Pre-pregnancy and pregnancy-related factors and the risk of excessive or inadequate gestational weight gain.

OBJECTIVE: Gestational weight gain consistent with the Institute of Medicine's recommendations is associated with better maternal and infant outcomes. The objective was to quantify the effect of pre-pregnancy factors, pregnancy-related health conditions, and modifiable pregnancy factors on the risks of inadequate and excessive gestational weight gain. METHOD: A longitudinal cohort of pregnant women (N=1100) who completed questions about diet and weight gain during pregnancy and delivered a singleton, full-term infant. RESULTS: Gestational weight gain was inadequate for 14% and excessive for 53%. Pre-pregnancy factors contributed 74% to excessive gain, substantially more than pregnancy-related health conditions (15%) and modifiable pregnancy factors (11%). Pre-pregnancy factors, pregnancy-related health conditions, and modifiable pregnancy factors contributed fairly equally to the risk of inadequate gain. CONCLUSION: Interventions to prevent excessive gestational gain may need to start before pregnancy. Women at risk for inadequate gain would also benefit from interventions directed toward modifiable factors during pregnancy.

The perinatal advantage of Mexican-origin Latina women.

PURPOSE: To determine if there is a perinatal advantage for birth outcomes among Mexican-origin Latina (Latina) women compared to white non-Hispanic (white) women, after adjusting for maternal, paternal, and infant factors. METHODS: 1,439,583 births from the 1990-1993 California linked birth and infant death certificate data sets were analyzed for the risk of low birth weight infants and infant mortality. RESULTS: Latina women had a statistically higher unadjusted risk of low birth weight infants and infant mortality compared to white women. After adjusting for potential confounders, Latina women had a similar risk of low birth weight infants and a lower risk of infant mortality relative to white women. In multivariate analyses, the most significant risk factor for low infant birth weight was young gestational age (OR = 82.91 for gestational age 1-230 days and OR = 10.62 for gestational age 231-258 days) and the most significant risk factor for infant mortality was low birth weight (OR = 53.99 for infant birth weight <500 grams and OR = 9.27 for infant birth weight 500-2499 grams). CONCLUSION: There was some evidence of a perinatal advantage for Latina women, when compared to white women and after adjusting for numerous potential confounders. To further reduce the risk of low birth weight infants and infant mortality, additional research is needed for etiologic clues beyond race/ethnicity and other traditional risk factors.

Low birth weight and Latino ethnicity. Examining the epidemiologic paradox.

OBJECTIVE: To assess the relation between Latino ethnicity, Latino subgroup, and low birth weight (LBW). DATA SOURCES: From the MEDLINE computer data-base, we used the key words birth weight; infant, LBW; Latinos; Hispanic Americans; Cuban Americans; Mexican Americans; and Puerto Ricans to identify studies that analyzed LBW in Latinos. STUDY SELECTION: Thirty-two studies, published from 1982 to 1996, that analyzed US Latinos and whites or multiple Latino subgroups, that used the revised definition of LBW (< 2500 g), and had a large sample size (> 10,000) were selected. DATA EXTRACTION: Two reviewers extracted LBW rates and data on the relation between Institute of Medicine risk factors and LBW by maternal ethnicity and Latino subgroup. DATA SYNTHESIS: Low-birth-weight rates were similar for Latino (median, 6.2%) and white infants (median, 5.8%). By Latino subgroup, LBW rates were similar for Central/South American, Cuban, Mexican, and white infants. Puerto Rican infants had consistently higher LBW rates (median, 9.1%). Two risk factors-maternal birth-place and gestational weight gain-were identified as confounders of the relation between Latino ethnicity, Latino subgroup, and LBW. CONCLUSIONS: Low-birth-weight rates of Latinos and whites are similar, consistent with the "epidemiologic paradox" of unexpectedly favorable perinatal outcomes for Latinos. However, this paradoxical relation for all Latinos masks the notably elevated LBW risk among Puerto Ricans. Further study of LBW among Latinos, including cultural factors, is needed.

Effects of vaccine information pamphlets on parents' attitudes.

