Relationship between plasma adenosine concentration and breathing movements in growth-retarded fetuses.

OBJECTIVE

The purpose of this study was to investigate the relationship between plasma adenosine concentration and breathing movements in growth-retarded fetuses.

STUDY DESIGN

We measured the incidence of fetal breathing movements and breathing rate immediately before cordocentesis in 26 growth-retarded fetuses at 31 to 38 weeks' gestation. Blood retrieved by cordocentesis was then analyzed for umbilical venous plasma adenosine concentration, blood gases, and pH.

RESULTS

In growth-retarded fetuses with hypoxia and acidosis plasma adenosine concentration was elevated and the incidence of fetal breathing movements was reduced. The change in plasma adenosine concentration correlated inversely and significantly with the incidence of fetal breathing movements.

CONCLUSION

Decreased breathing movements correlate with elevated plasma adenosine concentration in fetuses. We postulate that the enhanced adenosine formation in growth-retarded fetuses may modulate the inhibition of fetal breathing movements.