Fetal movement during labor Vma M. Reddy, MD, Lisa L. Paine, CNM, DrPH, Carolyn L. Gegor, CNM, MS, Mary Jo Johnson, MD, and Timothy R.B. Johnson, MD Baltimore, Maryland, and Providence, Rhode Island The prognostic significance of antepartum fetal movement is well known; therefore it may be a variable in intrapartum fetal well-being. We report the simultaneous observation of fetal movement with fetal heart rate and uterine contractions by processed Doppler actograph signals during spontaneous labor of 22 normal women with normal fetal outcome. The mean percent incidence of fetal movement during labor was 17.3%. The percentage occurring during uterine contractions was 65.9%. Of all uterine contractions, 89.8% were associated with fetal movement. The proportion of time the fetus spent moving during uterine contractions (21.4%) was higher than between uterine contractions (12.9%). Uterine contractions associated with fetal movement were significantly longer than those not associated with fetal movement (p < 0.0001). Mean percent incidence of fetal movement did not differ significantly between latent and active-phase labor. This study demonstrates a clear relationship between fetal movement and uterine contractions in labor. (AM J OBSTET GVNECOL 1991 ;165:1073-6.)
Key words: Fetal movement in labor, Doppler actograph, fetal well-being The presence of fetal heart rate (FHR) accelerations associated with fetal movement is the basis for antepartum nonstress testing, and the presence of coexisting fetal movement during the third trimester is indicative of fetal well-being. I. 2 Animal studies have demonstrated the cessation of fetal body movements as an initial response to hypoxia. 3 Therefore the absence of fetal activity may be a marker for hypoxia during labor in the human fetus. The few studies that have observed fetal movement during labor have done so with ultrasonography for only a small proportion of the entire course of labor. 4 - lo In spite of their limitations, these studies suggest both the presence of fetal movement during labor and a significant correlation of fetal movement with uterine contractions. The purpose of this observational study was to quantitate fetal movement during the entire course of the normal labor process with a Doppler transducer capable of simultaneous detection of fetal movement and FHR, coupled with standard measurements of uterine contractions. Material and methods Twenty-two low-risk pregnant women with singleton fetuses with vertex presentation who were seen in spontaneous labor at the Johns Hopkins Hospital between From the Division of Maternal-Fetal Medicine, Department of Gynecology and Obstetrics, The Johns Hopkins University School of Medicine, and the Brown University School of Medicine. Presented at the Eleventh Annual Meeting of the Society of Perinatal Obstetricians, San Francisco, California, January 28-February 2, 1991. Reprint requests: Timothy R. B. Johnson, MD, Director, MaternalFetal Medicine, The Johns Hopkins University, Houck 228,600 N. Wolfe St., Baltimore, MD 21205_ 6/6/30947
May and July 1990 were eligible for study. Maternal ages ranged from 15 to 31 years, with gestational ages between 36 and 42 weeks. All had essentially benign prenatal courses: One had sickle cell trait, none were illicit drug users (negative toxicology screens), the majority took no medications during pregnancy (four took short courses of antibiotics, two required terbutaline because of preterm contractions), and they were generally nonsmokers (two women smoked five or fewer cigarettes per day). All had adequate weight gain during pregnancy (between 21 and 55 pounds). The study group comprised 12 black and 10 white women. After these women were determined to be in labor (more than three uterine contractions per 10 minutes or rupture of membranes), informed consent for participation was obtained. All received epidural anesthetic between 2 and 9.5 cm cervical dilation. Eight required oxytocin augmentation. In eight women membranes ruptured spontaneously, whereas the remaining 14 had membranes ruptured artificially. All 22 fetuses had normal outcomes with I-minute Apgar scores ranging from 6 to 9, 5-minute Apgar scores ranging from 8 to 10, and an average umbilical artery pH of 7.29 (one pH was 30 arbitrary units corresponding to fetal movement. I I. 12 Uterine contractions were simultaneously recorded by the same monitor by external tocography or an intrauterine pressure catheter. Once fetal surveillance with the Doppler actograph was started, the principal investigator (U.R.) supervised the fetal monitor tracing. Continuous tracings were obtained throughout labor, excluding time periods of interference because of maternal movement, vaginal examinations, epidural catheter insertion, and misplaced Doppler or tocography devices. For study purposes fetal movement recorded at >30 units was used for evaluation (Fig. 1). Fetal movement was then grouped into epochs (period of movement las ting ::::::2 seconds) for easier evaluation. The end of an epoch occurred when there was no fetal movement for >4 seconds. The duration of each epoch was considered in 2- to 4-second intervals (e.g., an epoch lasting >6 and < 10 seconds would be rounded off to 8 seconds; an epoch >42 and ~46 seconds would be 44 seconds). A single movement, 40 mm Hg and lasting a minimum of 40 seconds. Uterine contractions were divided as not acco mpanied by fetal movement and accompanied by fetal movement. Finally, the labor process was divided into a latent phase (0 to 4 cm cervical dilatation) and an active phase (>4 em dilatation). Individual Friedman curves were plotted to determine the probable time at which 4 em h ad been reached. The SYSTAT statistical package was used to perform paired t tests on the sample data. The incidences of the following were compared: fetal movement with and without uterine contractions, uterine contractions with and without fetal movement, and percent fetal movement in the latent phase and the active phase of labor. Results
