Premature death of adult adoptees: analyses of a case-cohort sample

Genetic and environmental influence on risk of premature death in adulthood was investigated by estimating the associations in total and cause-specific mortality of adult Danish adoptees and their biological and adoptive parents. Among all 14,425 non-familial adoptions formally granted in Denmark during the period 1924 through 1947, we selected the study population according to a case-cohort sampling design. As the case-control design, the case-cohort design has the advantage of economic data collection and little loss in statistical efficiency, but the case-cohort sample has the additional advantages that rate ratio estimates may be obtained, and re-use of the cohort sample in future studies of other outcomes is possible. Analyses were performed using Kalbfleisch and Lawless's estimator for hazard ratio, and robust estimation for variances. In the main analyses the sample was restricted to birth years of the adoptees 1924 and after, and age of transfer to the adoptive parents before 7 years, and age at death was restricted to 16 to 70 years. The results showed a higher mortality among adoptees, whose biological parents died in the age range of 16 to 70 years; this was significant for deaths from natural causes, vascular causes and all causes. No influence was seen from early death of adoptive parents, regardless of cause of death.     

Genetic and environmental effects on mortality before age 70 years

BACKGROUND: There is a familial influence on risk of many diseases and on mortality in general, which, according to studies of twins, is due to a combination of genetic and environmental effects. Adoption studies, which rest on different assumptions, may also be used to estimate separately the genetic and environmental effects on rate of dying. METHODS: The genetic influence on the rate of dying before age 70 years was investigated by estimation of the associations in total and cause-specific mortality of Danish adoptees and their biologic full and half siblings. Familial environmental influences shared at the same time in life were investigated in adoptees and their adoptive siblings. The study basis is the 14,425 nonfamilial adoptions formally granted in Denmark during the period 1924 through 1947, recorded in the Danish Adoption Register. From this register we selected the 1552 "case" adoptees (who died before 01 April 1993) and 1710 "noncase" adoptees alive at that date. The siblings of the case and noncase adoptees were traced in the archives and followed forward, and the rates of dying before age 70 years were compared. RESULTS: Compared with mortality of the biologic siblings of noncase adoptees, the mortality of biologic siblings of dead adoptees was approximately 2-fold higher for death with infections and vascular causes, and around 45% increased for natural causes and for all causes. CONCLUSION: The results suggest that there is a genetic effect on the rate of death with infections, vascular causes, natural causes and all causes, whereas there is no indication of an influence of shared sibling environment.     

Genetic epidemiology utilizing the adoption method: studies of obesity and of premature death in adults

Genetic epidemiology gives no priority to genes or environment in the search of disease causation. However, a major problem in this field is the disentangling of the effects of environment and genes. The study of subjects separated very early in life from their biologic parents and adopted by unrelated parents provide a strong tool for estimation of genetic and familial environmental influences. The degree to which the trait or disease frequency of the adoptees is similar to that seen among the biologic relatives is an indication of the strength of the genetic influence. Similarity to the adoptive relatives suggests influences of the family environment shared between them. Adoption studies of adult obesity show that it is genes, and not the family environment, that is responsible for the familial aggregation of obesity. A study of the mortality of adult adoptees and their biologic and adoptive parents indicates a genetic influence on the risk of premature death from all causes, from natural causes, infections, and cardio- and cerebrovascular conditions, and suggests familial environmental influences on death from the vascular causes and from cancer.     

Releasing pre-adoption birth records: the impact of Oregon's experience on its vital records department

OBJECTIVE: In November 1998, Oregon voters passed Ballot Measure 58, which allowed Oregon adoptees > or = 21 years of age access to their original birth records, which are sealed at adoption. The objective of this study was to evaluate the impact of the measure on the Oregon Health Division (since renamed Oregon Health Services) by assessing procedures used and resources needed after implementation of Measure 58. METHODS: Vital records employees were interviewed about processing, storage, and archive retrieval procedures for pre-adoption birth records before, during, and after the implementation of Measure 58 and the effect on their usual workload. Personnel time, space, and fiscal resources used to process requests for pre-adoption records were also calculated. RESULTS: The Oregon Health Division began to receive requests from adoptees immediately following the passage of Measure 58 in November 1998, but due to legal challenges, they could not be processed until May 31, 2000. From June 2, 2000, through October 20, 2000, 12 staff members and two supervisors issued more than 4,700 pre-adoption birth records while also processing their normal workload, which averages more than 135,400 vital record orders annually. Due to the need for retrieval from archives, requests for pre-adoption birth records were estimated to take 75 hours to process vs. 2-3 minutes for standard requests. Each batch of approximately 75 pre-adoption birth records required approximately 12.5 person-hours from vital records staff and 3-4 person-hours from archive personnel; in addition, supervisors spent time responding to incomplete orders, informing the public and the media, and responding to concerns of adoptees, birth parents, and adoptive parents. Fewer than 1% of requests went unfilled. CONCLUSIONS: Implementation of Measure 58 utilized substantial resources of the Oregon Health Division. States contemplating similar legislation should consider increasing personnel and resources, preparing for intense public and media interest, and reorganizing the storage of adoptees' original birth records so they are easily retrieved.     

