Socioeconomic status, infant feeding practices and early childhood obesity.

BACKGROUND: Children from low socioeconomic households are at greater risk of obesity. As breastfeeding can protect against child obesity, disadvantaged infants are less likely to breastfeed relative to more advantaged children. Whether infant feeding patterns, as well as other maternal characteristics mediate the association between social class and obesity has not been established in available research. OBJECTIVES: Examine the impact of infant feeding practices on child obesity and identify the mechanisms that link socioeconomic status (SES) with child obesity. METHODS: Based on a nationally representative longitudinal survey (ECLS-B) of early childhood (n = 8030), we examine how breastfeeding practices, the early introduction of solid foods and putting an infant to bed with a bottle mediate the relationship between social class and early childhood obesity relative to the mediating influence of other maternal characteristics (BMI, age at birth, smoking, depression and daycare use). RESULTS: Infants predominantly fed formula for the first 6 months were about 2.5 times more likely to be obese at 24 months of age relative to infants predominantly fed breast milk. The early introduction of solid foods (< 4 months) and putting the child to bed with a bottle also increased the likelihood of obesity. Unhealthy infant feeding practices were the primary mechanism mediating the relationship between SES and early childhood obesity. Results are consistent across measures of child obesity although the effect size of infant feeding practices varies. CONCLUSIONS: The encouragement and support of breastfeeding and other healthy feeding practices are especially important for low socioeconomic children who are at increased risk of early childhood obesity. Targeting socioeconomically disadvantaged mothers for breastfeeding support and for infant-led feeding strategies may reduce the negative association between SES and child obesity. The implications are discussed in terms of policy and practice.

The decision to breastfeed in the United States: does race matter?

OBJECTIVES: To estimate the effects of maternal and birth characteristics on the decision to breastfeed and to relate breastfeeding practices to racial differences in infant mortality. METHODS: Using a sample of women with young children from the National Survey of Family Growth (NSFG), Cycle V, 1995, the likelihood of breastfeeding was modeled using logistic regression techniques. In addition, single, live births from the NSFG 1988 and 1995 surveys were analyzed to model the effects of race and breastfeeding on infant mortality using Cox regression methods. RESULTS: After controlling for socioeconomic background and birth characteristics, race remained a strong predictor of breastfeeding. Black women were less likely to breastfeed than nonblack women were, and the primary reason indicated by black women for not breastfeeding was that they "preferred to bottle-feed." Analyses of infant mortality indicated that breastfeeding accounts for the race difference in infant mortality in the United States at least as well as low birth weight does. CONCLUSIONS: Race is an important predictor of breastfeeding, with most black women reporting that they "preferred bottle-feeding." Efforts to increase breastfeeding of infants in the black community should help narrow the racial gap in infant mortality.

Infant feeding practices and child health in Bolivia.

The effects of breast-feeding and supplementation practices on recent diarrhoea occurrence and stunted growth are modelled using logistic regression techniques. Data from the Demographic and Health Survey of Bolivia, 1989, show that, among children aged 3-36 months at the date of interview, the benefits of breast-feeding to child health were most pronounced among children living in rural poverty. Reduced breast-feeding among these children increased the likelihood of diarrhoea and stunted growth. In addition, the introduction of solid foods to currently lactating infants negatively influenced child health.

PIP: This study assesses, in two models, the effects of infant feeding practices on stunted growth and diarrhea incidence among breast fed children aged 3-36 months in Bolivia. Data were obtained from the 1989 Demographic and Health Survey, which included 1143 breast-fed children. About 38% of the children were stunted. Stunting increased with age and parity. In the bivariate analysis, breast feeding increased stunting, and maternal characteristics were related. Stunting increased with maternal age and indigenous ethnicity. Stunting was associated with blue collar and agricultural households and households in the rural Altiplano and Valles regions. About 33% of the children had experienced an episode of diarrhea. Bivariate analysis revealed that only maternal education and having waste removal were related to the occurrence of diarrhea. Logistic models show that the positive effects of breast feeding were more prominent in impoverished environments. Cessation of breast feeding among infants 6 months or less and living in households with extreme rural poverty increased the risk of stunting fourfold. Children with birth intervals of 2-3 years were at 1.5 times lower risk. Children in rural areas were less likely to be stunted than children in urban areas, when socioeconomic status was controlled. Children who had diarrhea were 40% more likely to be stunted. Diarrhea decreased with maternal education. Diarrhea increased with the number of household members. Food supplementation introduced at about 6-9 months, when most infants are fed solids, increased the risk of stunting by about 75%. Introduction earlier or later had no significant impact on child growth. Only 30% of infants received solids before the age of 4 months. Personal living conditions or socioeconomic status were key explanatory factors in stunting and diarrhea.

