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The use of a rapid in situ technique for third-trimester diagnosis of trisomy 18
The use of a rapid in situ technique for third-trimester diagnosis of trisomy 18 Burton L. Rochelson, M.D., Carolyn Trunca, Ph.D., Alan G. Monheit, M.D., and David A. Baker, M.D. Stony Brook, New York A rapid in situ coverslip technique was used to diagnose trisomy 18 within 1 week of amniocentesis in the third trimester. Two cases are presented. The clinical significance and advantages over umbilical vein aspiration are discussed. (AM J OssTET GvNECOL 1986;155:835-6.)
Key words: Karyotyping, amniocentesis, in situ technique, umbilical vein aspiration
Prenatal diagnosis of a lethal chromosomal anomaly in the third trimester may prevent needlessly heroic intervention and intensive antepartum surveillance. In chromosomally normal fetuses, obstetric care is designed to maximize the newborn infant's chances of achieving its full potential even at the cost of increased maternal morbidity. In hopeless cases like trisomy 13 or I8, a choice may be made to omit intensive prenatal surveillance and needless cesarean sections may be prevented. An abnormal cytogenetic diagnosis in the third trimester may give the parents the necessary time to learn about the fetus's condition before birth or premature loss and give the obstetric staff and the nursery time to plan. Conventional culture techniques for amniotic fluid require 2 to 4 weeks for growth and karyotypic analysis. This may be even longer in the third trimester. Because this delay is sometimes unacceptable, fetal blood may be aspirated directly from the umbilical cord with ultrasound guidance. 1 A sample is obtained on which chromosomal diagnosis is made in 2 to 4 days. The risk of the procedure, however, is a fetal loss of 1.9%, significantly increased over that of third-trimester amniocentesis. The procedure requires special training and is done at only a few centers. An in situ technique for cytogenetic evaluation of amniocytes has been used for rapid midtrimester diagnoses. 2 There has been little written, however, about its application in the third trimester. Reported here are two cases of trisomy 18 diagnosed in the third trimester. The in situ technique was used and diagnosis made 1 week after amniocentesis. From the Department of Obstetrics and Gynecology, School of Medicine, State University of New York at Stony Brook. Received for publication December 27, 1985; revised April18, 1986; accepted April24, 1986. Reprint requests: Burton L. Rochelson, M.D., Department of Obstetrics and Gynecology, Health Sciences Center, T9 Room 080, Stony Brook, NY 11794.
Case reports Case 1. C. M. is a 33-year-old woman, gravida 4, para 2-0-1-2, at 41 weeks' gestational age by dates with ultrasound evidence of polyhydramnios and intrauterine growth retardation. Although the biparietal diameter was consistent with a 40-week gestation, other parameters were consistent with 33 weeks. There was a fluidfilled structure in the posterior fossa of the fetal brain and a suspicion of cleft lip and palate. Amniocentesis was performed. Lecithin/sphingomyelin ratio was 1 : 1. Fluid was sent for karyotyping. Until the results were obtained, the patient was managed by standard intrauterine growth retardation protocol, with nonstress tests and biophysical profile, which were normal. Seven days after the amniocentesis the diagnosis of trisomy 18 was reported. The patient and her husband were counseled by the genetics, neonatology, and perinatology staff and by the clergy. Antepartum monitoring was discontinued, and the patient was seen weekly with the plan to induce labor as soon as the cervix was favorable. At 45 weeks this was attempted unsuccessfully. At 46 weeks the patient had spontaneous rupture of the membranes and presented in labor. Unfortunately, the fetus was in transverse lie with back down, and cesarean section was necessary. The mother was delivered of a 2700 gm female infant with multiple anomalies that died 3 weeks later. Case 2. G. L. is a 36-year-old white woman, gravida 3, para 2, with two previous cesarean sections with normal infants. In the second trimester she was offered genetic amniocentesis, but she refused. At 29 weeks' gestational age she was noted to be large for gestational age. Ultrasound revealed polyhydramnios and intrauterine growth retardation. Amniocentesis was performed, and the case was managed according to protocol for intrauterine growth retardation. A fetal arrhythmia was noted, which made nonstress test interpretation difficult. Fetal echocardiography was performed which was suboptimal because of active fetal movement. One week after the amniocentesis the result of trisomy 18 was reported. The patient and her husband received counseling as in case I. No further
835
Rochelson et al.
antepartum monitoring was done. At 37 weeks she presented in labor with a fetal death. She was delivered vaginally of an 1870 gm stillborn female infant with multiple anomalies.
