Bearing
Abortion Incidence and Service Availability In the United States, 2011
Rachel Jones & Jenna Jerman
Perspectives on Sexual and Reproductive Health, forthcoming
Context: Following a long-term decline, abortion incidence stabilized between 2005 and 2008. Given the proliferation of state-level abortion restrictions, it is critical to assess abortion incidence and access to services since that time.
Methods: In 2012–2013, all facilities known or expected to have provided abortion services in 2010 and 2011 were surveyed. Data on the number of abortions were combined with population data to estimate national and state-level abortion rates. Incidence of abortions was assessed by provider type and caseload. Information on state abortion regulations implemented between 2008 and 2011 was collected, and possible relationships with abortion rates and provider numbers were considered.
Results: In 2011, an estimated 1.1 million abortions were performed in the United States; the abortion rate was 16.9 per 1,000 women aged 15–44, representing a drop of 13% since 2008. The number of abortion providers declined 4%; the number of clinics dropped 1%. In 2011, 89% of counties had no clinics, and 38% of women of reproductive age lived in those counties. Early medication abortions accounted for a greater proportion of nonhospital abortions in 2011 (23%) than in 2008 (17%). Of the 106 new abortion restrictions implemented during the study period, few or none appeared to be related to state-level patterns in abortion rates or number of providers.
Conclusions: The national abortion rate has resumed its decline, and no evidence was found that the overall drop in abortion incidence was related to the decrease in providers or to restrictions implemented between 2008 and 2011.
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Shifts in Intended and Unintended Pregnancies in the United States, 2001–2008
Lawrence Finer & Mia Zolna
American Journal of Public Health, February 2014, Pages S43-S48
Objectives: We monitored trends in pregnancy by intendedness and outcomes of unintended pregnancies nationally and for key subgroups between 2001 and 2008.
Methods: Data on pregnancy intentions from the National Survey of Family Growth (NSFG) and a nationally representative survey of abortion patients were combined with counts of births (from the National Center for Health Statistics), counts of abortions (from a census of abortion providers), estimates of miscarriages (from the NSFG), and population denominators from the US Census Bureau to obtain pregnancy rates by intendedness.
Results: In 2008, 51% of pregnancies in the United States were unintended, and the unintended pregnancy rate was 54 per 1000 women ages 15 to 44 years. Between 2001 and 2008, intended pregnancies decreased and unintended pregnancies increased, a shift previously unobserved. Large disparities in unintended pregnancy by relationship status, income, and education increased; the percentage of unintended pregnancies ending in abortion decreased; and the rate of unintended pregnancies ending in birth increased, reaching 27 per 1000 women.
Conclusions: Reducing unintended pregnancy likely requires addressing fundamental socioeconomic inequities, as well as increasing contraceptive use and the uptake of highly effective methods.
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A Generation of Childless Women: Lessons from the United States
Benjamin Craig et al.
Women's Health Issues, January–February 2014, Pages e21–e27
Background: Childlessness is a major public health concern in the United States, particularly among educated adults. Among women who turned 45 in 2006, one fifth had no children. We examine the likelihood that a childless woman wants a baby sometime in the future and its determinants.
Methods: From 2006 to 2010, 5,410 in-person interview surveys were conducted with childless women as part of the National Survey of Family Growth. Age-specific likelihoods of wanting a baby were compared with likelihoods of having a baby before age 45. Female respondents were 1) born after 1960, 2) age 15 to 44, 3) childless (never given birth to a live infant), and 4) not pregnant at time of interview.
Findings: Most childless women at any age want a baby sometime in the future. By age 32, fewer than half the childless women who want a baby will have one. At age 39, the majority of childless women (73%) still want a baby someday, but only 7% will have one. By age 45, more than 1 in 10 women will be childless, but still want to have a baby.
Conclusions: Although attitudes toward childlessness have become more positive over time, our findings suggest that the United States is experiencing a high prevalence of childless women who want a baby. Clinicians may consider counseling young women about age-related declines in fertility and the costs and success rates of assisted reproductive echnologies often required for women with advanced maternal age to better inform their career, family, and lifestyle decisions.
