Factors associated with high-risk pregnancies in Canadian Inuit ALAN I. MURDOCK,* B SC, MD, CM, PH D, FRCPIIC]
Antenatal risk factors and management problems during labour and delivery were examined for 141 consecutive deliveries in Canadian Inuit of the eastern Arctic. The applicability of three risk scoring systems for antenatal use was evaluated. Pregnancies were categorized as being at high, moderate or low risk according to the authors' published criteria. Only two of the systems gave statistically valid predictions of the outcome of pregnancy in terms of risk categorization. Sensitivity and uniformity of the systems were lacking: the risk scores were low in 320/o to 580/0 of the pregnancies in which the mother or the infant or both had problems during labour or delivery or both, and in 270/c to 360/c of the pregnancies in which the infant alone had problems. Antepartum factors that indicated a significantly increased risk of problems during labour or delivery or both were maternal age less than 16 or more than 35 years, previous stillbirth or neonatal death, previous birth weight of less than 2501 g, previous postpartum hemorrhage or other problem in the third stage of labour, antituberculosis therapy in the mother, and any of antepartum hemorrhage, multiple pregnancy, breech delivery, maipre. sentation or long period between rupture of the membranes and delivery in the current pregnancy. The data indicate that scoring systems should take into account regional or population variations if they are to have reasonable sensitivity. Les facteurs de risque prenataux et les problemes de traitement rencontres durant le travail et l'accouchement ont ete examines pour 141 accouche. ments consecutifs chez des Inuits canadiennes de l'est de l'Arctique. On a 6value l'applicabilit6 de trois systemes de cotation de risque durant Ia periode prenatale. Les grossesses ont ete classifiees selon qu'elles etaient a risque eleve, moyen ou faible, selon les criteres publies par les auteurs. Seulement deux des syst.mes ont permis des predictions statistiquement valides sur l'issue de Ia grossesse selon *Consultant, child and maternal care, medical services branch, Health and Welfare Canada, and department of pediatrics, University of Ottawa Reprint requests to: Dr. Alan I. Murdock, Jeanne Mance Building, Rm. 1914. Tunney's Pasture, Ottawa, Ont. KiA 0L3
Ia categorie de risque. Les systemes manquaient de sensibilite et d'uniformite: les cotes de risque etaient faibles dans 320/o a 580/o des grossesses ou Ia mere ou le bebe (ou les deux) eut des problemes durant le travail ou l'accouchement (ou les deux), et dans 270/0 a 360/c des grossesses ou le bebe seulement eut des problemes. Les facteurs antepartums qui se sont averes indicateurs d'une augmentation du risque de problemes durant le travail ou l'accouchement (ou les deux) ont ete les suivants: un ige maternel de moms de 16 ans ou de plus de 35 ans, une mortinatalite ou un deces neonatal prealable, un poids de 2501 g lors d'une naissance prealable, une hemorragie postpartum prealable ou un autre probleme au cours du troisieme stade du travail, un traitement antituberculeux chez la mere et, durant Ia presente grossesse, une hemorragie antepartum, une grossesse multiple, une presentation du siege, une mauvaise presentation ou une longue periode entre Ia rupture des membranes et I'accouchement. Ces donnees indiquent que les systemes de cotation devront prendre en consideration les variations regionales ou particulieres & Ia population si l'on veut qu'ils soient raisonnablement sensibles.
