Consequences of teenage childbearing on child health

This paper uses national longitudinal data to analyze the effects of having a teen mother on child health outcomes from birth to young adulthood. We use an empirical strategy that relies on miscarriages to put bounds on the causal effects of teen childbearing. Results show that having a teen mother does not have negative health consequences for children. In addition, children of teen mothers report fewer diagnosed disorders and conditions requiring medical attention. The results suggest that policies focused on delaying teen childbearing will not improve child health outcomes.     

Labor and delivery complications among teenage mothers

A broad set of academic literatures shows that childbearing is associated with a variety of negative health outcomes for teenage mothers. Many researchers question whether teenage childbearing is the causal explanation for the negative outcomes (i.e., whether there is a biological effect of teenage childbearing or whether the relationship is due to other factors correlated with health and teenage childbearing). This study investigates the relationship between teenage childbearing and labor and delivery complications using a panel of confidential birth certificate data over the period from 1994 to 2003 from the state of Texas. Findings show that compared to mothers aged 25 to 29 having their first child, teenager mothers appear to have superior health in most--but not all--labor and delivery outcomes.     

Aetiology of teenage childbearing: reasons for familial effects.

The aims of the present study were to evaluate the contribution of the genetic and environmental factors to the risk of teenage childbearing, and to study whether life style, socio-economic conditions, and personality traits could explain possible familial effects. We linked two population-based registers: the Swedish Twin Register and the Swedish Medical Birth Register. The study covers female twin pairs born between 1953 and 1958, having their first infant before the age of 30 years (n = 1885). In order to separate familial effects from other environmental influences, and genetic effects from shared environmental effects, only complete twin pairs with known zygosity were included, in all 260 monozygotic and 370 dizygotic twin pairs. We used quantitative genetic analyses to evaluate the importance of genetic and environmental effects for liability to teenage childbearing. Logistic regression analyses were used to estimate the effects of life style, socio-economic situation, and personality on the probability of teenage childbearing, and to study whether psychosocial factors could explain possible familial effects. Fifty-nine percent (0-76%) of the variance in being a teenage mother was attributable to heritable factors; 0% (0-49%) was due to shared environmental factors; and 41% (23-67%) was explained by non-shared environmental factors. Thus, the data were consistent with the hypothesis that the familial aggregation of teenage childbearing is completely explained by genetic factors, although the alternative hypothesis that familial aggregation is entirely explained by shared environmental factors cannot be ruled out. Significant effects of smoking habits, housing conditions, and educational level were found in relation to liability to teenage childbearing. However, the familial effects on risk of teenage childbearing were not mediated through similarities in life style and socio-economic factors. When studying risk factors for teenage childbearing, it is recommended to include life style and socio-economic variables as well as information about family history of teenage childbearing. Twin Research (2000) 3, 23-27.     

Effect of an abrupt change in sexual and reproductive health policy on teen birth rates in Ecuador, 2008–2017

Several countries have implemented “family-centered” abstinence-only policies for teenagers, as opposed to encouraging utilization and expansion of reproductive health services and education. Little is known, however, about the effects of these more restrictive policies on adolescent birth rates at the national level or their differential effects by race and ethnicity. The extant literature is even scarcer in low- and middle-income countries. We analyze an unexpected policy change in Ecuador that abruptly reversed course and restricted reproductive health services for teenage women in 2014. We use a canton- and time-fixed effects difference-in-differences analysis of Ecuador’s 221 cantons with time-varying controls to analyze the impact of the abrupt policy change on the difference of teen (15−19 years) minus young adult (20−24 years) birth rates. In a difference-in-difference-in-differences analysis, the policy change increases birth rates by 8.5 births per 1000 women in cantons with higher indigenous concentration. Results are robust to changes in the comparison population (young adults vs. women in their late 20 s or in their early 30 s), pre-intervention control periods, population weighting, serial correlation, logarithmic model specification, adjustments for intervention year, definition of indigenous concentration, and potential delays in policy implementation.     

