Diurnal cortisol variation during pregnancy in Turkish origin and non-migrant women in a German birth cohort study.

BACKGROUND: Immigrants from Turkey experience health disadvantages relative to non-immigrant populations in Germany that are manifest from the earliest stages of the lifespan onwards and are perpetuated across generations. Chronic stress and perturbations of stress-responsive physiological systems, including the hypothalamus-pituitary-adrenal (HPA)-axis, are believed to in part mediate this relationship. Cortisol plays an important role in the association between maternal stress during pregnancy and many pregnancy-, birth- and offspring-related outcomes. We therefore examined whether maternal migrant background is associated with diurnal cortisol variation during pregnancy. METHODS: 109 pregnant women (incl. n = 32 Turkish origin women) that participated in a multi-site prospective cohort study in Germany collected saliva samples across the day on two consecutive days around 24 and 32 weeks gestation. Hierarchical linear models were applied to quantify associations between migrant background and diurnal cortisol variation across pregnancy. RESULTS: Women of Turkish origin exhibited a significantly lower cortisol awakening response (CAR) and a flatter diurnal cortisol slope (DCS) compared to non-migrant women after adjusting for household income. These relationships between migrant status and diurnal cortisol variation were mainly driven by 2nd generation migrants. DISCUSSION: A potential HPA axis dysregulation of Turkish-origin pregnant women may contribute to the intergenerational transmission of health disadvantages in this group.

Association of maternal migrant background with inflammation during pregnancy - Results of a birth cohort study in Germany.

BACKGROUND: Health disparities in children of immigrants are prevalent from birth and are hypothesized to - in part - emerge as a biological consequence of migration's unfavorable social and psychological sequelae. The aim of this study was to examine whether maternal migrant background is associated with inflammation during pregnancy - a key pathway by which maternal states and conditions during pregnancy may influence fetal development and subsequent pregnancy, birth, and child developmental and health outcomes. MATERIAL AND METHODS: Data was available from 126 pregnant women who participated in a population based multi-site prospective birth cohort study in Bielefeld and Berlin, Germany. The study included two study visits in mid- and late pregnancy. At each visit, a composite maternal pro-inflammatory score was derived from circulating levels of plasma inflammatory markers (IL-6, CRP). Migrant background was defined by country of origin of participants and their parents' (Turkey or other) and generation status (1st or 2nd generation). We applied hierarchical linear models (HLM) in order to quantify the relationship between different migrant background variables and inflammation during pregnancy after adjustment for potential confounders (including socioeconomic status). RESULTS: Migrant background was significantly associated with inflammation during pregnancy. When compared to women without migrant background, levels of inflammation were increased in 1) pregnant women with migrant background in general (B = 0.35, SE = 0.12, p < .01); 2) 1st (B = 0.28, SE = 0.15, p < .10) and 2nd generation (B = 0.40, SE = 0.15, p < .01); 3) women with a Turkish migrant background (B = 0.28, SE = 0.14, p < .10) and women with another migrant background (B = 0.42, SE = 0.15, p < .01); and 4) 2nd generation Turkish origin women (B = 0.38, SE = 0.20, p < .10), 1st generation women with other migrant background (B = 0.44, SE = 0.26, p < .10), and 2nd generation women with other migrant background (B = 0.43, SE = 0.17, p < .05). DISCUSSION: Our findings support a role for maternal inflammation as a pathway of intergenerational transmission of migration-related health inequalities, suggest that the effect seems to persist in 2nd generation immigrants, and highlight the need for future research and targeted interventions in this context.

Multilevel Impact of Prenatal Risk and Protective Factors on Stress Biology and Infant Development: Study protocol of BABIP prospective birth cohort from Turkey.

Prenatal environment has long-lasting effects on offspring development and health. Research on prenatal stress identified various mechanisms of these effects, from changes in epigenetic and gene expression profiles to Maternal-Placental-Fetal (MPF) stress biology. There is also evidence for the role of additional risk and protective factors influencing the impact of prenatal stress on maternal and infant outcomes. Considering these findings, we present the study protocol of BABIP, a prospective birth cohort from Turkey. The aim of the project is to investigate the effect of prenatal stress on MPF stress biology (i.e. neuroendocrine, immune and metabolic systems), differential DNA methylation and gene expression patterns, and infant birth and developmental outcomes. We are recruiting 150 pregnant women and their babies for a longitudinal project with 4 time points: 20-24 (T1) and 30-34 (T2) weeks of pregnancy, and 1-month (T3) and 4-months (T4) after giving birth. Maternal early and prenatal environment (prenatal stress, early life stress, psychosocial resources, and health-related behaviors) are assessed during pregnancy with MPF stress biology, DNA methylation and gene expression measures. Infant birth outcomes, DNA methylation and development are assessed postpartum. BABIP is the first prospective birth cohort from Turkey with extensive measures on prenatal environment and health. Through investigating the multilevel impact of prenatal stress and related risk and protective factors during and after pregnancy, BABIP will contribute to our understanding of the mechanisms by which prenatal environment influences infant development and health. Being the first such cohort from Turkey, it may also allow identification of prenatal risk and protective factors specific to the context and population in Turkey.

A simple modification to the luminometric methylation assay to control for the effects of DNA fragmentation.

Variations in DNA methylation have been implicated in a number of disorders. Changes in global DNA methylation levels have long been associated with various types of cancer. One of the recently described methods for determining global DNA methylation levels is the LUminometric Methylation Assay (LUMA), which utilizes methylation sensitive and insensitive restriction endonucleases and pyrosequencing technology for quantification. Here we provide evidence suggesting that the global methylation level reported by LUMA is affected by the integrity of the DNA being analyzed. The less intact the DNA, the lower the global methylation levels reported by LUMA. In order to overcome this problem, we propose the use of undigested DNA alongside digested samples. Finally, we demonstrate that this results in a more accurate assessment of global DNA methylation levels.