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Transabdominal chorionic villus sampling: A freehand ultrasound- guided technique
Transabdominal chorionic villus sampling: A freehand ultrasound-guided technique B. Brambati, M.D., A. Oldrini, M.D., and A. Lanzani, M.D. Milan, Italy A simple transabdominal chorionic villus sampling method, carried out with a 20-gauge spinal needle under ultrasound guidance, was evaluated in 100 cases selected for genetic evaluation in the first trimester. Its use was limited to the management of anatomic a·nd clinical conditions that contraindicated transcervical aspiration. The high efficacy of the method was demonstrated by an ability to obtain enough villus tissue for karyotyping in all but one case. In 94% of the cases, only one pass of the needle was required. Although the only complication observed was light bleeding in four cases, the safety of the method needs more extensive evaluation. (AM J OBSTET GvNECOL 1987;157:134-7.)
Key words: Chorion biopsy, transabdominal needling, ultrasound
The ability to detect fetal genetic diseases by chorionic tissue analysis has resulted in a great number of sampling methods. Four main approaches are being used. In three of them, the catheter, 1 biopsy forceps, 2 or endoscope 3 is inserted via the cervical canal; in the fourth method, the aspiration is done by transabdominal puncture.< Most experience has been accumulated with transcervical catheter (Trophocan, Portex Inc., Wilmington, Maine) aspiration, a method that has proved to be highly efficient and relatively safe.' Some anatomic and clinical conditions have been recognized as being unfavorable for safe and successful transcervical sampling; therefore the feasibility of a simple transabdominal ultrasound-guided chorionic villus sampling (CVS) method has been evaluated and is described in this article. Patients The 100 cases in the present series were selected for transabdominal CVS because of absolute or relative contraindications to the transcervical route (Table I). CVS was performed at 8, 9, 10, 11, 12, 13, and 14 weeks in 4, 31, 30, 26, 6, 2, 1 cases, respectively. Maternal age was more than 35 years in 77% of the cases. The indication for first-trimester diagnosis was chromosome determination in 96 cases, metabolic disease in one case, fetal sex determination for X-linked disease in two cases, and deoxyribonucleic acid analysis for hemophilia A in one case. The placenta was anterior in 66% of cases and posterior in the remaining 34%. From the Clinica "L. Mangiagalli," First Institute of Obstetrics and Gynecology, Perinatal Unit, University of Milan. Received for publication July 10, 1986; accepted October 10, 1986. Reprint requests: Bruno Brambati, M:D., Clinica "L. Mangiagalli," First Institute of Obstetrics and Gynecology, Via Commenda 12,20122, Milan, Italy.
134
Table I. Conditions of absolute or relative contraindication to transcervical aspiration, in which a transabdominal sampling should be advised Vaginismus* Vaginitis* Inaccessible cervical canal* Pronounced angle of uterine corpus on cervixt Multiple pregnancyt ;;.12 weeks of gestationt Previous failure of transcervical samplingt *Absolute. tRelative.
Methods A freehand aspiration was achieved through the maternal abdominal wall with a 20-gauge, 90 mm spinal needle with sector scan guidance at 5 MHz (Sigma 1SC, Kontron Instruments Inc., Everett, Massachusetts) (Fig. 1, A). The placenta was identified and its depth calculated. A compromise was made between the extension and thickness of the placenta and its distance from the maternal wall. Bladder emptying or filling was sometimes required to obtain a more favorable position of the uterus. The skin was sterilized with topical application of povidone iodine and the area draped in a sterile fashion. Because the transducer was 5 to 10 em away from the insertion site, a nonsterilely dressed person could hold the scanner; neither sterile gloves nor sterile contact gel was needed. The needle was introduced under continuous ultrasonic surveillance without local administration of anesthetics. When the tip was clearly visible within the placenta (Fig. 1, B and C), the stylet was replaced by a 20 ml Luer-Lok syringe containing 3 ml of Henk's solution. The chorionic tissue was then aspirated by combining repeated strong sue-
Volume 157 Number l
Transabdominal chorionic villus sampling
135
Fig. I. Diagram of transabdominal chorion biopsy by 20-gauge spinal needle under ultrasound guidance (A). Ultrasound monitor shows needle (arrow) sampling chorionic villi in two cases at 10 weeks (B) and 9 weeks (C) with an anterior and a posterior placenta, respectively.
