MEDIATION MODELS OF PREGNANCY DESIRES AND UNPLANNED PREGNANCY IN YOUNG, UNMARRIED WOMEN.

This paper examines the proposition that sexual and contraceptive behaviours mediate the relationship between the pregnancy desires of young, unmarried women and their having an unplanned pregnancy. The sample consisted of 854 18- to 19-year-old women living in Michigan, USA. First, the positive and negative pregnancy desires of these women were measured, as were the women's perceptions of the positive and negative desires of their sexual partners. Then the extent to which these four types of desires, as well as several types of interactions between them, prospectively predicted the occurrence of subsequent pregnancies were tested with logistic regression analyses, initially alone and then after the addition of several types of sexual and contraceptive mediator variables. The results demonstrated that four of the ten significant motivational predictors became non-significant following the introduction of the contraceptive mediator variables and that the predictive strength of the other six significant motivational predictors was substantially reduced by their introduction. A number of factors that may account for only a partial mediational effect in some models are discussed.

Do perceptions of their partners' childbearing desires affect young women's pregnancy risk? Further study of ambivalence.

We explore whether young women's perceptions of their sexual partners' childbearing desires contribute to their risk of pregnancy. We used weekly journal data collected from 787 young women to measure their childbearing desires and their perceptions of their partners' childbearing desires. We then conducted hazard modelling to predict pregnancy risk with variables based on interactions between the women's desires and their perceived partners' desires. Models that include perceived partners' desires perform better than one based on women's desires alone. The best model contains three significant predictors: one confirms the importance of pronatal, ambivalent, and indifferent desires for pregnancy risk; one indicates that the perceived partners' antinatal desires reduce women's pregnancy risk; and one suggests that women who both perceive their partners accurately and are in agreement with them have a lower pregnancy risk. The results indicate that perceived partner data can improve prediction and enhance our understanding of pregnancy risk.

The NLSY Kinship Links: Using the NLSY79 and NLSY-Children Data to Conduct Genetically-Informed and Family-Oriented Research.

The National Longitudinal Survey of Youth datasets (NLSY79; NLSY-Children/Young Adults; NLSY97) have extensive family pedigree information contained within them. These data sources are based on probability sampling, a longitudinal design, and a cross-generational and within-family data structure, with hundreds of phenotypes relevant to behavior genetic (BG) researchers, as well as to other developmental and family researchers. These datasets provide a unique and powerful source of information for BG researchers. But much of the information required for biometrical modeling has been hidden, and has required substantial programming effort to uncover-until recently. Our research team has spent over 20 years developing kinship links to genetically inform biometrical modeling. In the most recent release of kinship links from two of the NLSY datasets, the direct kinship indicators included in the 2006 surveys allowed successful and unambiguous linking of over 94 % of the potential pairs. In this paper, we provide details for research teams interested in using the NLSY data portfolio to conduct BG (and other family-oriented) research.

The effects of ambivalent fertility desires on pregnancy risk in young women in the USA.

Many different definitions of the construct of motivational ambivalence have appeared in the literature on reproductive health. Using a theoretical framework in which motivational ambivalence is defined as an interaction between positive and negative pregnancy desires, we propose two hypotheses. The first is that positive and negative pregnancy desires independently predict the risk of an unplanned pregnancy. The second is that ambivalence and three related constructs that are also based on the interaction between positive and negative desires are each important predictors of pregnancy risk. We use weekly journal data collected from a US sample of 1,003 women aged 18-19 years and conduct hazard model analysis to test our hypotheses. Using both dummy and continuous predictors, we report results that confirm both hypotheses. The proposed interaction framework has demonstrated validity, compares favourably with previously reported alternative approaches, and incorporates a set of constructs that have potential importance for further research directed at the prevention of unplanned pregnancy.

The influence of depression on sexual risk reduction and STD infection in a controlled, randomized intervention trial.

BACKGROUND: A randomized controlled trial of SAFE, a cognitive/behavioral intervention, revealed that it significantly reduces reinfection and behavioral risks among participants compared with controls. However, studies suggest that depression may moderate intervention efficacy among affected persons because of impaired information processing, failure to recognize risk, or inability to change behavior. GOAL: We evaluated SAFE efficacy among depressed and nondepressed Mexican- and African American women after comparing initial risk factors by depression status. We further explored intervention effects in moderately and severely depressed women. STUDY DESIGN: We stratified 477 participants (249 intervention, 228 controls) according to their depression status at baseline determined by CES-D scores. Using chi and multivariate logistic regression, we evaluated differences in reinfection and behavioral risk at 6-month, 12-month, and 1-year cumulative follow-ups between groups within baseline depression strata. RESULTS: : At baseline, 74.4% of women were depressed and had significantly greater levels of behavioral risks than nondepressed women. At follow-up intervals, behavioral risks and reinfection rates were lower among intervention women compared with controls regardless of depression status. For example, at 1-year follow-up reinfection rates were 15.2% in nondepressed intervention women versus 21.4% in nondepressed controls (AOR = 0.6), and 18.6% in depressed intervention women versus 27.3% in depressed controls (AOR = 0.6). Moreover, reinfection was consistently lower among moderately and severely depressed intervention women than controls (moderately depressed: 19.3% vs. 27.2%, AOR = 0.6; severely depressed: 17.9% vs. 27.5%, AOR = 0.6). CONCLUSIONS: Despite significantly greater behavioral risk among depressed women at baseline, SAFE was equally successful in reducing reinfection and high-risk behavior among depressed and nondepressed participants.

