Impact of Fetal Somatic Growth on Pulmonary Valve Annulus Z-Scores During Gestation and Through Birth in Patients with Tetralogy of Fallot
Previous studies have suggested reduced pulmonary valve annulus (PVA) growth and progression of pulmonary outflow obstruction in fetuses with tetralogy of Fallot (TOF). The goals of this study were to (1) investigate the trajectory of PVA growth in utero, and (2) compare two methods of z-score determination for fetal and postnatal PVA size by echocardiography in order to improve prenatal counseling for patients with TOF. Fetal echocardiograms (FE) at a single institution with a diagnosis of TOF between 8/2008 and 12/2015 were retrospectively reviewed. Patients included had at least 2 FEs and 1 immediate postnatal echocardiogram (TTE). Fetal and postnatal demographic, clinical, and echocardiographic data were collected. Fetal body surface area (BSA) was calculated by estimating fetal weight and height; z-scores were determined based on fetal gestational age (GA) and BSA for both FEs and TTEs. Fetal PVA z-scores by GA or BSA were then compared to postnatal PVA z-scores by BSA. Twenty-two patients with 44 FEs and 22 TTEs were included. GA at the first FE was 23 weeks ± 3.4 and 32 weeks ± 3.1 at the second FE. There was no difference in PVA z-scores (by BSA) between the first and second FE (p = 0.34), but a decrease in PVA z-scores (by BSA) between the second FE and TTE (− 1.6 ± 0.5 vs. − 2.0 ± 0.7; p = 0.01). Repeat comparison with fetal PVA z-scores indexed to GA revealed no difference in z-scores between the first and second FE, but an increase in PVA z-scores between the second FE (by GA) and TTE (by BSA) (− 4.1 ± 1.0 vs. − 2.0 ± 0.7; p < 0.0001). The rate of PVA growth between the two FEs (23 µm/day ± 9.8) and between the second FE and TTE (28 µm/day ± 42) remained comparable (p = 0.57); however, the rate of BSA increase was greater in later gestation (9 cm2/day ± 3 vs. 20 cm2/day ± 11; p = 0.001). In patients with TOF, the rate of PVA growth appears to remain consistent through gestation; however, somatic growth rate increases in late gestation. Fetal PVA z-scores indexed to GA are thus inaccurate in predicting postnatal PVA z-scores typically indexed to BSA. This observation should be considered during prenatal consultation and delivery planning.
KeywordsFetal cardiology Congenital heart disease Tetralogy of Fallot Fetal ultrasound Fetal somatic growth Echocardiography
Body surface area
Pulmonary valve annulus
Tetralogy of Fallot
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article does not contain any studies with animals performed by any of the authors.
This is a retrospective data review study, hence need for consent was waived from the Institutional Review Board. Permission was granted for this retrospective data review.
- 8.Sluysmans T, Colan SD (2009) Structural measurements and adjustment for growth, Chap. 5. In: Lai WW, Cohen MS, Geva T, Mertens L (eds) Echocardiography in pediatric and congenital heart disease. Wiley-Blackwell, West SussexGoogle Scholar
- 9.Colan SD (2009) Normal echocardiographic values for cardiovascular structures. In: Lai WW, Cohen MS, Geva T, Mertens L (eds) Echocardiography in pediatric and congenital heart disease. Wiley-Blackwell, West Sussex, pp 765–785Google Scholar