- Email: [email protected]
Twins conceived through in vitro fertilization
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Letters to the Editors
thus providing further confirmation of the effectiveness of the percutaneous laser coagulation. Second, and in contrast to our study, De Lia’s paper does not give any details either on the methods and tests applied for follow-up, or on the investigators who performed these examinations. In our study, all survivors were prospectively investigated with standardized tests and by an experienced team. Furthermore, it is important to note that the youngest age at follow-up was 14 (median: 21) months in our group, while it was only 1 (median: 14) month in De Lia’s group, and it is well known that neurologic deficiencies may still be missed at that age. Kurt Hecher, MD* Corinna Banek, MD Peter Bartmann, MD
*Dept. of Prenatal Diagnosis and Therapy Barmbek Hospital, Rubenkamp 148 Hamburg 22291, Germany
References 1. Ville Y, Hecher K, Ogg D, Warren R, Nicolaides K. Successful outcome after Nd:YAG laser separation of chorioangiopagus-twins under sonoendoscopic control. Ultrasound Obstet Gynecol 1992;2: 429-31. 2. De Lia JE, Kuhlmann RS, Lopez KP. Treating previable twin-twin transfusion syndrome with fetoscopic laser surgery: outcomes following the learning curve. J Perinat Med 1999;27:61-7. 3. Senat MV, Bernard JP, Loizeau S, Ville Y. Management of single fetal death in twin-to-twin transfusion syndrome: a role for fetal blood sampling. Ultrasound Obstet Gynecol 2002;20:360-3.
0002-9378/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.ajog.2003.11.013
Twins conceived through in vitro fertilization To the Editors: In their informative article ‘‘Pregnancy outcome in spontaneous twins versus twins who were conceived through in vitro fertilization,’’ Nassar et al1 did not consider the possibility that some in vitro fertilization (IVF) twins may have originally been triplet or higher-order gestations that spontaneously reduced to twin gestations. In a retrospective analysis of the incidence of spontaneous reduction in multiple pregnancy we found that 19% of IVF twins and 9% of IVF singletons had started pregnancy as triplet or quadruplet gestations.2 A similar incidence of spontaneous reduction occurred in pregnancies resulting from ovulation induction without IVF. Compared with babies that had started as twin gestations, babies of twin pregnancies that had started as triplet gestations delivered an average 4 days earlier and weighed an average of 119 g less. Those that started as quadruplet gestations delivered an average 11 days earlier and weighed an average of 429 g less. The differences were significant. We would be interested to know if the outcome differences between spontaneous twins and IVF twins observed by the authors would still be present if pregnancies that started as triplet or higher order gestations were evaluated separately from IVF twin gestations that started as twins. As the authors amply 0002-9378/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.ajog.2003.11.011
demonstrate, IVF twin pregnancies are at increased risk of premature delivery and low birth weight. However, obstetricians managing any pregnancies in which there are initially 3 or more gestations, which later are spontaneously reduced to singleton or twin gestations, need to be aware that such pregnancies may deliver earlier and at lower birth weight than expected. Richard P. Dickey, MD, PhD* Peter Y. Lu, MD Belinda M. Sartor, MD *The Fertility Institute of New Orleans 6020 Bullard Avenue New Orleans, LA 70128USA E-mail: [email protected]
References 1. Nassar AH, Usta IM, Rechdan JB, Harb TS, Adra AM, Abu-Musa AA. Pregnancy outcome in spontaneous twins versus twins who were conceived through in vitro fertilization. Am J Obstet Gynecol 2003;189:513-8. 2. Dickey RP, Taylor SN, Lu PY, Sartor BM, Storment JM, Rye PH, et al. Spontaneous reduction of multiple pregnancy: incidence and effect on outcome. Am J Obstet Gynecol 2002;186:77-83.
Letters to the Editors
thus providing further confirmation of the effectiveness of the percutaneous laser coagulation. Second, and in contrast to our study, De Lia’s paper does not give any details either on the methods and tests applied for follow-up, or on the investigators who performed these examinations. In our study, all survivors were prospectively investigated with standardized tests and by an experienced team. Furthermore, it is important to note that the youngest age at follow-up was 14 (median: 21) months in our group, while it was only 1 (median: 14) month in De Lia’s group, and it is well known that neurologic deficiencies may still be missed at that age. Kurt Hecher, MD* Corinna Banek, MD Peter Bartmann, MD
*Dept. of Prenatal Diagnosis and Therapy Barmbek Hospital, Rubenkamp 148 Hamburg 22291, Germany
References 1. Ville Y, Hecher K, Ogg D, Warren R, Nicolaides K. Successful outcome after Nd:YAG laser separation of chorioangiopagus-twins under sonoendoscopic control. Ultrasound Obstet Gynecol 1992;2: 429-31. 2. De Lia JE, Kuhlmann RS, Lopez KP. Treating previable twin-twin transfusion syndrome with fetoscopic laser surgery: outcomes following the learning curve. J Perinat Med 1999;27:61-7. 3. Senat MV, Bernard JP, Loizeau S, Ville Y. Management of single fetal death in twin-to-twin transfusion syndrome: a role for fetal blood sampling. Ultrasound Obstet Gynecol 2002;20:360-3.
0002-9378/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.ajog.2003.11.013
Twins conceived through in vitro fertilization To the Editors: In their informative article ‘‘Pregnancy outcome in spontaneous twins versus twins who were conceived through in vitro fertilization,’’ Nassar et al1 did not consider the possibility that some in vitro fertilization (IVF) twins may have originally been triplet or higher-order gestations that spontaneously reduced to twin gestations. In a retrospective analysis of the incidence of spontaneous reduction in multiple pregnancy we found that 19% of IVF twins and 9% of IVF singletons had started pregnancy as triplet or quadruplet gestations.2 A similar incidence of spontaneous reduction occurred in pregnancies resulting from ovulation induction without IVF. Compared with babies that had started as twin gestations, babies of twin pregnancies that had started as triplet gestations delivered an average 4 days earlier and weighed an average of 119 g less. Those that started as quadruplet gestations delivered an average 11 days earlier and weighed an average of 429 g less. The differences were significant. We would be interested to know if the outcome differences between spontaneous twins and IVF twins observed by the authors would still be present if pregnancies that started as triplet or higher order gestations were evaluated separately from IVF twin gestations that started as twins. As the authors amply 0002-9378/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.ajog.2003.11.011
demonstrate, IVF twin pregnancies are at increased risk of premature delivery and low birth weight. However, obstetricians managing any pregnancies in which there are initially 3 or more gestations, which later are spontaneously reduced to singleton or twin gestations, need to be aware that such pregnancies may deliver earlier and at lower birth weight than expected. Richard P. Dickey, MD, PhD* Peter Y. Lu, MD Belinda M. Sartor, MD *The Fertility Institute of New Orleans 6020 Bullard Avenue New Orleans, LA 70128USA E-mail: [email protected]
References 1. Nassar AH, Usta IM, Rechdan JB, Harb TS, Adra AM, Abu-Musa AA. Pregnancy outcome in spontaneous twins versus twins who were conceived through in vitro fertilization. Am J Obstet Gynecol 2003;189:513-8. 2. Dickey RP, Taylor SN, Lu PY, Sartor BM, Storment JM, Rye PH, et al. Spontaneous reduction of multiple pregnancy: incidence and effect on outcome. Am J Obstet Gynecol 2002;186:77-83.