Child's Conception Research Articles

Effects of parental age and polymer composition on short tandem repeat de novo mutation rates.

Short tandem repeats (STRs) are hotspots of genomic variability in the human germline because of their high mutation rates, which have long been attributed largely to polymerase slippage during DNA replication. This model suggests that STR mutation rates should scale linearly with a father's age, as progenitor cells continually divide after puberty. In contrast, it suggests that STR mutation rates should not scale with a mother's age at her child's conception, since oocytes spend a mother's reproductive years arrested in meiosis II and undergo a fixed number of cell divisions that are independent of the age at ovulation. Yet, mirroring recent findings, we find that STR mutation rates covary with paternal and maternal age, implying that some STR mutations are caused by DNA damage in quiescent cells rather than polymerase slippage in replicating progenitor cells. These results echo the recent finding that DNA damage in oocytes is a significant source of de novo single nucleotide variants and corroborate evidence of STR expansion in postmitotic cells. However, we find that the maternal age effect is not confined to known hotspots of oocyte mutagenesis, nor are postzygotic mutations likely to contribute significantly. STR nucleotide composition demonstrates divergent effects on de novo mutation (DNM) rates between sexes. Unlike the paternal lineage, maternally derived DNMs at A/T STRs display a significantly greater association with maternal age than DNMs at G/C-containing STRs. These observations may suggest the mechanism and developmental timing of certain STR mutations and contradict prior attribution of replication slippage as the primary mechanism of STR mutagenesis.

Birth Spacing and Child Maltreatment: Population-Level Estimates for North Carolina.

We examine population-level associations between birth spacing and child maltreatment using birth records and child welfare records for 1,099,230 second or higher parity children born in North Carolina between 1997 and 2013. Building upon previous research, administrative data linkages were used to address out-of-state migration and family-level heterogeneity in birth spacing and child maltreatment risk factors. Findings provide the strongest evidence to date that very short birth spacing of zero through 6 months from last birth to the index child's conception is a prenatal predictor of child maltreatment (indexed as child welfare involvement) throughout early childhood. Consequently, information about optimal family planning during the postpartum period should become a standard component of universal and targeted child maltreatment prevention programs. However, challenging previous empirical evidence, this study reports inconsistent results for benefits of additional spacing delay beyond 6months with regard to child maltreatment risk reduction, especially for children of racial and ethnic minorities. These findings call for further inquiry about the mechanisms driving the connections between birth spacing and Child Protective Services assessments.

Grossesse et don d’ovocytes : remaniements psychiques chez les futurs parents

Few studies have investigated how couples prepare to become parents after receiving an oocyte donation, and no study has specifically focused on men's experiences. ObjectivesTo interest in the possible special features introduced by the oocyte donation within the psychic rearrangements that are taking place within women and men before and during the pregnancy. MethodsAt 7–8 months of pregnancy, interviews inspired by the interview for maternal and paternal representations during pregnancy were proposed to ten infertile women and eight men, met separately. ResultsBefore and during pregnancy, women and men were variably engaged in an elaboration process of the implications of using a donor and introducing asymmetry in terms of genetic filiation within the couple. According to the individual, minimizing the donor's role and the importance of genetic filiation in their child's conception is more or less effective in keeping at distance the disappointment and anxieties associated with oocyte donation. ConclusionIt is necessary to pay attention to both the woman's and the man's experience during medical interviews and the obligatory psychological interview prior to oocyte donation as well as during the perinatal period.

Children's Exploration of Their Surrogacy Origins in Gay Two-Father Families: Longitudinal Associations With Child Attachment Security and Parental Scaffolding During Discussions About Conception.

