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Successful delivery of monoamniotic triplets
British Journal of Obstetrics and Gynaecology August 2001, Vol. 108, pp. 892±894
CASE REPORT
Successful delivery of monoamniotic triplets Theodoros Giannopoulos a,*, Patrick O'Brien b, Rajiv Varma c Case report A 27 year old woman booked at 12 weeks of gestation in her ®rst pregnancy which was conceived spontaneously. A booking scan diagnosed a monochorionic monoamniotic triplet pregnancy, and serial weekly ultrasound scans were arranged to monitor this potentially high risk pregnancy. An ultrasound scan at 16 weeks showed marked entanglement of all three umbilical cords. At 17 weeks a repeat scan suggested twin to twin transfusion, one of the fetuses being larger than the others. The risk of polyhydramnios was discussed with the parents, and they were offered either serial amniodrainage or sulindac (Clinoril, APS, Generics) as a preventative measure. They opted for sulindac; this was started at a dose of 400 mg orally daily. Subsequent scans demonstrated good growth of all three fetuses, mild polyhydramnios and mild twin to twin transfusion involving two of the fetuses. No structural abnormalities were identi®ed and the Doppler indices remained normal. The sulindac was stopped at 25 weeks of gestation as the amniotic ¯uid volume was reduced. At the same time, dexamethasone injections were started (two injections of 12 mg intramuscularly once a week). During the following weeks the fetuses grew along the 5th to 10th centiles with normal growth velocities and the amniotic ¯uid volume remained within normal limits. Delivery by elective caesarean section was planned for 34 weeks of gestation. AT 33 weeks of gestation, however, the mother was admitted to the labour ward with a history of spontaneous rupture of the membranes and onset of regular contractions. The cervix was 4cm dilated, and an emergency caesarean section was carried out without delay.
The ®rst triplet was delivered cephalic, the other two as breech. There was dif®culty in delivering the second and third babies due to marked cord and limb entanglement. The babies' weights were 1430, 1490 and 1410 g, respectively, and all were structurally normal. They required admission to the neonatal intensive care unit for 11 days, but all three were well on discharge. Their renal function remained normal throughout their admission. Histological examination con®rmed a single placenta and a single amniotic sac Fig. 1 .
Discussion Successful delivery of live monoamniotic triplets has never previously been reported. Indeed, there is no record in the literature of monoamniotic triplets even with a less favourable outcome. Consequently, the incidence of this condition, even in early gestation, is unknown, but it is likely to be very rare. Although the sonographic diagnosis of amnionicity can be dif®cult 1, even with twins, in this case it was correctly diagnosed at 13 weeks of gestation. Most triplets are trizygotic because they result from assisted conception. In one study of spontaneously conceived triplets the incidence of monozygosity was 40%, but no case was monoamniotic 2. Monoamniotic fetuses are always monochorionic (i.e. share the same placenta, and therefore are of the same sex). In monozygotic triplet pregnancies, if division occurs early, (i.e three days after conception), each
a
Department of Obstetrics and Gynaecology, St. Peter's General Hospital, Surrey, UK b Department of Obstetrics and Gynaecology, University College Hospital, London, UK c Department of Obstetrics and Gynaecology, Basildon General Hospital, UK * Correspondence: Mr T. Giannopoulos, Department of Obstetrics and Gynaecology, St. Helier General Hospital, Wrythe Lane, Carshalton, Surrey SM5 1AA, UK. q RCOG 2001 British Journal of Obstetrics and Gynaecology PII: S03 06-5456(00)0018 6-8
Fig. 1. Photograph of the three umbilical cords with a single placenta and a single amniotic sac. www.bjog-elsevier.com
CASE REPORT 893
