Misconception
Advanced paternal age is associated with lower facial attractiveness
Susanne Huber & Martin Fieder
Evolution and Human Behavior, forthcoming
Abstract:
In view of disease risk, Kong et al. (2012) demonstrated that most of the new mutations are explained by the age of the father at conception. Accordingly, paternal age effects have been found for a variety of offspring traits, from physical and mental health to intelligence. Here, we investigated whether facial attractiveness is significantly associated with paternal age. We used the Wisconsin Longitudinal Study (n = 4018 male and 4416 female high school graduates) to analyze the association between an individual’s father’s age at birth and that individual’s facial attractiveness (estimated by rating the high school yearbook photographs from 1957), controlling for sex, age as well as mother’s age. We find that subject’s facial attractiveness decreased with advancing paternal but not maternal age, suggesting that facial attractiveness might be a cue of an individual’s new mutation load.
----------------------
Héctor Bellido & Miriam Marcén
Labour Economics, April 2014, Pages 56–70
Abstract:
This paper examines the effect of divorce law reforms on fertility using the history of legislation on divorce across Europe. Because the introduction of more liberal divorce laws permanently reduces the value of marriage relative to divorce, these permanent shocks should also affect the fertility decisions of individuals, to the extent that children are considered marriage-specific capital. Our results suggest that divorce liberalization has a negative and permanent effect on fertility. Divorce reforms have decreased the Total Fertility Rate by about 0.2. The magnitude of the effect is sizable, taking into account that the average Total Fertility Rate declined from 2.84 in 1960 to 1.66 in 2006. These findings are robust to alternative specifications and controls for observed (the liberalization of abortion and the availability of the birth-control pill, among others) and unobserved country-specific factors, as well as time-varying factors at the country level. Supplemental analysis, developed to understand the mechanisms through which divorce law reforms affect fertility, shows that both marital and out-of-wedlock fertility decline, but that the impact on marital fertility varies, depending on whether couples are married prior to or after the divorce law reforms, pointing to a selection effect on the composition of marriages.
----------------------
AIDing contraception: HIV and recent trends in abortion
Andrew Hussey, Alex Nikolsko-Rzhevskyy & Jay Walker
Applied Economics, Spring 2014, Pages 1788-1803
Abstract:
Using a difference-in-differences estimation framework and state-level data, we investigate the potential role of HIV/AIDS in contributing to declining abortion utilization in the United States. Our results suggest that the perceived risk of HIV contraction negatively affected unwanted pregnancies. Specifically, a 10% increase in HIV incidence is associated with 0.34–1.1% fewer abortions per live births, an effect that can account for at least one-tenth of the sharp decline in abortions observed from the early 1980s to mid-1990s.
----------------------
Change in Sexual Behavior With Provision of No-Cost Contraception
Gina Secura et al.
Obstetrics & Gynecology, April 2014, Pages 771–776
Objective: To estimate whether providing no-cost contraception is associated with the number of sexual partners and frequency of intercourse over time.
Methods: This was an analysis of the Contraceptive CHOICE Project, a prospective cohort study of 9,256 adolescents and women at risk for unintended pregnancy. Participants were provided reversible contraception of their choice at no cost and were followed-up with telephone interviews at 6 and 12 months. We examined the number of male sexual partners and coital frequency reported during the previous 30 days at baseline compared with 6-month and 12-month time points.
Results: From our total cohort, 7,751 (84%) women and adolescents completed both 6-month and 12-month surveys and were included in this analysis. We observed a statistically significant decrease in the fraction of women and adolescents who reported more than one sexual partner during the past 30 days from baseline to 12 months (5.2% to 3.3%; P<.01). Most participants (70-71%) reported no change in their number of sexual partners at 6 and 12 months, whereas 13% reported a decrease and 16% reported an increase (P<.01). More than 80% of participants who reported an increase in the number of partners experienced an increase from zero to one partner. Frequency of intercourse increased during the past 30 days from baseline (median, 4) to 6 and 12 months (median, 6; P<.01). However, greater coital frequency did not result in greater sexually transmitted infection incidence at 12 months.
Conclusions: We found little evidence to support concerns of increased sexual risk-taking behavior subsequent to greater access to no-cost contraception.
----------------------
Assessing the Impact of the Maternity Capital Policy in Russia
Fabián Slonimczyk & Anna Yurko
Labour Economics, forthcoming
Abstract:
With declining population and fertility rates below replacement levels, Russia is currently facing a demographic crisis. Starting in 2007, the federal government has pursued an ambitious pro-natalist policy. Women who give birth to at least two children are entitled to “maternity capital” assistance ($11,000). In this paper we estimate a structural dynamic programming model of fertility and labor force participation in order to evaluate the effectiveness of the policy. We find that the program increased long-run fertility by about 0.15 children per woman.
