Prenatal recruitment of participants for a birth cohort study including cord blood collection: results of a feasibility study in Bremen, Germany

Tehran environmental and neurodevelopmental disorders (TEND) cohort study: Phase I, feasibility assessment

PURPOSE

To advance knowledge about childhood neurodevelopmental disorders and study their environmental determinants, we conducted a study in Tehran, Iran to assess the feasibility of prospective birth cohort study.

METHODS

We evaluated participation of pregnant women, feasibility of sampling biological material, and health care services availability in Tehran in four steps: (1) first trimester of pregnancy; (2) third trimester of pregnancy; (3) at delivery; and (4) two to three months after delivery. We collected related data through questionnaires, also various biological samples were obtained from mothers (blood, urine, milk and nails-hands and feet) and newborns (umbilical cord blood, meconium, and urine samples) from February 2016 to October 2017.

RESULTS

overall 838 eligible pregnant women were approached. The participation rate was 206(25%) in our study and about 185(90%) of subjects were recruited in hospitals. Out of 206 participants in the first trimester, blood, urine, hand nail, and foot nail samples were collected from 206(100%),193(93%), 205(99%), and 205(99%), respectively. These values dropped to 65(54%), 83(69%), 84(70%), and 84(70%) for the remaining participants 120(58%) in the third trimester, respectively. Also, we gathered milk samples from 125(60%) of mothers at two to three months after delivery.

CONCLUSION

Our findings suggest that hospitals were better places for recruitment of subjects in a birth cohort in Tehran. We further concluded that birth cohort study recruitment can be improved by choosing appropriate gestational ages. Obtaining the newborn's urine, meconium, and umbilical cord blood were challenging procedures and require good collaboration between hospital staff and researchers.

KUNO-Kids birth cohort study: rationale, design, and cohort description

Background

Birth cohort studies can contribute substantially to the understanding of health and disease — in childhood and over the life course. The KUNO-Kids birth cohort study was established to investigate various aspects of child health, using novel omics technologies in a systems medicine approach.

Results

After 3 years of recruitment, 2515 infants and their families have joined the study. Parents with higher education are overrepresented as in many other birth cohorts and are more likely to complete follow-up assessments via self-report questionnaires. The vast majority of participants consented to clinical examinations of their child and to the non-invasive collection of diverse biosamples, which were processed specifically for their integrated use in omics technology covering genomics, epigenomics, transcriptomics, metabolomics, and microbiome analyses of the skin, oral cavity, and stool.

Conclusions

The data and diverse biomaterial collected in the KUNO-Kids birth cohort study will provide extensive opportunities for investigating child health and its determinants in a holistic approach. The combination of a broad range of research questions in one study will allow for a cost-effective use of biomaterial and omics results and for a comprehensive analysis of biological and social determinants of health and disease. Aiming for low attrition and ensuring participants’ long-term commitment will be crucial to fully exploit the potential of the study.

A pilot study to understand feasibility and acceptability of stool and cord blood sample collection for a large-scale longitudinal birth cohort

Background

Few data are available to guide biological sample collection around the time of birth for large-scale birth cohorts. We are designing a large UK birth cohort to investigate the role of infection and the developing immune system in determining future health and disease. We undertook a pilot to develop methodology for the main study, gain practical experience of collecting samples, and understand the acceptability of sample collection to women in late pregnancy.

Methods

Between February–July 2014, we piloted the feasibility and acceptability of collecting maternal stool, baby stool and cord blood samples from participants recruited at prolonged pregnancy and planned pre-labour caesarean section clinics at University College London Hospital. Participating women were asked to complete acceptability questionnaires.

Results

Overall, 265 women were approached and 171 (65%) participated, with ≥1 sample collected from 113 women or their baby (66%). Women had a mean age of 34 years, were primarily of white ethnicity (130/166, 78%), and half were nulliparous (86/169, 51%). Women undergoing planned pre-labour caesarean section were more likely than those who delivered vaginally to provide ≥1 sample (98% vs 54%), but less likely to provide maternal stool (10% vs 43%). Pre-sample questionnaires were completed by 110/171 women (64%). Most women reported feeling comfortable with samples being collected from their baby (<10% uncomfortable), but were less comfortable about their own stool (19% uncomfortable) or a vaginal swab (24% uncomfortable).

Conclusions

It is possible to collect a range of biological samples from women around the time of delivery, and this was acceptable for most women. These data inform study design and protocol development for large-scale birth cohorts.

Electronic supplementary material

The online version of this article (10.1186/s12884-017-1627-7) contains supplementary material, which is available to authorized users.