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The First World Congress On: Controversies in Obstetrics, Gynecology & InfertilityPrague, Czech Republic - 1999
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The incidence of multifetal pregnancies has increased dramatically over the past two decades, mainly because of the widespread use of ovulation induction agents and assisted reproduction techniques. These techniques have been a matter of concern since twin and higher order pregnancies have long been associated with an increased risk of maternal complications as well as a high prevalence of prenatal and neonatal morbidity and mortality [1-5].
In the USA, between 1973 and 1990, twin births increased from 1 in 55 births to 1 in 40, and the rate of triplets and higher rose from 1 in 3323 to 1 in 1343 .
The procedure of multifetal pregnancy reduction has, in recent years, become both clinically and ethically accepted as a therapeutic option in pregnancies with four or more fetuses ([7-16] and in multifetal pregnancies in which one or more of the fetuses has congenital abnormalities [8,17]. In cases of triplet gestations, however, this option remains controversial [7, 13,14, 16, 18-20]. Reports of the improving outcome of triplet pregnancies [21,22], the failure to demonstrate an improvement in the outcome of triplet pregnancies reduced to twins as compared with those managed expectantly [18,19], and the procedure-related risk of losing the entire pregnancy [13,24] have complicated the clinical and ethical discussion surrounding this procedure in triplet gestations.
Consideration of the clinical options and the ethical issues involved in the management of triplet or higher order gestations should include the probability of achieving a successful pregnancy outcome if an expectant management policy is undertaken. Dickey et al.  reported that when three viable embryos were diagnosed at first trimester ultrasound, the probability of delivering triplets and twins was 68.4 and 21%, respectively. This outcome was influenced by the chronological age of the mother.
The pregnancy loss subsequent to fetal reduction has been reported as ranging from O to 40% . However, in recent reports the reduction of triplets to twins resulted in a fairly consistent fetal loss of 6-8% [10,13,16, 19].
Several methods of multifetal pregnancy reduction have been proposed. Some authors have used transcervical aspiration of the gestational sac [26,27]. This method, however, was thought to be associated with an increased incidence of fetal loss due to infection caused by introduction of bacteria from the cervix, or due to cervical incompetence brought about by cervical dilatation .
Fetal reduction very early in gestation (6 to 8 weeks) by the transvaginal puncture and embryo aspiration also reported with fairly good pregnancy outcome. However, this method might have some theoretical limitations, such as, (1) using general anesthesia, (2) the possibility of spontaneous fetal reduction at this stage of gestation, (3) the inability to perform early fetal screening, such as, nuchal translucency test, which is done later on in pregnancy, and (4) the possibility of increasing infections. Multifetal pregnancy reduction using intrathoracic injection of potassium chloride, by both the transabdominal and the transvaginal approaches, has been reported [7,8, 10, 13-16,23,26,27]. No method has yet been proven to be superior to the others [14, 16].
Although several techniques ofMPR have been reported, however, the most popular is the intrathoracic inj action of potassium chloride by the transabdominal approach at 10-12 weeks gestation. It has been reported that MPR performed at later weeks of pregnancy may be accompanied by increased risk of pregnancy loss IfMPR, performed at around 14 weeks gestation, is not accompanied by greater risk to the pregnancy, it is logical to perform a detailed ultrasonographic fetal anomaly scan prior to the reduction This will allow the reduction to be performed more selectively and will decrease the chance of delivery of a chromosomal or structurally abnormal fetus.
1. Gonen R, Heyman E, Asztalos EV, et al. The outcome of triplet, quadruplet and quintuplet pregnancies managed in a perinatal unit: obstetric neonatal and follow-up data Am J Obstet Gynecol 162:454-459,1990
2. Ron-El R, Caspi E, Schreyer P, et al. Triplet and quadruplet pregnancies and management. Obstet Gynecol 57:458-463,1981
3. Holcberg G, Biale Y, Lewenthal H, Insler V Outcome of pregnancy in 31 trplet gestations Obstet Gynecol 59:472-476, 1982
4. Loucopoulos A, Jewelewicz R Management of multifetal pregnancies: sixteen years’ experience at the Sloane Hospital for Women. Am j Obstet Gynecol 143:902-905, 1982
5. Deale CJC, Cronje HS. A review of 367 triplet pregnancies. S Afr Med J 66:92-94.1984
6. Luke B The changing pattern of multiple births in the United States: maternal and infant characteristics, 1973-1990 Obstet Gynecol 84:101-106,1994
7. Berkowitz RL, Lynch, L, Chitkara U, et al. Selective reduction of multifetal pregnancies in the first trimester. N Engl J Med 318:1043-1047, 1988.