Experiential and hormonal correlates of maternal behavior in teen and adult mothers

This study explores the role of cortisol and early life experiences in the regulation of maternal behavior and mood in teen and adult mothers. Primiparous mothers (n=119) (teen mothers < 19 years, n=42), young mothers (19-25 years, n= 4), and mature mothers, (>25 years, n=43) were assessed for their maternal behavior, mood, and hormonal profile at approximately 6 weeks postpartum. Outcome measures were analyzed as a function of age and early life experience. Results showed an interaction between age and type of maternal behavior, where teen mothers engaged in more instrumental (e.g. changing diapers, adjusting clothes) less affectionate (e.g., stroking, kissing, patting) behavior, and mature mothers engaged in more affectionate and less instrumental behavior. When groups were reassessed based on early life experience (consistency of care during the first 12 years of life: consistent care; having at least one consistent caregiver, inconsistent care; having multiple and changing caregivers), an interaction was also found between consistency of care and type of behavior shown, where mothers who received inconsistent care engaged in more instrumental and less affectionate behavior. Compared to mature mothers, teen mothers who were breast feeding also had higher salivary cortisol levels, and high cortisol in teen mothers related to decreased fatigue and increased energy. These results suggest that early life experiences are linked to mothering behavior and are consistent with the emerging human and animal literature on intergenerational effects of mothering style.     

Mental health in primary care for adolescent parents

Mental health care is important for everyone, especially teenagers. However, seeking mental health services may be challenging for teenagers, particularly when they are also parents. Offering mental health care in a safe, attractive and easily accessible manner, such as primary care, increases the chances that teenage parents will receive help. Comprehensive care models need to be established to address the many needs that at-risk young mothers and their children face. There are a number of programmes available to teenage mothers that either address healthcare and psychosocial needs or focus primarily on improvements in parenting skills; yet an integrated model that delivers medical, psychiatric and psychosocial care and facilitates positive parenting skills seems to be missing. Through a university–community partnership we have recently developed a model curriculum – the Mom Power (MP) group programme – at the University of Michigan which aims to close this gap in service delivery. We elaborate on core elements and key features of this 10-week group intervention programme for high-risk teenage mothers and their children, and present preliminary outcomes data. Analyses on the first 24 MP group graduates suggest that despite ongoing life trauma during the intervention period, teenage mothers show improvements in depression and post-traumatic stress disorder symptoms post intervention, and also self-rate as less guilty and shameful regarding their parenting skills after programme completion. Although preliminary, due to design and statistical limitations, these results show promise regarding feasibility and effectiveness of this integrated approach for teenage mothers with young children delivered through primary care.     

The fitness of twin mothers: evidence from rural Gambia

We used a longitudinal database from a natural fertility population in rural Gambia to compare the overall fertility of mothers who had given birth to twins at some point in their reproductive history and mothers who had only ever given birth to singletons. We found that twin mothers had shorter birth intervals, higher age‐specific fertility and more surviving children than singleton mothers. This suggests that, despite the considerably higher mortality of twins found in this population, twin mothers have a fitness advantage over singleton mothers, even in the absence of modern medical care. We ran a simple simulation model to estimate the relative fitness of twin and singleton mothers, and found that the model also estimated higher fitness for twin mothers. Further, girls who went on to become twin mothers were of higher anthropometric status during their teenage years than those who became singleton mothers.     

Gastroschisis, low maternal age, and fetal morbidity outcomes

OBJECTIVE: To determine if the risk for fetal growth inhibition among gastroschisis-afflicted fetuses is heightened among younger gravidas (teen mothers). METHOD: This was a retrospective cohort study on live-born infants with isolated gastroschisis delivered in New York State from 1983 through 1999. We compared infants of mature (>20 years) mothers with those of younger (<20 years) mothers with respect to the following indices of fetal morbidity outcomes: low birth weight and very low birth weight, preterm and very pre-term, and small for gestational age. We used adjusted odds ratios to approximate relative risks. RESULTS: A total of 368 infants with isolated gastroschisis were analyzed. The two groups differed in terms of mean gestational age at delivery [Mean + standard deviation(SD) for infants with gastroschisis born to mature mothers = 37.2 weeks +/- 2.8 versus 36.3 weeks + 3.6 for those of teenage mothers(p = 0.01)], as well as mean birth weight [mean birth weight +/- SD for infants with gastroschisis born to mature mothers = 2562.4 grams +548.8 versus 2367.9 grams +/- 645.2 for those of younger mothers (p = 0.004)]. Infants of teen mothers were about twice as likely to be of low birth weight (OR = 1.70; 95% CI = 1.05-2.77) and about three times as likely to be born very preterm when compared to those of mature mothers (OR = 2.80; 95% Cl = 1.02-8.00). No significant differences were observed with respect to very low birth weight, pre-term and small for gestational age. CONCLUSION: Low maternal age appears to be a risk factor for low birth weight and very preterm birth among gastroschisis-affected fetuses. This information is potentially useful for planning by care providers and in counseling affected parents.     