The cross-generational mother-daughter-aunt-niece design: establishing validity of the MDAN design with NLSY fertility variables.

Using National Longitudinal Survey of Youth (NLSY) fertility variables, we introduce and illustrate a new genetically-informative design. First, we develop a kinship linking algorithm, using the NLSY79 and the NLSY-Children data to link mothers to daughters and aunts to nieces. Then we construct mother-daughter correlations to compare to aunt-niece correlations, an MDAN design, within the context of the quantitative genetic model. The results of our empirical illustration, which uses DF Analysis and generalized estimation equations (GEE) to estimate biometrical parameters from NLSY79 sister-sister pairs and their children in the NLSY-Children dataset, provide both face validity and concurrent validity in support of the efficacy of the design. We describe extensions of the MDAN design. Compared to the typical within-generational design used in most behavior genetic research, the cross-generational feature of this design has certain advantages and interesting features. In particular, we note that the equal environment assumption of the traditional biometrical model shifts in the context of a cross-generational design. These shifts raise questions and provide motivation for future research using the MDAN and other cross-generational designs.

Fertility motivations of youth predict later fertility outcomes: a prospective analysis of national longitudinal survey of youth data.

We examine how the motivational sequence that leads to childbearing predicts fertility outcomes across reproductive careers. Using a motivational traits-desires-intentions theoretical framework, we test a structural equation model using prospective male and female data from the National Longitudinal Survey of Youth. Specifically, we take motivational data collected during the 1979-1982 period, when the youths were in their teens and early twenties, to predict the timing of the next child born after 1982 and the total number of children born by 2002. Separate models were estimated for males and females but ivith equality constraints imposed unless relaxing these constraints improved the overall model fit. The results indicate substantial explanatory power of fertility motivations for both short-term and long-term fertility outcomes. They also reveal the effects of both gender role attitude and educational intentions on these outcomes. Although some gender differences in model pathways occurred, the primary hypothesized pathways were essentially the same across the genders. Two validity substudies support the soundness of the results. A third sub-study comparing the male and female models across the sample split on the basis of previous childbearing revealed a number of pattern differences within the four gender-by-previous childbearing groups. Several of the more robust of these pattern differences offer interesting insights and support the validity and usefulness of our theoretical framework.

Biodemographic modeling of the links between fertility motivation and fertility outcomes in the NLSY79.

In spite of long-held beliefs that traits related to reproductive success tend to become fixed by evolution with little or no genetic variation, there is now considerable evidence that the natural variation of fertility within populations is genetically influenced and that a portion of that influence is related to the motivational precursors to fertility. We conduct a two-stage analysis to examine these inferences in a time-ordered multivariate context. First, using data from the National Longitudinal Survey of Youth, 1979, and LISREL analysis, we develop a structural equation model in which five hypothesized motivational precursors to fertility, measured in 1979-1982, predict both a child-timing and a child-number outcome, measured in 2002. Second, having chosen two time-ordered sequences of six variables from the SEM to represent our phenotypic models, we use Mx to conduct both univariate and multivariate behavioral genetic analyses with the selected variables. Our results indicate that one or more genes acting within a gene network have additive effects that operate through child-number desires to affect both the timing of the next child born and the final number of children born, that one or more genes acting through a separate network may have additive effects operating through gender role attitudes to produce downstream effects on the two fertility outcomes, and that no genetic variance is associated with either child-timing intentions or educational intentions.

The measurement of childbearing motivation in couples considering the use of assisted reproductive technology.

Relatively little is known about the motivational antecedents to the use of assisted reproductive technology (ART). In this paper we measure the fertility motivations of infertile couples who are considering the use of ART, using an established instrument, the Childbearing Questionnaire (CBQ). Our sample consists of 214 men and 216 women who were interviewed at home after an initial screening for ART but before making a final decision. We conducted two sets of analyses with the obtained data. In one set, we compared the scores on scales and subscales of the CBQ for the males and females in our sample with the scores for males and females from a comparable normative sample. For these analyses we first examined sample and gender differences with a four-group analysis of variance. We then conducted a series of linear models that included background characteristics as covariates and interactions between sample, gender, and age and between those three variables and the background characteristics. The results showed the expected higher positive and lower negative motivations in the ART sample and a significant effect on positive motivations of the interaction between sample and age. In the second set of analyses, we developed several new subscales relevant to facets of the desire for a child that appear to be important in ART decision-making. These facets include the desire to be genetically related to the child and the desire to experience pregnancy and childbirth. A third facet, the desire for parenthood, is already well covered by the existing subscales. The results showed the new subscales to have satisfactory reliability and validity. The results also showed that the original and new subscales predicted the three facets of the desire for a child in a multivariate context. We conclude with a general discussion of the way our findings relate both to ART decision-making and to further research on the motivations that drive it.