tions (equivalent to about 20 ml depression) and a slow backward-and-forward movement of the needle tip. No more than two needle insertions were performed. Neither premedication nor postsampling care was required. Results
We failed to obtain chorionic tissue in six of the 100 cases with the first attempt, but tissue was obtained in these cases with a second insertion performed during the same session. The failures were apparently not related to the gestational age or to the placental location. The majority, five out of six cases, occurred in the first 30 cases, and the difficulties most likely represented inadequate technical experience. In a twin pregnancy with two separate placentas, chorionic tissue was easily obtained by cervical aspiration from one placenta, but the second placenta, located far from the internal cervical os, could be sampled only through the abdominal wall. The distribution of the weight of villus tissue obtained with a single aspiration is reported in Table II. For comparison, the villus weight distribution of 200 cases of transcervical aspiration is provided. Although the ranges of the weight distribution are quite similar for both techniques, the transabdominal aspirations more frequently produced samples of <5 mg, whereas the transcervical samples were frequently ;;,50 mg. The samples of <5 mg were more frequently obtained from anterior (14/66) than from posterior (2/34) placentas.
Five pregnancies were terminated by elective abortion (Table Ill); in three, a fetal aneuploidy was diagnosed by direct karyotyping, 6 and two fetuses at risk for X-linked disease were male. No fetal losses were observed at the time of writing in the 95 continuing pregnancies; 68% of these are currently more than 20 weeks of gestation. In four cases, bleeding or spotting was reported after CVS. Delivery has occurred in 17 cases; all were at term with birth weights between the tenth and ninetieth percentiles. Comment
Although the experience reported in large series seems conclusive with respect to the efficacy of the various chorionic villus sampling techniques ,5 no reliable clinical trials comparing the different approaches are yet available. While randomized trials between transcervical and transabdominal aspiration are awaited, 5 it is of practical interest to evaluate the suitability of the transabdominal puncture method in conditions unfavorable for the transcervical approach. In addition, we wanted to explore means of reducing the invasiveness and relative complexity of transabdominal sampling, as previously described.•·" The new sampling procedure was highly successful, without regard to the placental location or gestational age. An overall success rate of 99 % was obtained; a second puncture was required in only 6% of cases. Although the weight distribution of the aspirated specimens points to a shift toward smaller samples, in 95 %
136
Brambati, Oldrini, and Lanzani
July 1987 Am J Obstet Gynecol
Table II. Weight distribution of chorionic tissue specimens obtained by transabdominal or transcervical aspiration methods Chorionic villus sampling method
20-gauge spinal needle Trophocan
% Specimens obtained according to weight <5mg
5-10 mg
11-20 mg
21-50 mg
51-100 mg
17
35 16
19 15
27 45
2 22
1
Table III. Clinical data of 100 consecutive chorionic villus sampling cases obtained by a transabdominal aspiration Total No. of cases Twin pregnancies Successful sampling At first aspiration Selective abortion Concluded pregnancies Early complications Bleeding Spotting Fetal loss
100
1
100 94
5
17
I 3 0
of the last 40 cases, the amount of chorionic tissue obtained by a single insertion exceeded 10 mg. By this method it is possible, with two needle insertions, to provide a sufficient amount of tissue for successful deoxyribonucleic acid analysis in complicated diagnostic conditions. In only one case was fetal karyotyping not possible because of insufficient villi. The success of sampling was dependent on reliable needle tip detection and obtaining an adequate course through the placental substance. In fact, with poor ultrasound visualization, one may fail to enter the placenta, or, if the needle is placed in too thin a portion of the placenta, inadequate movement of the tip precludes the aspiration of a sufficient sample. Transabdominal CVS, as carried out in the present experience, has some advantages when compared with the previously described technique, in which a fixed biopsy guide attachment and a 17- or 18-gauge guide needle are used.