Material and methods The amniotic fluid samples were processed in situ." For each case, 30 ml of amniotic fluid was centrifuged, the supernatant removed, the cell button resuspended in 4.0 ml of culture medium which contained 65% modified Eagle's medium (Alpha medium), 25% Chang medium, and 10% fetal bovine serum that was supplemented with L-glutamine and penicillin/streptomycin solution; 0.5 ml of the suspension was pi petted onto a 22 mm square coverslip in each of eight Petri dishes. After 24 hours, 1.5 ml of medium was added to each dish. The cultures were harvested in situ on the fifth and sixth days by first adding Colcemid to the cultures for 2 hours, treating with 0.8% sodium citrate hypotonic solution for 20 minutes, and fixing in a I : 3 acetic acid/methanol fixative. G-banded mitoses from a minimum of 15 colonies from at least three different coverslips were analyzed so that a final cytogenetic diagnosis was made within a week of the amniocentesis.
October 1986 Am J Obstet Gynecol
ticularly important to make a diagnosis in the presence of polyhydramnios, which is frequently associated with a chromosomally abnormal pregnancy. A !-week interval for amniotic fluid analysis with use of the in situ technique reduces the advantage of the rapid turnaround time of umbilical vein aspiration, a more morbid procedure. In these cases the expense and anxiety of antepartum testing were avoided and the parents prepared for a negative outcome. In case I the patient was allowed to continue post dates without surveillance or intervention, and only fetal position prevented a vaginal delivery. In case 2 the difficulty of monitoring and interpreting non stress tests of a fetus with an arrythmia was avoided. It is likely that with regular monitoring the patient would have had an emergency cesarean section for fetal distress. The rapid in situ technique with use of amniocytes is safer and easier than umbilical vein aspiration of fetal blood. The rapid turnaround time allows intelligent and timely counseling of the parents and may prevent hopeless intervention. We gratefully acknowledge the technical assistance of Nedra Carlson.
Comment These cases illustrate the advantage of rapid amniotic fluid karyotyping in the third trimester. Daflos et a!.' have described percutaneous sampling of fetal cord blood with use of ultrasound guidance for karyotyping the late second- or third-trimester fetus. Knowledge of karyotype may be helpful in the management of growth retardation at term or in the preterm fetus. It is par-
REFERENCES I. Daffos F, Capella-Paulovsky M, Forestier F. Fetal blood
sampling during pregnancy with use of a needle guided by ultrasound: a study of 606 consecutive cases. A\t.J 011. STET (;Y:-.IECOL 1985; 153:655. 2. Peakman DC, Moreton MF, Corn B.J, Robinson A. Chromosomal mosaicism in amniotic fluid cell cultures. Am J Hum c;enet 1979;31: 149.
Monoamniotic twins: Antenatal diagnosis and management Joan Sutter, M.D., H. Arab, M.D., and F. A. Manning, M.D. Winnipeg, Manitoba, Canada Confident prenatal diagnosis of monoamniotic twins permits timed elective delivery, thereby reducing the risk of perinatal loss. In this report serial dynamic ultrasound fetal assessment and amniography were used to confirm this diagnosis and guide management to a successful outcome. (AM J OssTET GvNECOL 1986;155:836-7.)
Key words: Monoamniotic twins, antenatal diagnosis, amniography From the Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, Universit~ ofManitoba. Received for publication December 23, 1985; revised April21, 1986; accepted May 5, 1986. Reprint requests: Dr. F. A. Manning, Department of Obstetrics and Gynecology, Women's Hospital, WR-120, 735 Notre Dame Ave., Winnipeg, Manitoba, Canada R3E OL8.