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Media Influences on Social Outcomes: The Impact of MTV's 16 and Pregnant on Teen Childbearing
Melissa Kearney & Phillip Levine
NBER Working Paper, January 2014
Abstract:
This paper explores how specific media images affect adolescent attitudes and outcomes. The specific context examined is the widely viewed MTV franchise, 16 and Pregnant, a series of reality TV shows including the Teen Mom sequels, which follow the lives of pregnant teenagers during the end of their pregnancy and early days of motherhood. We investigate whether the show influenced teens’ interest in contraceptive use or abortion, and whether it ultimately altered teen childbearing outcomes. We use data from Google Trends and Twitter to document changes in searches and tweets resulting from the show, Nielsen ratings data to capture geographic variation in viewership, and Vital Statistics birth data to measure changes in teen birth rates. We find that 16 and Pregnant led to more searches and tweets regarding birth control and abortion, and ultimately led to a 5.7 percent reduction in teen births in the 18 months following its introduction. This accounts for around one-third of the overall decline in teen births in the United States during that period.
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US infant mortality and the President’s party
Javier Rodriguez, John Bound & Arline Geronimus
International Journal of Epidemiology, forthcoming
Background: Infant mortality rates in the US exceed those in all other developed countries and in many less developed countries, suggesting political factors may contribute.
Methods: Annual time series on overall, White and Black infant mortality rates in the US were analysed over the 1965–2010 time period to ascertain whether infant mortality rates varied across presidential administrations. Data were de-trended using cubic splines and analysed using both graphical and time series regression methods.
Results: Across all nine presidential administrations, infant mortality rates were below trend when the President was a Democrat and above trend when the President was a Republican. This was true for overall, neonatal and postneonatal mortality. Regression estimates show that, relative to trend, Republican administrations were characterized by infant mortality rates that were, on average, 3% higher than Democratic administrations. In proportional terms, effect size is similar for US Whites and Blacks. US Black rates are more than twice as high as White, implying substantially larger absolute effects for Blacks.
Conclusions: We found a robust, quantitatively important association between net of trend US infant mortality rates and the party affiliation of the president. There may be overlooked ways by which macro-dynamics of policy impact microdynamics of physiology, suggesting the political system is a component of the underlying mechanism generating health inequality in the USA.
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Danielle Atkins & David Bradford
Contemporary Economic Policy, forthcoming
Abstract:
One of the more contentious policy changes in the past decade in the United States involves the decisions by several state legislatures and the FDA to permit sales of emergency contraception on a non-prescription basis. We took advantage of a set of natural experiments to estimate the impact of changes in state and federal level non-prescription emergency contraception access on the probability high school students’ sexual and contraceptive behaviors. We extracted data from the Youth Risk Behavioral Survey for New England states that had data about contraceptive use (Maine, New Hampshire, Rhode Island and Vermont) from 2003 to 2009. We combined this student-level data with information on when states and the FDA began allowing non-prescription sales of EC. We estimated a series of difference-in-difference models on the impact of these policies on the probability that students were sexually active and on the probability of condom or hormonal birth control use conditional on sexual activity. We found that switching emergency contraception to a non-prescription status had no systematic effect on the probability of sexual activity or the conditional probability of hormonal birth control use, but that it significantly reduced the probability that public school students used condoms by between 5.2% and 7.2%.
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Association between Increased Emergency Contraception Availability and Risky Sexual Practices
Danielle Atkins & David Bradford
University of Georgia Working Paper, December 2013
Objective: We studied whether increased EC availability for women over age 18 was associated with a higher probability of risky sexual practices.
Data Sources: 34,030 individual/year observations on 3,786 women aged 18 and older were extracted from the National Longitudinal Survey of Youth, 1997 from October 1999 through November 2009.
Study Design: We modeled three binary outcome variables: whether or not the respondent reported any sexual activity; whether or not the respondent reported sexual activity with more than one partner; and whether or not the respondent’s with multiple sexual partners reported any unprotected sex. We estimate our models three times: once for the full sample of women; once for the sub-sample of married or cohabitating women; and once for the sub-sample of single women.
Principal Findings: We found that greater access to EC reduced the probability of sexual activity by about -5% for women and reduced the probability of multiple sexual partners for women by -4.4%, but also increased the probability of unprotected sex when women had multiple partners by about 5%.
Conclusions: Our results suggest that policies for expanding EC access may need to be paired with education about its inability to control STI risk.