How relationships of U.S. men affect contraceptive use and efforts to prevent sexually transmitted diseases.

CONTEXT: Comparatively little is known about how U.S. adult men's attitudes and characteristics influence their decision to use contraceptives to prevent pregnancy and to take actions to protect themselves from infection with sexually transmitted diseases (STDs). METHODS: Attitudinal and background data on 1,595 men from the 1991 and 1993 waves of the National Survey of Men (NSM) were used, through logistic regression techniques, to predict the likelihood of current contraceptive use to prevent pregnancy and recent efforts to avoid STD infection among men in three types of sexual relationship--marriage, cohabitation and dating. RESULTS: At the 1993 interview, 58% of men were using contraceptives to prevent pregnancy and 22% had recently taken actions to protect themselves from STDs. Men's concern about how easy a method was to use reduced the likelihood of STD protection, but had no influence on contraceptive use to prevent pregnancy; however, concerns about a method's risks to the female partner increased the likelihood of both outcomes. Couples in which the man expected his partner to take primary responsibility for contraception were 40% as likely to be protecting themselves against STDs as were couples in which the man believed he shared or had greater responsibility. Married men were the least likely to be protecting themselves against STDs, whereas men who were dating were the most likely to do so. CONCLUSIONS: Men's attitudes and characteristics were important predictors of contraceptive use to prevent pregnancy and of efforts to protect against STDs, even after controls for the female partner's characteristics were entered in the analysis. The findings emphasize the need to include men in interventions aimed at reducing unintended pregnancy and STD transmission.

Education as policy: the impact of education on marriage, contraception, and fertility in Colombia, Peru, and Bolivia.

Using data from the World Fertility and Demographic and Health Surveys of Colombia, Peru, and Bolivia, we model the effects of education on three demographic outcomes: the timing of first sexual union, contraceptive use, and fertility. These effects are examined over time and across geographic areas using a multivariate framework. We find substantial improvements in female educational attainment over the last fifty years and a strong relationship between education and the demographic outcomes. Each successive increment in education is associated with declines in the marriage rate, increased contraceptive use, and lower fertility. Education accounts for some of the changes over time in the demographic outcomes, but the pattern varies by outcome, time period, and geographic area. In support of the social diffusion hypothesis, our results indicate that educational differences in reproductive behavior are reduced as the level of development increases and societies pass through their demographic transition.

PIP: This study examined the effects of educational attainment on the timing of first union, contraceptive use, and fertility in Bolivia, Peru, and Colombia over the past 50 years. Data were obtained from World Fertility Surveys and Demographic and Health Surveys for Colombia (1976, 1986, and 1990); Peru (1977-78, 1986, and 1991-92); and Bolivia (1989 and 1993-94). Individual level data were used to examine the effects using various multivariate techniques: Cox proportional hazards models for age at first union; logistic models with controls for socioeconomic status for contraceptive use; and log linear techniques for fertility. Findings indicate a strong relationship between each demographic outcome: marriage age, contraceptive use, and fertility. In all countries, education influenced women's individual decisions about family formation. The strongest impact occurs between primary and secondary schooling, especially for marriage age. Increased educational attainment accounted for most of the decline in marriage rates over time. Increased education contributed to an increase in contraceptive use mostly in Peru. In Bolivia and Colombia, contraceptive availability was probably more important in the expansion of contraceptive use over time. Educational attainment over time only accounted for fertility decline in Peru and Colombia, and the effects were smaller than in other studies. Changes within educational categories appear to have contributed more to fertility decline than the expansion of educational opportunities. As countries progress through their transitions, there is a corresponding increase in contraceptive use and a later decline in actual fertility.

Sterilization among currently married men in the United States, 1991.

Data from the 1991 National Survey of Men indicate that about 12% of married men aged 20-39 have had a vasectomy and about 13% are married to a woman who is sterilized. Multivariate analyses indicate that the likelihood of sterilization rises with husband's age, wife's age, duration of marriage and number of children. Black couples are significantly less likely than white couples to rely on sterilization, and interracial couples are less likely than same-race couples to be sterilized. The likelihood of reliance on vasectomy rather than tubal ligation also rises with husband's age, while black men are significantly less likely than white men to elect male over female sterilization. Use of male sterilization is strongly associated with having had a recent contraceptive failure while using a male method.