Effects of motherhood on physiological and subjective responses to infant cries in teenage mothers: a comparison with non-mothers and adult mothers

The present study was designed to determine whether becoming a mother during the adolescent period changes maternal responsiveness or maternal motivation, assessed through hormonal, autonomic, and hedonic responses to recorded infant cries and interactions with their babies. Fifty-six teen mothers were compared to 58 teen non-mothers and 49 adult mothers. Teen mothers reported more sympathy and alertness in response to recorded infant cries compared to non -mother teens; however, among the teen women there were no differences between mothers and non-mothers in heart rate and cortisol responses to infant cries. In contrast, in comparison to adult mothers, teen mothers reported the same levels of sympathy and alertness to infant cries; however, adult mothers showed an 'alerted' pattern of heart rate and cortisol response to infant cries not seen in the teen mother group. Inclusion of the covariate, fathers' employment classification as an index of SES or time of testing and cortisol sampling did not affect this pattern of results. Taken together, these results show that where self-report is used as a measure of maternal responsiveness, teen mothers are no different in responsiveness than adult mothers; however, where physiological and interactional measures of responsiveness are considered, teen mothers are less likely to show heightened or selective responses to infant cries or respond 'attentively' to the infant.     

Reproduction: the Canadian family in transition

3 trends suggest that the reproductive function of the Canadian family is in transition. 1st, fertility has fallen and remains below the replacement level. In 1985, the total fertility rate was 1.67, the lowest in 60 years. Since 1971, it has not risen above 2.1 births/woman, the replacement level. 2nd, an increasing proportion of women are spending a larger part of their lives without having any children. In the 1981 census, 22% of ever-married women between 15 and 44 years had not yet borne children, compared with only 14% recorded in the 1961 census. While the proportion of women who are childless at the end of their reproductive years has risen only slightly, a larger number of women are postponing having children even as the risk of becoming sterile in the interim becomes greater. The combined effect of postponing both marriage and childbearing will most probably be to increase the proportion of women remaining without children. The 3rd trend is the increasing proportion of women who are having children without getting married. Among the consequences of premarital pregnancy are the stress on single mothers, the need for social assistance, the cost of maintenance programs, and the need for more child care. These changes in attitude toward marriage and family formation could have major implications for individuals and society. A fertility rate below replacement level could be stressful for society, resulting in population decline, and changes in age structure that could negatively affect the economy.     

Age estimates derived from hard parts of swordfish Xiphias gladius from the north-western Mediterranean Sea

Accurate age estimates for fish are critical for properly understanding stock dynamics and health; this is particularly true for larger billfishes. Here we determined the most accurate aging estimation methods for swordfish (Xiphias gladius). We compared age estimates obtained from fin-ray sections, otolith sections, whole otoliths, and vertebrae collected from 87 swordfish off the east coast of Corsica. Age estimates from otolith sections were most consistently estimated across different readers (lowest average percentage error), followed by fin-ray sections, third vertebrae, and whole otoliths. When the age estimates from the otolith sections were compared with the other three age sclerochronological methods, we found the average percentage error to be lowest between the otolith section and fin-ray methods. However, age estimates from fin rays proved most useful for estimating swordfish younger than 6 years, as the fin ray-based age diverged from that of the otolith sections as the swordfish aged. Combining fin ray and otolith section techniques, we estimated the growth parameters of 1–12-year-old females (L_∞ = 259.412, k = 0.113, t₀ = −2.499) and 1–7-year-old males (L_∞ = 175.543, k = 0.202, t₀ = −2.239). We found that females grew significantly faster than males after 3 years and remained larger thereafter. Our calculated growth rates for this region of the north-western Mediterranean Sea were lower than those of the Atlantic, Pacific, and eastern Mediterranean Sea swordfish populations, and similar to growth rates recorded for the western Mediterranean Sea populations. Our study provides critical knowledge on biological-related parameters to serve as a guide for preserving the swordfish population in the Mediterranean Sea.     