Releasing pre-adoption birth records: a survey of Oregon adoptees

OBJECTIVE: In June 2000, Oregon implemented a citizen-initiated ballot measure that grants adult adoptees access to their birth records, which contain their birth parents' identifying information. Because other states are considering similar policy changes, the authors explored whether Oregon's new law is meeting the information needs of adoptees. METHODS: Birth records were abstracted for a 9% (221/2,529) random sample of adoptees who obtained their records from June 20, 2000, to July 20, 2000, to describe the population and the information they obtained. Telephone interviews documented their motivations, expectations, and whether they considered the birth record useful. RESULTS: The mean age of the adoptees was 41 years, 64% were female, and 97% were white. Virtually all received information about their birth mother; however, only one-third received information about their birth father. Of the 221 sampled, 123 (59%) participated in the telephone survey, 12 were ineligible, 84 could not be reached, and 2 refused. The most common motivations for requesting records were to find birth parents (29%) and to obtain medical information (29%). Twenty-nine percent received less information than they expected, with many expecting, but not receiving, birth father information. Thirty-three (47%) of the 70 adoptees who tried to find their birth mother were successful. The records were considered "very" useful by 52% of respondents, "somewhat" or "a little" useful by 42%, and "not at all" useful by 6%. CONCLUSIONS: The results indicate that many adoptees received less information than they expected, and many did not meet their goals of finding birth parents or obtaining medical information. Nonetheless, the majority considered their birth records useful and important.     

Covering Adoption: General Depictions in Broadcast News

Abstract: Using theories of stigma ( Goffman, 1963 ) and media frames ( Iyengar, 1991 ), 292 news stories pertaining to adoption that appeared on major broadcast networks between 2001 and 2004 were analyzed. Media coverage of adoptees contained more problematic than positive depictions. Although birth parents were not always depicted, adoptive parent and adoptive family depictions were more positive than problematic. Fourteen percent of the news stories contained stigmatizing claims without refuting these claims. Stories that contained stigmatizing claims were more likely to use human interest, conflict, and morality frames. News coverage of reunions, open adoptions, and adoption recommendations is beginning to show a more forward view of adoption. Recommended programs for adoption education are included.     

Parental Bonding and Identity Style as Correlates of Self‐Esteem Among Adult Adoptees and Nonadoptees*

Abstract: Adult adoptees (n= 100) and nonadoptees (n= 100) were compared with regard to self‐esteem, identity processing style, and parental bonding. Although some differences were found with regard to self‐esteem, maternal care, and maternal overprotection, these differences were qualified by reunion status such that only reunited adoptees differed significantly from nonadoptees. Moreover, hierarchical regression analyses indicated that parental bonding and identity processing style were more important than adoptive status per se in predicting self‐esteem. Implications for practitioners who work with adoptees are discussed.     

Birth weight of offspring and subsequent cardiovascular mortality of the parents

BACKGROUND: Restricted fetal growth has been associated with increased blood pressure, insulin resistance, and cardiovascular disease in later life. These associations may be due to processes during fetal development with long-term consequences for metabolic and cardiovascular function (the fetal origins hypothesis). However, it has also been hypothesized that common genetic factors could underlie both restricted fetal development and disease risk (the fetal insulin hypothesis). METHODS: We have investigated associations between offspring size at birth and parental mortality in a record linkage study including all 783,814 children born in Sweden between 1973 and 1980. The deaths of 10,368 mothers and 22,807 fathers had been recorded by date and causes of death. Data were analyzed using Cox proportional hazards regression models, with parents' age as the time axis. RESULTS: Offspring birth weight (adjusted for gestational age) was inversely associated with all-cause mortality and cardiovascular mortality in the parents, with weaker associations for fathers than for mothers. The inverse association between birth weight and cardiovascular disease mortality was greatest for parents who died at younger ages. Cancer and alcohol-related causes of death were also related to offspring birth weight. A sensitivity analysis suggests that confounding by smoking is unlikely to entirely explain the associations. CONCLUSION: Associations between offspring birth characteristics and parents' mortality could, at least in part, reflect genetic factors that influence both birth weight and cardiovascular disease risk.     