<· 8 First, by reducing the size of the sampling device, one would expect to observe beneficial effects on the complication rate. A Canadian study on amniocentesis demonstrated a significantly lower incidence of fetal loss and maternal complications when a 20-gauge needle was used rather than a larger one." Second, although a transabdominal freehand sampling method may be more difficult to learn than the needleguided method and certainly requires coordinated teamwork, 10· 11 it allows an easier adjustment of the needle direction when necessitated by involuntary abdominal wall or uterine displacements. In our experience with first-trimester fetal diagnosis, transabdominal sampling was primarily introduced as a technique to complement transcervical aspiration ide-
>100 mg
ally to achieve a higher sampling success rate, reduce the need for a second transcervical insertion, and reduce complications. For the most part, these objectives seem to have been attained. In the second part of our transabdominal experience, having achieved adequate skill by combining transcervical and transabdominal aspiration, we obtained a sampling success rate of virtually 100% in a variety of anatomic and clinical conditions.12 A special advantage of the combined use of the two techniques should be evident in cases of multiple pregnancy, where placentas can be reliably sampled independent of their anatomic relationship. In conclusion, although in our hands transcervical aspiration was confirmed to be the method of choice 2 in clinical practice, the benefit of the transabdominal approach for optimizing the sampling success rate and reducing procedural difficulties was clearly demonstrated. Moreover, the transabdominal method described has the same advantages that have been previously reported.<· 8 In addition, the thinner needle and freehand ultrasound guidance of the sampling system make it easier to perform with a potentially lower risk for maternal and fetal complications. We gratefully acknowledge Dr. Angela Sciascia who made helpful comments during the preparation of this article and Dr. G. Simoni, Dr. L. Dalpra, and Dr. S. Guerneri for their cooperation in this investigation. REFERENCES I. Brambati B, OldriniJA. Methods of chorionic villus sam-
2.
3.
4.
5. 6.
pling. In: Brambati B, Simoni G, Fabro S, eds. Chorionic villus sampling. New York: Marcel Dekker, 1986:73-98. Dumez Y, Goossens M, Boue J, Poenaru L, Dommergues M, Henrion R. Chorionic villi sampling using rigid forceps under ultrasound control. In: Fraccaro M, Simoni G, Brambati B, eds. First trimester fetal diagnosis. New York: Springer-Verlag, 1985:38-45. Gustavii B. Direct vision technique for chorionic villi sampling in 100 diagnostic cases. In: Fraccaro M, Simoni G, Brambati B, eds. First trimester fetal diagnosis. New York: Springer-Verlag, 1985:46-50. Smidt-Jensen S, Hahnemann N,Jensen PKA, Therkelsen A]. Transabdominal chorionic villi sampling for first trimester fetal diagnosis. In: Fraccaro M, Simoni G, Brambati B, eds. First trimester fetal diagnosis. New York: Springer-Verlag, 1985:51-3. Jackson L. Chorion villus sampling newsletter, January 21, 1986. Simoni G, Terzoli GL, Romitti L. Fetal karyotyping by direct chromosome preparation. In: Brambati B, Sim-
Volume 157 Number I
oni G, Fabro S, eds. Chorionic villus sampling. New York: Marcel Dekker, 1986:99-118. 7. Bossi A, Caccamo ML, De Scrilli AM, Milani S. Weight of the Italian newborn infants (from the 32nd to the 43rd week of gestation). Ita! J Ped 1980;6: 153-70. 8. Maxwell D, Lilford R, Czepulkowski B, Heaton D, Coleman D. Transabdominal chorionic villus sampling. Lancet 1986; i:123-6. 9. Simpson NE, Dallaire L, Miller JR. Prenatal diagnosis of genetic disease in Canada: report of a collaborative study. Can Med Assoc J 1976; 115:739-46.
Transabdominal chorionic villus sampling
10. Daffos F, Cappella-Pavlovsky M, Forestier F. A new procedure for fetal blood sampling in utero: preliminary results of fifty-three cases. AM J 0BSTET GYNECOL 1983; 146:985-7. 11. Hobbins JC, Grannum PA, Romero R, Reece EA, Mahoney MJ. Percutaneous umbilical blood sampling. AM J 0BSTET GYNECOL 1985;152:1-6. 12. Brambati B, Oldrini A, Ferrazzi E, Lanzani A. Chorionic villus sampling: an analysis of the obstetric experience of 1,000 cases. Prenat Diagn 1987;7:157-69.
