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Second-trimester genetic amniocentesis in twin pregnancy
International Journal of Gynecology & Obstetrics 61 Ž1998. 285]287
Brief communication
Second-trimester genetic amniocentesis in twin pregnancy T.-M. KoU , L.-H. Tseng, H.-L. Hwa Department of Obstetrics and Gynecology, and Department of Medical Genetics, College of Medicine, National Taiwan Uni¨ ersity, Taipei, Taiwan Received 8 December 1997; received in revised form 11 February 1998; accepted 18 February 1998
Keywords: Genetic amniocentesis; Twin pregnancy; Genetic counseling
With the rapid progress in artificial reproductive technology, the demand for genetic amniocentesis in twin pregnancy has increased. However, its safety and accuracy have rarely been investigated w1]4x. This report is to address these topics. From May 1986 through August 1997, 128 women with twin pregnancies who underwent second-trimester amniocentesis were included in the study group. Patients in whom amniocentesis was performed after chorionic villus sampling or fetal reduction, or when one twin was already
U
Corresponding author, Department of Obstetricsr Gynecology, National Taiwan University Hospital, Taipei, Taiwan. Fax: q886 2 23970515; e-mail: [email protected]
dead at the time of amniocentesis, were excluded. Advanced maternal age accounted for 80% of the procedures. The control group included 205 women with twin pregnancies who attended our prenatal clinic before 18 weeks gestation and gave birth at our hospital. The mean gestational age at amniocentesis was 18.5 weeks ŽS.D.s 2.7 weeks.. All pregnancies had diamniotic twins. We paid special attention to the relationship between the septum and each twin. Amniocentesis was performed under continuous ultrasound guidance. b-iodine was used for pregnant women’s abdominal wall preparation and was also used as an acoustic medium. No indicator dyes were injected into the first sac for confirmation of fluid withdrawal from the second sac. After amniocentesis, neither antibiotics nor tocolytic agents were prescribed.
0020-7292r98r$19.00 Q 1998 International Federation of Gynecology and Obstetrics PII S0020-7292Ž98.00045-9
286
T.-M. Ko et al. r International Journal of Gynecology & Obstetrics 61 (1998) 285]287
Table 1 Comparison of pregnancy loss and fetal loss rates after amniocentesis in twin pregnancy Authors
Pregnancy No.
Pruggmayer et al. Anderson et al. Ghidini et al. Wapner et al. Ko et al. Žthis study.
98 336 101 70 128
Total
733
Fetus No.
196 681b 202 140 256 1475
Pregnancy loss Ž- 28 weeks.
Fetal lossa
Reference
8 Ž8.1%. 12 Ž3.6%. 2 Ž2.0%.c 2 Ž2.9%. 3 Ž2.3%.
21 Ž10.7%. 31 Ž4.5%. 7 Ž3.5%. 13 Ž9.3%. 11 Ž4.3%.
1 2 3 4
27 Ž3.6%.
83 Ž5.6%.
a
Including intrauterine death of one fetus and total pregnancy loss. Including nine sets of triplets. c Only pregnancy loss - 25 weeks included. b
The study group had a significantly higher maternal age Ž34.5" 3.9 years. than the control group Ž31.0" 3.0 years.. In the study group, there were 135 males and 121 females and all cytogenetic analyzes were compatible with the sex of the infants at birth. Two pregnancies underwent an artificial abortion, the first due to trisomy 21 in both twins and the second due to de novo double balanced translocations in both twins. Two other fetuses had major abnormalities, one with trisomy 13 and the other with acranium. None spontaneously aborted before 24 weeks gestation, five Ž1.9%. twins Žfive pregnancies. died intrauterine and three Ž2.3%. pregnancies had preterm birth before 28 weeks gestation. The mean gestational age at delivery was 36 weeks ŽS.D.s 3 weeks. and the mean birth weight of the newborns was 2432 g ŽS.D.s 522 g.. In the control group, two Ž1.0%. pregnancies spontaneously aborted, seven Ž1.7%. twins Žseven pregnancies. died intrauterine, and five Ž2.4%. pregnancies had preterm birth. The mean gestational age at delivery was 37 weeks ŽS.D.s 2 weeks. and the mean birth weight of the newborns was 2470 g ŽS.D.s 462 g.. In our study, pregnancy outcomes of women who underwent amniocentesis were similar to those of women who did not. The chromosomal abnormality rate of 2.0% was similar to those of other reports with amniocentesis performed in singleton or twin pregnancies w2,4x. Methylene blue or indigo carmine dye injection into the first amniotic sac has been used in other groups to