836
Monoamniotic twins, while rare, result in perinatal death in up to 68% of cases.' Umbilical cord entanglement is the most common cause of death (72% of cases). Reliable prenatal diagnosis of monoamniotic twins, as illustrated here, may permit elective early delivery, thereby reducing perinatal loss.
Key words: Karyotyping, amniocentesis, in situ technique, umbilical vein aspiration
Prenatal diagnosis of a lethal chromosomal anomaly in the third trimester may prevent needlessly heroic intervention and intensive antepartum surveillance. In chromosomally normal fetuses, obstetric care is designed to maximize the newborn infant's chances of achieving its full potential even at the cost of increased maternal morbidity. In hopeless cases like trisomy 13 or I8, a choice may be made to omit intensive prenatal surveillance and needless cesarean sections may be prevented. An abnormal cytogenetic diagnosis in the third trimester may give the parents the necessary time to learn about the fetus's condition before birth or premature loss and give the obstetric staff and the nursery time to plan. Conventional culture techniques for amniotic fluid require 2 to 4 weeks for growth and karyotypic analysis. This may be even longer in the third trimester. Because this delay is sometimes unacceptable, fetal blood may be aspirated directly from the umbilical cord with ultrasound guidance. 1 A sample is obtained on which chromosomal diagnosis is made in 2 to 4 days. The risk of the procedure, however, is a fetal loss of 1.9%, significantly increased over that of third-trimester amniocentesis. The procedure requires special training and is done at only a few centers. An in situ technique for cytogenetic evaluation of amniocytes has been used for rapid midtrimester diagnoses. 2 There has been little written, however, about its application in the third trimester. Reported here are two cases of trisomy 18 diagnosed in the third trimester. The in situ technique was used and diagnosis made 1 week after amniocentesis. From the Department of Obstetrics and Gynecology, School of Medicine, State University of New York at Stony Brook. Received for publication December 27, 1985; revised April18, 1986; accepted April24, 1986. Reprint requests: Burton L. Rochelson, M.D., Department of Obstetrics and Gynecology, Health Sciences Center, T9 Room 080, Stony Brook, NY 11794.
Case reports Case 1. C. M. is a 33-year-old woman, gravida 4, para 2-0-1-2, at 41 weeks' gestational age by dates with ultrasound evidence of polyhydramnios and intrauterine growth retardation. Although the biparietal diameter was consistent with a 40-week gestation, other parameters were consistent with 33 weeks. There was a fluidfilled structure in the posterior fossa of the fetal brain and a suspicion of cleft lip and palate. Amniocentesis was performed. Lecithin/sphingomyelin ratio was 1 : 1. Fluid was sent for karyotyping. Until the results were obtained, the patient was managed by standard intrauterine growth retardation protocol, with nonstress tests and biophysical profile, which were normal. Seven days after the amniocentesis the diagnosis of trisomy 18 was reported. The patient and her husband were counseled by the genetics, neonatology, and perinatology staff and by the clergy. Antepartum monitoring was discontinued, and the patient was seen weekly with the plan to induce labor as soon as the cervix was favorable. At 45 weeks this was attempted unsuccessfully. At 46 weeks the patient had spontaneous rupture of the membranes and presented in labor. Unfortunately, the fetus was in transverse lie with back down, and cesarean section was necessary. The mother was delivered of a 2700 gm female infant with multiple anomalies that died 3 weeks later. Case 2. G. L. is a 36-year-old white woman, gravida 3, para 2, with two previous cesarean sections with normal infants. In the second trimester she was offered genetic amniocentesis, but she refused. At 29 weeks' gestational age she was noted to be large for gestational age. Ultrasound revealed polyhydramnios and intrauterine growth retardation. Amniocentesis was performed, and the case was managed according to protocol for intrauterine growth retardation. A fetal arrhythmia was noted, which made nonstress test interpretation difficult. Fetal echocardiography was performed which was suboptimal because of active fetal movement. One week after the amniocentesis the result of trisomy 18 was reported. The patient and her husband received counseling as in case I. No further
835
Rochelson et al.
antepartum monitoring was done. At 37 weeks she presented in labor with a fetal death. She was delivered vaginally of an 1870 gm stillborn female infant with multiple anomalies.