Evaluating indirect genetic effects of siblings using singletons

Estimating effects of parental and sibling genotypes (indirect genetic effects) can provide insight into how the family environment influences phenotypic variation. There is growing molecular genetic evidence for effects of parental phenotypes on their offspring (e.g. parental educational attainment), but the extent to which siblings affect each other is currently unclear. Here we used data from samples of unrelated individuals, without (singletons) and with biological full-siblings (non-singletons), to investigate and estimate sibling effects. Indirect genetic effects of siblings increase (or decrease) the covariance between genetic variation and a phenotype. It follows that differences in genetic association estimates between singletons and non-singletons could indicate indirect genetic effects of siblings if there is no heterogeneity in other sources of genetic association between singletons and non-singletons. We used UK Biobank data to estimate polygenic score (PGS) associations for height, BMI and educational attainment in self-reported singletons (N = 50,143) and non-singletons (N = 328,549). The educational attainment PGS association estimate was 12% larger (95% C.I. 3%, 21%) in the non-singleton sample than in the singleton sample, but the height and BMI PGS associations were consistent. Birth order data suggested that the difference in educational attainment PGS associations was driven by individuals with older siblings rather than firstborns. The relationship between number of siblings and educational attainment PGS associations was non-linear; PGS associations were 24% smaller in individuals with 6 or more siblings compared to the rest of the sample (95% C.I. 11%, 38%). We estimate that a 1 SD increase in sibling educational attainment PGS corresponds to a 0.025 year increase in the index individual’s years in schooling (95% C.I. 0.013, 0.036). Our results suggest that older siblings may influence the educational attainment of younger siblings, adding to the growing evidence that effects of the environment on phenotypic variation partially reflect social effects of germline genetic variation in relatives.     

The effect of pharmaceutical innovation on longevity: Evidence from the U.S. and 26 high-income countries

This study examines the impact that pharmaceutical innovation, which accounts for most private biomedical research expenditure, has had on longevity. We perform two types of two-way fixed-effects analyses, which control for the effects of many potentially confounding variables. First, we analyze long-run (2006–2018) changes in longevity associated with different diseases in a single country: the U.S. Then, we analyze relative longevity levels associated with different diseases in 26 high-income countries during a single time period (2006–2016). The measure of longevity we analyze, mean age at time of death, is strongly positively correlated across countries with life expectancy at birth. The measure of pharmaceutical innovation we use is the mean vintage (year of initial world launch) of the drugs used to treat each disease in each country. Changes in the vintage distribution of drugs are due to both entry of new drugs and exit of old drugs. Our analysis of U.S. data indicates that the diseases for which there were larger increases in drug vintage tended to have larger increases in the longevity of Americans of all races and both sexes. In other words, the lower the mean age of the drugs, the higher the mean age at death. We test, and are unable to reject, the “parallel trends” hypothesis. We estimate that the 2006–2018 increase in drug vintage increased the mean age at death of Americans by about 6 months (66% of the observed increase). Controlling for sex, race, and education has only a small effect on the estimate of the vintage coefficient. The estimates indicate that drug vintage did not have a significant effect on the mean age at death of decedents with less than 9 years of education. Drug vintage had a positive and significant effect on the mean age at death of decedents with at least 9 years of education, and a larger effect on the mean age at death of decedents with at least 13 years of education. The finding that pharmaceutical innovation has a larger effect on the longevity of people with more education is consistent with previous evidence that more educated people are more likely to use newer drugs. Our analysis of data on 26 high-income countries indicates that the higher the vintage of drugs available to treat a disease in a country, the higher mean age at death was, controlling for fixed disease and country effects. The increase in drug vintage is estimated to have increased mean age at death in the 26 countries by 1.23 years between 2006 and 2016—73% of the observed increase. We obtain estimates of the cost of pharmaceutical innovation—its impact on drug expenditure—as well as estimates of an important benefit of pharmaceutical innovation—the number of life-years gained from it—and of their ratio, i.e., the incremental cost-effectiveness ratio. Estimates of the cost per life-year gained for the U.S. and the 26 countries are $35,817 and $13,904, respectively. Both figures are well below per capita GDP in the respective regions, suggesting that, overall, pharmaceutical innovation was highly cost-effective.     

