Influence of physical exercise in the third quarter of pregnancy on cardiocirculatory behavior of the maternal-fetal unit

Abstract

Objective. To know the influence of the maternal exercise during the third quarter of pregnancy using an exercise stationary bicycle on the behavior of the maternal-fetal hemodynamic circulation as well as the response of the fetal heart rate.

Methods. This study has been developed through the collaboration between the Department of Gynecology and Obstetrics of the Hospital Fuenlabrada of Madrid (SGOHF) and the Polytechnic University of Madrid. Approval was obtained from the ethics committee (EC). Sample: 20 pregnant women in the last quarter of pregnancy were studied, all of them without medical complications or contraindications for exercise. Each woman signed an informed consent and completed an initial interview. Protocol: a 20-minute session of moderate exercise on the stationary bicycle was carried out. Data regarding the pulsatility index (PI) and the fetal heart rate (FHR) were obtained.

Results. Increases of the FHR of 11-36 beats/min were detected (mean = 24 ± 7,6). There was no positive correlation between the days of gestation and the level of the increases. However, larger increases of the FHR were found in those with a second pregnancy: 152 ± 6,0 beats/min than in those with primiparous: 147 ± 4,6 beats/min (p = 0,04). The PI data of the umbilical artery and of the middle cerebral fetal artery did not show any significant changes before and after exercise.

Conclusion. Exercise increases the FHR without harmful effects. The parity of the pregnant woman influences the level of the increases. The PI of the umbilical artery and of the fetal middle cerebral artery presents minimum changes in normal values. It seems that these changes are a normal and adaptive fetal response.