Effects of lactation and contraceptive use on birth-spacing in Bolivia.

Based on the 1989 Demographic and Health Survey of Bolivia, analysis of the joint effects of breastfeeding and contraceptive use on birth-spacing showed the IUD to be the most effective contraceptive method used to delay conception. Breastfeeding significantly lengthened the birth interval, but only following second and higher parity births. In addition, conditions of poverty appeared to further inhibit the return of fecundity and delay conception.

PIP: This study examines the joint effects of breast feeding and contraceptive use on birth spacing in Bolivia during 1984-88. Data are obtained from the 1989 Bolivian Demographic and Health Survey conducted on a sample of 7923 women aged 15-49 years. The fertility model gives an estimate of the effects of contraceptive method chosen and lactation patterns on the likelihood of another conception following the birth of the index child in separate models by parity. Controls are included for demographic, family background, and community environmental factors. Stopping of breast feeding significantly increased the likelihood of another conception for second and higher order births. Breast-fed first-born infants did not affect the likelihood of a second conception. All use of contraception reduced the likelihood of a conception for all parities. Use of the IUD had the greatest contraceptive effect on the likelihood of a next birth for all parities. The likelihood of a conception was 6-7 times lower among women using an IUD following a third and lower-parity birth compared to women who used no contraception. For IUD-using women with four or more children the likelihood of a next birth was 40 times less likely compared to noncontraceptors. Sex of the index child was found to be unrelated to the likelihood of a subsequent birth. Older mothers, particularly women with high parity births, were less likely to have a subsequent conception. Higher education (9 or more years) lowered the odds of a next birth, but the effects of education decreased with the inclusion of contraceptive patterns in the model. Mothers working for pay were 1.3 times less likely to have a next birth at all parities compared to other women. Women married to men with no schooling were 1.4-2.0 times less likely to have a next birth compared to women with partners with some schooling. Living in Altiplano and Valles regions lowered the odds of conception by 1.3 times. Ethnicity and urbanization affected the likelihood of a next birth. The negative effect of poverty on conception was found to be exacerbated by multiple pregnancies.

Patterns of entry into cohabitation and marriage among mainland Puerto Rican women.

This paper adds to our limited knowledge of racial and ethnic variation in union formation by describing and analyzing the first unions of mainland Puerto Rican women. Retrospective history data show that Puerto Ricans have shared in the post-1970 shift toward cohabitation. Puerto Rican women, however, are much more likely to enter informal first unions than the general population, and have a low propensity to transform informal unions into legal marriages. The paper examines the influence of family background and current activities on union timing and type. The relationship between partner attributes and the choice between formal and informal coupling is also considered.

Initiation of sexual activity among female adolescents.

PIP: According to the 1982 National Survey of Family Growth, 46% women aged 15-19 had experienced premarital intercourse. Projections based on this study show that by their 20th birthdays, 70% of all women in the US will have experienced premarital intercourse. This article examines the effects of various factors on the likelihood that teenagers will become sexually active. Data for this study were taken from the National Survey of Family Growth, Cycle III. Fieldwork was done in 1982 and included interviews of 7969 women aged 15-44. Data include background characteristics, measures of fertility and contraception, measures of fecundity and birth expectations, use of family planning services, and the respondent's marital history. The study concludes that family stability (intact families), Hispanic ethnicity, high parental education, religious affiliation, regular church attendance, and reproductive education decrease the occurrence of 1st intercourse. Other factors characterize an environment that is unstable and unstructured and has a liberalizing influence upon 1st intercourse. Teens from broken homes, blacks, and the lower social classes are more likely to initiate intercourse. Geographic factors have a very small influence upon the initiation of sexual activity among teens. Similar patterns of influence appear regarding contraceptive use. The same factors that encourage stability, such as high father's education, Catholic or Jewish religious affiliation, religious attendance, and reproductive instruction shift the odds in favor of contracepted rather than noncontracepted sex. Family instability and low social class increase the risk that 1st intercourse will not be contracepted. Providing too much sex education, such as instruction on birth control, may actually contribute to the leniency of the environment, although the authors find no evidence that school-based birth control instruction increases the chances that contraceptives will be used. Environments that are too restrictive increase the chance that 1st intercourse will be noncontracepted. In sum, adolescents need an environment balanced between the liberal and conservative extremes to reduce the rate of 1st intercourse and to increase the use of contraception at intercourse.^ieng