Research Strategy

The Copenhagen Baby Heart Study (CBHS) is a multicentre population study, aiming to study the newborn cardiovascular structure and function, investigate the impact of prenatal exposures on the newborn heart and to understand how pre- and postnatal exposures affect cardiovascular structure and function and general health later in life.

The major aims of the CBHS are to:

i. determine the prevalence at birth of a wide range of structural congenital heart disease (CHD) and subtle morphological and functional abnormalities, in a large population-based cohort of newborns with echo- and electrocardiographic examinations performed shortly after birth.

ii. establish reference intervals for normal echo- and electrocardiographic

parameters in newborns and describe the variability in these parameters over the first 60 days of life;

iii. evaluate the clinical significance of abnormalities in infant cardiac structure and function and electrocardiographic measures for cardiovascular health across the life course.

In an effort designated CBHS-Impact, subgroups of CBHS participants will be followed longitudinally through childhood and into adulthood to provide data on normal childhood cardiac development and assess the long-term significance of abnormal findings from early childhood;

iv. evaluate potential associations between maternal conditions, prenatal exposures and biomarkers, and neonatal cardiac structure and function. The CBHS will study whether the fetal heart responds in subtle structural or functional ways to intrauterine exposure to maternal comorbidities and pregnancy complications and, through CBHS-Impact studies, determine whether the resulting cardiac changes observed in newborns are transient or permanent;

v. evaluate incidence and detection rate of CHDs not identified through routine prenatal screening; vi. investigate the genetic and hereditary aspects of cardiovascular conditions identified in the CBHS. CBHS participants with structural CHDs or subclinical morphological and functional cardiac abnormalities and their first-degree relatives will undergo clinical examinations as part of CBHS-Impact.


Design: From April 1, 2016 to November 28, the study incorporated pre-natal inclusion of children born at Rigshospitalet, Herlev Hospital and Hvidovre Hospital, three hospitals located in the capital region of Denmark.

Parents of all children born at one of the three hospitals during the study inclusion period were invited to participate in a comprehensive cardiac examination of their children including echocardiography, ECG, an umbilical cord blood sample and questionnaires.

In this period more than 25,500 children were included.

The study is the largest population study with a focus on congenital heart disease and pre-natal inclusion. During this period, if staff discovered infants with serious heart conditions during the examination, the infants were immediately referred to a pediatric heart unit. Researchers from CBHS continually followed infants withminor congenital heart conditions. If needed, the children were referred to clinical specialist care.


Design: The second phase of CBHS, called CBHS-Impact, began in late 2018 after the end of the inclusion period.

During CBHS-I we will continue to follow children with minor heart abnormalities or born to mothers with – certain risk factors, e.g. diabetes. throughout their lives. In addition, families of children diagnosed with conditions suspected to be hereditary will be invited to participate.
Additionally, the CBHS database, consisting of echocardiography, electrocardiogram and a biobank with biochemical markers and genetic information, will be connected to national registries, enabling lifelong follow up of participants.