Right ventricular dysfunction identified by abnormal strain values precedes evident growth restriction in small for gestational age fetuses

Objectives
Small for gestational age (SGA) fetuses have an increased risk for adverse outcome. Placental insufficiency leads to changes in the circulation, with secondary adaptation of the fetal heart resulting in changed cardiac deformation. This deformation can be measured with 2D speckle tracking echocardiography (2D‐STE). SGA is antenatally often undiagnosed. The measurement of deformation changes in the fetal heart might help in the prediction of SGA and identify fetuses in need of more intensive surveillance.

Methods
In this longitudinal prospective cohort study, global longitudinal strain (GLS) and strain rate (GLSR), measured before 23 weeks gestational age were compared between SGA and appropriate for gestational age (AGA) fetuses, based on birthweight corrected for gestational age at birth.

Results
The fetal heart rate was significantly increased in SGA; 158 beats per minute (146‐163) versus 148 (134‐156); p=0.035 in AGA. Right ventricle GLS (RV‐GLS) values were significantly increased in SGA; ‐15.87% (‐11.69% to ‐20.55%) versus ‐20.24% (‐16.29% to ‐24.28%); p=0.024, respectively.

Conclusion
RV‐GLS values, measured with 2D‐STE, were significantly increased in SGA, indicating systolic RV dysfunction before 23 weeks gestational age in fetuses who will become SGA later in pregnancy. A large longitudinal prospective cohort study is needed to confirm these findings.