OBJECTIVES: To describe how parents actually use federally mandated vaccine information pamphlets and to evaluate the pamphlets' effects on parents' opinions about vaccination. DESIGN: A controlled trial of vaccine information pamphlets based on a survey mailed to parents who either received (n = 140) or did not receive (n = 167) the pamphlets. STUDY POPULATION: Parents of infants aged 2 to 8 months in a suburban, mainly upper-middle class private group practice in northern California. RESULTS: More than 90% of parents believed that they had enough information to decide whether their child should be vaccinated, even among those who did not receive the pamphlets. Among parents who received the pamphlets, fewer than half (38%) read them thoroughly, and most (63%) said that they should be distributed only on the first visit for vaccinations. Parents who received the pamphlets did not differ from those who did not in terms of the proportions who would have liked more time to be spent discussing vaccines (34% vs 34%) or who were anxious about how the diphtheria and tetanus toxoids and pertussis vaccine would affect their child (60% vs 52%). CONCLUSIONS: Vaccine information pamphlets, when used as an adjunct to discussions with physicians and nurses, have little effect on the opinions of well-educated parents. Future research and policy changes might focus on how to make the contents of the pamphlets less frightening and on allowing greater flexibility in how they are distributed.

Maternal birthplace, ethnicity, and low birth weight in California.

BACKGROUND: Although immigrants to the United States are usually ethnic minorities and socioeconomically disadvantaged, foreign-born women generally have lower rates of low birth weight infants than do US-born women. OBJECTIVE: To measure the relationship between maternal birthplace, ethnicity, and low birth weight infants. DESIGN: Retrospective cohort study of birth certificate data. SETTING: California, 1992. SUBJECTS: Singleton infants (n = 497 868) born to Asian, black, Latina, and white women. MAIN OUTCOME MEASURES: Very low birth weight (500-1499 g), moderately low birth weight (1500-2499 g), and normal birth weight (2500-4000 g, reference category). RESULTS: Foreign-born Latina women generally had less favorable maternal characteristics than US-born Latinas, yet foreign-born Latina women were less likely to have moderately low birth weight infants (odds ratio, 0.91; 95% confidence interval, 0.86-0.96) than US-born Latinas after adjusting for maternal age, education, marital status, parity, tobacco use, use of prenatal care, and gestational age. While foreign-born Asian women generally had a less favorable profile of maternal characteristics than US-born Asians, there was no statistically significant difference in the odds of very low birth weight or moderately low birth weight infants between foreign- and US-born Asian women. Foreign-born black women had more favorable maternal characteristics than US-born women, but there was no significant nativity difference in very low birth weight or moderately low birth weight between foreign- and US-born black women after adjusting for maternal and infant factors. CONCLUSIONS: The relationship between maternal birthplace and low birth weight varies by ethnicity. Further study is needed to understand the favorable pregnancy outcomes of foreign-born Latina women.

Testing the epidemiologic paradox of low birth weight in Latinos.

BACKGROUND: Rates of low-birth-weight (LBW) infants are similar between Latina and white women, an epidemiologic paradox. However, few studies have analyzed the relationship between ethnicity, Latino subgroup, confounding variables, and LBW. METHODS: We analyzed 395070 singleton livebirths to Latina and non-Latina white women in California during 1992. Multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the risks due to Latino ethnicity and Latino subgroup for very LBW (VLBW, 500-1499 g) and moderately LBW (MLBW, 1500-2499 g) outcomes. RESULTS: Latina and white women had similar unadjusted rates of VLBW (0.7% vs. 0.6%) and MLBW infants (3.7% vs. 3.4%). After adjusting for maternal age, education, birthplace, marital status, parity, tobacco use, use of prenatal care, infant sex, and gestational age, there was no difference in the odds of VLBW infants between Latina and white women (OR, 0.93 [95% CI, 0.81-1.071). Latina women had minimally elevated odds of MLBW infants (OR, 1.06 [95% CI, 1.01-1.11]) compared with white women. By Latino subgroup, there was no difference in the adjusted odds of VLBW infants among Central and South American, Cuban, Mexican, Puerto Rican, and white women. The adjusted odds of MLBW infants were elevated among Central and South American (OR, 1.14 [95% CI, 1.05-1.25]) and Puerto Rican women (OR, 1.41 [95% CI, 1.12-1.78]), relative to white women. CONCLUSIONS: The epidemiologic paradox of LBW in Latinos is valid. New conceptual models are needed to identify Latina women who are at risk for adverse pregnancy outcomes.