The immediate effects of chorionic villus sampling on fetal movements A. Boogert, M.D., A. Mantingh, M.D., and G. H. A. Visser, M.D., Ph.D. Groningen, The Netherlands The immediate effects of chorionic villus sampling on the fetus was studied by real-time ultrasound observation of fetal movements. Thirty-minute recordings, directly before and after chorionic villus sampling, were made in 10 women. No changes were observed in the incidence or distribution of the four movement patterns studied. This held true even in the two cases that ended in a spontaneous abortion. It is concluded that chorionic villus sampling does not stimulate movements or alter the intrauterine situation in such a way that fetal movements decrease. (AM J OBSTET GYNECOL 1987;157:137-9.)
Key words: Chorionic villus sampling, real-time ultrasound, fetal movements, first trimester of pregnancy Chorionic villus sampling has become an increasingly popular technique for early prenatal diagnosis. More than I 0,000 investigations have been performed worldwide to date.' So far the fetal consequences of this procedure have been assessed in terms of the abortion rate, fetal growth as observed via serial ultrasound, and perinatal outcome. 2· 1 With real-time ultrasound equipment, distinct patterns of fetal behavior have been described from 7 weeks of gestation onward. 5 We attempted to determine the acute effects of this invasive diagnostic procedure on fetal motor behavior by means of two 30minute observations taken immediately before and after chorionic villus sampling. Patients and methods
Ten multiparous women were selected at random from those referred for chorionic villus sampling. After From the Department of Obstetrics and Gynaecology, University H ospital, The Netherlands. Received for publication November 7, 1986; accepted February 6, 1987. Reprint requests: G. H. A. Visser, M.D., Department of Obstetrics and Gynaecology, University Hospital, 59 Oostersingel, 9713 EZ Groningen, The Netherlands.
receiving a detailed explanation of the investigation, they agreed to take part in the study. Continuous real-time ultrasound images were obtained and recorded on videotape for 30 minutes immediately before and 30 minutes directly after chorionic villus sampling with an Aloka SSD-256, which was equipped with a 3.5 MHz linear array transducer. The fetuses were usually visualized in the mid- or parasagittal longitudinal section. The analysis of fetal motility was carried out during playback of the video recordings in the presence of an independent observer to minimize bias and reduce interobserver error. The incidence and duration of the different movements were marked on an event recorder (model 7754a, Hewlett-Packard, Palo Alto, Calif.) by a handheld push buttons. General movements, startles, hiccups, and breathing movements were analyzed according to the criteria described by de Vries et al.' General movements were expressed as a percentage of the time they were present; the other movements were simply counted. In case the recording time differed slightly from 30 minutes, the incidence of movements was normalized by conversion to 30 minutes. The results were analyzed by the Wilcoxon signed rank test. 137
Key words: Chorion biopsy, transabdominal needling, ultrasound
The ability to detect fetal genetic diseases by chorionic tissue analysis has resulted in a great number of sampling methods. Four main approaches are being used. In three of them, the catheter, 1 biopsy forceps, 2 or endoscope 3 is inserted via the cervical canal; in the fourth method, the aspiration is done by transabdominal puncture.< Most experience has been accumulated with transcervical catheter (Trophocan, Portex Inc., Wilmington, Maine) aspiration, a method that has proved to be highly efficient and relatively safe.' Some anatomic and clinical conditions have been recognized as being unfavorable for safe and successful transcervical sampling; therefore the feasibility of a simple transabdominal ultrasound-guided chorionic villus sampling (CVS) method has been evaluated and is described in this article. Patients The 100 cases in the present series were selected for transabdominal CVS because of absolute or relative contraindications to the transcervical route (Table I). CVS was performed at 8, 9, 10, 11, 12, 13, and 14 weeks in 4, 31, 30, 26, 6, 2, 1 cases, respectively. Maternal age was more than 35 years in 77% of the cases. The indication for first-trimester diagnosis was chromosome determination in 96 cases, metabolic disease in one case, fetal sex determination for X-linked disease in two cases, and deoxyribonucleic acid analysis for hemophilia A in one case. The placenta was anterior in 66% of cases and posterior in the remaining 34%. From the Clinica "L. Mangiagalli," First Institute of Obstetrics and Gynecology, Perinatal Unit, University of Milan. Received for publication July 10, 1986; accepted October 10, 1986. Reprint requests: Bruno Brambati, M:D., Clinica "L. Mangiagalli," First Institute of Obstetrics and Gynecology, Via Commenda 12,20122, Milan, Italy.