Effects of age, ethnicity and health behaviours on the prevalence of adverse birth outcomes in Taiwan

This study sampled 8432 singleton first live births from Taiwan's 2005 Birth Registration Database to determine if there were more pre-term or low birth weight deliveries among aboriginal women than there were among Han Chinese women, and if the 'weathering' hypothesis applied to aboriginal women in Taiwan. Although the aboriginal women were socially disadvantaged and engaged in more unhealthy behaviours, including smoking, drinking, chewing betel quid and exposure to second-hand smoke, the evidence did not support the hypothesis that these teenaged minority women would have better birth outcomes, as has been demonstrated among teenage African-American women in the United States. Behaviours and not ethnicity were risk factors for teenage aboriginal mothers, who started deleterious health behaviours earlier than did their older counterparts. Teenage mothers had more adverse outcomes regardless of ethnicity and aboriginal mothers had more risky behaviours in all age groups. The prevalence of detrimental health behaviour among teenage mothers in Taiwan is of concern, particularly for aboriginal teenage mothers.     

Early sexual maturity among Pumé foragers of Venezuela: fitness implications of teen motherhood

Because humans have slow life histories, discussions of the optimal age at first birth have stressed the benefits of delayed reproduction. However, given the diversity of ecological, fertility, and mortality environments in which humans live, reproductive maturity is expected to be highly variable. This article uses reproductive histories to examine a pattern of early menarche and first birth among the Pume, a group of South American foragers. Age at menarche and first birth are constructed using both retrospective and cross‐sectional data for females over the age of 10 (n = 83). The objectives are first to define these patterns and then discuss their reproductive consequences. On average, Pume girls reach menarche at age 12.9, and give birth to their first child at age 15.3–15.5 (retrospective and cross‐sectional data, respectively). This populational average falls several years prior to what often is considered the human norm. Two questions are then considered. What are the infant mortality costs across a mother's reproductive career? How does surviving fertility vary with age at first birth? Results indicate that the youngest of first‐time mothers (<14) are four times more likely to loose their firstborns than older first‐time mothers (≥17). Given parity‐specific mortality rates, the optimal strategy to minimize infant mortality and maximize reproductive span is to initiate childbearing in the midteens. Women gain no additional advantage in surviving fertility by delaying childbearing until their late teens. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.     

Combining Harvest and Genetics to Estimate Reproduction in Wolves

Parameters of reproductive success are important to the management of wildlife populations. Genetic monitoring can be an effective approach for acquiring this important demographic information when traditional methods are unsuccessful, inefficient, or too expensive. This study demonstrates a novel application of genetic data opportunistically collected from harvested game to estimate a minimum annual count of breeding packs of gray wolves (Canis lupus) and to provide a coarse index of harvest vulnerability of young of the year (YOY) across packs. We used 18 microsatellite loci to genotype 98 gray wolf YOY from 2014 and 105 from 2015 harvested in Idaho, USA. Using this genotype data, we reconstructed sibling groups for each cohort using the program COLONY and treated full-sibling litters as proxies for unique packs. In addition to evaluating our marker panel using simulations, we assessed the accuracy of empirical relationship assignments by adding YOY of known relationship from long-term study packs to the dataset (27 individuals from 2014 and 61 from 2015) and tracking correctly reconstructed relationships. We varied COLONY input parameters to evaluate the power of relationship assignments under conditions that may be encountered when working with empirical data. We also compared COLONY's estimates of effective number of breeders based on sibship frequency to estimates based on a commonly used linkage-disequilibrium method. All COLONY runs for both cohorts correctly identified the known sibling relationships. Among the other individuals, changes in the geographic clustering of putative siblings, probabilities of inclusion and exclusion for reconstructed sibling groups, and consistency of relationship assignments across COLONY runs suggested that marker number had a larger effect on accuracy than access to population-level genetic data. Our estimates of breeding packs subjected to harvest within the state (52 for 2014 and 63 for 2015) differed from estimates reported by Idaho Department of Fish and Game by ≤6 for both years. Among packs that had pups harvested, most packs had 1–2 YOY harvested, whereas other packs had as many as 5 YOY harvested. All estimates of the number of effective breeders had overlapping confidence intervals regardless of method, though sibship frequency-based estimates had larger confidence intervals than estimates using the linkage disequilibrium method. Our study shows that sibling relationships can be accurately and reliably reconstructed from harvested gray wolves, and demonstrates a valuable new use of samples collected through harvest. © 2020 The Wildlife Society.     

