The effect of infant death on subsequent fertility in Korea and the role of family planning

Short and long interpregnancy intervals: correlates and variations by pregnancy timing among U.S. women

CONTEXT

Short and long interpregnancy intervals are associated with adverse health outcomes. Little is known about the correlates of short and long interpregnancy intervals in the general population, and whether correlates vary by pregnancy intention.

METHODS

Data on 10,236 pregnancies following a live birth were drawn from the 1995, 2002 and 2006-2010 waves of the National Survey of Family Growth. Logistic regression was used to assess characteristics associated with women's reporting short interpregnancy intervals (less than 12 months) and long intervals (greater than 60 months). Analyses were stratified by whether women considered their pregnancies well timed or mistimed.

RESULTS

Thirty-one percent of pregnancies following short intervals and 47% following long intervals were well timed. Among well-timed pregnancies only, the odds of short intervals were elevated if women had been 35 or older, rather than aged 20-29, at last pregnancy (odds ratio, 2.3); if their prior infant had died (10.6); or if they had wanted their prior pregnancy sooner than it had occurred (2.2). Overall, the odds of long intervals were higher among minority groups than among whites (1.4-1.6) and were lower among women who had been 30 or older at prior pregnancy than among those who had been in their 20s (0.1-0.5); they increased with level of family income. Correlates of long intervals generally varied little by intention.

CONCLUSIONS

Although the majority of pregnancies at short intervals are unintended, specific subsets of women have elevated odds of intending short interpregnancy intervals.

Adaptation following perinatal loss: a critical review

Parental adaptation following perinatal loss has received increasing attention in the past 20 years. From early anecdotal accounts to recent more rigorous investigations, it is clear that perinatal loss in the developed world is a significant psychological trauma for parents. Major immediate consequences are likely for virtually all affected families, and long-term sequelae are likely for some. Despite widespread attention to the experience of families who lose a stillborn or newborn infant, including major changes in hospital practices regarding management of these families, many important questions remain unanswered. We know little, for instance, about which parents are at greatest risk for disordered mourning or what additional measures might minimize their psychological morbidity. In fact, because of a tendency to focus exclusively on affective symptomatology following the loss, other important features of the process of mourning have been overlooked or examined unsystematically. Suggestions for specific and general directions for further research are discussed.

Biological influence of infant death on fertility

This study examines the biological influence of infant death on subsequent fertility in three Asian countries--Indonesia, Nepal and Sri Lanka, comparing the birth interval between two consecutive births up to the sixth birth by survival status of the preceding infant among breast-feeding women not using contraception. There is consistent evidence of biological influence in each of the three countries. Infant death shortens birth intervals by up to 30%, though its influence varies between the countries.

The place of child-spacing as a factor in infant mortality: a recursive model

This study investigates the role of a preceding birth interval in infant mortality by considering a causal ordering of seven variables. Data are from the 1974 World Fertility Survey for Korea and cover the survival of 6,161 index children. A two-stage logit model was used. The analysis suggests that infant mortality is directly influenced by the preceding birth interval which, in turn, is influenced by five other explanatory variables: maternal age, birth order, immediately preceding infant's death, education of mother, and place of residence. Maternal age and prior infant death also exert direct effects on mortality. In terms of relative risk, prior infant death has the strongest effect of all the explanatory variables. A longer birth interval increases the odds of an infant's survival by 25 per cent, whereas the death of a preceding child decreases the odds by 45 per cent. However, infant deaths in Korea occur infrequently in comparison with short birth intervals. Thus, the two factors present comparable attributable risks in unadjusted measurements. The first-stage causal structure affecting a birth interval is more complicated than the second-stage structure affecting infant mortality.

The physiological effect of infant mortality in reproductive behavior in the Sudan

The present study examines the physiological effect of infant mortality on reproductive behavior for the Sudan using retrospective pregnancy history data for ever-married women, 15-49. The investigation has revealed that the death of an infant reduces the subsequent birth interval significantly, by about 6 months. This difference in the length of birth interval appears to be primarily a result of the interruption of lactation. When the birth intervals are examined by the fate of the two preceding children, the analysis shows insufficient evidence to indicate that infant mortality affects the length of birth intervals independently of the physiological effect.

Tay-Sachs disease and the role of reproductive compensation in the maintenance of ethnic variations in the incidence of autosomal recessive disease

Several deleterious and lethal autosomal recessive genes appear to exist in equilibrium with their normal alleles at a variety of stable, or near stable frequencies of considerable antiquity. One person in 25 is, for instance, a carrier of the Tay-Sachs gene among Ashkenazi Jews, compared with 1 in 300 among Sephardic and Oriental Jews and non-Jews. The explanations offered for this phenomenon have generally not been entirely satisfactory. It has been shown that parents replace fortuitous infant and childhood deaths with, on average, approximately two surviving sibs each. When mutation rates are low, this practice, which has also been shown to occur among other animals, can maintain considerable variations in the stable incidence of autosomal recessive disease, should such ethnic polymorphism arise through genetic drift, the founder effect or hitch-hiking. High mutation rates would appear to preclude ethnic variations in the stable incidence of genetic disease.

Preference for Sons, Family Size, and Sex Ratio: An Empirical Study in Korea

This study investigates the effects of son preference on sex ratio and fertility at the family level, utilizing World Fertility Survey data for Korea, whose population is known to have a strong preference for sons and a fairly high level of contraceptive use. The sex ratio (number of males per 100 females) of siblings in small families is considerably higher than in large families. The sex ratio of last-born children in families of any size is markedly higher than that of the previous children. The sex distribution of children for a given family size, if less than five, deviates significantly from the Bernoulli sequence. The observed frequency of all-girl families is especially small in comparison with the expected value. The sex of the last child strongly influences couples’ decision making regarding additional births in all steps of family building except for bearing a second child. In increasing their families to moderate size, parents appear to take into consideration the sex distribution of all earlier births.

Preference for sons, family size, and sex ratio: an empirical study in Korea

This study investigates the effects of son preference on sex ratio and fertility at the family level, utilizing World Fertility Survey data for Korea, whose population is known to have a strong preference for sons and a fairly high level of contraceptive use. The sex ratio (number of males per 100 females) of siblings in small families is considerably higher than in large families. The sex ratio of last-born children in families of any size is markedly higher than that of the previous children. The sex distribution of children for a given family size, if less than five, deviates significantly from the Bernoulli sequence. The observed frequency of all-girl families is especially small in comparison with the expected value. The sex of the last child strongly influences couples' decision making regarding additional births in all steps of family building except for bearing a second child. In increasing their families to moderate size, parents appear to take into consideration the sex distribution of all earlier births.

Abortion and contraception in the Korean fertility transition

Abstract In this paper the relationship between the use of abortion and contraception among married women in a society experiencing uronid decline in fertility is analysed using data from the Korean National Fertility Survey of 1974. The level and pattern of abortion before and after modern contraceptives became widely available are described, and the implications of the changing patterns of abortion and contraception are discussed.