Acta Obstet Gynecol Scand 55: 131-135, 1976
F E T A L MOVEMENTS DIAGNOSED BY ULTRASOUND IN EARLY PREGNANCY Pentti Jouppila From the Department of Obstetrics and Gynecology (Head: Prof. P . A . Jarvinen), University of Oulu, Oulu, Finland
Abstract. The purpose of this work was to ascertain whether ultrasonic techniques based on fetal movements were suitable for examinations in early pregnancy. The series consisted of 124 patients who came to be examined because of bleeding on the 6th-20th gestational week. The rapid B-scan method detected the fetal movements from the 8th week onwards, and the results were 100% reliable from the 10th week onwards. The combined A-B-scan method detected the fetal movements from the 12th week. Techniques based on the detection of fetal heart function were used as control methods. According to our results, the methods based on the indication of fetal movements constitute a practical alternative for elucidating the problems of early pregnancy.
During the last few years, ultrasonic examination has established its position in the diagnosis of early pregnancy and its complications. By means of the B-scan method, intrauterine pregnancy can be detected from the 6th gestational week onwards. This method can also be used to measure the growth of the gestation sac and the uterus in early pregnancy. But the use of the B-scan technique, which is the most advanced ultrasonic method, is restricted in early pregnancy by the fact that it does not show directly whether the fetus is alive or not. Attempts have therefore been made during recent years to develop new ultrasonic methods or to combine existing ones in such a way as to show fetal heart function (5,6,7, I I). These methods are, however, either relatively elaborate ultrasonic techniques or combinations of several methods, and hence require considerable experience of the examiner. In addition to displaying fetal heart function, fetal life can also be verified in early pregnancy by deTerms: “split image technique” and “rapid Picture formation” are also used.
tecting fetal movements. This can be done by two ultrasonic methods. One of these is the combined A-B-scan, in which an “ultrasonic beam” is directed towards the fetus on the basis of the information shown by the oscilloscope of the B-scan apparatus, and the movements of the fetal echoes on the A-oscilloscope then show the fetal movements. The other technique is based on the rapid B-scan method,’ whereby fetal movements are directly observable on the oscilloscope of the apparatus. In order to find out whether the mere diagnosis of fetal movements in early pregnancy can lead to a sufficiently early verification of fetal life, we compared the ultrasonic techniques showing fetal movements with those used to display fetal heart function. MATERIAL AND METHODS The patient series consisted of 124 patients admitted into the Department of Obstetrics and Gynecology, University of Oulu, on the 6th-20th gestational week because of bleeding. In each case, a rapid B-scan was obtained first using the ’Vidoson” (Siemens) apparatus (Fig. I). In this apparatus, a rotating probe transmitting and receiving ultrasound (2 MHz) gives two-dimensional cross section images of the object on the oscilloscope at such high frequency (16/sec) that spontaneous fetal movements can be demonstrated. The liquid filled probe of the apparatus can be placed in different positions above the object. Oil was used as a contact medium between the probe and the skin, and the “full bladder” technique was employed to localize the uterus. The first objective was to detect fetal echoes in the uterus. After this had been done their possible movements were followed for 5 minutes when necessary (Figs. 2 and 3). In the other method of verifying fetal movements, the combined A-B-scan method (Kretztecknik‘s 4100 MGS apparatus) was used (Fig. 4). A 2 MHz ultrasound was directed towards the fetus on the basis of the information shown on the B-scan oscilloscope. The fetal echoes were Acta Obstet Gynecol Scand 55 (1976)
Fig. 1 . Equipment (Vidoson") based on the rapid B-scan
method. The liquid filled probe on the patients abdomen. then seen as vertical echo peaks on the A-oscilloscope of the same apparatus (Fig. 5 ) . The rapid horizontal shifts of these echoes were taken as signs of fetal movements. Three control methods showing fetal heart function were used. The first of these was the combined A-B-scan with Kretztecknik's 4100 MGS apparatus and a 2 MHz probe, whereby after the initial information obtained from the B-scan the detection of the fetal heart function Fig. 3 . Longitudinal rapid B-scan in the 14th week. The
echoes of fetal head ( H ) can be seen in the uterus. Bl= bladder. was possible as a typical rotating movement on the A-oscilloscope (Fig. 6). The other methods included vaginal Doppler examination by means of Picker's EUD-I apparatus and a 5 MHz probe (5) and a combined B-scan and Doppler examination with Kretztecknik's 4100 MGS apparatus supplemented by Picker's EUD-I examination carried out transabdominally by a 5 MHz probe (7). If one of the methods employed showed the fetus to be alive on the first examination, no further scans were made. In the other cases, examinations were repeated at intervals of 1-2 weeks, until fetal life was verified or the pregnancy terminated spontaneously. From the 12th week onwards, however, no repeated examinations were made. Two examinations were made in altogether 13 cases and three examinations in 8 cases. Molar and ectopic pregnancies were excluded from the series. The pregnancies of the patients were further followed by clinical examination, quantitative daily urine HCG assays, and follow-up of the subsequent course of the pregnancy.
