Postgraduate Training Course in Reproductive Health/Chronic Disease

Maternal mortality

Review prepared for the 12th Postgraduate Course in Reproductive Medicine and Biology, Geneva, Switzerland

Dr Nasr Abdalla Mohamed
Consultant
Obstetrics & Gynaecology
Sudan Ministry of Health
Sudan Fertility Care Association (SFCA)
Khartoum, Sudan
Tutor: Dr Lale Say
World Health Organization

See also presentation

Abstract

OBJECTIVE: To review the available evidence on the levels of maternal mortality according to different estimation technique.

METHOD: The WHO ‘maternal mortality and morbidity systematic review database’ was searched for the articles from 1998. Medline was searched from 1995-2002 using the term “maternal mortality”. Studies were selected according to their methodological quality and included if they reported maternal deaths, with reported sample size of 200 and above and only if they specify the dates of the period of data collection.

RESULTS: Most of the reviewed studies indicated an underestimation in maternal mortality compared with their findings. The methods for data collection were either direct (e.g. vital registration system) or by using special surveys (e.g. direct/indirect sisterhood methods). The review revealed that there is an increase in maternal mortality in some regions while there is marked reduction in others. The leading causes of maternal death were haemorrhage, pre-eclampsia/eclampsia, sepsis, pulmonary embolism and abortion related complications.
Medical conditions and injuries have emerged among the most common causes of maternal death. An increased risk of pregnancy related death was found for adolescent pregnant women, women with parity more than five, women with no access to emergency obstetric care and women with no antenatal care. Different indicators were used in the reviewed studies.

CONCLUSION : The reported pregnancy-related mortality ratio has increased in some countries while decreased in others. There is a big gap in maternal mortality ratio between the developed and the developing countries in favour of the first. Other causes started to be among the leading ones of maternal death.
It is difficult to estimate maternal mortality, but important to know its extent in order to achieve improvement.
In addition to estimate maternal deaths it is important to identify the risk factors that have adverse effects on pregnancy outcomes.

Introduction

Maternal death refers to the death of a woman while pregnant or within 42 days after the termination of the pregnancy, irrespective of the duration and site of pregnancy, or cause related to or aggravated by the pregnancy, or its management; excluding death from accidental or incidental causes. Late maternal death is defined as maternal death from direct or indirect obstetric causes occurring more than 42 days but less than one year after the termination of pregnancy (1).
Maternal mortality rates are difficult to measure and maternal deaths are hard to identify because of inaccurate reporting. This occurs frequently with first trimester maternal death. The commonly used approaches for estimating the levels and causes of maternal deaths are many and vary between countries. Some of these different techniques are described below.

Sisterhood method

This is a survey-based approach to measure maternal mortality. The original indirect sisterhood method asks respondents 4 questions about how many of their sisters have died and whether those who died were pregnant around the time of death. This method should not be used in certain situations. For example, when fertility rates are low (TFR less than 3). It should not be used if maternal mortality is low, due to the need for a large sample size, as well as during immigration.

Reproductive Age Mortality Studies (RAMOS)

This method has been successfully applied in several countries. This method utilizes single as well as multiple means of methodology to obtain death related information e.g. interviews, questionnaire, verbal autopsy.

Vital Registration

This is a well known method of maternal mortality data collection in developed and in some developing countries. However, no single method is an exhaustive method for the estimation of maternal mortality. Even where sophisticated computerized linkages of fetal birth and death certificates to the death certificate of the mother exists, maternal deaths are frequently missed or misclassified.

In order to get accurate data, additional sources of information are used to complement the findings. Other such techniques could be direct household survey, census, clinical records, etc.
Information about the magnitude and causes of maternal deaths is crucial. By analysing the causes of maternal deaths and the timing of its occurrence can help in prioritising the health service delivery at the national level. Having correct information about maternal deaths helps to observe the changes in the trends of maternal mortality. Estimation of maternal mortality can assist in identifying the strength of the method used and its future application.