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The Effect of State-Level Sex Education Policies on Youth Sexual Behaviors
Danielle Atkins & David Bradford
University of Georgia Working Paper, December 2013
Abstract:
Two types of sex education are generally offered in the United States: abstinence-only and comprehensive sex education. There is no clear scientific consensus over which approach minimizes the risk of unintended pregnancy and sexually transmitted diseases for teens. While there have been many studies of specific programs in clinical or quasi-experimental settings, there are very few evaluations of how state-level sex education policies affect the youth population. We estimate the impact of various state-level sex education policies on youth sexual activity and contraceptive use using data from four waves of the Youth Risk Behavior Surveillance System from 39 states. We find that states that require sexuality (sex and/or HIV/STD) education and contraceptive content or states that mandate education but leave the actual content up to local districts have higher rates of contraception use when teens are sexually active. States that require sexuality education and require abstinence content decrease the likelihood that sexually active teens use condoms or hormonal birth control. None of the policies significantly reduce sexual activity.
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The Effect of Plan B on Teen Abortions: Evidence from the 2006 FDA Ruling
Inna Cintina & Morgen Johansen
University of Hawaii Working Paper, January 2014
Abstract:
The 2006 FDA ruling made Plan B, the popular brand of emergency contraception (EC), available without a doctor's prescription to women 18 and older; women younger than 18 still have to produce a doctor's prescription for the drug. We hypothesize that since unplanned pregnancies are more likely to be terminated, an increase in the availability of EC may lead to a decrease in the abortion rate among women affected by the ruling. Therefore, in the absence of a change in the sexual risk taking, we expect to observe a decline in the abortion rate among women aged 18 and 19 after 2006, and expect no change in the abortion rate for women aged 15 and 16. We use the difference-in-difference methodology on the age-by-year-by-state abortion data to test this hypothesis. In contrast to the related literature, we find a moderate reduction in abortion rates among women age 18 and 19 in years after 2006 in states that were affected by the change, compared to changes in the control group in the same states. Yet, we do not observe a similar large change in abortion rates among women age 20-24.
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Citizenship, Fertility and Parental Investment
Ciro Avitabile, Irma Clots-Figueras & Paolo Masella
American Economic Journal: Applied Economics, forthcoming
Abstract:
Citizenship rights are associated with better economic opportunities for immigrants. This paper studies how in a country with a large fraction of temporary migrants the fertility decisions of foreign citizens respond to a change in the rules that regulate child legal status at birth. The introduction of birthright citizenship in Germany, as part of the new German nationality law that came into force in 2000, represented a positive shock to the returns to investment in child human capital. Consistent with Becker's "quality-quantity" model of fertility, we find that birthright citizenship leads to a reduction in immigrant fertility and an improvement in health outcomes for the children affected by the reform.
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The Immigrant Paradox in Pregnancy: Explaining the First-Generation Advantage for Latina Adolescents
Tristan Guarini et al.
Journal of Research on Adolescence, forthcoming
Abstract:
The immigrant paradox is a population health pattern whereby later generation immigrant youth display less favorable outcomes when compared to first-generation co-ethnic peers. This study examines the role of number of sex partners in explaining the immigrant paradox in pregnancy among Latina adolescents. This secondary analysis utilized a nationally representative sample of Latinas in the National Longitudinal Study of Adolescent Health. As expected, first-generation Latina adolescents demonstrated less risk than second- or third+ generation Latinas for becoming pregnant. Further, the lower number of sexual partners fully accounted for the first generation's advantage in lower rate of adolescent pregnancy. These findings have important implications for healthcare providers who work with Latina girls in pregnancy prevention.
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Megan Swanson et al.
Contraception, forthcoming
Background: Delayed pregnancy testing has been associated with presentation for abortion in the second trimester. Little is known about acceptability of potential interventions to hasten pregnancy recognition.
Study design: 592 women presenting for abortion at six clinics in the United States completed surveys on contraceptive use, risk behavior, timing of first pregnancy test and interest in interventions to speed pregnancy recognition and testing.
Results: 48% of women presenting for second-trimester abortion delayed testing until at least 8 weeks. In multivariate analysis, women who often spotted between periods had higher odds of delaying pregnancy testing (odds ratio, OR, 2.7, 95% confidence interval, CI, 1.04-6.94). Women who often missed periods had higher odds of second trimester abortion (OR 2.1, 95% CI 1.34-3.13). The majority (64%) of women were not aware of a fertile time in the menstrual cycle; these women had higher odds of second trimester abortion (OR 2.0, 95% CI 1.21-3.37). 94% of women expressed interest in at least one potential intervention to help recognize pregnancy earlier.
Conclusions: While there was near universal interest in earlier pregnancy recognition, no single proposed intervention or scenario was endorsed by the majority. Improving sexual health awareness is an important consideration in future efforts to expedite pregnancy testing.