Counseling smoking parents of young children: comparison of pediatricians and family physicians.

BACKGROUND: Secondhand smoke is a major cause of morbidity in young children, and exposure to smoking parents is the principal source. Physician visits for young children present an opportunity to effect behavioral change among smoking parents. OBJECTIVE: To survey pediatricians and family physicians in their knowledge and practice of smoking cessation counseling with parents. DESIGN: Cross-sectional mail survey. SETTING: Urban California. PARTICIPANTS: Pediatricians and family physicians in urban areas of California, younger than 65 years, practicing in an ambulatory setting, and randomly selected from the American Medical Association Physician Masterfile. MAIN OUTCOME MEASURES: Reported frequency of asking about tobacco use, using cessation counseling techniques with smokers, and perceived barriers to providing cessation services. RESULTS: Of the 1000 mailed surveys, 899 were eligible and 499 (56% response rate) were returned and completed. A higher proportion of pediatricians compared with family physicians were women (44% vs 29%; P<.01) and nonwhite (44% vs 32%; P =.01). Family physicians compared with pediatricians were more likely to report referring a parent to a smoking cessation program (41% vs 30%), giving pamphlets on smoking cessation (40% vs 28%), asking for a quit date (41% vs 18%), scheduling a follow-up visit to discuss quitting (27% vs 5%), and recommending nicotine replacement therapy (41% vs 13%) (for each comparison, P<.001). Pediatricians were more likely to report recording in the medical record smoking by a parent as a problem for the child (65% vs 48%; P<.001), but a higher proportion of pediatricians perceived that parents would ignore the advice (39% vs 24%; P<.001) and lacked interest in quitting smoking (45% vs 27%; P<.001). Pediatricians were more likely to agree that they lacked smoking cessation counseling skills (26% vs 7%; P<.001). Multivariate models showed that pediatricians were less likely to report performing 5 of 14 smoking cessation techniques in at least 50% of smoking parents. CONCLUSIONS: Pediatricians appear to lack training to implement smoking cessation counseling with smoking parents. Physicians in private practice are less likely to counsel smoking parents. Educational interventions for pediatricians are needed to decrease secondhand smoke exposure for young children.

Interpregnancy interval and the risk of premature infants.

OBJECTIVE: Interpregnancy intervals are associated with the risk of low birth weight (LBW) infants, but the association between interpregnancy interval and prematurity is unknown. Our objective was to determine whether interpregnancy intervals were associated with the risk of premature infants and to define the degree of risk according to interpregnancy interval. METHODS: We analyzed 289,842 singleton infants born to parous Mexican-origin Hispanic and non-Hispanic white women in the United States who resided in the same county and delivered between January 1, 1991 and September 30, 1991. Interpregnancy interval was defined as the number of months between the previous live birth and conception of the index pregnancy. Multivariate logistic regression analysis was used to estimate odds ratios and 95% confidence intervals for the risk of interpregnancy interval on very premature (23-32 weeks), moderately premature (33-37 weeks), and term gestation (38-42 weeks). RESULTS: Nearly 37% of women had interpregnancy intervals less than 18 months, 45.5% of women had intervals of 18-59 months, and 17.6% of women had intervals over 59 months. After adjusting for confounding variables, women with intervals less than 18 months were 14-47% more likely to have very premature and moderately premature infants than women with intervals of 18-59 months. Women with intervals over 59 months were 12-45% more likely to have very premature and moderately premature infants than women with intervals of 18-59 months. CONCLUSION: Women with interpregnancy intervals from 18-59 months had the lowest risk of very premature and moderately premature infants. Further study is needed to define the mechanisms through which interpregnancy interval influences pregnancy outcome.

