with cesarean delivery without labor. LEVEL OF EVIDENCE: II.

Once more unto the breech: planned vaginal delivery compared with planned cesarean delivery.

This article provides a knowledge-based assessment of planned cesarean delivery compared with planned vaginal delivery for breech presentation at term gestation. The most critical evidence on this issue is the intention-to-treat analysis from the Term Breech Trial, which showed that planned cesarean delivery reduced composite perinatal death and serious neonatal morbidity. Although there was no difference in composite death or neurodevelopmental delay at 2 years of age, this finding was based on only 44% of randomized patients and was not an analysis by intention to treat. On the other hand, the design of the nonexperimental Presentation et Mode d'Accouchement: presentation and mode of delivery (PREMODA) study (which showed no difference in composite perinatal mortality or morbidity after planned cesarean delivery compared with planned vaginal delivery), likely favored the planned vaginal delivery group; lack of exclusion criteria led to higher risk women (with contraindications to vaginal delivery) being included in the planned cesarean delivery group. Such selection bias notwithstanding, both the Term Breech Trial and the PREMODA study showed significantly higher rates of 5-minute Apgar score less than 4, 5-minute Apgar score less than 7, intubation, and birth trauma in the planned vaginal delivery group. Finally, studies from the Netherlands, Denmark, and Canada have shown that increases in planned cesarean delivery after the Term Breech Trial led to improved neonatal outcomes. Nevertheless, planned vaginal delivery continues to be associated with higher rates of adverse perinatal outcomes in these countries. The totality of the evidence therefore unequivocally shows the relatively greater safety of planned cesarean delivery for breech presentation at term gestation.

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.

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.

Effects of socioeconomic position and clinical risk factors on spontaneous and iatrogenic preterm birth.

BACKGROUND: The literature shows a variable and inconsistent relationship between socioeconomic position and preterm birth. We examined risk factors for spontaneous and iatrogenic preterm birth, with a focus on socioeconomic position and clinical risk factors, in order to explain the observed inconsistency. METHODS: We carried out a retrospective population-based cohort study of all singleton deliveries in Nova Scotia from 1988 to 2003. Data were obtained from the Nova Scotia Atlee Perinatal Database and the federal income tax T1 Family Files. Separate logistic models were used to quantify the association between socioeconomic position, clinical risk factors and spontaneous preterm birth and iatrogenic preterm birth. RESULTS: The study population included 132,714 singleton deliveries and the rate of preterm birth was 5.5%. Preterm birth rates were significantly higher among the women in the lowest (versus the highest) family income group for spontaneous (rate ratio 1.14, 95% confidence interval (CI) 1.03, 1.25) but not iatrogenic preterm birth (rate ratio 0.95, 95% CI 0.75, 1.19). Adjustment for maternal characteristics attenuated the family income-spontaneous preterm birth relationship but strengthened the relationship with iatrogenic preterm birth. Clinical risk factors such as hypertension were differentially associated with spontaneous (rate ratio 3.92, 95% CI 3.47, 4.44) and iatrogenic preterm (rate ratio 14.1, 95% CI 11.4, 17.4) but factors such as diabetes mellitus were not (rate ratio 4.38, 95% CI 3.21, 5.99 for spontaneous and 4.02, 95% CI 2.07, 7.80 for iatrogenic preterm birth). CONCLUSIONS: Socioeconomic position and clinical risk factors have different effects on spontaneous and iatrogenic preterm. Recent temporal increases in iatrogenic preterm birth appear to be responsible for the inconsistent relationship between socioeconomic position and preterm birth.

Temporal trends in postpartum hemorrhage and severe postpartum hemorrhage in Canada from 2003 to 2010.