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Fertility Rate Trends Among Adolescent Girls With Major Mental Illness: A Population-Based Study
Simone Vigod et al.
Pediatrics, forthcoming
Objective: Fertility rates among adolescents have decreased substantially in recent years, yet fertility rates among adolescent girls with mental illness have not been studied. We examined temporal trends in fertility rates among adolescent girls with major mental illness.
Methods: We conducted a repeated annual cross-sectional study of fertility rates among girls aged 15 to 19 years in Ontario, Canada (1999–2009). Girls with major mental illness were identified through administrative health data indicating the presence of a psychotic, bipolar, or major depressive disorder within 5 years preceding pregnancy (60 228 person-years). The remaining girls were classified into the comparison group (4 496 317 person-years). The age-specific fertility rate (number of live births per 1000 girls) was calculated annually and by using 3-year moving averages for both groups.
Results: The incidence of births to girls with major mental illness was 1 in 25. The age-specific fertility rate for girls with major mental illness was 44.9 per 1000 (95% confidence interval [CI]: 43.3–46.7) compared with 15.2 per 1000 (95% CI: 15.1–15.3) in unaffected girls (rate ratio: 2.95; 95% CI: 2.84–3.07). Over time, girls with major mental illness had a smaller reduction in fertility rate (relative rate: 0.86; 95% CI: 0.78–0.96) than did unaffected girls (relative rate: 0.78; 95% CI: 0.76–0.79).
Conclusions: These results have key clinical and public policy implications. Our findings highlight the importance of considering major mental illness in the design and implementation of pregnancy prevention programs as well as in targeted antenatal and postnatal programs to ensure maternal and child well-being.
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Community-level education accelerates the cultural evolution of fertility decline
Heidi Colleran et al.
Proceedings of the Royal Society: Biological Sciences, 22 March 2014
Abstract:
Explaining why fertility declines as populations modernize is a profound theoretical challenge. It remains unclear whether the fundamental drivers are economic or cultural in nature. Cultural evolutionary theory suggests that community-level characteristics, for example average education, can alter how low-fertility preferences are transmitted and adopted. These assumptions have not been empirically tested. Here, we show that community-level education accelerates fertility decline in a way that is neither predicted by individual characteristics, nor by the level of economic modernization in a population. In 22 high-fertility communities in Poland, fertility converged on a smaller family size as average education in the community increased — indeed community-level education had a larger impact on fertility decline than did individual education. This convergence was not driven by educational levels being more homogeneous, but by less educated women having fewer children than expected, and more highly educated social networks, when living among more highly educated neighbours. The average level of education in a community may influence the social partners women interact with, both within and beyond their immediate social environments, altering the reproductive norms they are exposed to. Given a critical mass of highly educated women, less educated neighbours may adopt their reproductive behaviour, accelerating the pace of demographic transition. Individual characteristics alone cannot capture these dynamics and studies relying solely on them may systematically underestimate the importance of cultural transmission in driving fertility declines. Our results are inconsistent with a purely individualistic, rational-actor model of fertility decline and suggest that optimization of reproduction is partly driven by cultural dynamics beyond the individual.
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The quality–quantity trade-off: Evidence from the relaxation of China’s one-child policy
Haoming Liu
Journal of Population Economics, April 2014, Pages 565-602
Abstract:
This paper uses the exogenous variation in fertility introduced by China’s family planning policies to identify the impact of child quantity on child quality. We find that the number of children has a significant negative effect on child height, which supports the quality–quantity trade-off theory. Our instrumental quantile regression approach shows that the impact varies considerably across the height distribution, particularly for boys. However, the trade-off is much weaker if quality is measured by educational attainments, suggesting that the measurement of child quality is also crucial in testing the quality–quantity trade-off theory.
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Uterine Selection of Human Embryos at Implantation
Jan Brosens et al.
Scientific Reports, February 2014
Abstract:
Human embryos frequently harbor large-scale complex chromosomal errors that impede normal development. Affected embryos may fail to implant although many first breach the endometrial epithelium and embed in the decidualizing stroma before being rejected via mechanisms that are poorly understood. Here we show that developmentally impaired human embryos elicit an endoplasmic stress response in human decidual cells. A stress response was also evident upon in vivo exposure of mouse uteri to culture medium conditioned by low-quality human embryos. By contrast, signals emanating from developmentally competent embryos activated a focused gene network enriched in metabolic enzymes and implantation factors. We further show that trypsin, a serine protease released by pre-implantation embryos, elicits Ca2+ signaling in endometrial epithelial cells. Competent human embryos triggered short-lived oscillatory Ca2+ fluxes whereas low-quality embryos caused a heightened and prolonged Ca2+ response. Thus, distinct positive and negative mechanisms contribute to active selection of human embryos at implantation.