Teenage motherhood and infant mortality in Bangladesh: maternal age-dependent effect of parity one

Nuptiality norms in rural Bangladesh favour birth during the teenage years. An appreciable proportion of teenage births are, in fact, second births. This study examines the relationship between teenage fertility and high infant mortality. It is hypothesized that if physiological immaturity is responsible, then the younger the mother, the higher would be the mortality risk, and the effect of mother's 'teenage' on mortality in infancy, particularly in the neonatal period, would be higher for the second than the first births. Vital events recorded by the longitudinal demographic surveillance system in Matlab, Bangladesh, in 1990-92 were used. Logistic regression was used to estimate the effects on early and late neonatal (0-3 days and 4-28 days respectively) and post-neonatal mortality of the following variables: mother's age at birth, parity, education and religion, sex of the child, household economic status and exposure to a health intervention programme. The younger the mother, the higher were the odds of her child dying as a neonate, and the odds were higher for second children than first children of teenage mothers. First-born children were at higher odds of dying in infancy than second births if mothers were in their twenties. Unfavourable mother's socioeconomic conditions were weakly, but significantly, associated with higher odds of dying during late neonatal and post-neonatal periods. The results suggest that physical immaturity may be of major importance in determining the relationship between teenage fertility and high neonatal mortality.     

Age and growth of pallid sturgeon in the free-flowing Mississippi River

Trotlines were used to capture pallid sturgeon in the free‐flowing Mississippi River, which extends from the Gulf of Mexico to the mouth of the Missouri River. Trotlines were baited with worms, and set overnight usually along the channel border. The pectoral fin rays of 165 pallid sturgeon caught in the Mississippi River were aged; 118 were from the lower Mississippi River (LMR) between the Gulf and mouth of the Ohio River, and 47 were from the middle Mississippi River (MMR) between the mouths of the Ohio and Missouri rivers. Initial agreement within ±1 year between two readers ranged from 53% for the LMR specimens, which were read first, to 84% for the MMR. Final age was agreed upon by both readers. For LMR pallid sturgeon, final age estimates ranged from 3 to 21 years with a mean (±SD) of 11.0 ± 4.7. For MMR pallid sturgeon, final age estimates ranged from 5 to 14 years with a mean of 9.5 ± 2.1. Seven pallid sturgeon marked with coded wire tags (CWT), indicating hatchery origin, were collected in the MMR. Age estimates for CWT fish were 7–8 years representing 1997 stocked fish, and 11–12 years representing 1992 progeny stocked in 1994. Von Bertalanffy growth equations for length indicated that pallid sturgeon in the MMR had higher growth rates for a given age than pallid sturgeon in the LMR. However, there were no significant differences (anova , P > 0.5) in the length–weight relationships between reaches. In the LMR, pallid sturgeon fully recruited to trotlines at age 11 and instantaneous total mortality (Z; slope of catch curve) was estimated at −0.12 (n = 10 year classes, r² = 0.55, P = 0.01). Of the 118 sectioned rays from the LMR, 28 could not be reliably aged (only one section from the MMR could not be aged). Therefore, age was predicted from length using the von Bertalanffy equation. The catch curve was re‐calculated using the predicted ages of the 28 pallid sturgeon in the LMR resulting in Z = −0.07. In the MMR, pallid sturgeon fully recruited to trotlines at age 9 and Z was estimated at −0.36 (n = 6 year classes, r² = 0.67, P = 0.04), which was significantly higher (anova , P = 0.04) than the LMR estimate. Higher mortality in the MMR may be due to habitat limitations compared to a larger, more diverse channel in the LMR, and incidental take of larger, older individuals during commercial harvesting of shovelnose sturgeon. Commercial take of shovelnose does not occur in the LMR except in the northern portion of the reach. Considering the presence of pallid sturgeon with CWT, recruitment of older individuals in the MMR may have been influenced by stocking a decade earlier. Management strategies for this endangered species should consider the differences in mortality rates among reaches, the impacts of commercial fishing on recovery of pallid sturgeon in the MMR, and the long‐term effects of hatchery fish now recruiting into the free‐flowing Mississippi River.     