OBJECTIVE: Increases in postpartum hemorrhage have been reported from several countries. We assessed temporal trends in postpartum hemorrhage and severe postpartum hemorrhage in Canada between 2003 and 2010. METHODS: We carried out a population-based cohort study of all hospital deliveries in Canada (excluding Quebec) from 2003 to 2010 (n = 2 193 425), using data from the Canadian Institute for Health Information. Postpartum hemorrhage was defined as a blood loss of ≥ 500 mL following vaginal delivery or ≥ 1000 mL following Caesarean section, or as noted by the care provider. Severe postpartum hemorrhage was defined as postpartum hemorrhage plus blood transfusion, hysterectomy, or other procedures to control bleeding (including uterine suturing or ligation/embolization of pelvic arteries). Temporal trends were assessed using the chi-square test for trend, relative risks, and logistic regression. RESULTS: Postpartum hemorrhage increased by 22% (95% CI 20% to 25%) from 5.1% in 2003 to 6.2% in 2010 (P < 0.001), driven by a 29% increase (95% CI 26% to 33%) in atonic postpartum hemorrhage (3.9% in 2003 vs. 5.0% in 2010, P < 0.001). Postpartum hemorrhage with blood transfusion increased from 36.7 to 50.4 per 10 000 deliveries (P < 0.001), while postpartum hemorrhage with hysterectomy increased from 4.9 to 5.8 per 10 000 deliveries (P < 0.01). Postpartum hemorrhage with uterine suturing, or ligation/embolization of pelvic arteries, increased from 4.1 to 10.7 per 10 000 deliveries (P < 0.001). These increases occurred in most provinces and territories, and could not be explained by changes in maternal, fetal, and obstetric factors. CONCLUSION: Rates of postpartum hemorrhage and severe postpartum hemorrhage continued to increase in Canada between 2003 and 2010.

Objectif : Une hausse des taux d'hémorragie postpartum a été signalée dans plusieurs pays. Nous avons évalué les tendances temporelles en matière d'hémorragie postpartum et d'hémorragie postpartum grave au Canada pour la période se situant entre 2003 et 2010. Méthodes : Nous avons mené une étude de cohorte en population générale ayant porté sur tous les accouchements hospitaliers au Canada (exception faite du Québec) pour la période se situant entre 2003 et 2010 (n = 2 193 425), au moyen des données issues de l'Institut canadien d'information sur la santé. L'hémorragie postpartum a été définie comme étant une perte sanguine ≥ 500 ml à la suite d'un accouchement vaginal ou ≥ 1 000 ml à la suite d'une césarienne, ou encore conformément aux notes du fournisseur de soins. L'hémorragie postpartum grave a été définie comme étant une hémorragie postpartum s'accompagnant d'une transfusion sanguine, d'une hystérectomie ou d'autres interventions visant à juguler les saignements (y compris les sutures utérines ou la ligature / l'embolisation des artères pelviennes). Les tendances temporelles ont été évaluées au moyen d'un test du chi carré (pour ce qui est de l'évolution), des risques relatifs et d'une régression logistique. Résultats : Le taux d'hémorragie postpartum a connu une hausse de 22 % (IC à 95 %, 20 % - 25 %), soit de 5,1 % en 2003 à 6,2 % en 2010 (P < 0,001), déterminée par une hausse de 29 % (IC à 95 %, 26 % - 33 %) du taux d'hémorragie postpartum par atonie utérine (3,9 % en 2003 vs 5,0 % en 2010, P < 0,001). Le taux d'hémorragie postpartum s'accompagnant d'une transfusion sanguine est passé de 36,7 à 50,4 par 10 000 accouchements (P < 0,001), tandis que le taux d'hémorragie postpartum s'accompagnant d'une hystérectomie est passé de 4,9 à 5,8 par 10 000 accouchements (P < 0,01). Le taux d'hémorragie postpartum s'accompagnant de sutures utérines ou d'une ligature / embolisation des artères pelviennes est passé de 4,1 à 10,7 par 10 000 accouchements (P < 0,001). Ces hausses se sont manifestées dans la plupart des provinces et des territoires, et ne pouvaient être expliquées par des modifications affectant des facteurs maternels, fœtaux ou obstétricaux. Conclusion : Les taux d'hémorragie postpartum et d'hémorragie postpartum grave ont poursuivi leur croissance au Canada entre 2003 et 2010.