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Christine Markham et al.
Journal of Adolescent Health, February 2014, Pages 151–159
Purpose: An earlier randomized controlled trial found that two middle school sexual education programs—a risk avoidance (RA) program and a risk reduction (RR) program—delayed initiation of sexual intercourse (oral, vaginal, or anal sex) and reduced other sexual risk behaviors in ninth grade. We examined whether these effects extended into 10th grade.
Methods: Fifteen middle schools were randomly assigned to RA, RR, or control conditions. Follow-up surveys were conducted with participating students in 10th grade (n = 1,187; 29.2% attrition).
Results: Participants were 60% female, 50% Hispanic, and 39% black; seventh grade mean age was 12.6 years. In 10th grade, compared with the control condition, both programs significantly delayed anal sex initiation in the total sample (RA: adjusted odds ratio [AOR], .64, 95% confidence interval [CI], .42–.99; RR: AOR, .65, 95% CI, .50–.84) and among Hispanics (RA: AOR, .53, 95% CI, .31–.91; RR: AOR, .82, 95% CI, .74–.93). Risk avoidance students were less likely to report unprotected vaginal sex, either by using a condom or by abstaining from sex (AOR: .61, 95% CI, .45–.85); RR students were less likely to report recent unprotected anal sex (AOR: .34, 95% CI, .20–.56). Both programs sustained positive impact on some psychosocial outcomes.
Conclusions: Although both programs delayed anal sex initiation into 10th grade, effects on the delayed initiation of oral and vaginal sex were not sustained. Additional high school sexual education may help to further delay sexual initiation and reduce other sexual risk behaviors in later high school years.
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Risk Perceptions and Subsequent Sexual Behaviors After HPV Vaccination in Adolescents
Allison Mayhew et al.
Pediatrics, forthcoming
Objectives: Concerns have been raised that human papillomavirus (HPV) vaccination could lead to altered risk perceptions and an increase in risky sexual behaviors among adolescents. The aim of this study was to assess whether adolescent risk perceptions after the first vaccine dose predicted subsequent sexual behaviors.
Methods: Young women 13 to 21 years of age (N = 339) completed questionnaires immediately after HPV vaccination, and 2 and 6 months later, assessing demographic characteristics, knowledge/attitudes about HPV vaccination, risk perceptions, and sexual behaviors. Risk perceptions were measured by using 2 5-item scales assessing: (1) perceived risk of sexually transmitted infections (STI) other than HPV, and (2) perceived need for safer sexual behaviors after HPV vaccination. We assessed associations between risk perceptions at baseline and sexual behaviors over the next 6 months by using logistic regression, stratifying participants by sexual experience at baseline and age (13–15 vs 16–21 years).
Results: Among all sexually inexperienced participants (42.5%), baseline risk perceptions were not associated with subsequent sexual initiation; in age-stratified analyses, girls 16 to 21 years of age who reported lower perceived risk for other STI (an inappropriate perception) were less likely to initiate sex (odds ratio [OR] 0.13, 95% confidence interval [CI] 0.03–0.69). Among all sexually experienced participants (57.5%) and in age-stratified analyses, baseline risk perceptions were not associated with subsequent number of sexual partners or condom use.
Conclusions: Risk perceptions after HPV vaccination were not associated with riskier sexual behaviors over the subsequent 6 months in this study sample.
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Trends in Maternal Morbidity Before and During Pregnancy in California
Moshe Fridman et al.
American Journal of Public Health, February 2014, Pages S49-S57
Objectives: We examined trends in maternal comorbidities in California.
Methods: We conducted a retrospective cohort study of 1 551 017 California births using state-linked vital statistics and hospital discharge cohort data for 1999, 2002, and 2005. We used International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify the following conditions, some of which were preexisting: maternal hypertension, diabetes, asthma, thyroid disorders, obesity, mental health conditions, substance abuse, and tobacco use. We estimated prevalence rates with hierarchical logistic regression models, adjusting for demographic shifts, and also examined racial/ethnic disparities.
