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Biomedical subjects

J R Udry

Publications and source records attributed to J R Udry.

At least 55 records · Page 3Linked to original sources
PubMed1982

A cross-cultural examination of the relationship between ages at menarche, marriage, and first birth.

Recent work with samples of black and white urban American women showed a clear behavioral sequence relating age at menarche to age at first intercourse to age at first birth. This paper shows that the linking of ages at menarche, intercourse, marriage, and first birth is a pattern which occurs in very diverse cultures. We present confirmatory data from the United States, Belgium, and Pakistan, and from Malay and Chinese women in Malaysia. We interpret our findings as indicating a biological process leading to (a) social interpretations of readiness for reproduction, and (b) persisting biological differences between early and late maturing women.

Adolescent↗
PubMed1980

Changes in the frequency of marital intercourse from panel data.

Three waves of panel data from a sample of urban U.S. couples in which the wife was under 30 years of age at the first interview show that frequency of intercourse declined about 25% in a 4-year period. Declines were greatest among those with the shortest length of marriage.

Adult↗
PubMed1980

Parity-specific and two-sex utility models of reproductive intentions.

This paper uses married couples' anticipated consequences of having a (another) child to predict their reproductive intentions. Parity-specific models identify different variables as predictors of reproductive behavior at different parities but do not yield interpretable patterns of difference by parity. Parity-specific models are not significantly stronger predictors of reproductive behavior. Generally, wife-only models are distinctly superior to husband-only models. Two-sex models are usually better predictors than one-sex models but not enough better to justify the additional cost.

Family Planning Services↗
PubMed1977

A study of the relationship between coitus and the luteinizing hormone surge.

Twenty-seven wives participating in a study of sexual activity patterns had identifiable shifts in basal body temperature and midcycle surges of serum luteinizing hormone (LH). When sexual activity data were examined using the LH surge as a centering point, it was observed that the day before the LH surge had only an average probability of coitus and organism. These findings suggest that neither coitus nor orgasm often triggers ovulation in humans. This cannot be taken as evidence that coitus-induced ovulation never occurs.

Adult↗
PubMed1977

The distribution of events in the human menstrual cycle.

Daily reports of 85 married couples concerning their sexual behaviour for about 3 menstrual cycles per couple were organized according to menstrual events by using six techniques of aggregation. While there were some similarities among the different displays, including an apparent peak about 6 days before mid-cycle, different methods of aggregation produce widely different frequency curves. It is concluded that there is no single method of display of events of the menstrual cycle which will fit all investigations.

Coitus↗
PubMed1976

The effect of subsidized family planning services on reproductive behavior in the United States, 1969-1974.

This paper evaluates the impact of federally subsidized family planning programs in the United States, from 1969 to 1974, on the reproductive behavior of ever-married women, 15-44 years old. The study began with an experimental design and the random assigment of areas to treatment and control but was completed as a multivariate analysis, treating program input as an interval-scaled independent variable. Using "before" and "after" area sample surveys and patient service data from operating programs, the demographic impact of the program was estimated. The impact detected was nonsignificant; according to our analysis, overall use of physician-administered contraception was not affected by the subsidized programs. The only program-induced change of activity related to reproduction that we recorded was increased use of subsidized services in study areas with high program input and increased use of private physician services where program input was low. These findings need to be interpreted with the caution usually exercised in evaluating imperfect field experiments.

Adolescent↗