Gestational age-specific severe maternal morbidity associated with labor induction.

OBJECTIVE: The purpose of this study was to examine the association between labor induction and gestational age-specific severe maternal morbidity. STUDY DESIGN: Our study was restricted to women who delivered singletons at 37-42 weeks' gestation who had no pregnancy complications from 2003-2010 (n = 1,601,253) in Canada (excluding Quebec). Using a pregnancies-at-risk approach, the week-specific rates of specific morbidity after induction were contrasted with rates among ongoing pregnancies. Logistic regression was used to adjust for confounders. RESULTS: Induction increased the rate of postpartum hemorrhage that required blood transfusion at 38 weeks' gestation (adjusted rate ratio, 1.28; 95% confidence interval, 1.11-1.49) and 39 weeks' gestation (adjusted rate ratio, 1.21; 95% confidence interval, 1.06-1.38). Induction was also associated with higher rates of pueperal sepsis at 38 and 39 weeks' gestation and venous thromboembolism at 38 weeks' gestation. The absolute increase in morbidity rates was small; the number needed to harm was large (eg, 1270 for postpartum hemorrhage with blood transfusion at 38 weeks' gestation). CONCLUSION: Among women without pregnancy complications, induction at earlier term is associated with higher rates of specific severe maternal morbidity, although absolute risks are low.

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.

Temporal trends in maternal mortality in Canada I: estimates based on vital statistics data.

OBJECTIVES: Vital Statistics and World Health Organization reports show a recent increase in maternal mortality in Canada. We carried out a study of temporal trends, regional variations, and causes of death in Canadian maternal mortality using Vital Statistics data. METHODS: We used Vital Statistics death registrations to ascertain maternal deaths between 1981 and 2007. Maternal mortality rates, risk ratios, and 95% confidence intervals were estimated, and the Cochran-Armitage test was used to evaluate temporal trends. We used hospitalization data from the Canadian Institute for Health Information from 1996 to 2007 to confirm maternal mortality trends observed in the Vital Statistics data. RESULTS: Maternal mortality rates increased significantly from 4.5 (95% CI 3.3 to 5.8) in 1981 to 1983 to 4.7 (95% CI 3.5 to 6.2) in 1996 to 1998 and to 7.2 (95% CI 5.7 to 9.0) per 100 000 live births in 2005 to 2007 (P value for trend < 0.001). The most common causes of maternal death were diseases of the circulatory system, obstetric embolism (venous thromboembolism and amniotic fluid embolism), and hypertension. Deaths due to diseases of the circulatory system and puerperal infection increased significantly from 1981 to 2007. Maternal mortality rates in the hospitalization data were higher and did not show an increase over time. Provincial and territorial maternal mortality rates from Vital Statistics data showed varying degrees of under-ascertainment (12% to 70%) compared with hospitalization data. CONCLUSION: Temporal increases in maternal mortality in Canada observed in Vital Statistics data do not correspond with stable temporal trends observed in hospitalization data, and appear to be an artefact of changes in the coding and ascertainment of maternal deaths.

Temporal trends in maternal mortality in Canada II: estimates based on hospitalization data.

