Key Findings

Current Provincial/Territorial Maternal Death Review Activities

Table 2 contains information about maternal death review committees and coroner/medical examiner notification of maternal deaths in Canadian provinces and territories. Of note, only Manitoba, Saskatchewan, Alberta and Northwest Territories have established committees with a mandate to investigate all maternal deaths in their jurisdiction. Only six of thirteen provincial and territorial Coroner's Acts (or equivalent legislation) specifically mention pregnancy in the list of cases to be reported to the coroner/ medical examiner. However, in most provinces and territories, it was the opinion of the coroner/medical examiner or designate that they would likely be notified of all maternal deaths in their jurisdiction. In some provinces and territories, such as British Columbia, notification does not necessarily translate into formal investigation as some deaths may be classified as "non-coroner cases" based on initial information, with no further investigation. Quebec was the only province without a maternal death review committee where a coroner is not routinely notified of all deaths related to pregnancy.

Table 3 contains details of the four established provincial and territorial maternal death review committees.

Table 2 Provincial/territorial maternal death review activities
Province/territory	Province/ territory-wide maternal death review committee	Specific mention of "pregnancy" for notification of coroner/medical examiner in Coroner's Act (or equivalent)a	Coroner/medical examiner would likely be notified of all pregnancy-related deathsb
Newfoundland and Labrador	No	Yes	Yes
Prince Edward Island	No	No	Yes
Nova Scotia	No	No	Yes
New Brunswick	No	Yes	Yesc
Quebec	No	No	No
Ontario	No	Yes	Yes
Manitoba	Yes	Yes	Yes
Saskatchewan	Yes	No	No
Alberta	Yes	Yes	Yes
British Columbia	No	Yes	Yes
Yukon	No	No	Yesd
Northwest Territories	Yes	No	Yesd
Nunavut	No	No	Yes
a Five of six provinces/territories specifically mentioning pregnancy list "reasonably related to" or "reasonably attributed to"pregnancy. In these instances, incidental deaths may not be routinely reported; Manitoba simply lists "during pregnancy or during recovery from pregnancy." b Province/territory-specific coroner/medical examiner's opinion of likelihood of notification of all maternal deaths. c Would likely be notified, but may not be recorded or categorized as a maternal death within coroner/medical examiner's records. d Deaths must be sudden and/or unexpected to be notified to coroner/medical examiner; this may apply to other jurisdictions but was specifically mentioned by these coroners/medical examiners.

Table 3 Province/territory-wide maternal death review committees

Maternal Deaths in Canada (excluding Quebec), 1997-2000

For the provinces and territories excluding Quebec, maternal death reports/data collection forms were obtained for 72 out of a total of 91 (79.1%) deaths recorded in the administrative databases (see Figure 2). Reports were obtained for only three of twenty (15.0%) database deaths from Quebec. Therefore, Quebec cases were excluded from the expert review.

Of the nineteen database deaths with no available reports/data collection forms, only one had been found in both the vital statistics and hospitalization databases, two were found only in the vital statistics database and sixteen recorded only in the hospitalization database, the DAD. Of these sixteen records, four had codes suggesting malignancy as the underlying cause of death, suggesting that the DAD has a lower specificity for identifying true maternal deaths based on the ascertainment methods used. These 19 database deaths for which no additional case details were available were not included in either the case review or the calculated MMRs. An additional 30 reports/ data collection forms were obtained from provinces and territories for deaths which had not been identified in the databases. These 30 cases were included in the case reviews and in the calculated MMRs, where applicable. (Only one direct and two indirect maternal deaths were obtained that had not been identified in the database search.)

Of the 102 reports/data collection forms obtained, a total of 64 maternal deaths (44 direct maternal deaths and 20 indirect maternal deaths) were identified for a total, direct and indirect MMR of 6.1, 4.2 and 1.9 per 100,000 live births, respectively. Of these sixty-four cases, all but three were originally ascertained through the search of the databases. Thirty cases were classified as incidental deaths. Of these, only eight were identified through the combined database search. Finally, five deaths were due to unknown cause and three deaths did not meet the case definitions used for this report. The latter three cases included two incidental deaths occurring in the post-partum period that were neither direct nor indirect, and one death occurring 13 years after delivery. These eight deaths were not included in the MMR calculations.

As shown in Table 4, among women aged 20 years and older, the MMR increased with increasing maternal age. However, it should be noted that the number of deaths in several of the age categories was small and the resulting confidence intervals are wide.

The stage of pregnancy when maternal deaths occurred is presented in Figure 3. Over 70% of deaths occurred at 24 weeks' gestation or later. Of these deaths occurring at 24 weeks' gestation or later, almost half occurred in the post-partum period (less than 42 days after delivery).

Direct Maternal Deaths in Canada (excluding Quebec), 1997-2000

The principal causes of the 44 direct maternal deaths are listed in Table 5. Pulmonary embolism and pre-eclampsia/pregnancy-induced hypertension were the leading causes of direct maternal death, each accounting for nine or 20.5% of direct maternal deaths. The MMR for each of these two leading causes of direct maternal death was 0.85 per 100,000 live births.