Evidence is lacking about the factors that are pivotal in enhancing the exploration of surrogacy origins in children of gay fathers during middle childhood. The present study examined the separate and combined influences of child attachment security and parental scaffolding (i.e., fathers’ attempts to accept, encourage, and emotionally support their children’s expression of thoughts and feelings) during discussions about conception on children’s exploration of their surrogacy origins in 30 Italian children born to gay fathers through gestational surrogacy. Within each family, both father–child dyads (n = 60) participated in a 5-minute videotaped conversation regarding an aspect of the child’s conception when children were mean aged 8.3 years (t1). At this time, children were also administered the Security Scale Questionnaire to evaluate their attachment security. Approximately 18 months later (t2; Mage = 9.9 years), children were interviewed about their surrogacy origins. Linear mixed models (LMMs) for longitudinal data indicated that, with higher levels of parental scaffolding, only children who perceived greater attachment security reported greater exploration of their surrogacy origins. The findings are the first to underscore the importance of conversations about surrogacy within the context of parent–child attachment relationships, as well as the importance of fathers sensitively supporting their children as they explore their origins during middle childhood. In doing so, it is expected that fathers will likely facilitate their children’s positive integration of their surrogacy conception into a coherent sense of identity during adolescence.

A “Thick” Conception of Children’s Voices: A Hermeneutical Framework for Childhood Research

“Listening to children’s voices” can help foster respectful regard for their experiences and concerns and promote the recognition of children as active agents; that is, persons who have interests and capacities to participate in discussions and decisions that affect them and other people. However, “listening to children’s voices” can have many different forms, and the ways that these voices should be linked to children’s agency can be unclear. I outline several common misconceptions that can impede “listening to children’s voices” as forms of epistemological oppression. I argue for a thick conception of children’s voices, recognizing that children’s expressions are relationally embedded expressions of their agency. Understanding children’s voices and experiences requires hermeneutical approaches that can help discern what is meaningful for a child in a particular situation. I discuss ontological, epistemological, and methodological shifts that are required for hermeneutical inquiry with children and outline specific methods that can be used, oriented by guiding questions. This hermeneutical methodology can help advance our understanding of children’s experiences as well as their aspirations and concerns in research and in professional practice.

Three-to-five years old child's conception of a mechanism of rainfall

Three-to-five years old child's conception of a mechanism of rainfall

A Reflection on Park Mokwol's Conception of Children and Genre Consciousness - Focusing on the periods before and after Wild Bird's Eggs and Aquatic Bird's Eggs -

A Reflection on Park Mokwol's Conception of Children and Genre Consciousness - Focusing on the periods before and after Wild Bird's Eggs and Aquatic Bird's Eggs -

An Australian model of the First 1000 Days: an Indigenous-led process to turn an international initiative into an early-life strategy benefiting indigenous families.

Internationally, the 1000 days movement calls for action and investment in improving nutrition for the period from a child's conception to their second birthday, thereby providing an organising framework for early-life interventions. To ensure Australian Indigenous families benefit from this 1000 days framework, an Indigenous-led year-long engagement process was undertaken linking early-life researchers, research institutions, policy-makers, professional associations and human rights activists with Australian Indigenous organisations and families. The resultant model, First 1000 Days Australia, broadened the international concept beyond improving nutrition. The First 1000 Days Australia model was built by adhering to Indigenous methodologies, a recognition of the centrality of culture that reinforces and strengthens families, and uses a holistic view of health and wellbeing. The First 1000 Days Australia was developed under the auspice of Indigenous people's leadership using a collective impact framework. As such, the model emphasises Indigenous leadership, mutual trust and solidarity to achieve early-life equity.

Paternal intake of folate and vitamins B6 and B12 before conception and risk of childhood acute lymphoblastic leukemia.

We investigated whether paternal dietary intake of folate before conception is associated with the risk of childhood acute lymphoblastic leukemia (ALL) in a nationwide case-control study. Data on dietary folate intake during the 6months before the child's conception were collected from 285 case fathers and 595 control fathers using a dietary questionnaire. Nutrient intake was quantified using a customized computer software package based on Australian food composition databases. Data on folate intake were analyzed using unconditional logistic regression, adjusting for study-matching variables, total energy, and potentially confounding variables. In a subset of 229 cases and 420 controls, data on vitamin B6 and vitamin B12 intake were also analyzed. No consistent associations were seen with paternal dietary intake of folate or vitamin B6. Higher levels of paternal dietary vitamin B12 were appeared to be associated with an increased risk of childhood ALL, with those in the highest tertile of consumption having an OR of 1.51 (0.97, 2.36). The use of supplements containing folate and vitamins B6 or B12 was rare. We did not find any biologically plausible evidence that paternal nutrition in the period leading up to conception was associated with childhood ALL. Our finding for vitamin B12 may be a chance finding, given the number of analyses performed, or be attributable to participation bias because parents with a tertiary education had the lowest level of B12 intake and tertiary education was more common among control than case parents.