OBJECTIVES: World Health Organization reports based on Canadian Vital Statistics data suggest a recent increase in maternal mortality rates in Canada. Since Vital Statistics data typically provide inaccurate estimates of maternal mortality, we examined temporal trends in Canada using hospitalization data. METHODS: We identified in-hospital deaths among women aged 15 to 54 years from the Canadian Institute for Health Information's hospitalization database from 1996-1997 to 2007-2008. Maternal deaths during delivery were identified, and other in-hospital deaths were linked with prior pregnancy/delivery hospitalization records. Maternal mortality rates, 95% confidence intervals, and risk ratios (RRs) were estimated. RESULTS: The maternal mortality rate in Canada was 9.2 per 100 000 deliveries (95% CI 7.6 to 11.2) in 1996 to 1999 and 9.0 per 100 000 deliveries (95% CI 7.4 to 10.9) in 2005 to 2007 (P for trend = 0.22). Older maternal age (RR 9.9 and 3.1 for ≥ 45 years and 40 to 44 years vs. 20 to 24 years), delivery by Caesarean section (RR 4.5 vs. vaginal delivery), and early gestation delivery (RR 20.1 and 5.9 for 20 to 27 weeks and 28 to 36 weeks vs. ≥ 37 weeks) were associated with higher maternal mortality. Cardiovascular diseases (rate 4.7 per 100 000 deliveries, 95% CI 3.9 to 5.5) were the most common diagnoses associated with maternal death. The rate of late maternal death (from 43 to 365 days after delivery) was 5.4 per 100 000 deliveries. CONCLUSION: There was no increase in maternal mortality in Canada from 1996 to 2007. Increases observed in Canadian Vital Statistics data likely reflect improvements in the ascertainment of maternal death. Hospitalization data can serve as a timely and comprehensive source for monitoring trends in maternal mortality in Canada.

Incidence, risk factors, and associated complications of eclampsia.

OBJECTIVE: To estimate trends in incidence and identify risk factors and maternal and neonatal consequences of eclampsia in Canada. METHODS: We conducted a population-based cohort study of all women and their newborns (N=1,910,729) delivered in the hospital in Canada (excluding Quebec) from 2003 to 2009. The data were obtained from the Canadian Institute for Health Information. Logistic models were used to examine the association with potential determinants and consequences of eclampsia. RESULTS: The incidence of eclampsia declined dramatically from 12.4 per 10,000 deliveries in 2003 to 5.9 in 2009. Among singleton deliveries, nulliparity (adjusted odds ratio [OR] 2.3; 95% confidence interval [CI] 2.0-2.6), anemia (adjusted OR 2.4; 95% CI 2.0-3.0), and existing heart disease (adjusted OR 4.8; 95% CI 2.9-7.3) increased the risk of eclampsia. The declining trend in eclampsia remained unchanged after accounting for changes in potential determinants and risk factors during the study period. Eclampsia was associated with increased risks of maternal death (adjusted OR 26.8; 95% CI 9.7-73.8), assisted ventilation (adjusted OR 102.3; 95% CI 78.2-133.8), respiratory distress syndrome (adjusted OR 36.2; 95% CI 15.3-85.3), acute renal failure (adjusted OR 20.9; 95% CI 11.4-38.3), obstetric embolism (adjusted OR 9.1; 95% CI 4.1-19.9), and other complications. Adverse neonatal outcomes associated with eclampsia included neonatal death (adjusted OR 2.9; 95% CI 1.6-5.5), respiratory distress syndrome (adjusted OR 5.1; 95% CI 4.1-6.3), and small-for-gestational age birth (adjusted OR 2.6; 95% CI 2.3-3.0). CONCLUSION: Despite declining incidence and improved care of women with eclampsia, the condition remains strongly associated with serious adverse consequences.

The Canadian Perinatal Network: a national network focused on threatened preterm birth at 22 to 28 weeks' gestation.