Of the nine deaths attributed to pulmonary embolism, four were classic cases of post-partum pulmonary embolism, two of the nine women had evidence of an underlying condition predisposing them to pulmonary embolism, and at least two women had a history of potentially inadequate thromboprophylaxis. One woman experienced an air embolism. Of the nine deaths attributed to pre-eclampsia/ pregnancy-induced hypertension, five died from an intracranial hemorrhage. At least five of these nine women were under medical supervision and/or receiving medical management for pre-eclampsia/pregnancy-induced hypertension that had been identified prior to their death.

Amniotic fluid embolism (AFE) and intracranial hemorrhage (ICH) were the next leading causes of direct maternal death, each responsible for seven or 15.9% of direct maternal deaths. The MMRs for both AFE and ICH were 0.66 per 100,000 live births.

Table 4. Maternal mortality ratio (MMR) per 100,000 live births, by maternal age, Canada (excluding Quebec), 1997-2000
Age	Maternal deaths	Live births	MMR (95% CI)
< 20 years	2	62,236	3.2 (0.4-11.7)
20-24 years	4	187,062	2.1 (0.6-5.4)
25-29 years	16	321,753	5.0 (2.8-8.1)
30-34 years	24	316,588	7.6 (4.9-11.3)
35-39 years	15	142,968	10.5 (5.9-17.3)
40 years and older	3	24,221	12.4 (2.6-36.2)
Total	64	1,054,828	6.1 (4.7-7.7)

Of seven cases of AFE, five women had a clinical picture consistent with disseminated intravascular coagulation and hemorrhage. The seven cases of ICH included four with intracerebral hemorrhage, two with subarachnoid hemorrhage and one with pontine hemorrhage. The latter case was not typical of pregnancy-related ICH but was still classified as a direct maternal death due to ICH.

Ectopic pregnancies accounted for six or 13.6% of direct maternal deaths, for a MMR of 0.57 per 100,000 live births. In three of these cases, a diagnosis of ectopic pregnancy was missed, despite the women having sought medical attention. A fourth death was procedure related during laparoscopic management of an ectopic pregnancy.

Finally, hemorrhage was the principal cause of four or 9.1% of direct maternal deaths, for a MMR of 0.38 per 100,000 live births. Hemorrhage also played a significant role in several maternal deaths that were ultimately attributed to other causes. Of note, from 1997 to 2000, no maternal deaths were attributed to primary post-partum hemorrhage.

Indirect Maternal Deaths in Canada (excluding Quebec), 1997-2000

The principal causes of the 20 indirect maternal deaths are listed in Table 6. The leading cause of indirect maternal death was cardiovascular disease, accounting for 12 or 60% of indirect deaths, for a MMR of 1.1 per 100,000 live births. One of the leading causes of indirect death within the cardiovascular disease category was coronary artery disease. Two of the four women whose death was attributed to coronary artery disease had a history of diabetes.

Table 5 Direct maternal deaths, by principal cause, Canada (excluding Quebec), 1997-2000
Cause of death		Number
Pulmonary embolism			9
Pre-eclampsia/pregnancy-induced hypertension			9
Amniotic fluid embolism (AFE)			7
Intra-cranial hemorrhage (ICH)			7
Ectopic pregnancy			6
Hemorrhage			4
	Placenta previa	2
	Uterine artery tear	1
	Intra-abdominal hemorrhage of unknown etiology	1
Other			2
	Septic abortion	1
	Anaesthesia-related	1
Total			44
Note: Each death was assigned one principal cause by the expert review committee.

Table 6 Indirect maternal deaths, by principal cause, Canada (excluding Quebec), 1997-2000
Cause of death			Number
Cardiovascular disease			12
	Coronary artery disease	4
	Cardiomyopathy	4
	Primary pulmonary hypertension	1
	Dissecting aortic aneurysm	1
	Acute viral myocarditis	1
	Aortic valve disease	1
Other			8
	Cerebrovascular accident	3
	Connective tissue disorder	2
	Diabetes	1
	Thrombotic thrombocytopenia	1
	Adrenal insufficiency	1
Total			20

Note: Each death was assigned one principal cause by the expert review committee.

Incidental Deaths in Canada (excluding Quebec), 1997-2000

The principal causes of the 30 incidental deaths are listed in Table 7. Injuries, and motor vehicle crashes in particular, were the leading cause of incidental deaths. Motor vehicle crashes accounted for over 65% of the injury-related deaths and 50% of all the incidental deaths. Of the 15 women who died as a result of a motor vehicle crash, 14 were occupants of a vehicle. Of these fourteen women, at least two were not wearing seat belts. In an additional five cases, it was unclear from the case reports whether seat belts had been properly worn. There was evidence of seat belt malfunction in one death.

Severe Maternal Morbidity in Canada (excluding Manitoba, Quebec and Nova Scotia), 1991-1992 to 2000-2001

A total of 2,548,824 delivery records were abstracted from CIHI's DAD for the period 1991-1992 to 2000-2001. Overall, 11,775 cases of severe maternal morbidity were identified for a corresponding rate of 4.62 per 1,000 deliveries (see Table 8).