A non-genetic, epigenetic-like mechanism of telomere length inheritance?

A non-genetic, epigenetic-like mechanism of telomere length inheritance?

Parental occupational exposure to engine exhausts and childhood brain tumors

Childhood brain tumors (CBT) are the leading cause of cancer death in children; their risk factors are still largely unknown. Since most CBTs are diagnosed before five years of age, prenatal exposure and early postnatal factors may be involved in their etiology. We investigated the association between CBT and parental occupational exposure to engine exhausts in an Australian population-based case-control study. Parents of 306 cases and 950 controls completed detailed occupational histories. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for both maternal and paternal exposure in key time periods. Increased risks were observed for maternal exposure to diesel exhaust any time before the child's birth (OR 2.03, 95% CI 1.09-3.81) and paternal exposure around the time of the child's conception (OR 1.62, 95% CI 1.12-2.34). No clear associations with other engine exhausts were found. Our results suggest that parental occupational exposure to diesel exhaust may increase the risk of CBT.

Parental nutrient intake and risk of retinoblastoma resulting from new germline RB1 mutation

We conducted a case-control study to examine the role of parents' nutrient intake before their child's conception in the child's risk of sporadic bilateral retinoblastoma, which results from a new germline RB1 mutation. Parents of 206 cases from 9 North American institutions and 269 friend and relative controls participated; fathers of 182 cases and 223 controls and mothers of 202 cases and 260 controls provided useable information in telephone interviews on their diet in the year before the child's conception. We also asked parents about supplements, a significant source of nutrients in users. Father's intake of dairy-associated nutrients and his use of calcium supplements were associated with decreased risk, while his intake of copper, manganese, and vitamin E was associated with increased risk. Mother's use of multivitamins close to conception was associated with lower risk as was her intake of several micronutrients found in these supplements. In analyses to elucidate the primary factor from multiple correlated factors, the most robust findings were for father's calcium intake (adjusted OR = 0.46-0.63 for 700 mg increase) and calcium supplement use (OR = 0.35-0.41) and mother's multivitamin use (ORs 0.28-0.48). There are few directly relevant studies but some data indirectly support the biologic plausibility of the inverse associations with father's calcium intake and mother's use of multivitamins; however, we cannot rule out contributions of bias, confounding, or chance. Our findings provide a starting point for further investigation of diet in the etiology of retinoblastoma and new germline mutation generally.

Parental diet and risk of retinoblastoma resulting from new germline RB1 mutation

We conducted a case-control study of sporadic bilateral retinoblastoma, which results from a new germline RB1 mutation, to investigate the role of parents' diet before their child's conception. Parents of 206 cases from nine North American institutions and 269 controls participated; of these, fathers of 184 cases and 223 controls and mothers of 204 cases and 260 controls answered a food frequency questionnaire administered by phone about their diet in the year before the child's conception. Cases provided DNA for RB1 mutation testing. We assessed parents' diet by examining 19 food groups. Father's intake of dairy products and fruit was associated with decreased risk and cured meats and sweets with increased risk. Mother's intake was not associated with disease for any food group. Considering analyses adjusted for the other food groups significantly associated with disease, energy intake, and demographic characteristics as well as more fully adjusted models, the associations with father's dairy products and cured meat intake were the most robust. In the fully adjusted, matched analysis, the odds ratios per daily serving were 0.70 (95% confidence interval (CI) 0.49-1.00, P = 0.047) for dairy products and 5.05 (CI 1.46-17.51, P = 0.01) for cured meat. The pattern of associations with paternal but not maternal diet is consistent with the fact that 85% of new germline RB1 mutations occur on the father's allele. As few human data exist on the role of diet in any condition resulting from new germ-cell mutation, additional studies will be needed to replicate or refute our findings.