The development of instruments that can be used to assess the health status of native peoples is important in evolving priorities for specific programs directed towards lowering morbidity and mortality. This report examines the potential use of systems for scoring risk factors in pregnancy in the context of recent experience with a high-risk population - the Canadian Inuit living in the Keewatin and Baffin zones of the Northwest Territories. No consensus has been reached on what the appropriate risk factors are on a national or international basis.1 Furthermore, if one uses a scoring system the weighting of values varies considerably when applied to individuals and to different groups of individuals (e.g., upper middle-class urban groups v. native groups living in remote communities). In addition,
the diagnosis is not always available, and specificity may be lacking, which can result in either a falsely high or a falsely low score. Nevertheless, collection and analysis of quantifiable indices can provide data on the groups of women who are at highest risk, and will alert members of the health team of the criteria that contribute to placing the women at risk. The standardization of data can also give an indication of the profile of risk factors in the population and can assist in the planning of appropriate intervention programs and measuring their effect. Subjects and methods Data from 414 consecutive deliveries were studied; 230 took place in the Keewatin Zone between Jan. 1, 1975 and Dec. 1, 1976, and 184 took place in the Baffin Zone between Oct. 1, 1976 and Sept. 30, 1977. These deliveries represented approximately 60% of the total in the two zones between Jan. 1, 1975 and Dec. 30, 1977. Women who were between gravida 1 and gravida 5, were aged 17 to 34 years, and had no abnormalities in their reproductive history or the present pregnancy were usually delivered at the nursing stations by certified midwives. The remaining women were considered at risk and were referred to either the Churchill Health Centre in northern Manitoba or Frobisher Bay General Hospital in the Northwest Territories for delivery by members of the medical staff. Women at high risk were referred to the Women's Centre in Winnipeg or either the Montreal General Hospital or the Jewish General Hospital in Montreal. The place of delivery was a nursing station for 53 of the 414 (13%), a secondary-care hospital for 312 (75%) and a tertiary-care hospital for 49 (12%). The reproductive history, the antenatal course, the labour and de-
CMA JOURNAL/FEBRUARY 3, 1979/VOL. 120 291
livery experience, the postnatal course of the mother and the perinatal experience of the infant were reviewed by examination of individual charts. Three previously described and commonly used antenatal risk scoring 24 evaluated systems were . Individual pregnancies were scored in accordance with factors and weights of each scoring system, and the pregnancies were grouped into categories of high, moderate and low risk, as defined by those authors. The outcome of pregnancy - that is, the presence or absence of one or more problems of management during labour and delivery - was documented. Prolonged labour, precipitous delivery, retained placenta, and intrapartum and postpartum hemorrhage were defined as described by Oxorn and Foote.' Asphyxia neonatorum was defined as an Apgar score of less than 7 at 1 minute of age or the presence of apnea requiring ventilatory assistance. The significance of differences be.. tween groups was assessed by the chi-square test. The null hypothesis was rejected if the chi-square value was larger than the value corresponding to a probability of 0.05 on Fisher's tables of chi-square values. Results The antenatal risk factors identified in the 414 pregnancies are shown in Table I. Problems during labour or delivery or both The high-risk nature of the population is evident from Fig. 1, which shows that in 37% (154) of the pregnancies there was a management problem during this period with the mother or the infant or both. Specific problems are shown in Table II. Only 2% of the infants were delivered by cesarean section. Postpartum hemorrhage or retained placenta occurred in more than 10% of the pregnancies. The rate of stillbirths (14/1000 total births) was higher than the rate in 1975 for all of Canada (7.311000).' The rate of low birth weight (less than 2501 g) was also relatively high, at almost 12%. Half of the infants with
a low birth weight were born at term. The rate of asphyxia neonatorum was comparable to that reported for Quebec for l973.. Relation between risk scores and problems during labour and delivery The distribution of the pregnan-
100
cies in relation to the antenatal risk score and the outcome of pregnancy (Fig. I) indicates that the three scoring systems vary considerably in their assessment of the degree of risk. According to the scoring system of Nesbitt and Aubry4 66% of pregnancies were at moderate or high risk; in
-
90 -
80 70 -
Th.E Moderate
E High PROBLEMS
60 D None
50 Mother
40 30 -
. Infant Mother and Infant
20 _ 10 -
0.
A B C Problems Experienced FIG. 1-Distribution of 414 pregnancies in Canadian Inuit by risk category assigned with three antenatal scoring systems (A, B and C: references 2, 3 and 4 respectively) and by occurrence of management problems during labour or delivery or both.
