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close this bookCauses and Consequences of Intrauterine Growth Retardation, Proceedings of an IDECG workshop, November 1996, Baton Rouge, USA, Supplement of the European Journal of Clinical Nutrition (International Dietary Energy Consultative Group - IDECG, 1996, 100 pages)
close this folderLevels and patterns of intrauterine growth retardation in developing countries
View the document(introductory text...)
View the documentIntroduction
View the documentMethodology
View the documentResults
View the documentDiscussion
View the documentReferences
View the documentDiscussion

Discussion

The paper by de Onis et al. is a great achievement in obtaining for the first time global estimates of levels of IUGR in different countries and regions of the world. A problem that could introduce biases is that most of the data that are available from different parts of the world are from babies delivered at clinics, whereas in some regions, for instance in Africa, most babies are born at home, and it is not possible to judge the validity of extrapolations of prevalence and risk data from clinic to home deliveries. There is a need to determine whether data of hospital-born babies in developing countries are indeed representative of the larger proportion born at home.

Like Bakketeig, de Onis draws attention to the fact that while the focus of the workshop is primarily on IUGR infants born at term with a birthweight < 2500 g, there are also IUGR infants born prematurely and infants born with a birthweight ³ 2500 g who nevertheless were not able to attain their full growth potential and are therefore also to be considered IUGR. Figure 2 of the paper by de Onis et al. shows that perinatal mortality rates are highest among babies who are both premature and IUGR. In public health terms it is important to have data on newborns that are associated with the risk of one or more undesirable outcomes at a later stage in life. Birthweight, symmetry at birth, length of gestation, and the different etiologies underlying these parameters are all related to some extent, and at present it is not yet possible to say which of these factors or what combination (degree of IUGR being one of them) would permit to make the best prediction of preventable risk. In practical terms it is easiest to measure birthweight and to assess symmetry at birth using various anthropometric indicators. To get more valid estimates of length of gestation and degree of IUGR, a more frequent and universal use of ultrasonography dating would have to be advocated. Workshop participants agreed that this would not be making good use of scarce resources in developing countries and may even have unintended negative consequences in regions where female fetuses are more likely to be aborted than male ones. It was also emphasized that there is no evidence from randomized controlled trials that early diagnosis and delivery of IUGR babies with routine use of ultrasound has led to significantly improved outcomes in developed countries.

A WHO Expert Committee acknowledged and regretted the discontinuity in classification of growth retardation before and after delivery. The group dealing with fetal growth recommended that future growth curves be developed using the z-score system. It examined all available data sets on fetal growth using different criteria (an important one among these being associated risk data), to select the one of Williams in the US as the one with the fewest shortcomings. Williams' data were collected between 1972 and 1976, and Hoffman expressed the opinion that temporal trends may have rendered them obsolete in the US; nevertheless, WHO's Expert Committee has recommended them for international use as, on the basis of a number of criteria, they represent the best option presently available.

Some people still advocate the development of local growth curves. Several discussants reemphasized the evidence leading them to the conviction that all populations have the same growth potential (see discussion of Bakketeig paper), even though it may take more than one generation to attain it. The group's consensus is that, from a public health perspective (as opposed to case management), an international reference, based on the growth of healthy babies living under optimal conditions, should be used.

Appendix 1. Incidence of LBW and derived estimates of IUGR-LBW by country (1985-1995)

Country

Data source

Year

LBW (% < 2500g)

IUGR-LBW¹ (%)