Results

• Among the reviewed studies to estimate maternal mortality, direct methods (Table 2) were used in 12 studies and indirect (Table 3) methods in 3 studies.
• The selection and use of the methodology depends on the resources available.
• The studies reviewed are from different regions, (Africa 6, Latin America and Caribbean 3, United States of America 3, Europe 2, Asia 1) (Table 1).
• The study size ranges from 226 to 893 998.
• The study size was not available in one-third of the studies.
•  In 13 out of 15 studies, live births were used as denominator, while two of them used all deliveries as denominator.
• The populations studied are: 33% urban, 14% rural and 53% mixed (Table 1).
• A definition for maternal death is not available in 33% of the studies. Among the available definitions, 33% used ICD-10 within one year after delivery, and 67% used ICD-10 up to 42 days after delivery.
• Maternal mortality ratios range between 8 -1050 per 100 000 live births the lowest in Netherlands and the highest in Nigeria (Table 1 and Table 2).
• Listed by UN regions the highest maternal mortality ratio was estimated in the region of Africa (Table 5).
• By reviewing 15 studies, 1449 cases of maternal deaths were identified and analysed (Table 4).
• Direct obstetric causes constitute 56.9% and indirect 43.1%. The most frequent causes of direct maternal deaths were obstetric haemorrhage, hypertensive disorders of pregnancy and puerperal sepsis.

Discussion

Having the maternal goal set by the Safe Motherhood Initiative in Nairobi in 1987, means that policy makers, programmes managers, health service providers and community leaders need to have accurate estimates of maternal mortality to be able to measure progress towards this goal.
Measuring maternal mortality accurately is difficult. In most of the developing countries where maternal mortality is high, vital statistics which are crucial data sources do not exist. Worldwide, maternal mortality is generally underestimated because of misclassification or underreporting of maternal deaths or both. Different studies use different definitions of maternal death and different methodologies to analyze their data.
In the reviewed studies, maternal mortality was measured by direct counting or by using a special survey. In some studies, when underreporting of maternal mortality was suspected, the authors used the birth and death certificates in addition to patients’ medical records or special survey designs. For example, in one study conducted in Utah (2), United States of America, they identified an additional 21 cases of maternal death by using multiple sources.
The study conducted in Surinam (3) used a reproductive age mortality survey (RAMSO) in 5 hospitals, in which 85 cases of maternal deaths were identified. This was 1.3 times higher than the officially reported 65 cases of maternal deaths.
The populations studied in the reviewed studies were urban, rural or mixed. In the case of developing countries, the more the study is population-based the more it reflects the magnitude of the maternal mortality since most of the women deliver at home. Part of the reviewed studies offered a range of risk factors relevant to maternal death. The following risk factors were included:

• Poor or lack of antenatal care
• Illiteracy among pregnant women
• Teenage pregnancy  
• High parity
• Delay in referral from peripheral units
• Unsafe abortion in many settings due to lack of family planning programmes
• Malaria, HIV, anaemia
• Harmful traditional medical beliefs and practices
• Inadequate facilities to deal with obstetric emergencies
• Deteriorating economies
• Gender violence
• Pregnant women age >40, parity >5
• Civil war

Trends in maternal mortality show a decrease in some regions and a rise in others between years 1990-1995 (4). The possible explanation of the rising maternal mortality in Africa is a group of factors including the deterioration of the health services, poor resources, civil wars etc.
In the reviewed studies 1449 maternal deaths were identified. The direct obstetric causes constitute 56.9% and the indirect 43.1%. Haemorrhage, hypertensive disorders of pregnancy and sepsis are the main causes of maternal deaths. Abortion, malaria and injuries highly contributed to maternal deaths in some studies. In Mozambique (5), 15.5% of maternal deaths were due to malaria.
In Congo, Brazzaville (6), the study conducted in 1996 showed that 40% of maternal deaths were due to abortion complications. The study conducted in Argentina (7) revealed that 22 out of 29 maternal deaths were due to unsafe abortion.
This review of maternal mortality shows trends in the causes of maternal death are changing in the developed and the developing countries.

Conclusion

Many developing countries have no vital registration system, so they depend on special surveys. The policy makers, programme managers, health care providers and community leaders benefit from the estimates of maternal mortality and identification of the causes of maternal death.
There is more than one indicator to measure maternal mortality. Maternal mortality ratios vary from country to country, are high in the developing countries and lower in the developed countries. The causes and risk factors of maternal deaths are many and variable. Community-based surveys are more accurate when estimating maternal mortality in developing countries, since most of the deliveries are conducted at home, and no vital registration system exists.
Maternal mortality is difficult to measure for many reasons. A range of different techniques is used to estimate maternal mortality. Maternal mortality is a major tragedy. Its accurate estimation and assessment of risk factors is crucial and challengeable.