292 CMA JOURNAL/FEBRUARY 3, 1979/VOL. 120
contrast, 34% and 45% of the pregnancies were at moderate or high risk according to the scoring systems of Goodwin, Dunne and Thomas3 and of Coopland and colleagues2 respectively. Not all of the pregnancies with management problems during labour and delivery were at high or moderate risk. Of the 154 pregnancies with problems during this period, between
32% (by Nesbitt and Aubry's system) and 58% (by Goodwin and associates' system) were considered at low risk (Fig. 2). This lack of sensitivity and uniformity of the scoring systems is not entirely surprising since the systems were designed primarily to predict which infants, not which mothers, would have problems. Analysis of the data for the 73 pregnancies that ended with problems for the infant showed that the predictability of the scoring systems was less than optimal (Table III). Although the percentage of pregnancies with such problems was significantly higher for those at high risk than for Risk High
70 Moderate 60 . Low 50 40 -
those at low risk according to the systems of Coopland and Goodwin and their associates, between 27% (by Nesbitt and Aubry's system) and 36% (by Goodwin and associates' system) of pregnancies with such problems had been assigned low-risk scores. Furthermore, stillbirths and neonatal deaths were randomly distributed.
Relation between some antenatal factors and management problems during labour or delivery or both Risk scoring systems are of most practical value if they can predict not only the infants but also the mothers who are most likely to have problems at the time of labour or delivery or both. In an effort to increase the sensitivity of the scoring systems, data from the 414 pregnancies were analysed to determine what factors were of statistical significance in identifying mothers and infants who were at greater risk than the overall group, as well as pregnancies in which both the mother and the infant were likely to have a problem during labour or delivery or both. Table IV shows the factors that we found to indicate a significantly higher (P K 0.05) risk.
20 _
Discussion
0. A
B
C
SCORING SYSTEMS FIG. 2-Distribution of 154 pregnancies with management problems during labour or delivery or both according to risk category.
This study has identified the most common statistically significant risk factors in pregnancies of Inuit women living in the eastern Arctic. The results have indicated that the currently used risk scoring systems designed to predict perinatal problems cannot be used to identify mothers or in-
CMA JOURNAL/FEBRUARY 3, 1979/VOL. 120 293
fants at risk of having management problems during labour or delivery that re.quire hospital-based care. Risk scoring systems for use in remote areas of the country, where referral to secondary- or tertiary-care centres is necessary, require different criteria than systems used in urban centres. For example, what constitutes a complication of labour or delivery must be examined from the perspective of the primary-care centre - in this case, the nursing station. In Arctic settlements, induction of labour, forceps delivery and breech presentation must be considered important management problems; for this reason, they were included in the analysis of outcome. Premature rupture of the membranes should also be considered an important problem in so far as it indicates that labour will be complicated (usually obstructed, with accompanying uterine inertia) or prolonged because of medical intervention. This factor might best be considered a complication of labour and delivery rather than a predictive variable for use in an antepartum risk scoring system. Small populations, such as the one that formed the basis of this study, present problems in the development of a scoring system with appropriate weighting of factors that are evident risk conditions. For instance, the low rate of delivery by cesarean section in Inuit women is a recognized clinic-
al situation.8 A pregnancy in an Inuit woman who has previously had a cesarean section must automatically place the pregnancy at risk. The number of women in this circumstance in this study was too small to provide a weighting for statistical analysis. The value of this study in terms of health programs in the North is threefold. First, the factors to be taken into account in using risk scoring systems for women in this area should include those that place the infant at risk and those that place the mother at risk. For example, patients who were receiving antituberculosis therapy had a higher rate of problems than the overall study group. This factor emerged only when the data for problems during labour and delivery for mothers or infants or both were analysed. Second, the relative importance of some indirect variables (excluding distinct clinical problems such as chronic renal disease, cardiac disease and Rh isoimmunization) differed in this study from published reports. These included maternal age (an age of less than 16 years was associated with a higher frequency of complications than any other age group) and parity (which alone was not a significant variable in this group). Third, the development and implementation of a highly predictive and specific scoring system may not be feasible for this population
since risk factors will change with alterations in lifestyle and in health programs. In summary, this study has shown that at least three of the currently used systems for scoring risk factors in pregnancy are not appropriate for use in the eastern Arctic; that regional and ethnic differences can significantly affect the importance of some variables; and that scoring systems, if they are to be used, should be individualized to the population being cared for. I thank Dr. David Martin, zone director, Baffin Zone, and Mr. L. Sasakamoose and Miss V. Rowley, RN, zone directors, Keewatin Zone and their staff for their helpfulness; the nurses in the communities and the physicians
of the Churchill Health Centre and Frobisher Bay General Hospital for their courtesy in discussing their patients' problems; Dr. 0.1. Rath, senior consultant, Indian health, medical services branch, Health and Welfare Canada, for review of the manuscript; Drs. T.J. Baskett and Dr. H.F. Muggah for advice; and Mrs. Connie Lennon for secretarial assistance.
