Short summary

In this cohort we will examine the association between maternal self-reported alcohol use during pregnancy and:

Attention deficit hyperactivity disorder, hyperkinetic disorder and prescription of Ritalin (methylphenidate) in children and young adults up till 23 years of age

School performance at 15-16 years of age (elementary school graduation exams in 9th grade)

Furthermore, we will describe the prevalence and predictors for maternal self-reported use of cannabis during pregnancy and how it relates to pregnancy complications and neonatal outcome.

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Rationale

While, numerous studies have demonstrated that heavy drinking of alcohol during pregnancy can affect fetal brain development, the association between moderate, prenatal alcohol-exposure is less clear. Also, little is known about the long term effects of prenatal exposure to alcohol, and the association of different types of alcohol has not been studied. Prenatal exposure to cannabis may increase maternal and neonatal adverse outcome. In the general Danish population, cannabis use is increasing. However, little is known about prevalence and predictors for cannabis use during pregnancy.  

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Description of the cohort

This study is based on data from Aarhus Birth Cohort (ABC), which is a prospective cohort consisting of pregnant women referred to Aarhus University Hospital. ABC has consecutively been recruiting women in early pregnancy since 1989. The cohort is placed at Aarhus University hospital and led by Trine Brink Henriksen.

The study population includes children of all pregnant women enrolled in in this cohort until 2012. 

Data and biological material

Exposure: Pregnant women enrolled in the ABC have filled out a posted questionnaire at approximately gestational age (GA) 16 including information about the use of alcohol and cannabis in pregnancy. These will be the main exposures of the study and includes measures of the average weekly consumption of alcohol (units per week), the average weekly consumption of beer, wine and spirits (units per week), wine-preferences (red wine/white or rose wine), episodes of binge-drinking (number of episodes), timing of binge-drinking (GA), use of cannabis in pregnancy (yes/no) and episodes of cannabis use in pregnancy (number of episodes).

Outcome: The incidence of attention deficit hyperactivity disorder (ADHD) and hyperkinetic disorder (HKD) will be defined as diagnoses of ADHD and HKD and these will be based on data from the Danish Nationwide Psychiatric Central Registry and The Danish National Registry of Patients. Any prescription of Ritalin (methylphenidate) will be obtained from the Danish Drug Statistics Registry. The oral and written grades in Danish and math at the elementary school graduation exams in 9th grade will be retrieved from the Elementary School Registry, Statistics Denmark. In Denmark, elementary school is compulsory to children from the age of 6 until to graduation of 9th grade.

Covariates: In the questionnaire the women also provide information about age, parity, height, weight, educational level, marital status, other life style factors and partner's average weekly consumption of alcohol before and during pregnancy. Data on pregnancy complications and neonatal outcome includes GA, birth weight, congenital malformations and pregnancy and birth complications such as pre-eclampsia, gestational diabetes, post-partum hemorrhage and admission to neonatal intensive care unit will be obtained from ABC.

Collaborating researchers and departments

This project is a research-collaboration between:

The Research Unit of Gynecology and Obstetrics, Department of Clinical Research and University of Southern Denmark

• Ph.D.-student Louise Katrine Kjær Weile
• Professor Ellen Aagaard Nøhr

Department of Obstetrics and Gynecology, Herlev and Gentofte Hospital, Herlev

• Professor Ulrik Schiøler Kesmodel

Perinatal Epidemiology Research Unit, Department of Paediatrics, Aarhus University and Aarhus University Hospital

• Professor Tine Brink Henriksen