----------------------
Does grief transfer across generations? In-utero deaths and child outcomes
Sandra Black, Paul Devereux & Kjell Salvanes
NBER Working Paper, March 2014
Abstract:
While much is now known about the effects of physical health shocks to pregnant women on the outcomes of the in-utero child, we know little about the effects of psychological stresses. One clear form of stress to the mother comes from the death of a parent. We examine the effects of the death of the mother’s parent during pregnancy on both the short-run and the long-run outcomes of the infant. Our primary specification involves using mother fixed effects — comparing the outcomes of two children with the same mother but where a parent of the mother died during one of the pregnancies — augmented with a control for whether there is a death around the time of the pregnancy in order to isolate true causal effects of a bereavement during pregnancy. We find small negative effects on birth outcomes, and these effects are bigger for boys than for girls. The effects on birth outcomes seems to be driven by deaths due to cardiovascular causes suggesting that sudden deaths are more difficult to deal with. However, we find no evidence of adverse effects on adult outcomes. The results are robust to alternative specifications.
----------------------
Very Low Birthweight: Dysregulated gestation versus evolutionary adaptation
Ralph Catalano et al.
Social Science & Medicine, forthcoming
Abstract:
Much medical literature attributes persistently high rates of very low birthweight (VLBW) to "dysregulated" gestation. We offer the alternative view that natural selection conserved well-regulated, though nonconscious, decisional biology that protects the reproductive fitness of women by spontaneously aborting gestations that would otherwise yield frail infants, particularly small males. Modern obstetric practice, however, converts some fraction of these erstwhile spontaneous abortions into live births of very small infants. We further propose that the nonconscious decisional biology of gestation exhibits preferences also seen in consciously made decisions. We hypothesize that the incidence of VLBW among male infants should vary with the population’s self-reported intentions to assume financial risk. We apply time-series modeling to monthly birth counts by sex and weight from the Swedish Medical Birth Registry between January 1993 and December 2010. We gauge risk aversion with monthly data from the Micro Index of the Swedish Consumer Tendency Survey (MISCT). Consistent with our argument that nonconscious decisional biology shares risk aversion with conscious decisions, we find that the incidence of VLBW among male infants in Sweden varies with the population’s self-reported intentions to assume financial risk. We find increases above expected odds of a very low weight infant among males born 1 month after increases above expected levels of self-reported risk aversion in the Swedish population. We offer this finding as support for the argument that persistently high rates of VLBW arise, at least in part, from a combination of medical interventions and mechanisms conserved by natural selection to protect reproductive fitness.
----------------------
Family Planning: Fertility and Parenting Ideals in Urban Adolescents
Abigail Chipman & Edward Morrison
Archives of Sexual Behavior, forthcoming
Abstract:
Previous research on contemporary childbearing has identified a strong relationship between environmental conditions, such as economic deprivation, and early fertility. Less is known, however, about the social-psychological mechanisms that mediate these environmental predictors of early fertility at the individual level and the extent to which they are consistent with life history theory. The aim of this research was to determine how kin networks, mating and reproductive risk taking, discount preference, and perceptions of environmental risk predict individual differences in fertility preferences in a socioeconomically diverse sample of adolescents. Questionnaires were administered to 333 adolescents (245 female) between the ages of 13 and 19 years, attending schools in urban neighborhoods in Hampshire, United Kingdom. Individuals’ subjective life expectancy and perception of their environment better predicted fertility intentions than did structural measures of environmental quality. This suggests that by the time individuals reach adolescence they are monitoring the morbidity and mortality risk of their environment and are adjusting their reproductive ideals accordingly. Levels of grandparental investment also predicted parenting preferences, suggesting cooperative breeding may play a role in reproductive decision making. There was also evidence that patterns of risk taking behaviors could be adaptive to environmental conditions and some evidence that pro-natal attitudes, as opposed to knowledge of safe sexual practice, predict adolescents’ reproductive strategies. These findings suggest that studying individuals’ psychology from a life history perspective adds to my understanding of the persistently high rates of early reproduction within developed countries, such as the United Kingdom.
----------------------
ByKate Grindlay, Diana Greene Foster & Daniel Grossman
Perspectives on Sexual and Reproductive Health, forthcoming
Context: Women having abortions are at high risk for future unintended pregnancy, and removing the prescription requirement for oral contraceptives may increase continuation and adoption of this effective method.