References 1. LEsINsKI J: High-risk pregnancy; unresolved problems of screening, management, and prognosis. Obstet Gyneccl 46: 599, 1975 2. COOPLAND AT, PEDDLE U, BASKETr
TF, et al: A simplified antepartum high-risk scoring form: statistical analysis of 5459 cases. Can Med Assoc J 116: 999, 1977 3. GOODWIN JW, DLJNNE JT, THOMAS
BW: Antepartum identification of the fetus at risk. Can Med Assoc J 101:
57, 1969 4. NEsBrrr REL, AUBRY RH: High risk obstetrics. II. Value of semiobjective
-.
grading system in identifying the vulnerable group. Am J Obstet Gynecol 103: 972, 1969 5. OXORN H, FOOTE W: Human Labor and Birth, 3rd ed, Appleton-Century-
Crofts, New York, 1976 .A>
.
6. Statistics Canada: Vital Statistics, vol 3: Deaths, 1976, Supply and Services
.
$ .
.w4
Canada, Ottawa, 1978, p 182
4* .
7. Quebec Perinatal Mortality Commit-
)
tee: Analysis of Data Collected on the Medical Certification of a Childbirth and Some Relations with Pennatal Mortality Rates, 1973, minist.re
.7.f
I.Ii7:.4
des Affaires sociales du Qu6bec, Qu&
bec, 1976, pp 29-34 8. BASKETT TF: Obstetrical care in a
Canadian Arctic district. Presented at
. 294 GMA JOURNAL/FEBRUARY 3, 1979/VOL. 120
I1(.)
34th annual meeting, Society of Obstetricians and Gynaecologists of Canada, Winnipeg, June 17, 1978
Antenatal risk factors and management problems during labour and delivery were examined for 141 consecutive deliveries in Canadian Inuit of the eastern Arctic. The applicability of three risk scoring systems for antenatal use was evaluated. Pregnancies were categorized as being at high, moderate or low risk according to the authors' published criteria. Only two of the systems gave statistically valid predictions of the outcome of pregnancy in terms of risk categorization. Sensitivity and uniformity of the systems were lacking: the risk scores were low in 320/o to 580/0 of the pregnancies in which the mother or the infant or both had problems during labour or delivery or both, and in 270/c to 360/c of the pregnancies in which the infant alone had problems. Antepartum factors that indicated a significantly increased risk of problems during labour or delivery or both were maternal age less than 16 or more than 35 years, previous stillbirth or neonatal death, previous birth weight of less than 2501 g, previous postpartum hemorrhage or other problem in the third stage of labour, antituberculosis therapy in the mother, and any of antepartum hemorrhage, multiple pregnancy, breech delivery, maipre. sentation or long period between rupture of the membranes and delivery in the current pregnancy. The data indicate that scoring systems should take into account regional or population variations if they are to have reasonable sensitivity. Les facteurs de risque prenataux et les problemes de traitement rencontres durant le travail et l'accouchement ont ete examines pour 141 accouche. ments consecutifs chez des Inuits canadiennes de l'est de l'Arctique. On a 6value l'applicabilit6 de trois systemes de cotation de risque durant Ia periode prenatale. Les grossesses ont ete classifiees selon qu'elles etaient a risque eleve, moyen ou faible, selon les criteres publies par les auteurs. Seulement deux des syst.mes ont permis des predictions statistiquement valides sur l'issue de Ia grossesse selon *Consultant, child and maternal care, medical services branch, Health and Welfare Canada, and department of pediatrics, University of Ottawa Reprint requests to: Dr. Alan I. Murdock, Jeanne Mance Building, Rm. 1914. Tunney's Pasture, Ottawa, Ont. KiA 0L3
Ia categorie de risque. Les systemes manquaient de sensibilite et d'uniformite: les cotes de risque etaient faibles dans 320/o a 580/o des grossesses ou Ia mere ou le bebe (ou les deux) eut des problemes durant le travail ou l'accouchement (ou les deux), et dans 270/0 a 360/c des grossesses ou le bebe seulement eut des problemes. Les facteurs antepartums qui se sont averes indicateurs d'une augmentation du risque de problemes durant le travail ou l'accouchement (ou les deux) ont ete les suivants: un ige maternel de moms de 16 ans ou de plus de 35 ans, une mortinatalite ou un deces neonatal prealable, un poids de 2501 g lors d'une naissance prealable, une hemorragie postpartum prealable ou un autre probleme au cours du troisieme stade du travail, un traitement antituberculeux chez la mere et, durant Ia presente grossesse, une hemorragie antepartum, une grossesse multiple, une presentation du siege, une mauvaise presentation ou une longue periode entre Ia rupture des membranes et I'accouchement. Ces donnees indiquent que les systemes de cotation devront prendre en consideration les variations regionales ou particulieres & Ia population si l'on veut qu'ils soient raisonnablement sensibles.