A total of 6885 minutes (114 hours) of monitor tracing during labor on 22 healthy fetuses was recorded. After exclusion of poor observation time associated with maternal movement, vaginal examinations, epidural insertion, and misplaced Doppler and tocography devices, 6052 minutes (l00 hours) were evaluated. The
Volume 165 Number 4, Part I
average duration of fetal movement constituted 17,8% of the recording period (range, 2.1% to 47.5%; SD, 11.4%). The total durations of fetal movement without and with uterine contractions were 34.1 % and 65.9%, respectively (p < 0.001). The percentage of fetal movement occurring during uterine contractions was significantly higher (Table I). The proportion of time the fetus spent moving during uterine contractions was significantly higher than betwet;n uterine contractions, 21.4% and 12.9%, respectively (p < 0.001). A total of 1689 uterine contractions were recorded, occupying 3140 minutes, or 51.9%, of the recording period. Fetal movement accompanied 89.9% of the contractions, and 10.2% of the contractions were not accompanied by fetal movement (p < 0.001). The mean durations of uterine contractions without and with fetal movement were 65.8 and 117.0 seconds, respectively (p < 0.001). Therefore uterine contractions accompanied by fetal movement were significantly longer than those not accompanied by fetal movement. In nine women the mean percentage incidence of fetal movement (the percentage of observation time during which the fetus was moving) in latent-phase and active-phase labor was compared. There was no decrease in the mean percent incidence of fetal movement as labor progressed. Comment
Study findings concur with previous studies demonstrating fetal movement during labor. This study is unique in that fetal movement was conveniently monitored throughout the labor process concurrently with uterine contractions and FHR with the Doppler actograph. Previous studies have established the importance of antepartum fetal movement. Sadovsky and Yaffe l3 showed that pronounced decreases in movement, culminating in the cessation of fetal movement, occurred in the terminal stages of fetal death in utero. Roberts et al. 14 found that the incidence of fetal movement during the third trimester was 18%. Carmichael et al. 15 found that before spontaneous labor at term there is a normal decrease in the incidence of fetal breathing movements but no similar change in the incidence of gross fetal body movements. Therefore the presence of gross fetal body movements is a more consistent index of fetal health before spontaneous labor at term. Boylan and Lewis l6 observed a reduction, although not a statistically significant one, in the fetal movement index (percentage of observed time during fetal trunk movement) from the antepartum period to labor. Richardson et al. 6 observed that the intermittent patterns of increased body movement and heart rate variability continued throughout the first stage of labor in spite of the decrease in fetal breathing activity during latent-
Fetal movement in labor
Table I. Percent fetal movement time in labor Labor (mean) Between uterine contractions During uterine contractions
17.3 12.9 21.4
and active-phase labor. However, they found a decrease in fetal body movements, possibly related to the progress oflabor. Similar findings were reported by Yarkoni and Hobbins,5 who demonstrated that the mean incidence of fetal movement in labor was 19.5% and that there was a linear decrease in percent incidence of fetal movement as cervical dilatation increased. This study found a mean percentage incidence of fetal movement similar to that of Richardson et al. 6 and Yarkoni and Hobbins,' indicating fetal movement to be a stable parameter at the onset of and throughout the labor process. Although observed only in a limited number of women, we noted no decrease in the percentage incidence of fetal movement as cervical dilation progressed. However, further study is required. Similar to Sadovsky et al." and Zimmer et al.,. we found a close relationship between uterine contractions and fetal movement. We determined an incidence of fetal movement without and with uterine contractions, of 31.8% and 66.2%, respectively, similar to the study of Zimmer et al. However, we found a significantly greater number of uterine contractions associated with fetal movement (89.8% of all uterine contractions). This is probably because of the greater sensitivity of the Doppler acto graph apparatus for detecting isolated limb movements and the large number of uterine contractions that were evaluated. However, the effect of epidural anesthesia and oxytocin may have influenced these results, and further study is required on their effects. Few studies have examined the implications of intrapartum fetal movement monitoring. Wittmann et aU concluded that absence of any fetal activity for more than 45 of the 60 minutes of observation during labor is significantly correlated with an abnormal FHR throughout the course of labor. During labor a healthy fetus has short episodes of respiratory movements and reacts to contractions with bursts of movement that are associated with an increase in the FHR. Decreased total activity may indicate a fetus at risk. Chr et al. 17 found that fetal reactivity-not only antepartum but in the first stage of labor-is a reliable indicator of fetal wellbeing. They concluded that a nonreactive FHR pattern (lack of accelerations within 20 minutes of admission to the hospital for labor) during first-stage labor should arouse suspicion of intrauterine fetal compromise. The Doppler actograph in conjunction with traditional FHR and uterine contraction recording is a convenient method for intrapartum fetal surveillance. This study demonstrates the presence of movement of
Reddy et al.