Parental Prenatal Smoking and Risk of Childhood Acute Lymphoblastic Leukemia

The association between parental smoking and risk of childhood acute lymphoblastic leukemia (ALL) was investigated in an Australian population-based case-control study that included 388 cases and 868 controls aged <15 years, recruited from 2003 to 2006. Both of the child's parents provided information about their smoking habits for each year from age 15 years to the child's birth. Data were analyzed by logistic regression. Maternal smoking was not associated with risk of childhood ALL, but the odds ratio for paternal smoking of ≥15 cigarettes per day around the time of the child's conception was 1.35 (95% confidence interval: 0.98, 1.86). The associations between parental smoking risk of childhood ALL did not differ substantially by immunophenotypic or cytogenetic subtype. Meta-analyses of paternal smoking, including results from the Australian Study of Causes of Acute Lymphoblastic Leukemia in Children and those of previous studies, produced summary odds ratios of 1.15 (95% confidence interval: 1.06, 1.24) for any paternal smoking around the time of the child's conception and 1.44 (95% confidence interval: 1.24, 1.68) for smoking ≥20 cigarettes per day at that time. Study results suggest that heavier paternal smoking around the time of conception is a risk factor for childhood ALL. Men should be strongly encouraged to cease smoking, particularly when planning to start a family.

A longitudinal study of recipients' views and experiences of intra-family egg donation

For the past 10 years, we have been carrying out a longitudinal investigation of egg donation families in the UK; a subsample of recipients in these families had a child by egg donation from a sister or sister-in-law. In response to the current debate over the practice of intra-family donation, together with the general lack of available data on the consequences of donation between family members, we examined recipients' experiences of donation between sisters and sisters-in-law. We analysed data from a subsample of recipient mothers who were taking part in a larger investigation of gamete donation families. Mothers were visited at home and interviewed when their child was aged 1, 3, 7 and 10 years. Data from nine recipient mothers whose egg donor was either their sister or sister-in-law were examined to assess the nature of mothers', fathers' and the child's relationship with the donor, and whether mothers had disclosed the nature of their child's conception to others, including the child. The majority of recipient mothers reported positive relationships between the donor and members of their family (themselves, their partner and their children). Most mothers were happy with the donor's level of involvement with the child and reported that they and the donor maintained their social roles within the family, i.e. as mother and aunt, respectively. By age 10, two children had been told that they had been conceived using egg donation, both of whom had been told the identity of the donor. Although the sample was small, this study provides the first longitudinal data on the experiences of families created using donated gametes from a family member. Intra-family donation between sisters or sisters-in-law can be a positive experience for recipients during the first 10 years following the child's birth. Studies that are specifically designed to look at donation between family members are needed to better evaluate the practice.

Maternal exposure to polychlorinated biphenyls and the secondary sex ratio: an occupational cohort study

BackgroundThough commercial production of polychlorinated biphenyls was banned in the United States in 1977, exposure continues due to their environmental persistence. Several studies have examined the association between environmental polychlorinated biphenyl exposure and modulations of the secondary sex ratio, with conflicting results.ObjectiveOur objective was to evaluate the association between maternal preconceptional occupational polychlorinated biphenyl exposure and the secondary sex ratio.MethodsWe examined primipara singleton births of 2595 women, who worked in three capacitor plants at least one year during the period polychlorinated biphenyls were used. Cumulative estimated maternal occupational polychlorinated biphenyl exposure at the time of the infant's conception was calculated from plant-specific job-exposure matrices. A logistic regression analysis was used to evaluate the association between maternal polychlorinated biphenyl exposure and male sex at birth (yes/no).ResultsMaternal body mass index at age 20, smoking status, and race did not vary between those occupationally exposed and those unexposed before the child's conception. Polychlorinated biphenyl-exposed mothers were, however, more likely to have used oral contraceptives and to have been older at the birth of their first child than non-occupationally exposed women. Among 1506 infants liveborn to polychlorinated biphenyl-exposed primiparous women, 49.8% were male; compared to 49.9% among those not exposed (n = 1089). Multivariate analyses controlling for mother's age and year of birth found no significant association between the odds of a male birth and mother's cumulative estimated polychlorinated biphenyl exposure to time of conception.ConclusionsBased on these data, we find no evidence of altered sex ratio among children born to primiparous polychlorinated biphenyl-exposed female workers.