make sure that the same sac is not punctured a second time. We used continuous ultrasound guidance to sample the different sacs, thus avoiding the use of indicator dyes. Since we have not made any mistakes in fetal sexing, it is very unlikely that we sampled the same sac. Without the use of indicator dyes, we believe that chorioamnionitis can be minimized and dye-induced fetal damage can be avoided. The risk of amniocentesis in twin pregnancies has been reported as 15% in earlier reports. Table 1 summarizes the 1990s reports on amniocentesis in twin pregnancies. In terms of pregnancy and fetal loss rates, our series seems to compare favorable with recent studies. Our study suggests that in experienced hands second-trimester amniocentesis in twin pregnancies does not pose an increased risk to the pregnancy. Acknowledgments We are grateful to Dr. Fon-Jou Hsieh for providing some cases of amniocentesis. References w1x Pruggmayer M, Baumann P, Schutte H et al. Incidence of abortion after genetic amniocentesis in twin pregnancies. Prenat Diagn 1991;11:637]640. w2x Anderson RL, Goldberg JD, Golbus MS. Prenatal diagnosis in multiple gestation: 20 years’ experience with amniocentesis. Prenat Diagn 1991;11:263]270. w3x Ghidini A, Lynch L, Hicks C, Alvarez M, Lockwood CJ.
T.-M. Ko et al. r International Journal of Gynecology & Obstetrics 61 (1998) 285]287 The risk of second trimester amniocentesis in twin gestations: a case-control study. Am J Obstet Gynecol 1993;169:1013]1016. w4x Wapner RJ, Johnson A, Davis G, Urban A, Morgan P,
287
Jackson L. Prenatal diagnosis in twin gestation: a comparison between second-trimester amniocentesis and first-trimester chorionic villus sampling. Obstet Gynecol 1993;82:49]56.
Brief communication
Second-trimester genetic amniocentesis in twin pregnancy T.-M. KoU , L.-H. Tseng, H.-L. Hwa Department of Obstetrics and Gynecology, and Department of Medical Genetics, College of Medicine, National Taiwan Uni¨ ersity, Taipei, Taiwan Received 8 December 1997; received in revised form 11 February 1998; accepted 18 February 1998
Keywords: Genetic amniocentesis; Twin pregnancy; Genetic counseling
With the rapid progress in artificial reproductive technology, the demand for genetic amniocentesis in twin pregnancy has increased. However, its safety and accuracy have rarely been investigated w1]4x. This report is to address these topics. From May 1986 through August 1997, 128 women with twin pregnancies who underwent second-trimester amniocentesis were included in the study group. Patients in whom amniocentesis was performed after chorionic villus sampling or fetal reduction, or when one twin was already
U
Corresponding author, Department of Obstetricsr Gynecology, National Taiwan University Hospital, Taipei, Taiwan. Fax: q886 2 23970515; e-mail: [email protected]
dead at the time of amniocentesis, were excluded. Advanced maternal age accounted for 80% of the procedures. The control group included 205 women with twin pregnancies who attended our prenatal clinic before 18 weeks gestation and gave birth at our hospital. The mean gestational age at amniocentesis was 18.5 weeks ŽS.D.s 2.7 weeks.. All pregnancies had diamniotic twins. We paid special attention to the relationship between the septum and each twin. Amniocentesis was performed under continuous ultrasound guidance. b-iodine was used for pregnant women’s abdominal wall preparation and was also used as an acoustic medium. No indicator dyes were injected into the first sac for confirmation of fluid withdrawal from the second sac. After amniocentesis, neither antibiotics nor tocolytic agents were prescribed.
0020-7292r98r$19.00 Q 1998 International Federation of Gynecology and Obstetrics PII S0020-7292Ž98.00045-9
286
T.-M. Ko et al. r International Journal of Gynecology & Obstetrics 61 (1998) 285]287
Table 1 Comparison of pregnancy loss and fetal loss rates after amniocentesis in twin pregnancy Authors
Pregnancy No.