134
Table I. Conditions of absolute or relative contraindication to transcervical aspiration, in which a transabdominal sampling should be advised Vaginismus* Vaginitis* Inaccessible cervical canal* Pronounced angle of uterine corpus on cervixt Multiple pregnancyt ;;.12 weeks of gestationt Previous failure of transcervical samplingt *Absolute. tRelative.
Methods A freehand aspiration was achieved through the maternal abdominal wall with a 20-gauge, 90 mm spinal needle with sector scan guidance at 5 MHz (Sigma 1SC, Kontron Instruments Inc., Everett, Massachusetts) (Fig. 1, A). The placenta was identified and its depth calculated. A compromise was made between the extension and thickness of the placenta and its distance from the maternal wall. Bladder emptying or filling was sometimes required to obtain a more favorable position of the uterus. The skin was sterilized with topical application of povidone iodine and the area draped in a sterile fashion. Because the transducer was 5 to 10 em away from the insertion site, a nonsterilely dressed person could hold the scanner; neither sterile gloves nor sterile contact gel was needed. The needle was introduced under continuous ultrasonic surveillance without local administration of anesthetics. When the tip was clearly visible within the placenta (Fig. 1, B and C), the stylet was replaced by a 20 ml Luer-Lok syringe containing 3 ml of Henk's solution. The chorionic tissue was then aspirated by combining repeated strong sue-
Volume 157 Number l
Transabdominal chorionic villus sampling
135
Fig. I. Diagram of transabdominal chorion biopsy by 20-gauge spinal needle under ultrasound guidance (A). Ultrasound monitor shows needle (arrow) sampling chorionic villi in two cases at 10 weeks (B) and 9 weeks (C) with an anterior and a posterior placenta, respectively.
tions (equivalent to about 20 ml depression) and a slow backward-and-forward movement of the needle tip. No more than two needle insertions were performed. Neither premedication nor postsampling care was required. Results
We failed to obtain chorionic tissue in six of the 100 cases with the first attempt, but tissue was obtained in these cases with a second insertion performed during the same session. The failures were apparently not related to the gestational age or to the placental location. The majority, five out of six cases, occurred in the first 30 cases, and the difficulties most likely represented inadequate technical experience. In a twin pregnancy with two separate placentas, chorionic tissue was easily obtained by cervical aspiration from one placenta, but the second placenta, located far from the internal cervical os, could be sampled only through the abdominal wall. The distribution of the weight of villus tissue obtained with a single aspiration is reported in Table II. For comparison, the villus weight distribution of 200 cases of transcervical aspiration is provided. Although the ranges of the weight distribution are quite similar for both techniques, the transabdominal aspirations more frequently produced samples of <5 mg, whereas the transcervical samples were frequently ;;,50 mg. The samples of <5 mg were more frequently obtained from anterior (14/66) than from posterior (2/34) placentas.
Five pregnancies were terminated by elective abortion (Table Ill); in three, a fetal aneuploidy was diagnosed by direct karyotyping, 6 and two fetuses at risk for X-linked disease were male. No fetal losses were observed at the time of writing in the 95 continuing pregnancies; 68% of these are currently more than 20 weeks of gestation. In four cases, bleeding or spotting was reported after CVS. Delivery has occurred in 17 cases; all were at term with birth weights between the tenth and ninetieth percentiles. Comment
Although the experience reported in large series seems conclusive with respect to the efficacy of the various chorionic villus sampling techniques ,5 no reliable clinical trials comparing the different approaches are yet available. While randomized trials between transcervical and transabdominal aspiration are awaited, 5 it is of practical interest to evaluate the suitability of the transabdominal puncture method in conditions unfavorable for the transcervical approach. In addition, we wanted to explore means of reducing the invasiveness and relative complexity of transabdominal sampling, as previously described.•·" The new sampling procedure was highly successful, without regard to the placental location or gestational age. An overall success rate of 99 % was obtained; a second puncture was required in only 6% of cases. Although the weight distribution of the aspirated specimens points to a shift toward smaller samples, in 95 %
136
Brambati, Oldrini, and Lanzani
July 1987 Am J Obstet Gynecol
Table II. Weight distribution of chorionic tissue specimens obtained by transabdominal or transcervical aspiration methods Chorionic villus sampling method
20-gauge spinal needle Trophocan
% Specimens obtained according to weight <5mg
5-10 mg
11-20 mg
21-50 mg
51-100 mg
17
35 16
19 15
