Background: Congenital heart disease (CHD) is associated with neuro-developmental disorders. The influence of CHD on the brain may be present in the fetus. We hypothesize that fetal cerebral growth is impaired as early as 2nd trimester.Aim: To investigate if fetal cerebral growth is associated with major and minor CHD.: Pregnant women in Denmark (more than 95%) attend two publicly funded ultrasound scans; around 12 and 20 weeks gestational age (GA). During the first scan fetal bi-parietal-diameter (BPD) is routinely obtained. During the second scan fetal head- circumference (HC) is obtained and screening for fetal malformations is carried out. Our cohort includes all fetuses in Western Denmark (2.9 million inhabitants) screened in between January 1st 2012 and December 31st 2013, diagnosed with any structural, non-syndromic congenital heart disease either during pregnancy or up to 6 months after birth.Results 276 fetuses with CHD were identified.114 (41%) were genetically screened primarily by chromosomal microarray analysis (n=82). Fetuses with identified chromosomal abnormalities were excluded as were multiple gestation fetuses and fetuses with major extra cardiac malformations. Data from 208 fetuses (75%) with presumed non-syndromic CHD were included, 85 (41%) with minor and 123 (59%) with major CHD. Z-scores for head size were analysed.Conclusions: Our preliminary results suggest that Bi-parietal-diameter in children with CHD is within the normal range in the 1st trimester, but fetal cerebral growth may be disrupted as early as during 2nd trimester in major CHD.