fetus will have its own placenta and sac (i.e. trichorionic, triamniotic). If division occurs a little later (i.e. four to eight days), the fetuses will share a single placenta but have separate sacs i.e., monochorionic, triamniotic. If division occurs even later (9-15 days) a monochorionic, monoamniotic gestation results. This late division of embryonic cells may explain the increased incidence of congenital abnormalities occurring in monoamniotic pregnancies 3±5. Other complications of monoamniotic pregnancies include the increased risk of preterm labour (due to the increased liquor volume) and cord accidents, mainly entanglement 6 and compression. There is also the risk of twin to twin transfusion as the fetuses share the same placenta. As a result, the perinatal mortality and morbidity rates are markedly higher in monoamniotic than in diamniotic pregnancies. The incidence of monoamniotic twins in the ®rst trimester is 1.1% to 2.1% of all twin pregnancies 7±9. The perinatal mortality rate is 26% to 50%, compared with 6% for diamniotic twins 10,11. Cord entanglement has been reported in up to 71% of monoamniotic twins and more than 50% of deaths are directly connected with this complication 12. Equivalent ®gures for higher order monoamniotic gestations do not exist, but a similar picture of increased risk is likely. Medical treatment in this case concentrated on frequent fetal surveillance with ultrasound scans and control of amniotic ¯uid volume. Reduction of amniotic ¯uid volume is likely to reduce the risk of preterm labour in monoamniotic multiple pregnancies. It may also help to prevent excessive fetal movements, thereby reducing the risk of cord entanglement and cord compression. This argument is supported by the observation that the risk of death attributable to cord accidents decreases after 32 weeks, when there is a relative reduction in amniotic ¯uid volume 13. In this case the parents were offered either serial amniodrainage or sulindac. They opted for sulindac, a non-steroidal anti-in¯ammatory drug used for the treatment of arthritis, which has been shown to decrease fetal urine output 14 and therefore amniotic ¯uid volume. Its use in monoamniotic twin pregnancies has previously been reported, where it was felt that the reduction in liquor volume might have reduced the risk of cord entanglement. Its bene®t, compared with indomethacin, is that it does not cause signi®cant constriction of the fetal ductus arteriosus 15,16, making long term use feasible. In this case of monoamniotic triplets, it appears to have brought about a signi®cant reduction in amniotic ¯uid volume, such that the drug could be discontinued at 25 weeks of gestation. With colour ¯ow Doppler it is possible to identify cord entanglement by following the two cords to the suspicious area where there may be `branching' of the umbilical vessels 17. Entanglement should also be suspected in the presence of unprovoked decelerations q RCOG 2001 Br J Obstet Gynaecol 108, pp. 892±894
on an ante-partum cardiotocograph. Entanglement on its own is not necessarily an indication for immediate delivery but rather may suggest the need for intensive fetal surveillance 18 (e.g. umbilical artery velocity waveform, frequent fetal heart rate monitoring, biophysical pro®le), although there is no de®nite evidence that this will improve outcome. It has been suggested that in the presence of cord entanglement, deterioration of the umbilical artery velocity waveform detected by Doppler ultrasound may be useful in planning the timing of delivery 19. Given the marked entanglement of the three cords, it is perhaps fortunate that none of the fetuses was adversely affected. At the time of publication, all three babies are doing well. References 1. Kurtz AB, Wapner RJ, Mata J, Johnson A, Morgan P. Twin pregnancies: accuracy of ®rst trimester abdominal ultrasound in predicting chorionicity and amnionicity. Radiology 1992;185:759±762. 2. Machin GA, Bamforth F. Zygosity and placental anatomy in 15 consecutive sets of spontaneously conceived triplets. Am J Med Gen 1996;61:247±252. 3. Healey MG. Acardia. Predictive risk factors for the co-twin's survival. Teratology 1994;50:205±213. 4. Berry SA, Johnson DE, Thompson TR. Agenesis of the penis, scrotal raphe and anus in one of monoamniotic twins. Teratology 1984;29:173±176. 5. Yoshida K, Soma H. A study of twin placentation in Tokyo. Acta Genet Med Gemell 1984;33:115±120. 6. Dorum A, Nesheim BI. Monochorionic monoamniotic twins. The most precarious of twin pregnancies. Acta Obstet Gynecol Scand 1991;70:381±383. 7. Hill LM, Cheveney P, Hecker J, Martin JG. Sonographic deternination of ®rst trimester twin chorionicity and amnionicity. J Clin Ultrsounda 1996;24:305±308. 