27 45
2 22
1
Table III. Clinical data of 100 consecutive chorionic villus sampling cases obtained by a transabdominal aspiration Total No. of cases Twin pregnancies Successful sampling At first aspiration Selective abortion Concluded pregnancies Early complications Bleeding Spotting Fetal loss
100
1
100 94
5
17
I 3 0
of the last 40 cases, the amount of chorionic tissue obtained by a single insertion exceeded 10 mg. By this method it is possible, with two needle insertions, to provide a sufficient amount of tissue for successful deoxyribonucleic acid analysis in complicated diagnostic conditions. In only one case was fetal karyotyping not possible because of insufficient villi. The success of sampling was dependent on reliable needle tip detection and obtaining an adequate course through the placental substance. In fact, with poor ultrasound visualization, one may fail to enter the placenta, or, if the needle is placed in too thin a portion of the placenta, inadequate movement of the tip precludes the aspiration of a sufficient sample. Transabdominal CVS, as carried out in the present experience, has some advantages when compared with the previously described technique, in which a fixed biopsy guide attachment and a 17- or 18-gauge guide needle are used.<· 8 First, by reducing the size of the sampling device, one would expect to observe beneficial effects on the complication rate. A Canadian study on amniocentesis demonstrated a significantly lower incidence of fetal loss and maternal complications when a 20-gauge needle was used rather than a larger one." Second, although a transabdominal freehand sampling method may be more difficult to learn than the needleguided method and certainly requires coordinated teamwork, 10· 11 it allows an easier adjustment of the needle direction when necessitated by involuntary abdominal wall or uterine displacements. In our experience with first-trimester fetal diagnosis, transabdominal sampling was primarily introduced as a technique to complement transcervical aspiration ide-
>100 mg
ally to achieve a higher sampling success rate, reduce the need for a second transcervical insertion, and reduce complications. For the most part, these objectives seem to have been attained. In the second part of our transabdominal experience, having achieved adequate skill by combining transcervical and transabdominal aspiration, we obtained a sampling success rate of virtually 100% in a variety of anatomic and clinical conditions.12 A special advantage of the combined use of the two techniques should be evident in cases of multiple pregnancy, where placentas can be reliably sampled independent of their anatomic relationship. In conclusion, although in our hands transcervical aspiration was confirmed to be the method of choice 2 in clinical practice, the benefit of the transabdominal approach for optimizing the sampling success rate and reducing procedural difficulties was clearly demonstrated. Moreover, the transabdominal method described has the same advantages that have been previously reported.<· 8 In addition, the thinner needle and freehand ultrasound guidance of the sampling system make it easier to perform with a potentially lower risk for maternal and fetal complications. We gratefully acknowledge Dr. Angela Sciascia who made helpful comments during the preparation of this article and Dr. G. Simoni, Dr. L. Dalpra, and Dr. S. Guerneri for their cooperation in this investigation. REFERENCES I. Brambati B, OldriniJA. Methods of chorionic villus sam-
2.
3.
4.
5. 6.
pling. In: Brambati B, Simoni G, Fabro S, eds. Chorionic villus sampling. New York: Marcel Dekker, 1986:73-98. Dumez Y, Goossens M, Boue J, Poenaru L, Dommergues M, Henrion R. Chorionic villi sampling using rigid forceps under ultrasound control. In: Fraccaro M, Simoni G, Brambati B, eds. First trimester fetal diagnosis. New York: Springer-Verlag, 1985:38-45. Gustavii B. Direct vision technique for chorionic villi sampling in 100 diagnostic cases. In: Fraccaro M, Simoni G, Brambati B, eds. First trimester fetal diagnosis. New York: Springer-Verlag, 1985:46-50. Smidt-Jensen S, Hahnemann N,Jensen PKA, Therkelsen A]. Transabdominal chorionic villi sampling for first trimester fetal diagnosis. In: Fraccaro M, Simoni G, Brambati B, eds. First trimester fetal diagnosis. New York: Springer-Verlag, 1985:51-3. Jackson L. Chorion villus sampling newsletter, January 21, 1986. Simoni G, Terzoli GL, Romitti L. Fetal karyotyping by direct chromosome preparation. In: Brambati B, Sim-
Volume 157 Number I
oni G, Fabro S, eds. Chorionic villus sampling. New York: Marcel Dekker, 1986:99-118. 7. Bossi A, Caccamo ML, De Scrilli AM, Milani S. Weight of the Italian newborn infants (from the 32nd to the 43rd week of gestation). Ita! J Ped 1980;6: 153-70. 8. Maxwell D, Lilford R, Czepulkowski B, Heaton D, Coleman D. Transabdominal chorionic villus sampling. Lancet 1986; i:123-6. 9. Simpson NE, Dallaire L, Miller JR. Prenatal diagnosis of genetic disease in Canada: report of a collaborative study. Can Med Assoc J 1976; 115:739-46.