Results: The prevalence of these comorbidities increased over time for hospital admissions associated with childbirth, suggesting that pregnant women are getting sicker. Racial/ethnic disparities were also significant. In 2005, maternal hypertension affected more than 10% of all births to non-Hispanic Black mothers; maternal diabetes affected nearly 10% of births to Asian/Pacific Islander mothers (10% and 43% increases, respectively, since 1999). Chronic hypertension, diabetes, obesity, mental health conditions, and tobacco use among Native American women showed the largest increases.
Conclusions: The prevalence of maternal comorbidities before and during pregnancy has risen substantially in California and demonstrates racial/ethnic disparity independent of demographic shifts.
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Whitney Witt et al.
American Journal of Public Health, February 2014, Pages S73-S80
Objectives: We determined whether and to what extent a woman’s exposure to stressful life events prior to conception (PSLEs) was associated with preterm birth and whether maternal age modified this relationship.
Methods: We examined 9350 mothers and infants participating in the first wave of the Early Childhood Longitudinal Study, Birth Cohort, a nationally representative sample of US women and children born in 2001, to investigate the impact of PSLEs on preterm birth in the United States. We estimated the effect of exposure on preterm birth with weighted logistic regression, adjusting for maternal sociodemographic and health factors and stress during pregnancy.
Results: Of the women examined, 10.9% had a preterm birth. In adjusted analyses, women aged 15 to 19 years who experienced any PSLE had over a 4-fold increased risk for having a preterm birth. This association differed on the basis of the timing of the PSLE.
Conclusions: Findings suggest that adolescence may be a sensitive period for the risk of preterm birth among adolescents exposed to PSLEs. Clinical, programmatic, and policy interventions should address upstream PSLEs, especially for adolescents, to reduce the prevalence of preterm birth and improve maternal and child health.
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Whitney Witt et al.
American Journal of Public Health, February 2014, Pages S81-S89
Objectives: We sought to determine if and to what extent a woman’s exposure to stressful life events prior to conception (PSLEs) were associated with subsequent infant birth weight by using a nationally representative sample of US women.
Methods: We examined 9350 mothers and infants participating in the first wave of the Early Childhood Longitudinal Study, Birth Cohort in 2001. Weighted regressions estimated the effect of exposure on very low and low birth weight, adjusting for maternal sociodemographic and health factors and stress during pregnancy.
Results: Twenty percent of women experienced any PSLE. In adjusted analyses, exposed women were 38% more likely to have a very low birth weight infant than nonexposed women. Furthermore, the accumulation of PSLEs was associated with reduced infant birth weight.
Conclusions: This was the first nationally representative study to our knowledge to investigate the impact of PSLEs on very low and low birth weight in the United States. Interventions aimed to improve birth outcomes will need to shift the clinical practice paradigm upstream to the preconception period to reduce women’s exposure to stress over the life course and improve the long-term health of children.
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A Quasi-Experimental Analysis of Maternal Altitude Exposure and Infant Birth Weight
Sammy Zahran et al.
American Journal of Public Health, February 2014, Pages S166-S174
Objectives: We analyzed singleton births to determine the relationship between birth weight and altitude exposure.
Methods: We analyzed 715 213 singleton births across 74 counties from the western states of Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, and Washington from January 1, 2000, to December 31, 2000. Birth data were obtained from the Division of Vital Statistics, National Center for Health Statistics, for registered births.
Results: Regression analyses supported previous research by showing that a 1000-meter increase in maternal altitude exposure in pregnancy was associated with a 75.9-gram reduction in birth weight (95% confidence interval = −84.1, −67.6). Quantile regression models indicated significant and near-uniform depressant effects from altitude exposure across the conditional distribution of birth weight. Bivariate sample-selection models showed that a 1000-meter increase in altitude exposure, over and above baseline residential altitude, decreased birth weight by an additional 58.8 grams (95% confidence interval = −98.4, −19.2).
Conclusions: Because of calculable health care–related costs associated with lower birth weight, our reported results might be of interest to clinicians practicing at higher altitudes.
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Construction of Early and Midlife Work Trajectories in Women and Their Association With Birth Weight
Miriam Mutambudzi & John Meyer
American Journal of Public Health, February 2014, Pages S58-S64
Objectives: We derived trajectories of the substantive complexity (SC) of work across mid-adult life in women and determined their association with term birth weight. SC is a concept that encompasses decision latitude, active learning, and ability to use and expand one’s abilities at work.
Methods: Using occupational data from the National Longitudinal Survey of Youth 1979 and O*NET work variables, we used growth mixture modeling (GMM) to construct longitudinal trajectories of work SC from the ages of 18 to 34 years. The association between work trajectories and birth weight of infants born to study participants was modeled using generalized estimating equations, adjusting for education, income, and relevant covariates.
