2018 ISPD Conference

The impact of additional anomalies on head growth in fetuses with congenital heart defects
Amber van Nisselrooij1, Fenna AR Jansen2, Nan van Geloven3, Ingeborg Linskens4, Eva Pajkrt5, Sally A.B. Clur6, Jarda Hruda, Jan van Lith3, Nico A. Blom3, Monique C Haak7

1Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands
2Leiden University Medical Center, Department of Obstetrics and Fetal Medicine, Leiden, Netherlands
3Leiden University Medical Center, Leiden, Netherlands
4VU University Medical Center, Amsterdam, Netherlands
5Academic Medical Center, Amsterdam, Netherlands
6Academic Medical Center, Amsterdam, United States
7Leiden University Medical Center, Department of Obstetrics and Fetal Medicine, Leiden, NH, Netherlands
Objectives
Neurodevelopmental delay is frequently encountered in children with congenital heart defects (CHD). Recent cohorts have shown lower head circumference (HC) z-scores in isolated CHD, irrespective of type of CHD, altered cerebral flow or brain oxygenation. This study compares HC in non-isolated and isolated cases with CHD to evaluate the effect of additional pathology on head size. 
Methods
All prenatally diagnosed CHD cases were selected from our previously described regional CAHAL database (2002-present). Cases with multiple pregnancy, maternal diabetes, severe structural brain anomalies and functional CHD were excluded. If additional pathology was present, cases were allocated to the non-isolated group and according to the type of pathology assigned to one of the three subgroups: genetic diagnosis, extra-cardiac structural malformation or maternal pathology/placental insufficiency. We used mixed-linear regression model to compare HC z-scores between isolated and non-isolated subjects based on the mean in- or decrease over time and HC at 20 and 36 weeks gestational age (GA). 
Results
We included 916 prenatally diagnosed CHD cases, of which 379 (41,4%) were non-isolated. Non-isolated cases had significantly lower HC z-scores at 20- (z = –1.03 vs -0.35; p<0.001 ) and 36-weeks GA (z= –1.51 / –0.60; p<0.001) compared to isolated cases. The placental pathology group (N=37) showed the fastest the decrease in the mean HC z-score throughout pregnancy (z= –2.02 / –3.12; p=0.004), as head growth decreased with an estimated –0.06 (SD per week). Abdominal circumference (AC) z-scores were also significantly lower in non-isolated fetuses. 
Conclusions
The significantly smaller HC observed amongst CHD cases appears to be strongly associated with additional pathology, in particular, factors causing placental insufficiency. We hypothesize that developmental pathways involved in both cardiogenesis as overall growth, combined with other perinatal factors, determine the risk of neurodevelopmental delay (ND).