Risk of low birth weight infants among black and white parents.

OBJECTIVE: To determine whether racial differences in risk of low birth weight infants among black and white parents can be attributed to differences in demographic, behavioral, medical, and socioeconomic factors. METHODS: We analyzed 203,815 singleton births from the 1992 California birth certificate data set for the risk of very low birth weight (500-1499 g) and moderately low birth weight (1500-2499 g) infants. Additional study variables included maternal (race, age, education, marital status, parity, obstetric history, tobacco use, medical complications, medical insurance, and use of prenatal care), paternal (race, age, and education), infant (gestational age and gender), and community (median household income from the 1990 US Census) characteristics. RESULTS: For both very low and moderately low birth weight infants, the unadjusted risk associated with parental race showed a gradient of risk, from highest to lowest, for black mother/black father, black mother/white father, white mother/black father, and white mother/white father parents. After adjusting for other risk factors, the odds ratio associated with black mother/black father parents was reduced from 3.37 to 1.73 for very low birth weight infants and from 2.51 to 1.60 for moderately low birth weight infants, but both remained elevated. Interracial parents no longer had an elevated risk of very low birth weight infants and white mother/black father parents no longer had an elevated risk of moderately low birth weight, compared with white parents. CONCLUSION: After controlling for parental, infant, and community factors, most but not all of the increased risk of low birth weight infants associated with black parental race was explained.

Ethnic disparity in the performance of prenatal nutrition risk assessment among Medicaid-eligible women.

In this study, the authors compare perinatal health outcomes and nutrition risk assessments in Latina, African American, and white women receiving Medicaid enhanced perinatal services. The objective is to analyze how proper assessment of obesity and underweight depend upon ethnic group, provider practice setting and credentials, and the implications for perinatal outcomes. The medical records of women who received enhanced perinatal services from specially certified Medicaid providers in California were abstracted for information on nutrition risk assessment and outcomes. Logistic regression analysis was used to test the associations first of obesity and underweight with adverse outcomes in Latina, African American and white women, then the associations of ethnicity with the failure of these women to be classified as overweight or underweight during assessment. Finally, the associations between misclassification of body mass with provider practice setting type and credentials are also tested. Obese Latinas are twice as likely not to be properly classified as overweight, despite evidence of substantial risk of unfavorable outcomes. For all three ethnic groups, underweight women are uniformly underreported as being at risk. The appropriate classifications of obesity and underweight are not associated with private or public types of obstetric practice settings or whether nutrition risk assessors are registered dietitians, health workers, or nurses of any particular credential. Providers of prenatal care to low-income women could improve the quality of nutrition risk assessment of overweight Latina women and underweight women of all ethnic groups with expectations of improving perinatal outcomes.

CYP2A6 genotype but not age determines cotinine half-life in infants and children.

The formation of cotinine, the main proximate metabolite and a biomarker of nicotine exposure, is mediated primarily by cytochrome P450 (CYP)2A6. Our aim was to determine whether higher cotinine levels in young children exposed to secondhand smoke (SHS) are a result of age-related differences in pharmacokinetics. Forty-nine participants, aged 2-84 months, received oral deuterium-labeled cotinine, with daily urine samples for up to 10 days for cotinine half-life measurement. DNA from saliva was used for CYP2A6 genotyping. The estimate of half-life using a mixed-effect model was 17.9 h (95% confidence interval: 16.5, 19.3), similar to that reported in adults. There was no statistically significant effect of sex, race, age, or weight. Children with normal-activity CYP2A6*1/*1 genotypes had a shorter half-life than those with one or two reduced-activity variant alleles. Our data suggest that higher cotinine levels in SHS-exposed young children as compared with adults are due to greater SHS exposure rather than to different cotinine pharmacokinetics.

Risk factors for macrosomia in infants born to Latina women.