Results: GMM yielded a 5-class solution for work trajectories in women. Higher work trajectories were associated with higher term birth weight and were robust to the inclusion of both education and income. A work trajectory that showed a sharp rise after age 24 years was associated with marked improvement in birth weight.
Conclusions: Longitudinal modeling of work characteristics might improve capacity to integrate occupation into a life-course model that examines antecedents and consequences for maternal and child health.
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Gentrification and Preterm Birth in New York City, 2008–2010
M. Huynh & A.R. Maroko
Journal of Urban Health, February 2014, Pages 211-220
Abstract:
Adverse birth outcomes have been linked to neighborhood level socioeconomic status. However, little work has examined the influence of social and economic change over time (i.e., gentrification) on health. This study aims to assess the association between gentrification and preterm birth (PTB) while examining the modifying effect of maternal race/ethnicity and educational attainment. New York City births, 2008–2010, (n = 126,165) were linked to a measure of gentrification at the community district level (n = 59). The gentrification measure was calculated using percent change in education level, poverty level, and median household income (MHI) between the 2005–2009 American Community Survey and the 1990 Census. PTB was defined as clinical gestational age less than 37 weeks. Generalized estimating equations were utilized to examine the association. Gentrification (i.e., increase in residents with a college education, increase in MHI, and decrease in residents living below the poverty line) was not associated with PTB. However, among Non-Hispanic Blacks, very high gentrification was adversely associated with PTB (AOR, 1.16; 95 % CI, 1.01–1.33) as compared to those who lived in a very low gentrified neighborhood. Among non-Hispanic Whites, living in a very high gentrified neighborhood was protective as compared to living in a very low gentrified neighborhood (AOR, 0.78; 95 % CI, 0.64–0.94). Although there is a need to develop a more nuanced measure of gentrification, these results indicate that changes in the economic character of a neighborhood may have a significant influence on birth outcomes.
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Jostein Grytten, Irene Skau & Rune Sørensen
Social Science & Medicine, March 2014, Pages 84–92
Abstract:
Birth weight is an important predictor of health and success in later life. Little is known about the effect of mothers’ education on birth weight. A few causal analyses have been done, but they show conflicting results. We estimated the effect of mothers’ education on birth weight by using data on a school reform in Norway. During the period 1960-1972, all municipalities in Norway were required to increase the number of compulsory years of schooling from seven to nine years. We used this education reform to create exogenous variation in the education variable. The education data were combined with large sets of data from the Medical Birth Registry and Statistics Norway. Since municipalities implemented the reform at different times, we have cross-sectional as well as time-series variation in the reform instrument. In the analyses, we controlled for municipality fixed effects, municipality-specific time-trends and mothers’ and infants’ year of birth. Using this procedure we found a fairly large effect of mothers’ education on birth weight. Increasing mothers’ education reduces the likelihood of low birth weight, even in a publically financed health care system. In interpreting these results it is important to keep in mind that we have examined only one channel, which is through birth weight, through which education may explain differences in health. There are other potential channels that should be explored by future research. In particular, it would be of interest to examine whether education has causal effects on the broader determinants of health, such as psychopathology, social capital and networks, and family stress and dysfunction.
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Maria Rita Testa
Advances in Life Course Research, forthcoming
Abstract:
Increasing shares of European women are making large investments in their human capital. Whether and to what extent these investments are in conflict with reproductive behavior are issues that have repercussions for fertility levels. Using two Eurobarometer survey data (2006 and 2011) on individuals clustered in the 27 EU countries, I investigate the relationship between women's education and lifetime fertility intentions. Results suggest that a positive association between women's level of education and lifetime fertility intentions exists at both the individual and country levels, as well as in a micro-macro integrated framework. The main explanation for these findings — which remains to be proven by future research — is that, in institutional contexts allowing highly educated women to have large families, women of reproductive ages are more prone to make investments in both human capital and family size, because these choices are not seen as incompatible alternatives.