Familial aggregation of blood pressure and weight in adoptive families. I. Comparisons of blood pressure and weight statistics among families with adopted, natural, or both natural and adopted children

Tests of homogeneity of means, variances and correlations for systolic blood pressure (BP), diastolic BP and weight among subdivisions of a smple of adoptive families are presented. The means and variances of either type of BP, but not weight, were not significantly heterogeneous among families grouped according to the number of parents and children, natural and/or adopted, in the family unit. Estimates of correlation between family members wree not heterogeneous among subdivisions for each of the three variables. Our results indicate that these data are suitable for a genetic analysis of familial aggregation. Pooled correlations suggest that the degree of resemblance of BP and of weight between family members varies within and across generations. Correlations involving the adoptees were significantly different from zero only for diastolic BP.     

The effect of parental age, birth order and other variables on early childhood mortality: a Caribbean example.

The 4275 births to women of native ancestry that took place on the island of St Barthélemy, French West Indies between 1878 and 1970 were analyzed according to the sex of the child, the year of birth, maternal age, maternal parity, paternal age and the number of children the father already had to determine the effects of these variables on rates of perinatal death, death before age 1 and death before age 5. The year of birth, the number of children the father already had, and maternal parity influenced death before age 1 and death before age 5. The sex of the child also influenced the probability of dying in the first year of life but not the first 5 yr of life when the other variables were controlled. Perinatal deaths were influenced only by the sex of the child, but even this effect disappeared when the other variables were controlled.     

Parenting concepts and experiences of adults abandoned as infants

Parental concepts are crucial in understanding family, relationships and psychological functioning of parents. How these evolve and manifest may vary according to family and personal experience. This study of adults who were abandoned as infants explores three perspectives—their concepts of their biological parents who have abandoned them, their concepts of their adoptive parents who have raised them and finally their concepts of themselves as parents on the birth of their own children. Qualitative interviews with 16 adult survivors of infant abandonment were conducted and thematically analysed to explore parenting. The interviews revealed that although some justified and felt forgiveness for their biological mothers, others sustained feelings of anger and resentment. Participants reported a desire for further knowledge regarding their biological mother, with some reporting a desire for a reunion and others highlighting concerns regarding their genetic health. The majority had no views or thoughts on their biological father. Relationships with adoptive parents were mixed—some were supportive and loved yet others were distant and troubled. For most who had children of their own, such births represented the first moment of true biological and genetic continuity and were reported as precious. Others, however, were challenged or avoided parenting altogether. This study is the one of the first steps to understanding the long-term effects of abandoned infants in terms of the parenting they receive and the intergenerational effects on the parenting they provide in turn to the next generation. Such insight should inform parenting preparation for adoptive parents in the case of those abandoned and subsequently adopted as well as support for survivors of infant abandonment when they reach adulthood and become parents themselves.     

The effect of air pollution on infant mortality appears specific for respiratory causes in the postneonatal period.

To examine the association between individual lifetime measures of mean exposure to air pollution and postneonatal respiratory deaths, we have conducted a matched population-based case-control study covering all births registered in the Czech Republic from 1989 to 1991 that were linked to death records. For each case of infant death, we have randomly selected 20 controls from infants of the same sex born on the same day and alive when the case died. Exposure was assigned as the arithmetic mean of all 24-hour air pollution measurements in the district of residence of each case and control for the period between the birth and death of the index case. We used conditional logistic regression to estimate the effects of suspended particles, sulfur dioxide, and nitrogen oxides on risk of death in the neonatal and postneonatal period, controlling for maternal socioeconomic status and birth weight, birth length, and gestational age. There were 2,494 infant deaths with exposure data on at least one pollutant, 133 of them from respiratory causes. The effects of all pollutants were strongest in the postneonatal period and were specific for respiratory causes. For these, rate ratios for a 50 microg/m3 increase in particles, sulfur dioxide, and nitrogen oxides were 1.95 [95% confidence interval (CI) = 1.09-3.50], 1.74 (95% CI = 1.01-2.98), and 1.66 (95% CI = 0.98-2.81), respectively, after controlling for all covariates. Only particles showed a consistent association when all pollutants were entered in one model. We found no evidence of a relation between any pollutant and mortality from other causes. These results indicate that the effects of air pollution on infant mortality are specific for respiratory causes in the postneonatal period, are independent of socioeconomic factors, and are not mediated by birth weight or gestational age.     

