[Objective evaluation of physical exertion in pregnant women based on long-term recording of heart action. Results of a pilot study].

The heart rate during whole day, periods of activity and sleep as well as repeatable daily activities were identified in a group of 22 women, aged 19-40, and pregnant for 12-36 weeks, following a 24-hour recording of the heart work. In four women only, mean circadian heart rate was under 87/min, a value considered as normal in moderate active persons. That indicates a significant pregnancy-related increase of heart rate. A considerable great variation of heart rates was observed during a day. The highest heart rate (97-140/min) was caused by mounting the stairs; it was also noted during performing minor household jobs and/or preparing meals. While using transportation means, heart rate ranged from 78 to 130/min, and at leisure form 89 to 108/min. It was found that the level of an acceptable load for women (100 heart beats/min) was already higher than the mean value for the whole period of activity. An analysis of the relationship between heart rate in certain situations and the age of women under study, and the pregnancy advancement, shows that heart rate was, in each period of recording, positively correlated with the women's age. That means an increasing, with age pregnancy-related load. Heart rate during a 24-hour period, periods of activity and sleep, during the use of transportation means, watching television and resting in a sitting position, was positively correlated with the duration of pregnancy. Negative correlation between heart rate and the duration of pregnancy was observed while mounting the stairs, preparing meals and performing other household jobs. The negative correlation indicates that the pace of activities performed can be easily regulated, and thus, the load magnitude adjusted to physical abilities, whereas the positive correlation indicates that such a possibility does not exist in regard to the expenditure of energy (work pace). To sum up, the data presented shows that the use of transportation means increased the women's load but they could easily perform minor household jobs. However, there were no occupationally working women in the study group, it can be concluded that this kind od analysis, and conclusions drawn, can be used in identifying types of work and workplaces which pose too much load to pregnant women.