8. Lumme RH, Saarikoski SV. Monoamniotic twin pregnancy. Acta Genet Med Gemell 1986;35:99±105. 9. Watson WJ, Valea FA, Seeds JW. Sonographic evaluation of growth discordance and chorionicity in twin gestation. Am J Perinatol 1991;8:342±344. 10. Harrison SD, Cyr DR, Patten RM, Mack LA. Twin growth problems: causes and sonographic analysis. Seminars in Ultrasound 1993;14:56± 57. 11. Tessen JA, Zlatnik FJ. Monoamniotic twins. A retrospective controlled study. Obstet Gynecol 1991;77:832±834. 12. Hart I, Daw E. Monoamniotic twin pregnancy with entanglement of the umbilical cords, but no fetal heart abnormality. J Obstet Gynaecol 1991;11:347±348. 13. Carr SR, Aronson MP, Coustan DR. Survival rates of monoamniotic twins do not decrease after 30 weeks gestation. Am J Obstet Gynecol 1990;163:719±722. 14. Peek MJ, Macarthy A, Kyle P, Sepulveda W, Fisk NM. Medical amnioreduction with sulindac to reduce cord complications in monoamniotic twins. Am J Obstet Gynecol 1997;176:334±336. 15. Rasanen J, Jouppila P. Fetal cardiac function and ductus arteriosus during indomethacin and sulindac for the treatment of refractory preterm labour: a randomised study. Am J Obstet Gynecol 1995;173:20±25. 16. Carlan SJ, Brien WF, Leary TD, Mastrogiannis D. Randomised controlled trial of indomethacin and sulindac for the treatment of refractory preterm labour. Obstet Gynaecol 1992;79:223±228. 17. Belfort MA, Moise KJ, Kirshon B, Saade G. The use of color ¯ow
894 CASE REPORT ultrasonography to diagnose umbilical cord entanglement in monoamniotic twin gestations. Am J Obstet Gynecol 1993;168:601± 604. 18. Annan B, Hutson RC. Double survival despite cord entwinement. Br J Obstet Gynaecol 1990;97:950±951.
19. Abuhamad AZ, Mari G, Copel GA, Cantwell CJ, Evans AT. Umbilical artery velocity waveforms in monoamniotic twins with cord entanglement. Obstet Gynaecol 1992;185:759±762. Accepted 7 February 2001
q RCOG 2001 Br J Obstet Gynaecol 108, pp. 892±894
CASE REPORT
Successful delivery of monoamniotic triplets Theodoros Giannopoulos a,*, Patrick O'Brien b, Rajiv Varma c Case report A 27 year old woman booked at 12 weeks of gestation in her ®rst pregnancy which was conceived spontaneously. A booking scan diagnosed a monochorionic monoamniotic triplet pregnancy, and serial weekly ultrasound scans were arranged to monitor this potentially high risk pregnancy. An ultrasound scan at 16 weeks showed marked entanglement of all three umbilical cords. At 17 weeks a repeat scan suggested twin to twin transfusion, one of the fetuses being larger than the others. The risk of polyhydramnios was discussed with the parents, and they were offered either serial amniodrainage or sulindac (Clinoril, APS, Generics) as a preventative measure. They opted for sulindac; this was started at a dose of 400 mg orally daily. Subsequent scans demonstrated good growth of all three fetuses, mild polyhydramnios and mild twin to twin transfusion involving two of the fetuses. No structural abnormalities were identi®ed and the Doppler indices remained normal. The sulindac was stopped at 25 weeks of gestation as the amniotic ¯uid volume was reduced. At the same time, dexamethasone injections were started (two injections of 12 mg intramuscularly once a week). During the following weeks the fetuses grew along the 5th to 10th centiles with normal growth velocities and the amniotic ¯uid volume remained within normal limits. Delivery by elective caesarean section was planned for 34 weeks of gestation. AT 33 weeks of gestation, however, the mother was admitted to the labour ward with a history of spontaneous rupture of the membranes and onset of regular contractions. The cervix was 4cm dilated, and an emergency caesarean section was carried out without delay.
The ®rst triplet was delivered cephalic, the other two as breech. There was dif®culty in delivering the second and third babies due to marked cord and limb entanglement. The babies' weights were 1430, 1490 and 1410 g, respectively, and all were structurally normal. They required admission to the neonatal intensive care unit for 11 days, but all three were well on discharge. Their renal function remained normal throughout their admission. Histological examination con®rmed a single placenta and a single amniotic sac Fig. 1 .