Material and methods The amniotic fluid samples were processed in situ." For each case, 30 ml of amniotic fluid was centrifuged, the supernatant removed, the cell button resuspended in 4.0 ml of culture medium which contained 65% modified Eagle's medium (Alpha medium), 25% Chang medium, and 10% fetal bovine serum that was supplemented with L-glutamine and penicillin/streptomycin solution; 0.5 ml of the suspension was pi petted onto a 22 mm square coverslip in each of eight Petri dishes. After 24 hours, 1.5 ml of medium was added to each dish. The cultures were harvested in situ on the fifth and sixth days by first adding Colcemid to the cultures for 2 hours, treating with 0.8% sodium citrate hypotonic solution for 20 minutes, and fixing in a I : 3 acetic acid/methanol fixative. G-banded mitoses from a minimum of 15 colonies from at least three different coverslips were analyzed so that a final cytogenetic diagnosis was made within a week of the amniocentesis.
October 1986 Am J Obstet Gynecol
ticularly important to make a diagnosis in the presence of polyhydramnios, which is frequently associated with a chromosomally abnormal pregnancy. A !-week interval for amniotic fluid analysis with use of the in situ technique reduces the advantage of the rapid turnaround time of umbilical vein aspiration, a more morbid procedure. In these cases the expense and anxiety of antepartum testing were avoided and the parents prepared for a negative outcome. In case I the patient was allowed to continue post dates without surveillance or intervention, and only fetal position prevented a vaginal delivery. In case 2 the difficulty of monitoring and interpreting non stress tests of a fetus with an arrythmia was avoided. It is likely that with regular monitoring the patient would have had an emergency cesarean section for fetal distress. The rapid in situ technique with use of amniocytes is safer and easier than umbilical vein aspiration of fetal blood. The rapid turnaround time allows intelligent and timely counseling of the parents and may prevent hopeless intervention. We gratefully acknowledge the technical assistance of Nedra Carlson.
Comment These cases illustrate the advantage of rapid amniotic fluid karyotyping in the third trimester. Daflos et a!.' have described percutaneous sampling of fetal cord blood with use of ultrasound guidance for karyotyping the late second- or third-trimester fetus. Knowledge of karyotype may be helpful in the management of growth retardation at term or in the preterm fetus. It is par-
REFERENCES I. Daffos F, Capella-Paulovsky M, Forestier F. Fetal blood
sampling during pregnancy with use of a needle guided by ultrasound: a study of 606 consecutive cases. A\t.J 011. STET (;Y:-.IECOL 1985; 153:655. 2. Peakman DC, Moreton MF, Corn B.J, Robinson A. Chromosomal mosaicism in amniotic fluid cell cultures. Am J Hum c;enet 1979;31: 149.
Monoamniotic twins: Antenatal diagnosis and management Joan Sutter, M.D., H. Arab, M.D., and F. A. Manning, M.D. Winnipeg, Manitoba, Canada Confident prenatal diagnosis of monoamniotic twins permits timed elective delivery, thereby reducing the risk of perinatal loss. In this report serial dynamic ultrasound fetal assessment and amniography were used to confirm this diagnosis and guide management to a successful outcome. (AM J OssTET GvNECOL 1986;155:836-7.)
Key words: Monoamniotic twins, antenatal diagnosis, amniography From the Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, Universit~ ofManitoba. Received for publication December 23, 1985; revised April21, 1986; accepted May 5, 1986. Reprint requests: Dr. F. A. Manning, Department of Obstetrics and Gynecology, Women's Hospital, WR-120, 735 Notre Dame Ave., Winnipeg, Manitoba, Canada R3E OL8.
836
Monoamniotic twins, while rare, result in perinatal death in up to 68% of cases.' Umbilical cord entanglement is the most common cause of death (72% of cases). Reliable prenatal diagnosis of monoamniotic twins, as illustrated here, may permit elective early delivery, thereby reducing perinatal loss.