Afghanistan

Monitoring system

1987

19.0

13.0

Albania

Registration data

1990

6.5

NA

Algeria

Field estimate

1988

9.0

4.4

Angola

Monitoring system

1987

21.4

15.0

Argentina

Registration data

1992

5.9

1.8

Australia

Western Pacific region data bank

1994

6.3

NA

Austria

Registration data

1985

5.8

NA

Bahamas

Monitoring system

1987

8.0

3.6

Bahrain

Registration data

1994

34.0

25.8

Bangladesh

Monitoring system

1987

50.0

39.4

Belarus

Monitoring system

1987

5.1

NA

Belgium

Registration data

1987

6.1

NA

Benin

Field estimate

1988

8.0

3.6

Bolivia

Field estimate

1988

12.0

7.0

Botswana

Field estimate

1988

8.0

3.6

Brazil

Registration data

1989

11.7

6.7

Brunei

Western Pacific region data bank

1994

5.0

1.0

Bulgaria

Monitoring system

1987

6.3

NA

Burkina Faso

Monitoring system

1987

10.8

6.0

Cambodia

Western Pacific region data bank

1994

18.4

12.4

Cameroon

Monitoring system

1987

10.0

5.3

Canada

Monitoring system

1987

5.6

NA

Central African Rep.

Monitoring system

1987

14.5

9.1

Chile

Registration data

1988

7.2

2.9

China

Western Pacific region data bank

1991

6.0

1.9

Colombia

Monitoring system

1987

17.3

11.5

Comoros

Monitoring system

1987

6.8

2.5

Costa Rica

Government report

1989

7.5

3.2

Cote d'Ivoire

Monitoring system

1987

15.0

9.6

Cuba

Registration data

1990

7.6

3.2

Cyprus

Monitoring system

1987

5.0

1.0

Czech Republic

Registration data

1994

5.5

NA

Denmark

Registration data

1991

5.4

NA

Djibouti

Monitoring system

1987

11.0

6.1

Dominica

Monitoring system

1985

10.5

5.7

Dominican Republic

Unknown source

1991

11.0

6.1

Ecuador

Field estimate

1988

11.0

6.1

El Salvador

Community-based data

1993

8.9

4.3

Eritrea

Unknown source

1993

13.0

7.8

Ethiopia

Hospital data

1988-93

8.9

4.3

Fiji

Western Pacific region data bank

1991

18.0

12.1

Finland

Registration data

1985

4.0

NA

Gabon

Monitoring system

1987

7.7

3.3

The Gambia

Unknown source

1989

24.0

17.2

Ghana

Monitoring system

1987

6.0

1.9

Greece

Registration data

1985

6.0

NA

Guatemala

Field estimate

1988

14.0

8.7

Guinea

Field estimate

1988

25.0

18.1

Guinea-Bissau

Hospital data

1987

20.4

14.1

Guyana

Monitoring system

1987

12.0

7.0

Haiti

Monitoring system

1987

15.0

9.6

Honduras

Field estimate

1988

20.0

13.8

Hungary

Government report

1993

9.9

NA

India

Estimate

1991

28.0

20.6

Indonesia

Monitoring system

1987

8.2

3.8

Iran

Government report

1991

8.0

3.6

Iraq

Hospital data

1991

8.0

3.6

Ireland

Registration data

1987

4.4

NA

Israel

Hospital data

1992

6.9

2.6

Jamaica

Monitoring system

1987

12.0

7.0

Japan

Western Pacific region data bank

1994

7.0

NA

Jordan

Monitoring system

1985

10.0

5.3

Lebanon

Monitoring system

1985

10.0

5.3

Lesotho

Monitoring system

1987

10.0

5.3

Libyan A.J.

