The Physical Work Capacity of the Expectant Mother and Its Effect on Pregnancy, Labor and the Newborn

149 healthy primigravidae participated in the study dealing with the correlation between the physical work capacity of the mother and the course of pregnancy and labor and the possible influence of physical work capacity on the development of the fetus and placenta. 62 of the mothers were followed prospectively from the end of the first trimester and their physical work capacity was determined on two occasions prior to the 38th week of the pregnancy. All mothers were examined during the 38th week. Physical work capacity was determined using a voluntarily maximal pulse‐conducted work test on a bicycle ergometer. Prospectively the healthy mothers and the mothers which later developed toxemia or had a threatening premature labor had similar work capacities. When studied during the 38th week, the physical work capacity of the mothers treated because of threatening premature labor was significantly lower than that of the healthy or toxemic mothers. They were also very significantly more sick written and at rest during the pregnancy than other mothers. The mothers with a physical work capacity above the non‐pregnant average had an almost significantly shorter labor, when it was spontaneous. This group gave birth to more infants weighing over 3 500 g, had significantly greater placentas and fewer low values of relative placental weight than the mothers with a physical work capacity below the nonpregnant average. The physical work capacity of the mother had no influence on the duration of pregnancy, duration of induced labor, duration of the time which passed from the moment when the baby was visible until the delivery, nor on the Apgar scores recorded at one minute.