Prenatal or early postnatal events predict infectious deaths in young adulthood in rural Africa

BACKGROUND: Research over the past decade has suggested that prenatal and early postnatal nutrition influence the risk of developing chronic degenerative diseases up to 60 years later. We now present evidence that risk of death from infectious diseases in young adulthood is similarly programmed by early life events. METHODS: In three rural Gambian villages, affected by a marked annual seasonality in diet and disease, we have kept detailed demographic, anthropometric and health records since 1949. Fate was known with certainty for 3,162 individuals (2,059 alive/1,103 dead, most dying in childhood). For this case-control analysis of antecedent predictors of premature mortality, all adult deaths (n = 61) were paired with two randomly selected controls matched for sex and year of birth. RESULTS: Mean age at death was 25 (SD: 8) years. Adult death was associated with a profound bias in month of birth with 49 cases born in the nutritionally-debilitating hungry season (Jul-Dec) versus 12 in the harvest season (Jan-Jun). Relative to harvest season the hazard ratio for early death in hungry-season births rose from 3.7 (for deaths >14.5 years, P = 0.000013) to 10.3 (for deaths >25 years, P = 0.00002). Anthropometric and haematological status at 18 months of age was identical in cases and controls, indicating an earlier origin to the defect. Most deaths for which cause was known had a definite or possible infectious aetiology; none were from degenerative diseases of affluence. CONCLUSIONS: Early life exposures, correlated with season of birth, strongly influence susceptibility to fatal infections in young adulthood. The evidence suggests that nutritionally-mediated intrauterine growth retardation may permanently impair the development of immune function.     

Genetic and environmental influences on the relation between parental social class and mortality

BACKGROUND: Genetic and maternal prenatal environmental factors as well as the post-natal rearing environment may contribute to the association between childhood socioeconomic circumstances and later mortality. In order to disentangle these influences, we studied all-cause and cause-specific mortality in a cohort of adoptees, in whom we estimated the effects of their biological and adoptive fathers' social classes as indicators of the genetic and/or prenatal environmental factors and the post-natal environment, respectively. METHODS: In all 12 608 children born 1924-47 in Denmark who were placed early in life with adoptive parents were followed up for causes of death until 2000. Hazard ratios for paternal social class retrieved from adoption records were estimated using Cox regression models. RESULTS: Adoptees with biological fathers from higher social classes had a lower rate of mortality after their fifth decade of life, mainly due to a lower risk of cardiovascular, infectious, and respiratory diseases. Adoptive father's social class showed no clear relation with adoptee's mortality risk. The risk estimates for paternal social class were slightly attenuated after adjustment for adoptee's adult social class, which as expected was inversely related to mortality from both natural and external causes. CONCLUSION: Genetic and/or prenatal environmental factors contribute to the development of the relation of paternal social class to mortality from natural causes later in adult life independently of the effect of own social class, whereas there is no evidence for such long-term effect of the rearing environment.     

Childhood Family Correlates of Heterosexual and Homosexual Marriages: A National Cohort Study of Two Million Danes

Children who experience parental divorce are less likely to marry heterosexually than those growing up in intact families; however, little is known about other childhood factors affecting marital choices. We studied childhood correlates of first marriages (heterosexual since 1970, homosexual since 1989) in a national cohort of 2 million 18–49 year-old Danes. In multivariate analyses, persons born in the capital area were significantly less likely to marry heterosexually, but more likely to marry homosexually, than their rural-born peers. Heterosexual marriage was significantly linked to having young parents, small age differences between parents, stable parental relationships, large sibships, and late birth order. For men, homosexual marriage was associated with having older mothers, divorced parents, absent fathers, and being the youngest child. For women, maternal death during adolescence and being the only or youngest child or the only girl in the family increased the likelihood of homosexual marriage. Our study provides population-based, prospective evidence that childhood family experiences are important determinants of heterosexual and homosexual marriage decisions in adulthood.     