Monitoring system

1987

5.0

1.0

Lithuania

Registration data

1992

4.4

NA

Luxembourg

Monitoring system

1987

6.2

NA

Madagascar

Estimate

1994

15.0

9.6

Malawi

Monitoring system

1987

10.0

5.3

Malaysia

Western Pacific region data bank

1994

8.3

3.8

Maldives

Government report

1993

20.0

13.8

Malta

Hospital data

1985

4.2

NA

Mauritania

Monitoring system

1985

10.0

5.3

Mauritius

Monitoring system

1987

7.7

3.3

Mexico

Field estimate

1988

12.0

7.0

Mongolia

Community-based data

1992

6.0

1.9

Morocco

Monitoring system

1985

9.0

4.4

Mozambique

Monitoring system

1987

11.3

6.4

Myanmar

Monitoring system

1987

15.9

10.3

Namibia

Hospital data

1990

11.9

6.9

New Zealand

Western Pacific region data bank

1994

5.7

NA

Nicaragua

Hospital data

1987

10.0

5.3

Niger

Monitoring system

1985

20.0

13.8

Nigeria

Field estimate

1988

20.0

13.8

Norway

Monitoring system

1985

4.5

NA

Oman

Hospital data

1992

9.0

4.4

Pakistan

Monitoring system

1987

25.0

18.1

Palau

Western Pacific region data bank

1994

9.6

4.9

Panama

Registration data

1985

9.8

5.1

Papua New Guinea

Western Pacific region data bank

1994

16.0

10.4

Paraguay

Monitoring system

1987

8.0

3.6

Peru

Field estimate

1988

9.0

4.4

Philippines

Western Pacific region data bank

1994

11.0

6.1

Poland

Registration data

1993

8.6

NA

Portugal

Registration data

1985

5.4

NA

Qatar

Monitoring system

1987

5.0

1.0

Rep. of Korea

Western Pacific region data bank

1988

4.3

0.4

Romania

Hospital data

1992

10.1

NA

Russian Federation

Monitoring system

1987

5.1

NA

Rwanda

Unknown source

1985

17.0

11.3

Saint Kitts and Nevis

Monitoring system

1985

9.4

4.8

Saint Lucia

Monitoring system

1985

9.7

5.0

Sao Tome and Principe

Monitoring system

1987

7.0

2.7

Saudi Arabia

Hospital data

1989

8.3

3.8

Senegal

Monitoring system

1985

10.0

5.3

Seychelles

Monitoring system

1987-88

10.1

5.4

Sierra Leone

Monitoring system

1987

13.0

7.8

Singapore

Western Pacific region data bank

1994

7.3

3.0

Slovenia

Government report

1992

6.0

NA

Solomon Islands

Western Pacific region data bank

1994

10.0

5.3

Sri Lanka

Community-based data

1993

18.7

12.7

Sudan

Estimate

1990

12.5

7.4

Suriname

Monitoring system

1987

13.0

7.8

Swaziland

Hospital data

1990

8.0

3.6

Sweden

Registration data

1985

4.2

NA

Switzerland

Registration data

1992-93

5.4

NA

Syrian Arab Republic

Unknown source

1990

11.0

6.1

Tajikistan

Registration data

1992

6.5

2.3

Thailand

Monitoring system

1987

7.7

3.3

Togo

Field estimate

1988

20.0

13.8

Trinidad and Tobago

Monitoring system

1987

13.0

7.8

Tunisia

Unknown source

1989

9.2

4.6

Turkey

Field estimate

1988

7.0

2.7

U. Rep. Tanzania

Community-based data

1992

16.9

11.2

U. Arab Emirates

Hospital data

1992

6.0

1.9

Ukraine

Monitoring system

1987

5.1

NA

United Kingdom

Monitoring system

1985

6.5

NA

United States

Registration data

1992

7.1

NA

Uruguay

Registration data

1992-93

7.6

3.2

Vanuatu

Western Pacific region data bank

1994

7.4

3.1

Venezuela

Monitoring system

1987

9.8

5.1

Viet Nam

Western Pacific region data bank

1994

10.8

6.0

Western Samoa

Western Pacific region data bank

1991

4.0

0.2

Yugoslavia

Monitoring system

1985

6.4

NA

Zaire

Government report

1990-93

25.0

18.1

Zimbabwe

Registration data

1989

5.6

1.5

¹ Derived using regression model Y= - 3.2452+0.852 X [see figure 1].
Data source: WHO Database on Low Birth Weight (update September 1996) (WHO, 1992).
NA = not applicable (developed country)