healthy fetuses throughout labor and a clear relationship between fetal movement and uterine contractions. Ultimately, the Doppler actograph will allow us to evaluate fetal behavioral states during labor and determine the clinical implications of fetal movement during labor.
REFERENCES 1. Lee CY, DiLoreto PC, Logrand B. Fetal activity accelerations determination for the evaluation of fetal reserve. Obstet Gynecol 1976;48: 19-23. 2. Neldam S. Fetal movements as an indicator of fetal wellbeing. Lancet 1980;1:1222-4. 3. Natale R, Clewlow F, Dawes GS. Measurement of fetal forelimb movements in lambs in utero. AM] OBSTET GyNECOL 1981; 140: 545-55. 4. Zimmer E, Divon M, Vadasz A. The relationship between fetal movements and uterine contractions in the active phase of labor.] Reprod Med 1988;33:289-91. 5. Yarkoni S, Hobbins]. Intrapartum fetal activity. ] Perinatol Med 1987;15:316-22. 6. Richardson B, Natale R, Patrick]. Human fetal breathing activity during electively induced labor at term. AM] OBSTET GYNECOL 1979;133:247-55. 7. Wittmann BK, Lyons E, Frohlich], Towell ME. Real-time ultrasound observation of fetal activity in labour. Br ] Obstet Gynaecol 1979;86:278-81.
October 1991 Am J Obstet Gynecol
8. Sadovsky E, Rabinowitz R, Freeman A, Yarkoni S. The relationship between fetal heart rate accelerations, fetal movements and uterine contractions. AM ] OBSTET GyNECOL 1984;149:187-9. 9. Griffin RL, Caron F, van Geijn HP. Behavioral states in the human fetus during labor. AM ] OBSTET GYNECOL 1985; 152:828-33. 10. Zimmer EZ, Vadasz A. Influence of the fetal scalp electrode stimulation test on fetal heart rate and body movements in quiet and active behavioral states during labor. Am] Perinatol 1989;6:24-9. 11. Maeda K. Studies on new ultrasonic Doppler fetal actograph and continuous recording of fetal movement. Acta Obstet Gynecol] pn 1984;36:280-8. 12. Besinger RE, Johnson TRB. Doppler recordings of fetal movement: clinical correlation with real-time ultrasound. Obstet Gynecol 1989;74:277-80. 13. Sadovsky E, Yaffe H. Daily fetal movement recording and fetal prognosis. Obstet Gynecol 1973;41:845-50. 14. Roberts AB, Little D, Cooper D, Campbell S. Normal patterns of fetal activity in the third trimester. Br] Obstet Gynaecol 1979;86:4-9. 15. Carmichael L, Campbell K, Patrick]. Fetal breathing, gross fetal body movements, and maternal and fetal heart rates before spontaneous labor at term. AM] OBSTET GyNECOL 1984; 148:675-9. 16. Boylan P, Lewis P]. Fetal breathing in labor. Obstet Gynecol 1980;56:35-8. 17. Chr H, Nyholm T, N eldam S. Fetal activity acceleration during early labor. Acta Obstet Gynecol Scand 1983;62:131-3.
Editors' note The AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY introduces a new format for abstracts accompanying regular articles, society articles, and Current Investigation articles. Authors submitting these manuscripts to the JOURNAL should provide an abstract of no more than 150 words structured according to the following headings: Objective(s), Study Design, Results, and Conclusion(s). Exceptions to this requirement include Clinical Opinion, Current Development, case reports, and brief communications articles. Abstracts for these articles will continue to follow the standard abstract format. Please consult the Information for Authors for details.