Discussion Successful delivery of live monoamniotic triplets has never previously been reported. Indeed, there is no record in the literature of monoamniotic triplets even with a less favourable outcome. Consequently, the incidence of this condition, even in early gestation, is unknown, but it is likely to be very rare. Although the sonographic diagnosis of amnionicity can be dif®cult 1, even with twins, in this case it was correctly diagnosed at 13 weeks of gestation. Most triplets are trizygotic because they result from assisted conception. In one study of spontaneously conceived triplets the incidence of monozygosity was 40%, but no case was monoamniotic 2. Monoamniotic fetuses are always monochorionic (i.e. share the same placenta, and therefore are of the same sex). In monozygotic triplet pregnancies, if division occurs early, (i.e three days after conception), each
a
Department of Obstetrics and Gynaecology, St. Peter's General Hospital, Surrey, UK b Department of Obstetrics and Gynaecology, University College Hospital, London, UK c Department of Obstetrics and Gynaecology, Basildon General Hospital, UK * Correspondence: Mr T. Giannopoulos, Department of Obstetrics and Gynaecology, St. Helier General Hospital, Wrythe Lane, Carshalton, Surrey SM5 1AA, UK. q RCOG 2001 British Journal of Obstetrics and Gynaecology PII: S03 06-5456(00)0018 6-8
Fig. 1. Photograph of the three umbilical cords with a single placenta and a single amniotic sac. www.bjog-elsevier.com
CASE REPORT 893
fetus will have its own placenta and sac (i.e. trichorionic, triamniotic). If division occurs a little later (i.e. four to eight days), the fetuses will share a single placenta but have separate sacs i.e., monochorionic, triamniotic. If division occurs even later (9-15 days) a monochorionic, monoamniotic gestation results. This late division of embryonic cells may explain the increased incidence of congenital abnormalities occurring in monoamniotic pregnancies 3±5. Other complications of monoamniotic pregnancies include the increased risk of preterm labour (due to the increased liquor volume) and cord accidents, mainly entanglement 6 and compression. There is also the risk of twin to twin transfusion as the fetuses share the same placenta. As a result, the perinatal mortality and morbidity rates are markedly higher in monoamniotic than in diamniotic pregnancies. The incidence of monoamniotic twins in the ®rst trimester is 1.1% to 2.1% of all twin pregnancies 7±9. The perinatal mortality rate is 26% to 50%, compared with 6% for diamniotic twins 10,11. Cord entanglement has been reported in up to 71% of monoamniotic twins and more than 50% of deaths are directly connected with this complication 12. Equivalent ®gures for higher order monoamniotic gestations do not exist, but a similar picture of increased risk is likely. Medical treatment in this case concentrated on frequent fetal surveillance with ultrasound scans and control of amniotic ¯uid volume. Reduction of amniotic ¯uid volume is likely to reduce the risk of preterm labour in monoamniotic multiple pregnancies. It may also help to prevent excessive fetal movements, thereby reducing the risk of cord entanglement and cord compression. This argument is supported by the observation that the risk of death attributable to cord accidents decreases after 32 weeks, when there is a relative reduction in amniotic ¯uid volume 13. In this case the parents were offered either serial amniodrainage or sulindac. They opted for sulindac, a non-steroidal anti-in¯ammatory drug used for the treatment of arthritis, which has been shown to decrease fetal urine output 14 and therefore amniotic ¯uid volume. Its use in monoamniotic twin pregnancies has previously been reported, where it was felt that the reduction in liquor volume might have reduced the risk of cord entanglement. Its bene®t, compared with indomethacin, is that it does not cause signi®cant constriction of the fetal ductus arteriosus 15,16, making long term use feasible. In this case of monoamniotic triplets, it appears to have brought about a signi®cant reduction in amniotic ¯uid volume, such that the drug could be discontinued at 25 weeks of gestation. With colour ¯ow Doppler it is possible to identify cord entanglement by following the two cords to the suspicious area where there may be `branching' of the umbilical vessels 17. Entanglement should also be suspected in the presence of unprovoked decelerations q RCOG 2001 Br J Obstet Gynaecol 108, pp. 892±894