Pruggmayer et al. Anderson et al. Ghidini et al. Wapner et al. Ko et al. Žthis study.
98 336 101 70 128
Total
733
Fetus No.
196 681b 202 140 256 1475
Pregnancy loss Ž- 28 weeks.
Fetal lossa
Reference
8 Ž8.1%. 12 Ž3.6%. 2 Ž2.0%.c 2 Ž2.9%. 3 Ž2.3%.
21 Ž10.7%. 31 Ž4.5%. 7 Ž3.5%. 13 Ž9.3%. 11 Ž4.3%.
1 2 3 4
27 Ž3.6%.
83 Ž5.6%.
a
Including intrauterine death of one fetus and total pregnancy loss. Including nine sets of triplets. c Only pregnancy loss - 25 weeks included. b
The study group had a significantly higher maternal age Ž34.5" 3.9 years. than the control group Ž31.0" 3.0 years.. In the study group, there were 135 males and 121 females and all cytogenetic analyzes were compatible with the sex of the infants at birth. Two pregnancies underwent an artificial abortion, the first due to trisomy 21 in both twins and the second due to de novo double balanced translocations in both twins. Two other fetuses had major abnormalities, one with trisomy 13 and the other with acranium. None spontaneously aborted before 24 weeks gestation, five Ž1.9%. twins Žfive pregnancies. died intrauterine and three Ž2.3%. pregnancies had preterm birth before 28 weeks gestation. The mean gestational age at delivery was 36 weeks ŽS.D.s 3 weeks. and the mean birth weight of the newborns was 2432 g ŽS.D.s 522 g.. In the control group, two Ž1.0%. pregnancies spontaneously aborted, seven Ž1.7%. twins Žseven pregnancies. died intrauterine, and five Ž2.4%. pregnancies had preterm birth. The mean gestational age at delivery was 37 weeks ŽS.D.s 2 weeks. and the mean birth weight of the newborns was 2470 g ŽS.D.s 462 g.. In our study, pregnancy outcomes of women who underwent amniocentesis were similar to those of women who did not. The chromosomal abnormality rate of 2.0% was similar to those of other reports with amniocentesis performed in singleton or twin pregnancies w2,4x. Methylene blue or indigo carmine dye injection into the first amniotic sac has been used in other groups to
make sure that the same sac is not punctured a second time. We used continuous ultrasound guidance to sample the different sacs, thus avoiding the use of indicator dyes. Since we have not made any mistakes in fetal sexing, it is very unlikely that we sampled the same sac. Without the use of indicator dyes, we believe that chorioamnionitis can be minimized and dye-induced fetal damage can be avoided. The risk of amniocentesis in twin pregnancies has been reported as 15% in earlier reports. Table 1 summarizes the 1990s reports on amniocentesis in twin pregnancies. In terms of pregnancy and fetal loss rates, our series seems to compare favorable with recent studies. Our study suggests that in experienced hands second-trimester amniocentesis in twin pregnancies does not pose an increased risk to the pregnancy. Acknowledgments We are grateful to Dr. Fon-Jou Hsieh for providing some cases of amniocentesis. References w1x Pruggmayer M, Baumann P, Schutte H et al. Incidence of abortion after genetic amniocentesis in twin pregnancies. Prenat Diagn 1991;11:637]640. w2x Anderson RL, Goldberg JD, Golbus MS. Prenatal diagnosis in multiple gestation: 20 years’ experience with amniocentesis. Prenat Diagn 1991;11:263]270. w3x Ghidini A, Lynch L, Hicks C, Alvarez M, Lockwood CJ.
T.-M. Ko et al. r International Journal of Gynecology & Obstetrics 61 (1998) 285]287 The risk of second trimester amniocentesis in twin gestations: a case-control study. Am J Obstet Gynecol 1993;169:1013]1016. w4x Wapner RJ, Johnson A, Davis G, Urban A, Morgan P,
287
Jackson L. Prenatal diagnosis in twin gestation: a comparison between second-trimester amniocentesis and first-trimester chorionic villus sampling. Obstet Gynecol 1993;82:49]56.