The development of instruments that can be used to assess the health status of native peoples is important in evolving priorities for specific programs directed towards lowering morbidity and mortality. This report examines the potential use of systems for scoring risk factors in pregnancy in the context of recent experience with a high-risk population - the Canadian Inuit living in the Keewatin and Baffin zones of the Northwest Territories. No consensus has been reached on what the appropriate risk factors are on a national or international basis.1 Furthermore, if one uses a scoring system the weighting of values varies considerably when applied to individuals and to different groups of individuals (e.g., upper middle-class urban groups v. native groups living in remote communities). In addition,
the diagnosis is not always available, and specificity may be lacking, which can result in either a falsely high or a falsely low score. Nevertheless, collection and analysis of quantifiable indices can provide data on the groups of women who are at highest risk, and will alert members of the health team of the criteria that contribute to placing the women at risk. The standardization of data can also give an indication of the profile of risk factors in the population and can assist in the planning of appropriate intervention programs and measuring their effect. Subjects and methods Data from 414 consecutive deliveries were studied; 230 took place in the Keewatin Zone between Jan. 1, 1975 and Dec. 1, 1976, and 184 took place in the Baffin Zone between Oct. 1, 1976 and Sept. 30, 1977. These deliveries represented approximately 60% of the total in the two zones between Jan. 1, 1975 and Dec. 30, 1977. Women who were between gravida 1 and gravida 5, were aged 17 to 34 years, and had no abnormalities in their reproductive history or the present pregnancy were usually delivered at the nursing stations by certified midwives. The remaining women were considered at risk and were referred to either the Churchill Health Centre in northern Manitoba or Frobisher Bay General Hospital in the Northwest Territories for delivery by members of the medical staff. Women at high risk were referred to the Women's Centre in Winnipeg or either the Montreal General Hospital or the Jewish General Hospital in Montreal. The place of delivery was a nursing station for 53 of the 414 (13%), a secondary-care hospital for 312 (75%) and a tertiary-care hospital for 49 (12%). The reproductive history, the antenatal course, the labour and de-
CMA JOURNAL/FEBRUARY 3, 1979/VOL. 120 291
livery experience, the postnatal course of the mother and the perinatal experience of the infant were reviewed by examination of individual charts. Three previously described and commonly used antenatal risk scoring 24 evaluated systems were . Individual pregnancies were scored in accordance with factors and weights of each scoring system, and the pregnancies were grouped into categories of high, moderate and low risk, as defined by those authors. The outcome of pregnancy - that is, the presence or absence of one or more problems of management during labour and delivery - was documented. Prolonged labour, precipitous delivery, retained placenta, and intrapartum and postpartum hemorrhage were defined as described by Oxorn and Foote.' Asphyxia neonatorum was defined as an Apgar score of less than 7 at 1 minute of age or the presence of apnea requiring ventilatory assistance. The significance of differences be.. tween groups was assessed by the chi-square test. The null hypothesis was rejected if the chi-square value was larger than the value corresponding to a probability of 0.05 on Fisher's tables of chi-square values. Results The antenatal risk factors identified in the 414 pregnancies are shown in Table I. Problems during