Crude Birth Rate (CBR)
Definition: number of live births per 100 people per year
Strength: Quick and easy way of measuring and comparing fertility between different countries. Data required is usually readily available.
Limitation: Does not take into account sex composition and age structure of the population
Age-Specific Fertility Rate (ASFR)
Definition: annual number of live births per 1,000 women in particular age groups (usually in 5-year bands: 15-19, 20-24, 25-30, etc.)
Strength: More precise as it takes into consideration the age of the mothers at the point of childbirth, enabling comparisons between the different age groups, with and between countries. This is important for the government to refine its pro-natal policies.
Limitations: Data provided by countries may not be accurate due to large amount of resources needed to track and record births in the country, especially in rural areas in LDCs. Secondly, while the data from ASFR has quantitative value as a policy tool, it does not have explanatory value.
Total Fertility Rate (TFR) - Best
Definition: average number of children a woman is likely to have if she lives to the end of her child-bearing age conforming to the age-specific fertility rates of a given year.
Strength: Takes into account both the age and sex composition of a country, thus allowing demographers to have a more accurate understanding of the fertility situation
Limitations: Data provided by countries may not be accurate due to large amount of resources needed to track and record births in the country, especially in rural areas in LDCs. Secondly, the TFR does not measure the actual number of births per women. It is simply a projection.
VARAIABLES AFFECTING FETILITY
Age and years of marriage
- The longer past puberty a woman waits to have intercourse, the fewer children she will probably have because of the shorter time she will be at risk of bearing children.
- LDCs – lower marrying age, DCs- higher marrying age
- LDCs like Niger has a tradition of marrying their daughters off at an early age. For example, among Fulani herders, marriages are arranged for babies who are still in the womb (strengthen ties, out-of wedlock pregnancy shameful). Even though the legal age of marriage in Niger is 15,girls are often married by 12 and have had children by 16. Contribute to Niger very high TFR of 7.68
- DCs like Singapore; average age of bride is 27. With out-of wedlock children still seen as taboo in Singapore, this has led to a low TFR of 1.10 (2011)
Patterns of sexual activity
- Impacted by several factors like divorce separation, work stress and physical separation of families
- Couples who do not observe postpartum amenorrhea tend to have their next child very quickly.
- LDCs – In Lesotho, mothers are separated from their husbands for as long as they breastfeed. Hence, there would be less chance of having a baby the next time the couple has intercourse.
Length of breastfeeding
- Breastfeeding decreases a woman’s fertility as it suppresses ovulation
- Women who do not breastfeed undergo only 2 months of infertility after giving birth while women who breastfeed undergo 10-18 months of infertility
- Although breastfeeding is a natural contraceptive, the percentage of women who breastfeed has declined with modernization. It is looked upon as a peasant activity. Modern women prefer to bottle-feed as it allows them the freedom to work and have someone else care for their child.
- However, in recent years, there has been an upward trend of women in DCs engaging in breastfeeding. This is due to the increased knowledge of the benefits of breastfeeding to a child like better immune system and the mother who breastfeeds has a 24% reduced chance of having breast cancer. For example, in US, 84% of women with a university degree breastfeed their babies while only 64% of...