on an ante-partum cardiotocograph. Entanglement on its own is not necessarily an indication for immediate delivery but rather may suggest the need for intensive fetal surveillance 18 (e.g. umbilical artery velocity waveform, frequent fetal heart rate monitoring, biophysical pro®le), although there is no de®nite evidence that this will improve outcome. It has been suggested that in the presence of cord entanglement, deterioration of the umbilical artery velocity waveform detected by Doppler ultrasound may be useful in planning the timing of delivery 19. Given the marked entanglement of the three cords, it is perhaps fortunate that none of the fetuses was adversely affected. At the time of publication, all three babies are doing well. References 1. Kurtz AB, Wapner RJ, Mata J, Johnson A, Morgan P. Twin pregnancies: accuracy of ®rst trimester abdominal ultrasound in predicting chorionicity and amnionicity. Radiology 1992;185:759±762. 2. Machin GA, Bamforth F. Zygosity and placental anatomy in 15 consecutive sets of spontaneously conceived triplets. Am J Med Gen 1996;61:247±252. 3. Healey MG. Acardia. Predictive risk factors for the co-twin's survival. Teratology 1994;50:205±213. 4. Berry SA, Johnson DE, Thompson TR. Agenesis of the penis, scrotal raphe and anus in one of monoamniotic twins. Teratology 1984;29:173±176. 5. Yoshida K, Soma H. A study of twin placentation in Tokyo. Acta Genet Med Gemell 1984;33:115±120. 6. Dorum A, Nesheim BI. Monochorionic monoamniotic twins. The most precarious of twin pregnancies. Acta Obstet Gynecol Scand 1991;70:381±383. 7. Hill LM, Cheveney P, Hecker J, Martin JG. Sonographic deternination of ®rst trimester twin chorionicity and amnionicity. J Clin Ultrsounda 1996;24:305±308. 8. Lumme RH, Saarikoski SV. Monoamniotic twin pregnancy. Acta Genet Med Gemell 1986;35:99±105. 9. Watson WJ, Valea FA, Seeds JW. Sonographic evaluation of growth discordance and chorionicity in twin gestation. Am J Perinatol 1991;8:342±344. 10. Harrison SD, Cyr DR, Patten RM, Mack LA. Twin growth problems: causes and sonographic analysis. Seminars in Ultrasound 1993;14:56± 57. 11. Tessen JA, Zlatnik FJ. Monoamniotic twins. A retrospective controlled study. Obstet Gynecol 1991;77:832±834. 12. Hart I, Daw E. Monoamniotic twin pregnancy with entanglement of the umbilical cords, but no fetal heart abnormality. J Obstet Gynaecol 1991;11:347±348. 13. Carr SR, Aronson MP, Coustan DR. Survival rates of monoamniotic twins do not decrease after 30 weeks gestation. Am J Obstet Gynecol 1990;163:719±722. 14. Peek MJ, Macarthy A, Kyle P, Sepulveda W, Fisk NM. Medical amnioreduction with sulindac to reduce cord complications in monoamniotic twins. Am J Obstet Gynecol 1997;176:334±336. 15. Rasanen J, Jouppila P. Fetal cardiac function and ductus arteriosus during indomethacin and sulindac for the treatment of refractory preterm labour: a randomised study. Am J Obstet Gynecol 1995;173:20±25. 16. Carlan SJ, Brien WF, Leary TD, Mastrogiannis D. Randomised controlled trial of indomethacin and sulindac for the treatment of refractory preterm labour. Obstet Gynaecol 1992;79:223±228. 17. Belfort MA, Moise KJ, Kirshon B, Saade G. The use of color ¯ow
894 CASE REPORT ultrasonography to diagnose umbilical cord entanglement in monoamniotic twin gestations. Am J Obstet Gynecol 1993;168:601± 604. 18. Annan B, Hutson RC. Double survival despite cord entwinement. Br J Obstet Gynaecol 1990;97:950±951.
19. Abuhamad AZ, Mari G, Copel GA, Cantwell CJ, Evans AT. Umbilical artery velocity waveforms in monoamniotic twins with cord entanglement. Obstet Gynaecol 1992;185:759±762. Accepted 7 February 2001
q RCOG 2001 Br J Obstet Gynaecol 108, pp. 892±894