labour or delivery or both The high-risk nature of the population is evident from Fig. 1, which shows that in 37% (154) of the pregnancies there was a management problem during this period with the mother or the infant or both. Specific problems are shown in Table II. Only 2% of the infants were delivered by cesarean section. Postpartum hemorrhage or retained placenta occurred in more than 10% of the pregnancies. The rate of stillbirths (14/1000 total births) was higher than the rate in 1975 for all of Canada (7.311000).' The rate of low birth weight (less than 2501 g) was also relatively high, at almost 12%. Half of the infants with
a low birth weight were born at term. The rate of asphyxia neonatorum was comparable to that reported for Quebec for l973.. Relation between risk scores and problems during labour and delivery The distribution of the pregnan-
100
cies in relation to the antenatal risk score and the outcome of pregnancy (Fig. I) indicates that the three scoring systems vary considerably in their assessment of the degree of risk. According to the scoring system of Nesbitt and Aubry4 66% of pregnancies were at moderate or high risk; in
-
90 -
80 70 -
Th.E Moderate
E High PROBLEMS
60 D None
50 Mother
40 30 -
. Infant Mother and Infant
20 _ 10 -
0.
A B C Problems Experienced FIG. 1-Distribution of 414 pregnancies in Canadian Inuit by risk category assigned with three antenatal scoring systems (A, B and C: references 2, 3 and 4 respectively) and by occurrence of management problems during labour or delivery or both.
292 CMA JOURNAL/FEBRUARY 3, 1979/VOL. 120
contrast, 34% and 45% of the pregnancies were at moderate or high risk according to the scoring systems of Goodwin, Dunne and Thomas3 and of Coopland and colleagues2 respectively. Not all of the pregnancies with management problems during labour and delivery were at high or moderate risk. Of the 154 pregnancies with problems during this period, between
32% (by Nesbitt and Aubry's system) and 58% (by Goodwin and associates' system) were considered at low risk (Fig. 2). This lack of sensitivity and uniformity of the scoring systems is not entirely surprising since the systems were designed primarily to predict which infants, not which mothers, would have problems. Analysis of the data for the 73 pregnancies that ended with problems for the infant showed that the predictability of the scoring systems was less than optimal (Table III). Although the percentage of pregnancies with such problems was significantly higher for those at high risk than for Risk High
70 Moderate 60 . Low 50 40 -
those at low risk according to the systems of Coopland and Goodwin and their associates, between 27% (by Nesbitt and Aubry's system) and 36% (by Goodwin and associates' system) of pregnancies with such problems had been assigned low-risk scores. Furthermore, stillbirths and neonatal deaths were randomly distributed.
Relation between some antenatal factors and management problems during labour or delivery or both Risk scoring systems are of most practical value if they can predict not only the infants but also the mothers who are most likely to have problems at the time of labour or delivery or both. In an effort to increase the sensitivity of the scoring systems, data from the 414 pregnancies were analysed to determine what factors were of statistical significance in identifying mothers and infants who were at greater risk than the overall group, as well as pregnancies in which both the mother and the infant were likely to have a problem during labour or delivery or both. Table IV shows the factors that we found to indicate a significantly higher (P K 0.05) risk.
20 _
Discussion
0. A
B
C
SCORING SYSTEMS FIG. 2-Distribution of 154 pregnancies with management problems during labour or delivery or both according to risk category.
