المؤلفون: Boyd, Heather A.¹ hoy@ssi.dk, Poulsen, Gry, Wohlfahrt, Jan, Murray, Jeffrey C., Feenstra, Bjarke, Melbye, Mads

المصدر: American Journal of Epidemiology. Dec2009, Vol. 170 Issue 11, p1358-1364. 7p. 3 Charts.

مصطلحات موضوعية: *PREMATURE labor, *DELIVERY (Obstetrics), *CHILDBIRTH, *PREGNANCY, *HEREDITY, *GENETICS

مصطلحات جغرافية: DENMARK

مستخلص: Preterm delivery (PTD) is a complex trait with a significant familial component. However, no specific inheritance patterns have been established. The authors examined the contribution of PTDs in both the woman's family and her partner's family to her risk of PTD. The authors linked birth information from Danish national registers with pedigree information from the Danish Family Relations Database for 1,107,124 live singleton deliveries occurring from 1978 to 2004. Risk ratios were estimated comparing women with and without various PTD histories. Women with previous PTDs were at greatly increased risk of recurrent PTD (risk ratio = 5.6, 95% confidence interval: 5.5, 5.8); however, their PTD risk was unaffected by a partner's history of preterm children with other women. PTDs to a woman's mother, full sisters, or maternal half-sisters also increased her PTD risk (risk ratio = 1.6, 95% confidence interval: 1.5, 1.6), whereas PTDs in her paternal half-sisters, the female partners of her male relatives, or members of her partner's family did not affect her PTD risk. Inheritance patterns were similar for all gestational ages from very early through late PTD. The substantial portion of PTD risk explained by effects passed through the female line suggests a role for either imprinting or mitochondrial inheritance. [ABSTRACT FROM PUBLISHER]

المؤلفون: Svensson, Anna C.¹ anna.svensson@ki.se, Sandin, Sven, Cnattingius, Sven, Reilly, Marie, Pawitan, Yudi, Hultman, Christina M., Lichtenstein, Paul

المصدر: American Journal of Epidemiology. Dec2009, Vol. 170 Issue 11, p1365-1372. 8p. 1 Diagram, 3 Charts.

مصطلحات موضوعية: *PREMATURE labor, *GENETIC epidemiology, *MOLECULAR epidemiology, *LOGISTIC regression analysis, *CHILDBIRTH, *EPIDEMIOLOGY

مستخلص: This study was undertaken to disentangle the maternal genetic from the fetal genetic effects for preterm birth and to study the possibility of these effects being explained by known risk factors. By cross-linking of the population-based Swedish Multigeneration and Medical Birth registers, 989,027 births between 1992 and 2004 were identified. Alternating logistic regression was applied to model the familial clustering with pairwise odds ratios (PORs), and covariates were included to evaluate if the familial aggregation was explained by exposure to shared risk factors. Generalized linear mixed models were used to estimate the contribution of genetic and environmental effects. Sisters of women who had a preterm delivery had themselves an increased odds of having a preterm delivery (POR = 1.8, 95% confidence interval: 1.5, 2.1), while there was no corresponding increase in odds in families joined by brothers (POR = 1.1, 95% confidence interval: 0.9, 1.4). Twenty-five percent of the variation in preterm birth was explained by maternal genetic factors, whereas fetal genetic factors only marginally influenced the variation in liability. The increased odds ratio between offspring of sisters was independent of maternal risk factors for preterm birth, suggesting that the relative importance of maternal effects is not explained by these well-known risk factors. [ABSTRACT FROM PUBLISHER]

المؤلفون: Weinberg, Clarice R.¹ weinber2@niehs.nih.gov, Min Shi

المصدر: American Journal of Epidemiology. Dec2009, Vol. 170 Issue 11, p1373-1381. 9p. 5 Charts, 4 Graphs.

مصطلحات موضوعية: *PREMATURE labor, *LABOR complications (Obstetrics), *PREGNANCY, *CHILDBIRTH, *LOG-linear models, *PREMATURE infants, *GENETICS

مستخلص: Women delivering preterm are at greatly increased risk of another preterm birth in subsequent pregnancies, reflecting effects of the environment, genetics, or both. Recent literature tells an increasingly coherent story about genetic susceptibility. Women who change partners after delivering preterm retain their elevated risk, whereas fathers who change partners do not. Women who themselves were preterm are at increased risk, an association not seen in fathers. Women with a half-sister who delivered preterm are at increased risk only if the shared parent was the mother. Concordance for preterm delivery is elevated in monozygotic compared with dizygotic twin mothers but not in monozygotic twin fathers. Several mechanisms could be operating: mitochondrial genes, maternal genes, or fetal genes expressing only the maternally derived copy. The authors compare 3 study designs for their ability to detect variants and to distinguish among mechanisms underlying heritability of this common outcome. The case-parent triad design offers robustness against self-selection and genetic population stratification, providing for estimation of genetic effects that are fetal, maternal, or that depend on the parent of origin. A case-base approach compares case-mothers with randomly sampled baby-mother pairs and permits estimation of the same relative risk parameters. Both designs offer important advantages over the commonly applied case-mother/control-mother design. [ABSTRACT FROM PUBLISHER]

المؤلفون: Whitehead, Nedra, Hill, Holly A., Brogan, Donna J., Blackmore-Prince, Cheryl

المصدر: American Journal of Epidemiology; Jan2002, Vol. 155 Issue 2, p117-124, 8p

مصطلحات موضوعية: DURATION of pregnancy, PSYCHOLOGICAL stress, PREMATURE labor, HORMONES, RISK assessment, CHILDBIRTH, LABOR complications (Obstetrics), MENTAL health, U.S. states

مصطلحات جغرافية: UNITED States

مستخلص: Biologic evidence suggests that the hormones activated by stress affect gestational length, but the results of epidemiologic investigations are inconsistent. The authors of this paper know of no threshold models that have been studied; these models assume that stress does not affect preterm delivery until a certain amount of stress has been experienced but that each unit of stress above the threshold adds to the risk of preterm delivery. By using standard logistic regression, the authors compared threshold and nonthreshold models of the relation between number of stressful life events and preterm delivery in 11 US states. They used data on 1990–1995 births from the Pregnancy Risk Assessment Monitoring System. The risk of preterm delivery among multiparas who gave birth in 1990–1993 increased 7% for each event over five they experienced, but no relation was found for 1994–1995 births. Among primiparas who gave birth in 1994–1995, the risk increased 5% for each event over two, but no relation was found for 1990–1993 births. These results suggest that a threshold model may fit the relation between stress and preterm delivery better than one with no threshold. However, the inconsistent results are difficult to reconcile with a biologic threshold in the relation between stress and preterm delivery. [ABSTRACT FROM PUBLISHER]

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المؤلفون: Svensson, Anna C.¹ anna.svensson@ki.se, Sandin, Sven, Cnattingius, Sven, Reilly, Marie, Pawitan, Yudi, Hultman, Christina M., Lichtenstein, Paul

المصدر: American Journal of Epidemiology. Dec2009, Vol. 170 Issue 11, p1386-1387. 2p.

مصطلحات موضوعية: *PREMATURE labor, *LABOR (Obstetrics), *PREGNANCY, *BODY mass index, *CHILDBIRTH, *BODY weight, *GENETICS

مستخلص: A response to a commentary about the article "Maternal Genes and Environment in Preterm Birth--A Genetic Epidemiologic Study of 630,000 Families" is presented. The authors mention the importance of maternal factors to preterm birth. They consider the misclassification of self-reported body mass index (BMI) and BMI. They cite risk factors to preterm birth.