OBJECTIVE: To assess risk factors for macrosomic infant birth among Latina women. STUDY DESIGN: Prospective study of Latina women recruited during pregnancy from prenatal clinic at San Francisco General Hospital. Information was obtained through a structured interview and review of medical records. RESULT: A total of 11% of women delivered macrosomic infants (birth weight >4000 g). In unadjusted analyses, significant risk factors for macrosomia included older maternal age, increasing gravidity, previous history of macrosomic birth and pre-pregnancy overweight. After adjusting for confounders using multivariate analyses, older mothers (10-year increments) had an elevated risk of macrosomia (odds ratio (OR) 2.59; 95% confidence interval (CI) 1.28 to 5.24). CONCLUSION: Efforts to reduce macrosomia in Latina women should focus on older mothers.

Impact of Asian ethnicity and national origin on infant birth weight.

To investigate the relation between Asian ethnicity/national origin and low birth weight (< 2,500 g), the authors analyzed singleton live births among 50,044 Asian and 221,866 white women who delivered in California during 1992. Ethnic and subgroup differences in prenatal characteristics and birth weight outcomes were found between Asian and white women and between Asian subgroups. In unadjusted comparisons, very low birth weight (500-1,499 g) was more likely among Filipino women and less likely among Chinese women, relative to whites. Moderately low birth weight (1,500-2,499 g) was more likely among Cambodian, Filipino, Indian, Japanese, Laotian, and Thai women and was less likely among Koreans, relative to whites. In multivariate analyses, Filipino women remained at increased risk of both very low and moderately low birth weight, while Cambodian, Indian, and Laotian women had elevated odds of moderately low birth weight. Chinese women were less likely to have very low birth weight infants than were whites. Utilization of prenatal care was also associated with low birth weight. Perinatal outcomes among Asians vary by national origin, and accepted risk factors that were studied only partially explain this variation.

Latino children's health and the family-community health promotion model.

A majority of Latino children in the US live in poverty. However, unlike other poor children, Latino children do not seem to have a consistent association between poverty and poor health. Instead, many poor Latino children have unexpectedly good health outcomes. This has been labeled an epidemiologic paradox. This paper proposes a new model of health, the family-community health promotion model, to account for this paradox. The family-community health promotion model emphasizes the family-community milieu of the child, in contrast to traditional models of health. In addition, the family-community model expands the outcome measures from physical health to functional health status, and underscores the contribution of cultural factors to functional health outcomes. In this paper, we applied the family-community health promotion model to four health outcomes: low birthweight, infant mortality, chronic and acute illness, and perceived health status. The implications of this model for research and policy are discussed.

Nonclient factors in the reporting of prenatal psychosocial risk assessments.

Psychosocial and nutrition risk assessments at 27 randomly selected sites of a Medicaid-funded enhanced prenatal program were examined for completeness and uniformity of reporting. The recording of psychosocial data, but not of nutrition data, was found to be associated with a substantial number of nonclient factors, including geographical location and abstractor, assessor, and service provider characteristics. The variability in recording of psychosocial problems reflects the numerous ways that assessments are performed and the subsequent difficulty in interpreting the practice of psychosocial assessment. A uniform system of defining and classifying risks is needed to improve both service delivery and service evaluation.

Role of clinicians in cigarette smoking prevention.

Despite a gradual decrease in smoking rates among adults, the proportion of youth who smoke regularly has remained stable. Among high school students in 1997, 19.9% of white, 7.2% of African American, and 10.9% of Latino youth reported smoking during at least 20 of the previous 30 days. Ethnic differences in beliefs, attitudes, and behavior about smoking have not been systematically considered in developing prevention interventions for adolescents. Effective school-based smoking-prevention interventions have been developed, but these are usually not appropriately implemented. Policy proposals and current laws that affect the marketing of tobacco to youth need to be emphasized as evidence increases that marketing by the tobacco industry targets youth and leads to more smoking. Smoking-prevention programs have been designed to involve physicians and other health care professionals in the clinical setting, but limited data exist on their efficacy. We review the guidelines for involving the clinicians who provide care to children in preventing the onset of tobacco use, counseling parents of children who smoke, and counseling adolescents who have started smoking. Finally, we summarize the future directions of smoking-prevention research and programs.