Does maternal respiration modulate maternal-fetal cardiovascular coupling?

Objective : Maternal Fetal Cardiac Coupling (MFCC) is an understudied physiological phenomenon that could play a key role in the understanding and early detection of pregnancy-related pathologies. In this study, we aimed to investigate the role of maternal respiration in the short-term directed interactions between the maternal heart rate (MHR) and fetal heart rate (FHR) in healthy fetuses. Additionally, we investigated how such coupling patterns might be impaired in fetuses affected by conotruncal anomalies (CTA). Methods : FHR, MHR and maternal respiration were extracted from non-invasive abdominal electrophysiological recordings from over 300 pregnant women in the second trimester of gestation. Linear coupling metrics—Directed Coherence (DC), Partial Directed Coherence (PDC), and generalized PDC (gPDC)—were computed with and without including the respiratory signal in the Multivariate Autoregressive model. Results between healthy and CTA fetuses were compared. Results : Maternal respiration Granger-causes both the FHR and the MHR, suggesting respiration is a dominant source of directional influence in MFCC during the second trimester. Preliminary results suggest that the directed interaction from maternal respiration to the FHR is reduced in fetuses with CTA. Conclusion : Maternal respiration plays a main role in the physiological phenomenon of MFCC. Significance : This work sheds light on a fundamental dynamic regulating MFCC, which might improve the monitoring of pregnancy-related cardiovascular pathologies and pave the way for their early diagnosis.