Fig. 2 . Longitudinal rapid B-scan of the uterus in the 9th
week. The examination is based on the possible movements of fetal echoes ( F )on the oscillosco~e.BI=bladder. GS=gestation sac. Acla Obstet Gynecol Scand 55 (1976)
In the series investigated (124 patients), the ultrasonic examinations and subsequent follow-up showed continuation of the pregnancy in 7 1 (57.2%)- In the remaining 53 (42.8 %) the pregnancy terminated in a spontaneous abortion. In
Fetal movements and ultrasound
Fig. 6 . Fetal heart action ( F H ) on the A-oscilloscope.
Echoes of fetal heart seen as a typical rotating movement. Fig. 4. Combined A-B ultrasound equipment (Kretztechnik 4100 MGS). Longitudinal examination.
7 of these cases the diagnosis was missed abortion, and uterine evacuation revealed a dead fetus on the 13th-19th week of pregnancy. In 3 cases out of these 7, signs of fetal life had previously been demonstrated by ultrasound. The size of the fetus suggested, however, that death had taken place after the scan. In the other cases which terminated in spontaneous abortion, no signs of fetal lilt: nad been revealed by ultrasound. Most of them turned out to be cases of blighted ova. The results obtained with the present ultrasonic methods are shown in Table I. The rapid B-scan revealed the first fetal movements in the 8th gesta-
Fig. 5. Fetal echoes (F)on the A-oscilloscope. The rapid horizontal movements of the echoes indicates the fetal life.
tional week in 3 cases. From the 10th week onwards, the results were 100% correctly positive or correctly negative. N o false positive findings were obtained. This method showed the fetal movements to be slight on the 8th-9th gestational week, and their detection often required a long time. It was also relatively difficult to see the fetal echoes in the gestation sac at this time. From the 10th week onwards, the intensity of fetal echoes, the frequency of movements, and the duration of each series of movements clearly increased until the end of the period of investigation. Though the fetal movements were not analyzed in any more detail, two types of movement could be distinguished. The first type included violent movements of the whole fetus, which changed entirely its position in the amniotic cavity. The other type consisted of smaller movements, probably of the limbs, after which the fetus retained its previous position in the amniotic cavity. The period of immobility between movements was shorter in the first type. In the cases where no movements in the uterus could be detected, the oscilloscope showed whether the case was one of intrauterine pregnancy, whether the size of the gestation sac was equivalent to the duration of pregnancy or smaller, and whether fetal echoes were detectable in the gestation sac or whether the sac wasempty. Fetal movements were detected later by the combined A-B-scan method than by the rapid B-scan. The first movements of fetal echoes were observable in the 10th gestational week, and full reliability was only achieved from the 12th week Acta Obstet Gynecol Scand 55 (1976)
Table I. The percentages of correctly positive and correctly negative findings from the total number of examinations ( N ) made by ultrasonic methods to show fetal life in the 6th-20th gestational weeks. 124 patients with symptoms of threatened abortion (153 examinations) Gestational weeks Ultrasonic method Rapid B-scan Combined A-B-scan" Methods based on the detection) of fetal heart function
6th 7th N=5 9
Used to detection of fetal movements.
onwards (Table I). In this method, too, the horizontal movements appeared to become the stronger gnd the more easily discernible, the longer was the duration of pregnancy. No false positive findings were obtained. The B-scan oscilloscope further permitted the usual diagnostic observations on the size of the gestation sac and the uterus and on the fetal echoes. The control methods based on the detection of fetal heart function by ultrasound yielded the first positive findings in the 7th gestational week in the same series of patients. The findings were almost completely reliable from the 9th week; a false negative finding was only obtained in one case out of 18. The findings were 100% correctly positive or correctly negative from the 10th gestational week onwards. DISCUSSION The present findings showed that ultrasonic methods based on fetal movements indicate fetal life from the 10th gestational week onwards. Although the rapid B-scan method detected fetal life in the 8th and 9th gestational weeks less often than did the ultrasonic methods based on fetal heart function, both techniques yielded 100% diagnostic reliability in the same week (the 10th gestational week). The findings obtained by rapid B-scan are also very clear and illustrative. The combined A-B-scan method revealed fetal movements about two weeks later than rapid B-scan. One explanation for this might be that ultrasound directed by the former method only to the fetal body may not reveal movements, which involve the limbs alone. The movements of fetal echoes in positive cases, however, are clearly interpretable in the A-B-scan Actn Obstet Gynecol Scand 55 (1976)