OBJECTIVE: The Canadian Perinatal Network (CPN) maintains an ongoing national database focused on threatened very preterm birth. The objective of the network is to facilitate between-hospital comparisons and other research that will lead to reductions in the burden of illness associated with very preterm birth. METHODS: Women were included in the database if they were admitted to a participating tertiary perinatal unit at 22+0 to 28+6 weeks' gestation with one or more conditions most commonly responsible for very preterm birth, including spontaneous preterm labour with contractions, incompetent cervix, prolapsing membranes, preterm prelabour rupture of membranes, gestational hypertension, intrauterine growth restriction, or antepartum hemorrhage. Data were collected by review of maternal and infant charts, entered directly into standardized electronic data forms and uploaded to the CPN via a secure network. RESULTS: Between 2005 and 2009, the CPN enrolled 2524 women from 14 hospitals including those with preterm labour and contractions (27.4%), short cervix without contractions (16.3%), prolapsing membranes (9.4%), antepartum hemorrhage (26.1%), and preterm prelabour rupture of membranes (23.0%). The mean gestational age at enrolment was 25.9 ± 1.9 weeks and the mean gestation age at delivery was 29.9 ± 5.1 weeks; 57.0% delivered at < 29 weeks and 75.4% at < 34 weeks. Complication rates were high and included serious maternal complications (26.7%), stillbirth (8.2%), neonatal death (16.3%), neonatal intensive care unit admission (60.7%), and serious neonatal morbidity (35.0%). CONCLUSION: This national dataset contains detailed information about women at risk of very preterm birth. It is available to clinicians and researchers who are working with one or more CPN collaborators and who are interested in studies relating processes of care to maternal or perinatal outcomes.

Maternal mortality and severe maternal morbidity surveillance in Canada.

The Canadian Perinatal Surveillance System has provided a comprehensive review of maternal mortality and severe maternal morbidity in Canada, and has identified several important limitations to existing national maternal data collection systems, including variability in the detail and quality of mortality data. The Canadian Perinatal Surveillance System report recommended the establishment of an ongoing national review and reporting system, as well as consistency in definitions and classifications of maternal mortality and severe maternal morbidity, in order to enhance surveillance of maternal mortality and severe maternal morbidity. Using review articles and studies that examined maternal mortality in general as opposed to maternal mortality associated with particular management strategies or conditions, maternal mortality and severe morbidity classifications, terminology, and comparative statistics were reviewed and employed to evaluate deficiencies in past and current methods of data collection and to seek solutions to address the need for enhanced and consistent national surveillance of maternal mortality and severe maternal morbidity in Canada.

Severe maternal morbidity in Canada, 2003 to 2007: surveillance using routine hospitalization data and ICD-10CA codes.

OBJECTIVE: To examine the feasibility of using routine labour and delivery hospitalization data and international classification of diseases (ICD-10CA) codes for carrying out surveillance of severe maternal morbidity in Canada. METHODS: We identified ICD-10CA diagnosis codes and Canadian Classification of Interventions (CCI) procedure codes associated with severe maternal illness. Severe maternal morbidity rates in Canada (excluding Quebec) for the period 2003 to 2007 were estimated using the Discharge Abstract Database of the Canadian Institute for Health Information. Rates were compared across maternal age, parity, plurality, labour induction, delivery by Caesarean section, and other factors. Case fatality rates and length of hospitalization were also estimated. RESULTS: Among the 1 336 356 women who delivered between 2003 and 2007, the rate of severe maternal morbidity was 13.8 per 1000 deliveries. The mean length of hospital stay for women with and without a severe illness was 5.4 days vs. 2.5 days, while the frequency of prolonged hospital stay (>or=7 days) was 19.8% vs. 1.8%, respectively (rate ratio 9.3; 95% CI 9.0 to 9.6). Case fatality rates differed significantly between women with and without a severe illness at 2.98 vs. 0.008 per 1000, respectively (rate ratio 392.8; 95% CI 200.3 to 700.4). Rates of severe maternal morbidity were higher among deliveries to older and nulliparous women and to those delivering twins or triplets. CONCLUSION: Disease frequency, case fatality, and length of hospitalization patterns suggest that comprehensive and timely surveillance of severe maternal morbidity in Canada is feasible using the Canadian Institute for Health Information hospitalization data and ICD-10CA/CCI codes.