This study has identified the most common statistically significant risk factors in pregnancies of Inuit women living in the eastern Arctic. The results have indicated that the currently used risk scoring systems designed to predict perinatal problems cannot be used to identify mothers or in-
CMA JOURNAL/FEBRUARY 3, 1979/VOL. 120 293
fants at risk of having management problems during labour or delivery that re.quire hospital-based care. Risk scoring systems for use in remote areas of the country, where referral to secondary- or tertiary-care centres is necessary, require different criteria than systems used in urban centres. For example, what constitutes a complication of labour or delivery must be examined from the perspective of the primary-care centre - in this case, the nursing station. In Arctic settlements, induction of labour, forceps delivery and breech presentation must be considered important management problems; for this reason, they were included in the analysis of outcome. Premature rupture of the membranes should also be considered an important problem in so far as it indicates that labour will be complicated (usually obstructed, with accompanying uterine inertia) or prolonged because of medical intervention. This factor might best be considered a complication of labour and delivery rather than a predictive variable for use in an antepartum risk scoring system. Small populations, such as the one that formed the basis of this study, present problems in the development of a scoring system with appropriate weighting of factors that are evident risk conditions. For instance, the low rate of delivery by cesarean section in Inuit women is a recognized clinic-
al situation.8 A pregnancy in an Inuit woman who has previously had a cesarean section must automatically place the pregnancy at risk. The number of women in this circumstance in this study was too small to provide a weighting for statistical analysis. The value of this study in terms of health programs in the North is threefold. First, the factors to be taken into account in using risk scoring systems for women in this area should include those that place the infant at risk and those that place the mother at risk. For example, patients who were receiving antituberculosis therapy had a higher rate of problems than the overall study group. This factor emerged only when the data for problems during labour and delivery for mothers or infants or both were analysed. Second, the relative importance of some indirect variables (excluding distinct clinical problems such as chronic renal disease, cardiac disease and Rh isoimmunization) differed in this study from published reports. These included maternal age (an age of less than 16 years was associated with a higher frequency of complications than any other age group) and parity (which alone was not a significant variable in this group). Third, the development and implementation of a highly predictive and specific scoring system may not be feasible for this population
since risk factors will change with alterations in lifestyle and in health programs. In summary, this study has shown that at least three of the currently used systems for scoring risk factors in pregnancy are not appropriate for use in the eastern Arctic; that regional and ethnic differences can significantly affect the importance of some variables; and that scoring systems, if they are to be used, should be individualized to the population being cared for. I thank Dr. David Martin, zone director, Baffin Zone, and Mr. L. Sasakamoose and Miss V. Rowley, RN, zone directors, Keewatin Zone and their staff for their helpfulness; the nurses in the communities and the physicians
of the Churchill Health Centre and Frobisher Bay General Hospital for their courtesy in discussing their patients' problems; Dr. 0.1. Rath, senior consultant, Indian health, medical services branch, Health and Welfare Canada, for review of the manuscript; Drs. T.J. Baskett and Dr. H.F. Muggah for advice; and Mrs. Connie Lennon for secretarial assistance.
References 1. LEsINsKI J: High-risk pregnancy; unresolved problems of screening, management, and prognosis. Obstet Gyneccl 46: 599, 1975 2. COOPLAND AT, PEDDLE U, BASKETr
TF, et al: A simplified antepartum high-risk scoring form: statistical analysis of 5459 cases. Can Med Assoc J 116: 999, 1977 3. GOODWIN JW, DLJNNE JT, THOMAS
BW: Antepartum identification of the fetus at risk. Can Med Assoc J 101:
57, 1969 4. NEsBrrr REL, AUBRY RH: High risk obstetrics. II. Value of semiobjective
-.
grading system in identifying the vulnerable group. Am J Obstet Gynecol 103: 972, 1969 5. OXORN H, FOOTE W: Human Labor and Birth, 3rd ed, Appleton-Century-
Crofts, New York, 1976 .A>
.
6. Statistics Canada: Vital Statistics, vol 3: Deaths, 1976, Supply and Services
.
$ .
.w4
Canada, Ottawa, 1978, p 182
4* .
7. Quebec Perinatal Mortality Commit-
)
tee: Analysis of Data Collected on the Medical Certification of a Childbirth and Some Relations with Pennatal Mortality Rates, 1973, minist.re
.7.f
I.Ii7:.4
des Affaires sociales du Qu6bec, Qu&
bec, 1976, pp 29-34 8. BASKETT TF: Obstetrical care in a
Canadian Arctic district. Presented at
. 294 GMA JOURNAL/FEBRUARY 3, 1979/VOL. 120
I1(.)
34th annual meeting, Society of Obstetricians and Gynaecologists of Canada, Winnipeg, June 17, 1978
