Danish National Birth Cohort (DNBC) www.dnbc.dk

I4C_Lyon 2009

Methods and Data collection

Population sampleYears of recruitment: 1996-2002

Sampling method: All pregnant women in Denmark during the recruitment period. Approx. 60% of all pregnant women were invited and approx. 30% of the invited enlisted. Participants had to live in Denmark and speak Danish well enough to be able to complete telephone interviews.

Response rate: Differs for the diff. collection waves but is between 93% and 60%.

Number of live births at baseline: 96,841

Exposure domains in questionnaires

Environmental Samples

Acknowledgements

”The Danish National Research Foundation has established the Danish Epidemiology Science Centre that initiated and created the Danish National Birth Cohort. The cohort is furthermore a result of a major grant from this Foundation. Additional support for the Danish National Birth Cohort is obtained from the Pharmacy Foundation, the Egmont Foundation, the March of Dimes Birth Defects Foundation, the Augustinus Foundation, and the Health Foundation”

Jørn Olsen, UCLA & Aarhus University, Denmark

EXPOSURE DATA COLLECTED (Yes or No)

NUMBERS (%)

(If available)

Prenatal folic acid intakeAny amount during 1st trim (from gw -4 to gw +6) Any amount during 2nd trimester (gw 21 to 25)

Yes 19,3 % 49,8 %

- Dose, Frequency of use, Trimester of use Yes

Smoking

- Smoked (yes/no)Yes Overall, at some point during

pregnancy 24,739 cases (%)

- Number per day Yes

- Passive smoking (yes/no) Yes 29,425 cases (34 %) yes

- Trimester when smokedyes 26 %, 18%, 16% in first, second,

third trimester respectively

Alcohol

- Consumed (yes/no) yes 51977 55%) yes

- Type yes

- Trimester when consumedyes 41 %, 43%, 35% in first, second,

third trimester respectively

- Drinks per day yes

- >= 5 drinks on one occasion yes

Chemical Exposures

- Exposed (yes/no) and Frequency of use yes 3710 cases (approx. 3%)

- Type of chemicalPesticides, solvents, cytostatica..

SES- Education, Marital status, Employment status, Income, Based on job title

May be obtained from other national registers in Denmark

Siblings

- Number of previous live births May be obtained from other national registers in Denmark

Child Growth - Weight (grams), Head circumference (cm), Body length (cm)

yes Average weight, head circumference, body length

Early Childhood Infections

- Fever (yes/no) yes n (%) yes

- Chicken pox (yes/no) yes n (19 %) yes

- Asthma (yes/no)

yes n (12%) reported by mothers6% submitted to hospital

- Others- please specify

Biospecimens

SPECIMENS COLLECTED

( yes/no)Maternal

• Prenatal Blood Yes

Other: None

• At birth Cord blood Yes

Baby/Child

• First year of life Blood Not in cohort, but may be obtained from national biobank

SPECIMEN COLLECTED

( yes/no)

Maternal None

Baby/Child None

Population sample

Research Questions and Primary Outcomes

Identifying prenatal and perinatal determinants of importance for reproductive failiures and diseases that manifest themselves later in life.

Main exposures of interest are: Lifestyle factors, diet, social conditions, infections, drugs & environmental exposures.

Ascertainment of Cancer cases: Danish National Patient Registry, August 2008

Number of Cancer Cases Total: 185Leukemia: 62 - ALL 33 cases (%) - AML 3 cases(%)Brain: 29 cases (%)Others: n (%)

Cancer CasesDescription:

Samples/ Records

1st trimester

Blood from the mother taken at first visit to GP

93,000

12th week of gestation

13 minutes CATI interview 92,892

25th week of gestation

Self-administered questionnaire on dietary habits

66,874

2nd trimester

Sample taken at antenatal GP visit

71,000

30th week of gestation

12 minutes CATI interview 87,802

Birth Blood from the child taken from the umbilical cord

61,000

Child age 6 months

16 minutes CATI interview 70,296

Child age 18 months

10 minutes CATI interview 66,712

Child age 7 years

(Current) Self-administered questionnaire to mother

53,211 (1st October

2009)

Child age 11 years

Self-administered web questionnaire to both child and

mother

To start in June 2010

Dr. Jørn OlsenDr. Mads MelbyeDr. Thorkild IA SørensenDr. Anne-Marie Nybo AndersenDr. Sjurdur F. Olsen Dr. Peter Aaby

DNBC Management

The DNBC 11-year follow-up started in June 2010. Approx. 22.000 records - 50% response rate in September 2011.

www.club11.dk