Methods: A survey fielded from May to July 2011 collected information from 651 women aged 15–46 seeking abortion services at six urban clinics from across the United States. Descriptive statistics, chi-square tests and logistic regression analyses were conducted to estimate women's interest in over-the-counter access to oral contraceptives.
Results: Eighty-one percent of respondents supported over-the-counter access to oral contraceptives; while 42% of women planned to use the pill after their abortion, 61% said they would likely use this method if it were available over the counter. Thirty-three percent of women who planned to use no contraceptive following their abortion said they would use an over-the-counter pill, as did 38% who planned to use condoms afterward. In multivariable analysis, several subgroups had increased odds of likely over-the-counter use: women who were older than 19 (odds ratios, 1.8 for those aged 20–29 and 1.6 for those aged 30–46), were uninsured (1.5), had ever used the pill (1.4), had had difficulty obtaining a prescription refill for hormonal contraceptives (2.7) or planned to use the pill postabortion (13.0). By contrast, compared with white respondents, women of other races or ethnicities were less likely to say they would use over-the-counter pills (0.4–0.7).
Conclusions: Interest in a hypothetical over-the-counter oral contraceptive was high in this sample, and this delivery model has the potential to reduce unintended pregnancy among abortion patients.
----------------------
Hidden consequences of a first-born boy for mothers
Andrea Ichino, Elly-Ann Lindström & Eliana Viviano
Economics Letters, June 2014, Pages 274–278
Abstract:
Women whose first child is a boy work less than women with first-born girls. After a first-born boy the probability that women have more children increases. Higher fertility is a possible explanation for the lower labor supply of mothers.
----------------------
Empowering Women: The Effect of Schooling on Young Women's Knowledge and Use of Contraception
Mabel Andalón, Jenny Williams & Michael Grossman
NBER Working Paper, March 2014
Abstract:
Large differences in fertility between women with high and low levels of education suggest that schooling may have a direct impact on knowledge and use of contraception. We investigate this issue using information on women in Mexico. In order to identify the causal effect of schooling, we exploit temporal and geographic variation in the number of lower secondary schools built following the extension of compulsory education in Mexico from 6th to 9th grade in 1993. We show that raising females' schooling beyond 6th grade increases their knowledge of contraception during their reproductive years and increases their propensity to use contraception at sexual debut. This indicates that the impact of schooling on women's wellbeing extends beyond improved labor market outcomes and includes greater autonomy over their fertility.
----------------------
Early Motherhood and Long-Term Economic Outcomes: Findings From a 30-Year Longitudinal Study
Sheree Gibb et al.
Journal of Research on Adolescence, forthcoming
Abstract:
This study examined linkages between early motherhood (before age 20) and long-term economic disadvantage, using data from a birth cohort of 509 New Zealand-born women followed to age 30. Associations between early motherhood and economic outcomes were examined using linear and logistic regression models and were adjusted for a range of prepregnancy factors. The findings suggested that early motherhood was associated with several indicators of economic disadvantage at age 30, including working fewer hours, welfare dependence, lower personal incomes, and exposure to economic hardship. These associations remained statistically significant even after extensive adjustment for confounding factors. These findings suggest that having a child before age 20 leads to long-term economic disadvantage that persists for at least a decade.
----------------------
Prime Time: Long-Term Sexual Health Outcomes Of a Clinic-Linked Intervention
Renee Sieving et al.
Perspectives on Sexual and Reproductive Health, forthcoming
Context: Evidence about long-term effects of preventive health services for youth with complex needs is lacking. Prime Time, a youth development intervention, aims to reduce pregnancy risk among vulnerable adolescent females seeking clinic services.
Methods: In a randomized trial, 253 sexually active females aged 13–17 who were at high risk for pregnancy were assigned to the Prime Time intervention or usual clinic services. The 18-month intervention, initiated in 2007–2008, comprised regular meetings with case managers and participation in youth leadership groups. Trial participants completed surveys at baseline and 30 months. Regression analyses were used to evaluate differences between groups in sexual and psychosocial outcomes at follow-up.
Results: At 30 months, the intervention group reported more months of consistent condom use (adjusted means, 1.8 vs. 1.1) and dual contraceptive use (0.9 vs. 0.3) in the past seven months than did controls. The intervention was most effective in promoting consistent use among participants with relatively high levels of connectedness to family or school. Fifteen percent of intervention participants, but only 6% of controls, reported having abstained from sex in the past six months (adjusted odds ratio, 2.9). Moreover, among high school graduates, those in the intervention group were more likely than those in the control group to have enrolled in college or technical school (72% vs. 37%; odds ratio, 4.5).
Conclusion: Health services grounded in a youth development framework can lead to reductions in sexual risk among vulnerable youth that are evident one year following conclusion of services.
