682
Letters
Survival in a fetus with sacrococcygeal teratoma and hydrops To the Editors: Langer et al. (Langer JC, Harrison MR,
Schmidt KG, et al. Fetal hydrops and death from sacrococcygeal teratoma: Rationale for fetal surgery. AM J OBSTET GYNECOL 1989; 160: 1145-50) reported on three fetuses with sacrococcygeal teratoma and hydrops, a combination of findings with a high rate of perinatal death. lOne of the three underwent resection of the tumor at 24 weeks and was returned to the uterus. Hydrops resolved and cardiac output decreased, based on echocardiographic and Doppler measurements. From their experience the authors recommended that fetal surgery may prove to be the most effective treatment for fetuses with sacrococcygeal teratoma and hydrops. We recently treated two newborn infants with sacrococcygeal teratoma and hydrops without fetal surgery, and both survived. Detailed descriptions are to be published! They were born at 30 and 33 weeks and thus were more mature than those in the study of Langer et al. The latter infant had severe respiratory insufficiency despite maximal ventilatory support and vasodilator infusions, and oliguric acute renal failure. Removal of the tumor on the second day of life led to an immediate improvement in respiratory function, with Pao2 increasing from 48 mm Hg with use of 100% oxygen to 253 to 357 mm Hg intraoperatively. This allowed a decrease in the FI0 2 to 0.45 by the first postoperative day and extubation on the tenth day. Renal function returned in a pattern typical of recovery from acute tubular necrosis. The former case, delivered at 30 weeks, also had respiratory insufficiency that improved after surgery. Both infants are presently alive and without neurologic, pulmonary, or renal sequelae. We therefore agree with the assertion of Langer et al. that cardiopulmonary physiology improves after tumor resection. However, affected infants born as early as 30 weeks can survive without intrauterine tumor removal. Allowing gestation (and thus fetal lung maturation) to continue constitutes an alternative to fet 11 surgery for affected fetuses closer to term (28 to 30 weeks). However, the combination of a sacrococcygeal teratoma and hydrops reflects severe physiologic instability; fetal death is an ever-present risk. 1 A delay in tumor resection to allow further lung maturation may result in stillbirth. One of the fetuses of Langer et al. died the day before planned fetal surgery; we were able to delay 3 weeks in a fetus of later gestation (21 vs 30 weeks). If fetal surgery has a role in sacrococcygeal teratoma, we suggest that it may be indicated in fetuses with hydrops detected before 28 weeks. Don K. Nakayama, MD Children's Hospital of Pittsburgh, One Childrens Place, 3705 Fifth Ave. at DeSoto St., Pittsburgh, PA 15213-2583
REFERENCES 1. Flake AW, Harrison MR, Adzick NS, et al. Fetal sacrococcygeal teratoma. J Pediatr Surg 1986;21 :563-6. 2. Nakayama DK, Killian A, Hill LM, et al. The newborn with hydrops and sacrococcygeal teratoma. J Pediatr Surg [In press]. Response declined
August 1990 Am J Obstet Gynecol
Ascertainment bias in diabetic outcome data To the Editors: Drs. Damm and Molsted-Petersen have retrospectively studied a group of infants born to mothers with diabetes in an effort to determine a trend in the rate of congenital malformation (Damm P, M~lsted Petersen L. Significant decrease in congenital malformation in newborn infants of an un selected population of diabetic women. AM J OBSTET GYNECOL 1989; 161: 1163-7). They found that this rate has decreased, particularly over the last 5 years, and ascribe this improvement in outcome to better control of maternal diabetes. However, ascertainment bias may have seriously compromised their findings. The study group was identified through the records of infants born after 26 weeks' gestation. Therefore if a mother with diabetes was found to have a fetus with a congenital anomaly in the second trimester and elected to have a termination, this case would be missed according to the methodology described by the authors. Prenatal diagnostic procedures, particularly ultrasonography and maternal serum a-fetoprotein testing, have become more widely used over the time period under study, pnd the sensitivity and accuracy of ultrasound examination for congenital anomalies has improved significantly. It appears possible that the authors have documented the enlarging role of prenatal diagnosis in the care of diabetic women and the subsequent termination of anomalous fetuses. The authors state that the "decline in congenital malformations was not due to an increased rate of induced abortions." However, no data are presented to support this statement. Indeed, a change in the overall rate of induced abortion would not necessarily be expected because improved diagnostic techniques have allowed for more selective use of termination. The authors may certainly conclude from their study that the risk of delivering a child with a congenital defect has decreased in their sample. However, the question remains as to whether this finding results from a decreased frequency of anomalies because of better metabolic control or from improved detection because of advances in second-trimester fetal diagnosis. Jack FitzSimmons, MD, and Susan Davidson, MD Department of Obstetrics and Gynecology, University of WisconsinMadison Medical School, H4/654 Clinical Science Center, 600 Highland Ave., Madison, WI 53792
Reply
To the Editors: We welcome the opportunity to respond to the relevant comments of Drs. FitzSimmons and Davidson. The primary goal of our study was to investigate the incidence of congenital malformations in infants delivered by mothers with diabetes. We therefore decided only to consider infants born after 26 weeks' gestation. Drs. FitzSimmons and Davidson speculate that this cutoff point leads us to miss malformations diagnosed by antenatal screening and followed by termination in the second trimester. Furthermore, they hypothesize that the demonstrated decline in congenital malformations could be caused by better antenatal