A Comparison of Self-Esteem, School Achievement, and Friends Between Intercountry Adoptees and Their Siblings

Self-esteem, school achievement, and friends are important factors in social development. A cohort of 123 Canadian families who had adopted 155 international adoptees during the 1970s participated in a recent research project.¹ The project tested these areas and then compared their results with 121 Canadian-born siblings in these adoptive families as well as adolescents and young adults in the general population. These international adoptees fare as well as or better than adolescents and young adults in the general population but not quite as well in some areas as their siblings. Differences were found in some instances between male and female respondents. The authors discuss these findings from a developmental perspective.     

Gene–Environment Interaction in the Intergenerational Transmission of Asthma

Researchers have found strong linkages between parent and child health, but the mechanisms underlying intergenerational health transmission are not well understood. This paper investigates how the importance of genetic health transmission mechanisms varies by environmental conditions in the case of pediatric asthma, the single most common chronic health condition among American children. Using a sample that includes approximately 2000 adoptees and a large number of similar biological families, I find that the relative importance of genetic transmission differs strongly by socioeconomic status (SES). In high SES families, parent–child asthma associations are approximately 75% weaker among adoptees than biological children, suggesting a dominant role for genetic transmission. In lower SES families, parent–child asthma associations are virtually identical across biological and adoptive children, suggesting a negligible role for genetic transmission. A potential interpretation of this difference is that as environmental conditions affecting asthma improve among higher SES children, an increasingly large share of asthma variation is due to genetics. Copyright © 2016 John Wiley & Sons, Ltd.     

Families with a perinatal death: is there an association between the loss and the birthweight of surviving siblings?

Our objective was to study birthweight among surviving siblings in families with and without a perinatal loss, and to evaluate whether different causes of death were associated with the results. Data were for 1967-98 from the Norwegian Medical Birth Registry. Births were organised with the mother as the observation unit through the personal identification number, providing sibship files. We analysed 550 930 sibships with at least two singletons, 208 586 sibships with at least three singletons and 45 675 sibships with at least four singleton births. We compared mean birthweight and gestational age between infants in sibships with and without a perinatal loss, total losses and the different causes of death. Surviving siblings in families with a perinatal loss had significantly lower mean birthweights than their counterparts in unaffected families, after adjusting for gestational age, interpregnancy interval, time period and marital status. An exception was found when cause of death was a birth defect, when growth retardation among surviving siblings was not found on average. We conclude that families who have lost an infant because of a birth defect do not appear to have an increased risk of adverse birth outcome associated with growth restriction.     

Patterns and Predictors of Adoption Openness and Contact: 14 Years Postadoption

Increased attention is being paid to open adoption arrangements between birth parents and adopted children and families. This study examines openness and contact among 469 adoptions at 14 years postadoption from the fourth wave of the California Long‐Range Adoption Study (CLAS) and 378 adoptions matched across all waves. The proportion of families reporting contact declined from Wave 3 (1997) to Wave 4 (2003) although contacts increased within open adoptions. Positive ratings of the contact's effect on the family increased the likelihood of contact between adoptive and birth families, although greater levels of overall satisfaction lowered the likelihood of openness over time. At any point in time, public agency adoptions were less likely to be open. Findings suggest that increased attention should be paid within agencies to how open arrangements are pursued for adoptive placements.     

Comparison of case-cohort estimators based on data on premature death of adult adoptees

A case-cohort sample of adoptees was collected to investigate genetic and environmental influences on premature death, which motivated us to supplement existing simulation results to explore the performance of various estimators proposed for case-cohort samples of survival data. We studied six regression coefficients estimators, which differ with regard to the weighting scheme used in a pseudo-likelihood function, and two different estimators of their variances. Compared to earlier simulation studies, we changed the following conditions: type of explanatory variable, the distribution of lifetimes, and the percentage of deaths in the full cohort. The latter condition affected the performance of the estimated variances of the regression coefficients, where we found a systematic bias of the estimator, proposed by Self and Prentice, dependent on the percentages of deaths. This dependence of percentages of death was different for different sizes of case-cohort studies. A robust variance estimator showed a better overall performance. The estimators of regression coefficients compared did not differ much, the estimators proposed by Kalbfleisch and Lawless and by Prentice performing very well. Results of the case-cohort data of adoptees were not in conflict with earlier findings of a moderate genetic influence on premature death in adulthood.