Relationship between phenylalanine tolerance and psychological characteristics of phenylketonuric families

The purpose of this study was to find out how genetic and biochemical limitations influence psycho-social performance and to partially test the validity of justification theory. The ability to convert phenylalanine to tyrosine was compared with intellectual and personality characteristics in PKU family members. Each of the tested persons was given an oral dose of phenylalanine, the Shipley-Hartford Intelligence Test, and the Minnesota Multiphasic Personality Inventory (MMPI). Only those persons with reading ability at the sixth grade level or higher were tested. Eighty-six persons were tested: fifteen PKUs, forty-three siblings, and twenty-eight parents. A comparison was made among parents, PKUs, and the siblings. Siblings with the higher 2/3's of P2/T ratios were contrasted with those with the lowest 1/3 of ratios on measures of intelligence and psychopathology. Statistical analyses of the data reflected a trend in support of the justification theory. PKUs had significantly lower intelligence than their sibs and parents. The PKUs' mean IQ was 95 (homozygotes born of heterozygotes), followed by the upper 2/3's sibling mean IQ of 105 (heterozygotes born of nonheterozygote mothers). The lower 1/3 siblings' mean IQ was 107 (nonheterozygotes born from heterozygote mothers), and finally, the parents' mean IQ was 109 (heterozygotes, among them 50% were born from nonheterozygote mothers). The latter three mean IQs are not significantly different from each other. The personality tests revealed a trend toward more abnormality in PKUs than in their heterozygote siblings. The lowest rate of abnormality occurred in the nonheterozygote sibling group; that rate was significantly lower than in all other groups. The parents had the highest absolute rate of personality abnormality, but statistically so compared to the low-ratio siblings.     

Epidemiology of gastroschisis in metropolitan Atlanta, 1968 through 2000

BACKGROUND: An increase in the rate of gastroschisis has been documented by birth defects surveillance systems in the United States and in other countries. This study sought to evaluate historical trends in the rate of gastroschisis in Atlanta, Georgia, and to describe the epidemiology of gastroschisis over 33 years. METHODS: Gastroschisis cases were identified through the Metropolitan Atlanta Congenital Defects Program (MACDP) from 1968 through 2000. Poisson regression techniques were used to evaluate trends over time. Data on covariates were compared for three maternal age groups (< or =19, 20-24, and > or =25 years). RESULTS: From 1968 through 1975, the rate of gastroschisis was stable at 0.8 per 10,000 births. After 1975, the rate of gastroschisis was 2.3 per 10,000 births with no significant increase observed from 1976 through 2000. The rate of gastroschisis was six times higher among teenage mothers compared with mothers > or =25 years of age. Affected infants born to teenage mothers were less likely to be born to Black mothers compared to White mothers (rate ratio [RR], 0.4; 95% confidence interval [CI], 0.2-0.6). This was also true for mothers 20-24 years of age (RR, 0.5; 95% CI, 0.3-0.8) but not for mothers 25 years of age or older (RR, 1.6; 95% CI, 0.9-2.7). CONCLUSIONS: An increase in the rate of gastroschisis was observed in the mid-1970s, but no temporal trend has been observed since that time. In light of recent reports of an increasing prevalence of gastroschisis in the United States, continued monitoring of this birth defect is warranted.