References

1. The sisterhood method for estimating maternal mortality: Guidance for potential users 1997.  WHO/RHT/97.28.  [Free Full Text]
2. Jacob S, Bloebaum L, Shah G, Varner MW. Maternal mortality in Utah. Obstet Gynecol. 1998 Feb;91(2):187-91. [PubMed]
3. Mungra A, van Bokhoven SC, Florie J, van Kanten RW, van Roosmalen J, Kanhai HH. Reproductive age mortality survey to study under-reporting of maternal mortality in Surinam. Eur J Obstet Gynecol Reprod Biol. 1998 Mar;77(1):37-9. [PubMed]
4. Maternal mortality in 1995: Estimates developed by WHO, UNICEF, UNFPA. 2001 WHO/RHR01.9. [Free Full Text]
5. Granja AC, Machungo F, Gomes A, Bergstrom S, Brabin B. Malaria-related maternal mortality in urban Mozambique. Ann Trop Med Parasitol. 1998 Apr;92(3):257-63. [PubMed]
6. Le Coeur S, Pictet G, M'Pele P, Lallemant M. Direct estimation of maternal mortality in Africa. Lancet. 1998 Nov 7;352(9139):1525-6. [PubMed]
7. Rizzi RG, Cordoba RR, Maguna JJ. Maternal mortality due to violence. Int J Gynaecol Obstet. 1998 Dec;63 Suppl 1:S19-24. [PubMed]
8. Schuitemaker N, van Roosmalen J, Dekker G, van Dongen P, van Geijn H, Gravenhorst JB. Increased maternal mortality in The Netherlands from group A streptococcal infections. Eur J Obstet Gynecol Reprod Biol. 1998 Jan;76(1):61-4. [PubMed]
9. Jocums SB, Berg CJ, Entman SS, Mitchell EF Jr. Postdelivery mortality in Tennessee, 1989-1991. Obstet Gynecol. 1998 May;91(5 Pt 1):766-70. [PubMed]
10. MacLeod J, Rhode R. Retrospective follow-up of maternal deaths and their associated risk factors in a rural district of Tanzania. Trop Med Int Health. 1998 Feb;3(2):130-7. [PubMed]
11. Vigil-De Gracia P. Maternal mortality in Panama city (CHMCSS), 1992-1996. Int J Gynaecol Obstet. 1998 Jun;61(3):283-4. [PubMed]
12. Chandra A. Maternal mortality in Fiji. Int J Gynaecol Obstet. 1998 Dec;63(3):289-91. [PubMed]
13. Ronsmans C, Vanneste AM, Chakraborty J, Van Ginneken J. A comparison of three verbal autopsy methods to ascertain levels and causes of maternal deaths in Matlab, Bangladesh. Int J Epidemiol. 1998 Aug;27(4):660-6. [Free Full Text]
14. Aboyeji AP. Trends in maternal mortality in Ilorin, Nigeria 1987-1996. Int J Gynaecol Obstet. 1998 Nov;63(2):183-4. [PubMed]
15. Wall LL. Dead mothers and injured wives: the social context of maternal morbidity and mortality among the Hausa of northern Nigeria. Stud Fam Plann. 1998 Dec;29(4):341-59. [PubMed]
16. Miller FC, Greene JW, Petry JA. Maternal mortality in Kentucky. J Ky Med Assoc. 1998 Apr;96(4):135-9. [PubMed]
17. Smith JB, Fortney JA, Wong E, Amatya R, Coleman NA, de Graft Johnson J. Estimates of the maternal mortality ratio in two districts of the Brong-Ahafo region, Ghana. Bull World Health Organ. 2001;79(5):400-8. [PubMed]

 

Table 1 : Reviewed studies.

 

Table 2 : Levels of Maternal Mortality (Studies with actual counting).

 

Table 3 : Levels of Maternal Mortality (Studies with estimation).

 

Table 4 : Causes of maternal deaths in 12 reviewed studies (n=1449).

 

Table 5 : New regional estimates of maternal mortality ratios (per 100 000 live births).

UN Region	Maternal mortality ratio
	1990	1995
World total	430	400
Africa	870	1000
Asia	390	280
Latin America & Caribbean	190	190
Europe	36	28
Northern America	11	11

Source: WHO/UNICEF/UNFPA 1995 (4)