The child's conception of the world: A 20th-century classic of child psychology, Second Edition. Edited by Jean Piaget, Forward by Jacques Voneche. Rowman &amp; Littlefield Publishers, Inc, Lanham, MD, 2007. pp. 432. Price: £19.99, €31.48. ISBN 9780742559516

The child's conception of the world: A 20th-century classic of child psychology, Second Edition. Edited by Jean Piaget, Forward by Jacques Voneche. Rowman &amp; Littlefield Publishers, Inc, Lanham, MD, 2007. pp. 432. Price: £19.99, €31.48. ISBN 9780742559516

Increasing openness in oocyte donation families regarding disclosure over 15 years

Worldwide there is an increasing number of families created by oocyte donation (OD). The aim of this study was to gather information about parents' plans of disclosure to their child and to other people, as well as parents' attitudes and level of satisfaction up to 15 years after their OD treatment. A questionnaire with separate material for each partner was sent to all parents (167 mothers, 163 fathers) who had had a child after treatment with donated oocytes at Väestöliitto Fertility Clinics in Helsinki during 1992-2006. These parents had a total of 231 children aged 1-14 years. Parents were asked if they had told or intended to tell their child about his/her origin and how and when they had done so and about the reasons to disclose or not. Other questions were about openness towards other people, concerns about donor characteristics, counselling and feelings towards the child. Of the mothers, 61.1%, and of the fathers, 60.0%, had told or intended to tell the child of his/her conception. Of children over 3 years of age, 26% had already been informed. There was a statistically significant difference between parental telling in different age groups of children (P = 0.011, χ(2)). In the youngest age group (1-3 years), 83.3% of parents were inclined to disclosure compared with 44.4% in the oldest age group (13-14 years). A high proportion of mothers (86.7%) and fathers (71.0%) had told other people about the nature of their child's conception. The majority of parents did not have much concern about the characteristics of the donor. A higher proportion of the mothers (24%) compared with fathers (11%) thought that the psychological support had been insufficient. They thought that discussions with health professionals should be arranged routinely after delivery or when it was time to inform the child. Parents with young OD children are clearly more inclined to disclosure compared with parents with older children.

Medical radiation exposure and risk of retinoblastoma resulting from new germline RB1 mutation

Although ionizing radiation induces germline mutations in animals, human studies of radiation-exposed populations have not detected an effect. We conducted a case-control study of sporadic bilateral retinoblastoma, which results from a new germline RB1 mutation, to investigate gonadal radiation exposure of parents from medical sources before their child's conception. Parents of 206 cases from nine North American institutions and 269 controls participated; fathers of 184 cases and 223 friend and relative controls and mothers of 204 cases and 260 controls provided information in telephone interviews on their medical radiation exposure. Cases provided DNA for RB1 mutation testing. Of common procedures, lower gastrointestinal (GI) series conferred the highest estimated dose to testes and ovaries. Paternal history of lower GI series was associated with increased risk of retinoblastoma in the child [matched odds ratio (OR) = 3.6, 95% confidence interval (CI) = 1.2-11.2, two-sided p = 0.02], as was estimated total testicular dose from all procedures combined (OR for highest dose=3.9, 95% CI = 1.2-14.4, p = 0.02). Maternal history of lower GI series was also associated with increased risk (OR = 7.6, 95% CI = 2.8-20.7, p < 0.001) as was the estimated total dose (OR for highest dose = 3.0, 95% CI = 1.4-7.0, p = 0.005). The RB1 mutation spectrum in cases of exposed parents did not differ from that of other cases. Some animal and human data support our findings of an association of gonadal radiation exposure in men and women with new germline RB1 mutation detectable in their children, although bias, confounding, and/or chance may also explain the results.

Language development of a 1 to 2 years old child in Macedonian context: Morphological and semantic approach (case study)

In this paper, we analyze the data gathered from the longitudinal case study of language development of 1–2 years old boy in Macedonian context. The data that are important to the process of determination of the language development stadiums are presented in English, and Macedonian when necessary. There fore we open possibility of comparing language developmental characteristics of children that speak different languages, in the future research projects. Morphological and semantic approach is used to reveal the child's conception of the world manifested through its speech.