method, and the examiner finds it easy to diagnose movements after a few positive findings. The fetal movements diagnosed in the present investigation proved to be similar to those detected previously by Reinold with the rapid B-scan method (8, 9, 10). Our own experience is limited almost exclusively to abnormal pregnancies, and we therefore know little of the fetal movements in normal early pregnancy. Reinold (9) showed, however, that restricted spontaneous fetal motility in the uterus results in the birth of a healthy infant in only 75 % of the cases, while the prognosis for infants with normal fetal motility is good in 94%. He (10) also demonstrated that absence of fetal response to extrauterine manipulation signifies a poor prognosis for the fetus, even if signs of life were visible at the time of the examination. According to Reinold (8), the observation period must last for at least 5 minutes. Haller et al. (3), who employed the same ultrasonic technique, were able to show that the frequency and duration of fetal movements were significantly reduced in pregnancies subsequently terminating in an abortion than in cases with a favourable prognosis. It is hence possible that the rapid B-scan method may give prognostic information for the subsequent course of the pregnancy. The diagnosis of fetal movements by the methods described above is a new advance in the study of early pregnancy. It has been shown previously that fetal movements begin at a very early stage. Dellepiane (1) demonstrated fetal movements at the age of 8 weeks in a gestation sac removed intact from a tuba1 pregnancy. Muscular contractions have been observed in fetuses 6 weeks old (13). Szendi (12) demonstrated fetal movements in the gestation sac during the first four months by contrast medium and X-rays. The ultrasonic methods
Fetal movements and ultrasound
REFERENCES employed in the present work did not reveal fetal movements until the 8th gestational week, because I . Dellepiane, G.: ref. in Zbl Gynakol 75: 828, 1953. 2. Donald, I., Morley, P. & Barnett, E.: The diagnosis of no fetal echoes could be seen prior to this time. The blighted ovum by sonar. J Obstet Gynaecol Br Comm acoustic properties of the fetal tissues at an early 79:304, 1972. stage differ so little from the surrounding amniotic 3. Haller, U., Ruttgers, H., Wille, F., Heinrich, D., Mulfluid that the detection of the fetal echoes requires ler, P. & Kubli, F.: Aktive Kindsbewegungen im particularly sensitive equipment ( 1 I). schnellen Ultraschall-B-Bild. Gynakol und Rsch 13, Suppl. 1: 118, 1973. The ultrasonic research into early pregnancy car4. Hellman, L. M., Kobayashi, M. & Cromb, E.: ried out during the last few years has focussed inUltrasonic diagnosis of embryonic malformations. creasingly on the demonstration of signs of fetal Am J Obstet Gynecol 115:615, 1973. life. The main reason for this has been the fact that 5. Jouppila, P.: Ultrasound in the diagnosis of early when the B-scan method alone is used, diagnostic pregnancy and its complications. A comparative study of the A-, B- and Doppler methods. Acta Obstet reliability after a single examination is only 78-87 % Gynecol Scand 50: Suppl. 15, 1971. (2, 4) Absence of fetal heart function from the 6. Kratochwil, A. & Eisenhut, L.: Der friiheste Nach9th-10th gestational week onwards, on the other weis der fetalen Herzaktion durch Ultraschall. hand, is a certain sign of a poor prognosis for the Geburtsh Frauenheilk27: 176, 1967. 7. Piiroinen, 0.: Detection of fetal heart activity during pregnancy ( 5 , 7). Robinson (1 1) achieved complete early pregnancy by combined B-scan and Doppler diagnostic reliability from the end of the 7th gestaexamination: A new application. Acta Obstet Gynecol tional week onwards by using a combined B-A-TM Scand 53: 23 1, 1974. method in the demonstration of fetal heart function. 8. Reinold, E.: Fetale Bewegungen in der Friihgravidittit. Z Geburtsh Gynakoll74: 220, 1971. On the basis of the present results, it appears that a 9. Reinold, E.: Klinische Bedeutung der fetalen diagnosis of fetal movements leads to 100% Spontanbewegungen in der Friihgraviditat. J Perinat diagnostic reliability in the verification of fetal life Med I: 65, 1973. sufficiently early, i.e. from the 10th gestational 10. Reinold, E. & Georgiades, E.: Der intrauterine Paweek onwards. The present work also confirmed a tient: Diagnose aus dem fetalen Bewegungsverhalten in der ersten Halfte der Graviditat. Zbl Gynakol previous observation ( 5 ) showing that verifiable 96:641, 1974. signs of fetal life signify a favourable prognosis for 11. Robinson, H. P.: Detection of fetal heart movement in the pregnancy despite symptoms of imminent first trimester of pregnancy using pulsed ultrasound. abortion in over 90% of the cases. Since, moreBr Med J 4: 1972,466. over, the findings are perhaps easier to interpret 12. Szendi, B.: Weitere Aufkliimng der Morphologie und Biologie des schwangeren Uterus und des Fetallebens in the ultrasonic examinations based on fetal mittels Rontgenuntersuchungen (Embryographie). movements than in the other ultrasonic examinaArch Gynakol17:429, 1940. tions of early pregnancy, these methods, particu- 13. Yamase: Pflugers Archiv 117: 119, 1907. In Seitzlarly the rapid B-scan method, can be considered Amreich (eds.), Biologie und Pathologie des Weibes. Urban und Schwarzenberg, 1952. practicable alternatives in the choice of ultrasonic techniques for studying early pregnancy. As the Submitted for publication Jan. 16. 1975 findings are unambiguous and easy to interpret, the method can also be recommended for examiners Pentti Jouppila Department of Obstetrics and Gynecology who have little experience with ultrasound. University of Oulu Oulu Finland
Acta Obstet Gynecol Scand 55 (1976)