Title: Family-size control.

POPLINE Document Number: 266701

Author(s):

Bongaarts J
Potter RG

Source citation:

In: Bongaarts J, Potter RG. Fertility, biology, and behavior: an analysis of the proximate determinants. New York, New York, Academic Press, 1983. :151-179. (Studies in population)

Abstract:

Family size control has 2 main aspects: attaining the number of children desired and holding family size to that level. Subfertility constitutes a failure to achieve the first objective. When youthful marriage combines with modest family size aspirations to assure that the mother potentially completes her childbearing before age 30, the proportion subfertile remains well below 10%. Under these conditions, whether or not the couple deliberately space their desired births, and thereby prolong intervals between consecutive children by 1 or 2 years, has little influence on the fraction subfertile. Only when marriage age approaches 30, and 2 or 3 children are wanted rather than 1, do spacing goals appreciably differentiate the incidence of subfertility. The incidence of subfertility associated with seeking a specified number of boys (or a predesignated number of girls) is nontrivially higher than the subfertility associated with the goal of having twice that number of children but without regard to sex composition. This inequality arises from the large chance variations in the number of sons and daughters required to reach a given number of children of the same sex. The combination of youthful marriage and modest family size goal, which reduces the risk of subfertility thanks to a relatively early completion of desired childbearing, at the same time increases the length of the "risk period" from attainment of desired family size to onset of fertility, and consequently contributes to excess fertility. In a series of REPMOD runs simulating modern conditions, risk period length is explored in relation to marriage age, number of children wanted, spacing goals, and effectiveness of contraception employed for spacing purposes. Respecting excess fertility, 3 standards of family limitation were investigated by means of REPMOD in an American context. These stanards involve averages of .20, .38, and .50 excess births per couple whose first marriage remained intact until past menopause. The most demanding standard of .20 corresponds to what was claimed by married respondents in the middle 1970s. The medium standard of .38 constituted the counterpart for the early 1970s. The more lax standard of .50 excess births/couple represents an upward adjustment of the latter in order to encompass the estimated incidence of induced abortion and associated unreported accidental pregnancies. 3 further issues were addressed, 2 of them applicable to the American setting. First, assuming that induced abortion is eschewed, highly efficient contraception can be counted on to lower the fraction of family limiters who suffer an unwanted birth, but unfortunately that same highly efficient contraception also raises the likelihood of an inconveniently long interval to any first unwanted birth that does occur. Secondly, when a marriage is precipitated by a premarital conception allowed to go to term, the risk period is augmented, with a correspondingly higher expectation of excess fertility. The Bangladesh context is invoked in order to demonstrate a final point. Prolonged, as opposed to brief postpartum anovulation, significantly reduces fertility when contraception is absent or least efficient.

Keywords:

Family Size, Ideal
Fertility Determinants
Computer Programs and Programming
United States
Bangladesh
Research Report
Marriage
Infertility
Mothers
Birth Spacing
Birth Intervals
Sex Factors
Probability
Age Factors
Menopause
Abortion
Puerperium
Anovulation
Childbirth
Sex Preference
Contraception Failure
Correlation Studies
Use-Effectiveness
Family Size
Family Characteristics
Family and Household
Fertility
Population Dynamics
Demographic Factors
Population
Information Processing
Information
North America
Americas
Developed Countries
Asia, Southern
Asia
Developing Countries
Nuptiality
Reproduction
Parents
Family Relationships
Family Planning
Fertility Measurements
Population Characteristics
Statistical Studies
Studies
Research Methodology
Fertility Control, Postconception
Ovarian Effects
Ovary
Genitalia, Female
Genitalia
Urogenital System
Physiology
Biology
Pregnancy Outcomes
Pregnancy
Value Orientation
Psychological Factors
Behavior
Contraceptive Usage
Contraception
Contraceptive Effectiveness