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Socioeconomic Differences in the Unemployment and Fertility Nexus: Evidence from Denmark and Germany
Michaela Kreyenfeld & Gunnar Andersson
Advances in Life Course Research, forthcoming
Abstract:
Studies that have investigated the role of unemployment in childbearing decisions have often shown no or only barely significant results. We argue that many of these “non-findings” may be attributed to a neglect of group-specific differences in behavior. In this study, we examine how the association of unemployment and fertility varies by socio-demographic subgroups using data from the German Socio-Economic Panel (GSOEP) and from Danish population registers. We find that male unemployment is related to a postponement of first and second childbearing in both countries. The role of female unemployment is less clear at these two parities. Both male and female unemployment is positively correlated with third birth risks. More importantly, our results show that there are strong educational gradients in the unemployment and fertility nexus, and that the relationship between unemployment and fertility varies by socioeconomic group. Fertility tends to be lower during periods of unemployment among highly educated women and men, but not among their less educated counterparts.
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Selma Idring et al.
International Journal of Epidemiology, forthcoming
Background: The objectives of this study were to examine the independent and dependent associations of maternal and paternal age and risk of offspring autism spectrum disorders (ASD), with and without intellectual disability (ID).
Methods: The sample consisted of 417 303 Swedish children born 1984–2003. ASD case status (N = 4746) was ascertained using national and regional registers. Smoothing splines in generalized additive models were used to estimate associations of parental age with ASD.
Results: Whereas advancing parental age increased the risk of child ASD, maternal age effects were non-linear and paternal age effects were linear. Compared with mothers at the median age 29 years, those <29 had similar risk, whereas risk increased after age 30, with an odds ratio (OR) of 1.75 [95% (CI): 1.63–1.89] at ages 40–45. For fathers, compared with the median age of 32 years, the OR for ages 55–59 was 1.39 (1.29–1.50). The risk of ASD was greater for older mothers as compared with older fathers. For example, mothers aged 40–45 (≥97.2th percentile) had an estimated 18.63 (95% CI: 17.25–20.01) ASD cases per 1000 births, whereas fathers aged 55–59 (≥99.7th percentile) had 16.35 (95% CI: 15.11–17.58) ASD cases per 1000 births. In analyses stratified by co-parental age, increased risk due to advancing paternal age was evident only with mothers ≤35 years. In contrast, advancing maternal age increased risk regardless of paternal age. Advancing parental age was more strongly associated with ASD with ID, compared with ASD without ID.
Conclusions: We confirm prior findings that advancing parental age increases risk of ASD, particularly for ASD with ID, in a manner dependent on co-parental age. Although recent attention has emphasized the effects of older fathers on ASD risk, an increase of n years in maternal age has greater implications for ASD risk than a similar increase in paternal age.
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Wicked or Warranted? US press coverage of contraception 1873–1917
Ana Garner
Journalism Studies, forthcoming
Abstract:
This study examines the New York Times and the Los Angeles Times press coverage of contraception during one key period: 1873–1917. The first 30 years after the passage of the Comstock Act in 1873 were difficult for contraception advocates. The New York Times narrative reflected a battle between those who supported the Comstock Act and the men and women who opposed it. Conversely, the Los Angeles Times narrative portrayed the birth control debate as a wide-ranging battle of ideas occurring in a variety of venues. Press coverage revealed that the use of birth control was common and the real debate was over who had access and whether the information should be publicly available. The battle that began in 1873 is not over as contemporary press coverage reveals the debate over birth control continues.
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Stefanie Mollborn, Benjamin Domingue & Jason Boardman
Advances in Life Course Research, June 2014, Pages 1–15
Abstract:
Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys’ perceived norms, while peer network norms predict girls’ perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens’ likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys’ contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors.
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Jenni Pettay et al.
Behavioral Ecology and Sociobiology, January 2014, Pages 135-143
Abstract:
The fitness benefits of multiple mating determine the strength of sexual selection in each sex. This is traditionally quantified by the number of offspring born to once versus multiply mated individuals. In species with (bi)parental care, however, this measure may overestimate the benefits of multiple mating since having several mates can increase offspring number but decrease offspring quality. We analyzed short- and long-term fitness consequences of multiple marriages for both sexes in humans in preindustrial Finnish populations, where monogamy was socially enforced and remarriage was possible only after widowhood. Remarriage increased the lifetime number of offspring sired by men by lengthening their reproductive span but was unrelated to the lifetime number of births for women. However, neither men's nor women's long-term fitness, measured as their number of grandchildren, was significantly increased or decreased by remarriage. These associations were not modified by individual wealth. Our results suggest that despite increasing the number of offspring sired by men, the long-term fitness benefits of serial monogamy may be negligible for both sexes when parental investment is crucial for offspring success and continues to adulthood. They also demonstrate the importance of incorporating long-term fitness measures when quantifying the benefits of mating and reproductive strategies.