Multivariate Cholesky models of human female fertility patterns in the NLSY.

Substantial evidence now exists that variables measuring or correlated with human fertility outcomes have a heritable component. In this study, we define a series of age-sequenced fertility variables, and fit multivariate models to account for underlying shared genetic and environmental sources of variance. We make predictions based on a theory developed by Udry [(1996) Biosocial models of low-fertility societies. In: Casterline, JB, Lee RD, Foote KA (eds) Fertility in the United States: new patterns, new theories. The Population Council, New York] suggesting that biological/genetic motivations can be more easily realized and measured in settings in which fertility choices are available. Udry's theory, along with principles from molecular genetics and certain tenets of life history theory, allow us to make specific predictions about biometrical patterns across age. Consistent with predictions, our results suggest that there are different sources of genetic influence on fertility variance at early compared to later ages, but that there is only one source of shared environmental influence that occurs at early ages. These patterns are suggestive of the types of gene-gene and gene-environment interactions for which we must account to better understand individual differences in fertility outcomes.

Bio-social determinants of fertility.

This paper reviews several studies that investigated the potential role of genetic factors in determining fertility outcomes. Our review demonstrates convincingly that fertility contains genetic variance; that is, differences between humans in their genetic make-up affects their fertility outcomes and fertility-related behaviours. This finding is robust using both heritabilities and coefficients of genetic variation, and using both direct measures of fertility outcomes and also fertility precursors like fecundity, marriage, fertility expectations and attempts to get pregnant (proception). Moreover, genetic variance can change over short periods of time or across educational levels, specifically for females, and the relevance of genetic variance seems to increase during times of increasing reproductive choice.

Measuring the childbearing motivation of couples referred to the Shiraz Health Center for premarital examinations.

Millions of children who were born during the first decade after the Islamic revolution in Iran are now reaching the age of marriage and childbearing. Short spacing between marriage and the birth of the first child has the potential to cause an excessive and costly increase in the growth of population in Iran. Research into the motivations for the birth of first child among newly married couples can create a knowledge base that will enable health centres to help these couples make better decisions about the timing of their first pregnancy. Using a consecutive sampling technique and administering Miller's Childbearing Questionnaire, data were gathered regarding the childbearing motivations and desires of 300 couples who had been referred to the Shiraz Health Center for premarital counselling. The Childbearing Questionnaire, with some minor modifications, was found to be a valid and reliable instrument for measuring the childbearing motivations of newly married couples of Shiraz County, Fars Province, Iran. The utility of these findings for counselling in health centres is discussed. Based on the results, a longitudinal study is being designed that will allow the development of models for predicting the time of first pregnancy after marriage.

A framework for modelling fertility motivation in couples.

We present a theoretical framework that organizes individual-level fertility motivations into a couple-level model. One feature of this framework is the Traits-Desires-Intentions-Behaviour (TDIB) sequence through which the fertility motivations of individuals produce instrumental behaviours that are designed to promote or prevent childbearing. A second feature of this framework is the cognitive capacity of individuals to perceive a partner's motivational structure. We combine these two features into a dyad-level model that addresses interactions between partners at each step of the motivational sequence. We elaborate this model first with respect to the perception of partner's motivational structure and second with respect to the combination of partner's and own motivational structure. In the process we consider how couple-level processes of communication, influence, and disagreement can be measured and studied through these interactions. We conclude with a summary discussion of the framework and a consideration of the implications it has for a theory of reproductive psychology, population surveys, and family planning services.

The effect of the nurturant bonding system on child security of attachment and dependency.

This paper uses a biopsychosocial theory of human bonding to explore the intergenerational transmission of bonding traits. More specifically, it examines how the nurturant bonding system of the mother affects the succorant bonding system of the young child. In the first section of the paper, we take the bonding framework proposed by Miller and Rodgers (2001) and elaborate its implications for mother-child dyads. Next, we describe the collection of data from 78 mothers prior to their pregnancy with an index child and again when that child is between the ages of two and four and a half. These data allow the creation of a number of mother and child variables that are derived from the bonding framework. Using these variables, we construct a temporally organized, structural equation model of maternal effects on the child, with the two main outcome variables being child security of attachment and child dependency. We then test the model using LISREL. Although the results are tentative and require further confirmatory research, they lend support to three broad hypotheses derived from the bonding framework. In particular, the results support the construct of a motivational substrate that affects both maternal childbearing and her child-rearing behaviors. They also indicate the importance of child temperament in the formation of the succorant bond. Finally, they demonstrate that the preconception nurturant characteristics of the mother have multiple effects on the two main outcome variables, child security of attachment and dependency. Two submodels based on predictors of these two outcomes reveal a number of pathways along which these effects take place. We conclude with a brief discussion of the lessons learned that might strengthen future studies of mother-child bonding and, more generally, the intergenerational transmission of bonding traits.