----------------------
Trans fatty acid intake is inversely related to total sperm count in young healthy men
Jorge Chavarro et al.
Human Reproduction, March 2014, Pages 429-440
Study question: Is intake of fatty acids related to semen quality among young men?
Study design, size, duration: Cross-sectional study of 209 men recruited between October 2010 and November 2011.
Participants/materials, setting, methods: A group of 209 healthy young university students 18–23 years of age provided a semen sample and completed a previously validated food frequency questionnaire. The association between intake of fatty acids with semen quality parameters (sperm concentration, motility, morphology and total count) was assessed using multivariate linear regression.
Main results and the role of the chance: Trans fatty acid intake was inversely related to total sperm count after adjusting for potential confounders (P, trend = 0.03). The multivariate adjusted mean (95% confidence interval) total sperm count in increasing quartiles of trans fat intake was 144 (110–190), 113 (87–148), 100 (18–130) and 89 (69–117). There also was an inverse association between cholesterol intake and ejaculate volume (P, trend = 0.04). No other statistically significant relations were observed.
Wider implications of the findings: The results of this study, together with previous experimental work in rodents and biomarker studies among infertility patients, suggest that intake of trans fatty acids may be related to lower semen quality. Although the data provide further evidence that diet is a modifiable factor that could impact male fertility, it is not known whether the observed differences in sperm count translate into differences in fertility.
----------------------
IVF culture medium affects post-natal weight in humans during the first 2 years of life
Sander Kleijkers et al.
Human Reproduction, April 2014, Pages 661-669
Study question: Is post-natal growth during the first 2 years of life in IVF singletons affected by type of medium used for culturing human embryos during an IVF treatment?
Study design, size, duration: From July 2003 to December 2006, a total of 1432 IVF treatment cycles with fresh embryo transfer were randomly allocated to have all embryos cultured in medium from Vitrolife AB (n = 715) or from Cook (n = 717). Two years after delivery, questionnaires were sent to the parents of all children requesting data about weight, height and head circumference around 1, 2, 3, 4, 6, 7.5, 9, 11, 14, 18 and 24 months of age. These measurements were collected as part of the children's health programme at municipal infant welfare centres in the Netherlands by health professionals unaware of this study.
Participants/materials, setting, methods: Patients requiring donor oocytes or applying for PGD were excluded from the study. From the 294 live born singletons that fulfilled our inclusion criteria, 29 were lost to follow-up. The remaining 265 singletons (Cook group: 117, Vitrolife group: 148) were included in the analysis. Data analysis included linear regression, to compare cross-sectionally weight standard deviation score (SDS), height SDS and head circumference, and the first order Berkey-Reed model for a longitudinal analysis of the growth data.
Main results and the role of chance: Singletons in the Vitrolife group were heavier during the first 2 years of life compared with singletons in the Cook group. Cross-sectional analyses showed that adjusted weight SDS differed between groups at 1 (0.35 ± 0.14, P = 0.010), 2 (0.39 ± 0.14, P = 0.006), 3 (0.35 ± 0.14, P = 0.011), 4 (0.30 ± 0.13, P = 0.020), 11 (0.28 ± 0.13, P = 0.036), 14 (0.32 ± 0.13, P = 0.014) and 24 (0.39 ± 0.15, P = 0.011) months of age, while adjusted height SDS was only significantly different at 1 (0.21 ± 0.11, P = 0.048) month of age. Head circumference was similar between the two groups at all ages. Longitudinal analyses showed that both post-natal weight (P = 0.005) and height (P = 0.031) differed between the groups throughout the first 2 years of life, while the growth velocity was not significantly different between the two groups.
Wider implications of the findings: The effect of culture medium during the first few days after fertilization on prenatal growth and birthweight persists during the first 2 years of life. This suggests that the human embryo is sensitive to its very early environment, and that the culture medium used in IVF may have lasting consequences. Further monitoring of the long-term growth, development and health of IVF children is therefore warranted.
----------------------
A. Pinborg et al.
Human Reproduction, March 2014, Pages 618-627
Study question: Are singletons born after frozen embryo transfer (FET) at increased risk of being born large for gestational age (LGA) and if so, is this caused by intrinsic maternal factors or related to the freezing/thawing procedures?
Study design, size, duration: The national register–based controlled cohort study involves two populations of FET singletons. The first population (A: total FET cohort) consisted of all FET singletons (n = 896) compared with singletons born after Fresh embryo transfer (Fresh) (n = 9480) and also with that born after natural conception (NC; n = 4510) in Denmark from 1997 to 2006. The second population (B: Sibling FET cohort) included all sibling pairs, where one singleton was born after FET and the consecutive sibling born after Fresh embryo transfer or vice versa from 1994 to 2008 (n = 666). The sibling cohort included n = 550 children with the sibling combination first child Fresh/second child FET and n = 116 children with the combination first child FET/second child Fresh.
