Most, but not all, investigators report excellent correlation between maternally perceived fetal motion and movements documented by instrumentation. For example, Rayburn (1980) found that 80 percent of all movements observed during sonographic monitoring were perceived by the mother. In contrast, Johnson and colleagues (1992) reported that beyond 36 weeks, mothers perceived only 16 percent of fetal body movements. Fetal motions lasting more than 20 seconds were more likely to be identified than shorter episodes. Although several fetal-movement counting protocols have been used, neither the optimal number ofmovements nor the ideal duration for counting them has been defined. For example, in one method, perception of 10 fetal movements in up to 2 hours is considered normal (Moore, 1989). Commonly, women may present in the third trimester complaining of subjectively reduced fetal movement. Harrington and associates (1998) reported that 7 percent of nearly 6800 women presented with a complaint of decreased fetal movement. Fetal heart rate monitoring tests were employed if sonographic scans for fetal growth or Doppler velocimetry were abnormal. Pregnancy outcomes for women who complained of decreased fetal movement were not significantly diferent from those for women without this complaint. Scala and colleagues (2015) reported that 6 percent of women at term reported decreased fetal movements at 36 weeks or more. Women with two or more episodes of reduced fetal movements had greater risks of growth-restricted newborns and abnormal Doppler uterine artery low studies. However, stillbirth rates were not increased. Measurement ofthe myocardial performance index did not improve accuracy (Ho, 2017).
Grant and coworkers (1989) performed an unparalleled investigation of maternally perceived fetal movements and pregnancy outcome. More than 68,000 pregnancies were randomly assigned between 28 and 32 weeks' gestation. Women in the fetal movement arm of the study were instructed by specially employed midwives to record the time needed to feel 10 movements each day. his required an average of2.7 hours each day. Women in the control group were informally asked about movements during prenatal visits. Reports of decreased fetal motion were evaluated with tests of fetal well-being. Antepartum death rates for otherwise normal singleton fetuses were similar in the two study groups. Despite the counting policy, most stillborn fetuses were dead by the time the mothers reported for medical attention. Importantly, rather than concluding that maternal perceptions of fetal activity were meaningless, these investigators concluded that informal maternal perceptions were as valuable as formally recorded fetal movement.
Saastad and associates (2011) reported a total of 1076 women who were randomly assigned to standardized fetal movement counting from gestational week 28 versus no counting. Growth-restricted fetuses were identiied before birth signiicantly more often when fetal movement counting was used. he rate of I-minute Apgar scores :;3 was signiicant reduced (0.4 versus 2.3 percent) when counting was used. Also, Warrander and coworkers (2012) described placental pathology in pregnancies complicated by diminished fetal movements. Decreased movement was associated with various placental abnormalities including infarction.
After decades of uncertainty as to whether the fetus normally breathes, Dawes and coworkers (1972) showed small inward and outward flows of tracheal fluid in fetal sheep, indicating thoracic movement. These chest wall movements difered from those following birth in that they were discontinuous. Another interesting feature of fetal respiration was paradoxical chest wal movement (Fig. 17-3). In the newborn or adult, the opposite occurs. One interpretation of the paradoxical respiratory motion might be coughing to clear amnionic fluid debris. Although the physiological basis for the