Transabdominal chorionic villus sampling
10. Daffos F, Cappella-Pavlovsky M, Forestier F. A new procedure for fetal blood sampling in utero: preliminary results of fifty-three cases. AM J 0BSTET GYNECOL 1983; 146:985-7. 11. Hobbins JC, Grannum PA, Romero R, Reece EA, Mahoney MJ. Percutaneous umbilical blood sampling. AM J 0BSTET GYNECOL 1985;152:1-6. 12. Brambati B, Oldrini A, Ferrazzi E, Lanzani A. Chorionic villus sampling: an analysis of the obstetric experience of 1,000 cases. Prenat Diagn 1987;7:157-69.
The immediate effects of chorionic villus sampling on fetal movements A. Boogert, M.D., A. Mantingh, M.D., and G. H. A. Visser, M.D., Ph.D. Groningen, The Netherlands The immediate effects of chorionic villus sampling on the fetus was studied by real-time ultrasound observation of fetal movements. Thirty-minute recordings, directly before and after chorionic villus sampling, were made in 10 women. No changes were observed in the incidence or distribution of the four movement patterns studied. This held true even in the two cases that ended in a spontaneous abortion. It is concluded that chorionic villus sampling does not stimulate movements or alter the intrauterine situation in such a way that fetal movements decrease. (AM J OBSTET GYNECOL 1987;157:137-9.)
Key words: Chorionic villus sampling, real-time ultrasound, fetal movements, first trimester of pregnancy Chorionic villus sampling has become an increasingly popular technique for early prenatal diagnosis. More than I 0,000 investigations have been performed worldwide to date.' So far the fetal consequences of this procedure have been assessed in terms of the abortion rate, fetal growth as observed via serial ultrasound, and perinatal outcome. 2· 1 With real-time ultrasound equipment, distinct patterns of fetal behavior have been described from 7 weeks of gestation onward. 5 We attempted to determine the acute effects of this invasive diagnostic procedure on fetal motor behavior by means of two 30minute observations taken immediately before and after chorionic villus sampling. Patients and methods
Ten multiparous women were selected at random from those referred for chorionic villus sampling. After From the Department of Obstetrics and Gynaecology, University H ospital, The Netherlands. Received for publication November 7, 1986; accepted February 6, 1987. Reprint requests: G. H. A. Visser, M.D., Department of Obstetrics and Gynaecology, University Hospital, 59 Oostersingel, 9713 EZ Groningen, The Netherlands.
receiving a detailed explanation of the investigation, they agreed to take part in the study. Continuous real-time ultrasound images were obtained and recorded on videotape for 30 minutes immediately before and 30 minutes directly after chorionic villus sampling with an Aloka SSD-256, which was equipped with a 3.5 MHz linear array transducer. The fetuses were usually visualized in the mid- or parasagittal longitudinal section. The analysis of fetal motility was carried out during playback of the video recordings in the presence of an independent observer to minimize bias and reduce interobserver error. The incidence and duration of the different movements were marked on an event recorder (model 7754a, Hewlett-Packard, Palo Alto, Calif.) by a handheld push buttons. General movements, startles, hiccups, and breathing movements were analyzed according to the criteria described by de Vries et al.' General movements were expressed as a percentage of the time they were present; the other movements were simply counted. In case the recording time differed slightly from 30 minutes, the incidence of movements was normalized by conversion to 30 minutes. The results were analyzed by the Wilcoxon signed rank test. 137