Participants/materials, setting, methods: Main outcome measures were LGA defined as birthweight of >2 SD from the population mean (z-score >2) according to Marsáls curves. Macrosomia was defined as birthweight of >4500 g. Crude and adjusted odds ratios (AORs) of LGA and macrosomia were calculated for FET versus Fresh and versus NC singletons in the total FET cohort. Similarly, AOR was calculated for FET versus Fresh in the sibling cohort. Adjustments were made for maternal age, parity, child sex, year of birth and birth order in the sibling analyses. Meta-analyses were performed by pooling our data with the previously published cohort studies on LGA and macrosomia.
Main results and the role of chance: The AORs of LGA (z-score >2) and macrosomia in FET singletons versus singletons conceived after Fresh embryo transfer were 1.34 [95% confidence interval (95% CI) 0.98–1.80] and 1.91 (95% CI 1.40–2.62), respectively. The corresponding risks for FET versus NC singletons were 1.41 (95% CI 1.01–1.98) for LGA and 1.67 (95% CI 1.18–2.37) for macrosomia. The increased risk of LGA and macrosomia in FET singletons was confirmed in the sibling cohort also after adjustment for birth order. Hence, the increased risk of LGA in FET singletons cannot solely be explained by being the second born or by intrinsic maternal factors, but may also partly be related to freezing/thawing procedures per se. In the meta-analysis, the summary effects of LGA and macrosomia in FET versus singletons conceived after Fresh embryo transfer were AOR 1.54 (95% CI 1.31–1.81) and AOR 1.64 (95% CI 1.26–2.12), respectively. The corresponding figures for FET versus NC singletons were for LGA AOR 1.32 (95% CI 1.07–1.61) and macrosomia AOR 1.41 (95% CI 1.11–1.80), respectively.
----------------------
G.M. Chambers et al.
Human Reproduction, March 2014, Pages 601-610
Study question: Do singletons conceived following assisted reproduction technologies (ARTs) have significantly different hospital utilization, and therefore costs, compared with non-ART children during the first 5 years of life?
Study design, size, duration: A population cohort study using linked birth, hospital and death records. Perinatal outcomes, hospital utilization and costs, and mortality rates were compared for non-ART and ART singletons to 5 years. Adjustments were made for maternal age, parity, sex, birth year, socioeconomic status and funding source. Australian Diagnosis Related Groups cost-weights were used to derive costs. All costs are reported in 2009/2010 Australian dollars.
Participants/materials, setting, methods: All babies born in Western Australia between 1994 and 2003 were included; 224 425 non-ART singletons and 2199 ART conceived singletons. Hospital admission and death records in Western Australia linked to 2008 were used.
Main results and the role of chance: Overall, ART singletons had a significantly longer length of stay during the birth-admission (mean difference 1.8 days, P < 0.001) and a 20% increased risk of being admitted during the first 5 years of life. The average adjusted difference in hospital admission costs up to 5 years of age was $2490, with most of the additional cost occurring during the birth-admission ($1473). The independent residual cost associated with ART conception was $342 during the birth-admission and an additional $548 up to 5 years of age, indicating that being conceived as an ART child predicts not only higher birth-admission costs but excess costs to at least 5 years of age.
----------------------
Randomized Trial of Harp Therapy During In Vitro Fertilization–Embryo Transfer
Erin Murphy et al.
Journal of Evidence-Based Complementary & Alternative Medicine, April 2014, Pages 93-98
Objective: This study evaluated whether harp therapy reduces levels of stress and improves clinical outcomes in patients undergoing embryo transfer.
Design: This prospective randomized trial enrolled 181 women undergoing embryo transfer, who were randomized to harp therapy during embryo transfer or standard treatment. Patients underwent standardized psychological testing and physiologic assessment of stress.
Results: No statistically significant differences were found in the heart and respiratory rates, nor was there a significant difference in event-based anxiety at baseline. Harp therapy had a significantly larger decrease in state anxiety from pre– to post–embryo transfer. Clinical pregnancy was 53% versus 48% for the harp therapy and standard treatment groups, respectively.
Conclusion: Harp therapy decreases state, or event-based, anxiety, significantly lowering state scores posttransfer and having a positive effect on acute levels of stress. There was an increased pregnancy rate, but larger sample sizes are needed to evaluate whether harp therapy has an effect on clinical outcomes.