Letters
Survival in a fetus with sacrococcygeal teratoma and hydrops To the Editors: Langer et al. (Langer JC, Harrison MR,
Schmidt KG, et al. Fetal hydrops and death from sacrococcygeal teratoma: Rationale for fetal surgery. AM J OBSTET GYNECOL 1989; 160: 1145-50) reported on three fetuses with sacrococcygeal teratoma and hydrops, a combination of findings with a high rate of perinatal death. lOne of the three underwent resection of the tumor at 24 weeks and was returned to the uterus. Hydrops resolved and cardiac output decreased, based on echocardiographic and Doppler measurements. From their experience the authors recommended that fetal surgery may prove to be the most effective treatment for fetuses with sacrococcygeal teratoma and hydrops. We recently treated two newborn infants with sacrococcygeal teratoma and hydrops without fetal surgery, and both survived. Detailed descriptions are to be published! They were born at 30 and 33 weeks and thus were more mature than those in the study of Langer et al. The latter infant had severe respiratory insufficiency despite maximal ventilatory support and vasodilator infusions, and oliguric acute renal failure. Removal of the tumor on the second day of life led to an immediate improvement in respiratory function, with Pao2 increasing from 48 mm Hg with use of 100% oxygen to 253 to 357 mm Hg intraoperatively. This allowed a decrease in the FI0 2 to 0.45 by the first postoperative day and extubation on the tenth day. Renal function returned in a pattern typical of recovery from acute tubular necrosis. The former case, delivered at 30 weeks, also had respiratory insufficiency that improved after surgery. Both infants are presently alive and without neurologic, pulmonary, or renal sequelae. We therefore agree with the assertion of Langer et al. that cardiopulmonary physiology improves after tumor resection. However, affected infants born as early as 30 weeks can survive without intrauterine tumor removal. Allowing gestation (and thus fetal lung maturation) to continue constitutes an alternative to fet 11 surgery for affected fetuses closer to term (28 to 30 weeks). However, the combination of a sacrococcygeal teratoma and hydrops reflects severe physiologic instability; fetal death is an ever-present risk. 1 A delay in tumor resection to allow further lung maturation may result in stillbirth. One of the fetuses of Langer et al. died the day before planned fetal surgery; we were able to delay 3 weeks in a fetus of later gestation (21 vs 30 weeks). If fetal surgery has a role in sacrococcygeal teratoma, we suggest that it may be indicated in fetuses with hydrops detected before 28 weeks. Don K. Nakayama, MD Children's Hospital of Pittsburgh, One Childrens Place, 3705 Fifth Ave. at DeSoto St., Pittsburgh, PA 15213-2583
REFERENCES 1. Flake AW, Harrison MR, Adzick NS, et al. Fetal sacrococcygeal teratoma. J Pediatr Surg 1986;21 :563-6. 2. Nakayama DK, Killian A, Hill LM, et al. The newborn with hydrops and sacrococcygeal teratoma. J Pediatr Surg [In press]. Response declined
August 1990 Am J Obstet Gynecol
Ascertainment bias in diabetic outcome data To the Editors: Drs. Damm and Molsted-Petersen have retrospectively studied a group of infants born to mothers with diabetes in an effort to determine a trend in the rate of congenital malformation (Damm P, M~lsted Petersen L. Significant decrease in congenital malformation in newborn infants of an un selected population of diabetic women. AM J OBSTET GYNECOL 1989; 161: 1163-7). They found that this rate has decreased, particularly over the last 5 years, and ascribe this improvement in outcome to better control of maternal diabetes. However, ascertainment bias may have seriously compromised their findings. The study group was identified through the records of infants born after 26 weeks' gestation. Therefore if a mother with diabetes was found to have a fetus with a congenital anomaly in the second trimester and elected to have a termination, this case would be missed according to the methodology described by the authors. Prenatal diagnostic procedures, particularly ultrasonography and maternal serum a-fetoprotein testing, have become more widely used over the time period under study, pnd the sensitivity and accuracy of ultrasound examination for congenital anomalies has improved significantly. It appears possible that the authors have documented the enlarging role of prenatal diagnosis in the care of diabetic women and the subsequent termination of anomalous fetuses. The authors state that the "decline in congenital malformations was not due to an increased rate of induced abortions." However, no data are presented to support this statement. Indeed, a change in the overall rate of induced abortion would not necessarily be expected because improved diagnostic techniques have allowed for more selective use of termination. The authors may certainly conclude from their study that the risk of delivering a child with a congenital defect has decreased in their sample. However, the question remains as to whether this finding results from a decreased frequency of anomalies because of better metabolic control or from improved detection because of advances in second-trimester fetal diagnosis. Jack FitzSimmons, MD, and Susan Davidson, MD Department of Obstetrics and Gynecology, University of WisconsinMadison Medical School, H4/654 Clinical Science Center, 600 Highland Ave., Madison, WI 53792
Reply
To the Editors: We welcome the opportunity to respond to the relevant comments of Drs. FitzSimmons and Davidson. The primary goal of our study was to investigate the incidence of congenital malformations in infants delivered by mothers with diabetes. We therefore decided only to consider infants born after 26 weeks' gestation. Drs. FitzSimmons and Davidson speculate that this cutoff point leads us to miss malformations diagnosed by antenatal screening and followed by termination in the second trimester. Furthermore, they hypothesize that the demonstrated decline in congenital malformations could be caused by better antenatal