As Table 9 demonstrates, the rates of obstetrical pulmonary embolism (not including AFE), uterine rupture, adult respiratory distress syndrome, pulmonary edema, myocardial infarction, severe post-partum hemorrhage requiring hysterectomy and assisted ventilation increased substantially (50% or greater); the rates of cerebrovascular disorders in the puerperium (including intracranial venous sinus thrombosis) increased moderately (increase of less than 50%); and the rates of shock, severe post-partum hemorrhage requiring transfusion, and severe post-partum hemorrhage requiring hysterectomy or transfusion decreased. The rates of AFE, eclampsia, pulmonary, cardiac and central nervous system (CNS) complications of anaesthesia, acute renal failure following labour and delivery, cardiac arrest/failure or cerebral anoxia following obstetrical surgery, and overall severe maternal morbidity showed no consistent trends.

Table 7 Incedental deaths, by principal cause, Canada (excluding Quebec), 1997-2000
Cause of death		Number
Injuries			23
	Motor vehicle traffic crashes	15
	Intentional self-inflicted injury or poisoning	4
	Injury or poisoning of undetermined intent	2
	Injury due to assault	1
	Unintentional poisoning	1
Other			7
	Sepsis	3
	Eplilepsy	2
	Hemorrhage	2
Total		30

Note: Each death was assigned one principal cause by expert review committee.

Table 8 Occurrence of severe maternal morbidity in Canada (excluding Manitoba, Quebec and Nova Scotia), 1991-1992 to 2000-2001
Condition	Number of cases	Rate (per 1,000 deliveries)	95% CI
Amniotic fluid embolism (AFE)	151	0.06	0.05-0.07
Obstetrical pulmonary embolism (not including AFE)	407	0.16	0.14-0.18
Eclampsia	973	0.38	0.36-0.41
Shock (obstetrical, septic and other)	829	0.33	0.30-0.35
Pulmonary, cardiac and central nervous system (CNS) complications of anaesthesia	1,246	0.49	0.46-0.52
Cerebrovascular disorders in the puerperium (including intracranial venous sinus thrombosis)	412	0.16	0.15-0.18
Uterine rupture	1,898	0.74	0.71-0.78
Adult respiratory distress syndrome	205	0.08	0.07-0.09
Pulmonary edema	402	0.16	0.14-0.17
Myocardial infarction	31	0.01	0.01-0.02
Acute renal failure following labour and delivery	219	0.09	0.07-0.10
Cardiac arrest/failure or cerebral anoxia following obstetrical surgery	2,677	1.05	1.01-1.09
Post-partum hemorrhage requiring hysterectomy	892	0.35	0.33-0.37
Post-partum hemorrhage requiring transfusion	2,317	0.91	0.87-0.95
Post-partum hemorrhage requiring hysterectomy or transfusion	3,114	1.22	1.18-1.27
Assisted ventilation	387	0.15	0.14-0.17
Delivering women with one or more conditions	11,775	4.62	4.54-4.70
CI - confidence interval.

Table 9 Occurrence of severe maternal morbidity in Canada (excluding Manitoba, Quebec and Nova Scotia), 1991-1992 to 1993-1994 and 1998-1999 to 2000-2001
Condition	Rate (per 1,000 deliveries) 1991-1993	Rate (per 1,000 deliveries)1998-2000	Relative risk (95% CI)
Amniotic fluid embolism (AFE)	0.06	0.05	0.83	(0.54-1.31)
Obstetrical pulmonary embolism (not including AFE)	0.12	0.20	1.73	(1.33-2.24)
Eclampsia	0.38	0.33	0.88	(0.75-1.05)
Shock (obstetrical, septic and other)	0.38	0.28	0.75	(0.63-0.89)
Pulmonary, cardiac and central nervous system (CNS) complications of anaesthesia	0.48	0.51	1.06	(0.92-1.22)
Cerebrovascular disorders in the puerperium (including intracranial venous sinus thrombosis)	0.14	0.19	1.42	(1.10-1.82)
Uterine rupture	0.58	0.92	1.60	(1.42-1.81)
Adult respiratory distress syndrome	0.07	0.10	1.50	(1.05-2.13)
Pulmonary edema	0.10	0.22	2.09	(1.60-2.72)
Myocardial infarction	0.00	0.02	3.70	(1.21-11.35)
Acute renal failure following labour and delivery	0.07	0.09	1.20	(0.84-1.71)
Cardiac arrest/failure or cerebral anoxia following obstetrical surgery	1.05	0.96	0.91	(0.82-1.00)
Post-partum hemorrhage requiring hysterectomy	0.26	0.46	1.76	(1.48-2.08)
Post-partum hemorrhage requiring transfusion	1.27	0.63	0.50	(0.44-0.55)
Post-partum hemorrhage requiring hysterectomy or transfusion	1.51	1.04	0.69	(0.63-0.76)
Assisted ventilation	0.10	0.24	2.47	(1.89-3.23)
Delivering women with one or more conditions	4.63	4.62	1.00	(0.95-1.04)
* Based on 1991-1993 as the reference. CI - confidence interval.

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