8. Wapner RJ, Davis G, Johnson A et al. Selective reduction of multifetal pregnancies. Lancet 335:90-93,1990
9. Evans JI, Fletcher JC, Zador IE, et al. Selective first trimester termination in octuplet and quadruplet pregnancies: clinical and ethical issues. Obstet Gynecol 71:289-296,1988
10. Lynch L, Berkowitz RL, Chitkara U, et al. First trimester transabdominal multifetal pregnancy reduction: a report of 85 cases. Obstet Gynecol 75:735-738,1990
11. Evans MI, May M, Drugan A, et al. Selective termination: clinical experience and residual risks. Am J Obstet Gynecol 162:1568-1575,1990
12. Dommergues M, Nisand I, Mandelbrot L, et al. Embryo reduction in multifetal pregnancies after infertility therapy: obstetrical risks and perinatal benefits are related to operative strategy Fertil Steril 55:805-811,1991
13. Berkowitz RL, Lynch L, Lapinski R, Bergh P First trimester transabdominal multifetal pregnancy reduction: a report of two hundred completed cases. Am J Obstet Gynecol 169:17-21,1993
14. Timor-Tritsch IE, Peisner DB, Monteagudo A, et al. Multifetal pregnancy reduction by transvaginal puncture: evaluation of the technique used in 134 cases. Am J Obstet Gynecol 168:799-804, 1993
15. Evans MI, Dommergues M, Wapner RJ, et al. Efficacy of transabdominal multifetal pregnancy reduction: collaborative experience among the world’s largest centers. Obstet Gynecol 82:61-62, 1993
16. Evans MI, Dommergues M, Timor-Tritsch I, et al. Trasnabdominal versus transcervical and transvaginal multifetal pregnancy reduction: international collaborative experience of more than one thousand cases. Am J Obstet Gynecol 170:902-909, 1994
17. American College of Obstetrics & Gynecology. Multifetal pregnancy reduction and selective fetal termination ACOG Committee Opinion 94:,1991
18. Melgar CA, Rosenfeld DL, Rawlinson K, Greenberg M. Perinatal outcome after multifetal reduction to twins compared with nonreduced multiple gestations. Obstet Gynecol 78:763-767,1991.
19. Porreco RP, Burjke MS, Hendrix ML. Multiple reduction of triplets and pregnancy outcome. Obstet Gynecol 78:135-339, 1991.
20. Vauthier-Brouzes D, Lefebvre G. Selective reduction in multifetal pregnancies: technical and psychological aspects Fertil Steril 57:1012-1016,1992
21. Lipitz S, Reichman B, Paret G, et al. The improving outcome of triplet pregnancies. Am J Obstet Gynecol 161:1279-1284,1989.
22. Newman RE, Hamer C, Miller MC Outpatient triplet management: a contemporary review. Am J Obstet Gynecol 161:547-555, 1989
23. Shalev J, Frenkel Y, Goldenberg M, et al. Selective reduction in multiple gestations: pregnancy outcome after transvaginal and transabdominalneedle-guided procedures. Fertil Steril 52:416-420, 1989.
24. Dickey RP, Olar TT, Curole DN, et at. The probability of mulitple births when multiple gestational sacs or viable embryos are diagnosed at first trimester ultrasound. Hum Reprod 5:880-882,1990
25. Itskovitz-Eldor J, Fmgan A, Levron J, et al. Transvaginal embryo aspiration a safe method for selective reduction in multiple pregnancies. Fertil Steril 58:351-355,1992.
26. Salat-Baroux J, Aknin J, Antoine JM, et al. The management of multiple pregnancies after induction for superovulation. Hum Reprod 3:399-401,1988
27. Itskovitz J, Roldes R, Thaler I, et al. First trimester selective reduction in multiple pregnancy guided by transvaginal sonography. J Clin Ultrasound 18:323-327,1990.