Intergenerational transmission of health disparities among Turkish-origin immigrants in Germany: study protocol of a multi-centric cohort study (BaBi-stress and BaBeK study)

Jacob Spallek,Sonja Entringer,Medlin Kurt,Laura Scholaske,Denise Lindner-Matthes

doi:10.1186/s12884-020-2853-y

Abstract

BackgroundImmigrants in Germany exhibit higher levels of social disadvantage when compared to the non-immigrated population. Turkish-origin immigrants constitute an important immigrant group in Germany and show disparities in some health domains that are evident from birth onwards. Several studies have shown the mechanisms by which social disadvantage is biologically embedded to affect health over the lifespan. Relatively little, however, is still known about if and how the maternal social situation is transmitted to the next generation. This study therefore aims to analyse the effects of maternal socioeconomic status and migration status on stress-related maternal-placental-fetal (MPF) biological processes during pregnancy on infant birth and health outcomes.MethodsThis longitudinal cohort study of N = 144 child-mother dyads is located at two study sites in Germany and includes pregnant women of Turkish origin living in Germany as well as pregnant German women. During pregnancy, MPF stress biology markers from maternal blood and saliva samples, maternal socio-economic and migration-related information, medical risk variables and psychological well-being are assessed. After birth, infant anthropometric measures and developmental outcomes are assessed. The same measures will be assessed in and compared to Turkish pregnant women based on a collaboration with BABIP study in Istanbul.DiscussionThis is the first study on intergenerational transmission of health disparities in Germany with a focus on women of Turkish-origin. The study faces similar risks of bias as other birth cohorts do. The study has implemented various measures, e.g. culturally sensitive recruitment strategies, attempt to recruit and follow-up as many pregnant women as possible independent of their social or cultural background. Nevertheless, the response rate among lower-educated families is lower. The possibility to compare results with a cohort from Turkey is a strength of this study. However, starting at different times and with slightly different recruitment strategies and designs may result in cohort effects and may affect comparability of the sub-cohorts.Trial registrationN.A. (Observational study, no clinical trial, no interventions on human participants).

Highlights

Immigrants in Germany exhibit higher levels of social disadvantage when compared to the nonimmigrated population
We suggest that stress-related MPF endocrine and immune processes in gestation constitute an attractive underlying biological candidate mechanism for transmitting the effects of different maternal exposure to the fetus for the following reasons: First, these measures are among the most reliable, objective indicators of human fetal exposure to in utero stress
The study is located at two study sites: BaBi-Stress study in Bielefeld (Germany) and BaBeK study in Berlin (Germany)

Summary

Introduction

Immigrants in Germany exhibit higher levels of social disadvantage when compared to the nonimmigrated population. A substantial body of research has uncovered the cascading pathways and underlying mechanisms by which social disadvantage gets biologically embedded “under the skin” to impact health and disease risk across the life span [19] This body of work treats the emergence of health inequalities as a process that operates within the individual life span. Origins of population health disparities may, in part, trace back to the intergenerational effects of maternal migration-related experiences and social disadvantage on her child’s development during the critical period of intrauterine life [23, 24], and we advance the hypothesis that context- and time-inappropriate levels of the resultant stress biology exposures (maternal-placentalfetal endocrine and immune/inflammatory state) during embryonic and fetal life may “program” the structural and functional integrity of cells, tissues and organ systems in a manner that impacts subsequent health and disease riskrelated outcomes. We assess endocrine (placental corticotrophin-releasing hormone (pCRH), cortisol, and inflammatory (interleukin (IL)-6; C-reactive protein (CRP)) measures of MPF biology serially over the course of gestation as key markers of exposure to adverse intrauterine conditions

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