ated with elevated histamine levels. This patient was able to carry a pregnancy to term using multiple toco• lytics and antihistamines.
References 1. Carter OM, O'Keeffe EJ. Hereditary cutaneous disorders. In: Mos• cheller SL, Hurley HJ, eds. Dermatology. 3rd ed. Philadelphia: WB
Saunders, 1992:1364-7. 2. Cruz MA, Gonzalez C, Acevedo CG, Sepulveda WH, Rudolph MI. Effects of histamine and serotonin on the contractility of isolated pregnant and nonpregnant human myometrium. Gynecol OOOtet Invest 1989;28:1-4. 3. Horakova Z, Keisler HR, Beaven MA. Blood and urine histamine levels in normal and pathological states as measured by a radio• chemical assay. Clin Chem Acta 1977;79:447-56. 4. Oemis OJ, Walton MO, Higdon RS. Histaminuria in urticaria pigmentosa. Arch Oermatol 1961;83:127-38. 5. Dale HH, Laidlow PP. The physiological action of beta• iminazolylethylamine. J Physiol 1910;41:318-44.
POLYHYDRAMNIOS AND HYPERCALCEMIA ASSOCIATED WITH
6. Holinka CF, Gurpide E. Diamine oxidase activity in human decidua and endometrium. Am J Obstet Gynecol 1984;150:359-63. 7. Caldwell EJ. Carlson SE, Palmer SM, Rhodes PG. Histamine and ascorbic acid: A survey of women in labor at term and significantly before term. Int J Vitam Nutr Res 1988;58:318-25. Address reprint requests to:
James G. Donahue, MD Department of Obstetrics and Gynecology CI-134 Medical College of Georgia Augusta, GA 30912 Received April 29, 1994. Received in revised form August 1, 1994. Accepted August 15, 1994. Copyright © 1995 by The American College of Obstetricians and Gynecologists.
lying polyhydramnios in cases of congenital mesoblastic nephroma. Calcium levels should be monitored after deliv• ery, and prompt surgical removal of the tumor should be performed. (Obstet Gynecol 1995;85:815-7)
CONGENITAL MESOBLASTIC NEPHROMA: CASE REPORT AND A NEW APPRAISAL
T. Y. Fung, MBBS, MRCOG, Y. M. Hedy Fung, MBBS, MRCOG, P. C. Ng, MBChB, MRCP, DCH, C. K. Yeung, FRCS, FRACS, DCH, and M. Z. Allan Chang, PhD, FRCOG, FRACOG Background: Polyhydramnios and hypercalcemia are known complications of congenital mesoblastic nephroma. Hyper• calcemia has been shown to cause polyuria. Polyuria is believed to be the probable cause for the polyhydramnios, but the exact mechanism remains unknown. To our knowl• edge, this is the first reported case of a relationship between hypercalcemia and polyhydramnios. Case: A 26-year-old primigravida was diagnosed with congenital mesoblastic nephroma and polyhydramnios at 36 weeks' gestation. Neonatal hypercalcemia was detected im• mediately after delivery at 40 weeks' gestation. After re• moval of the nephroma, the calcium level normalized. Conclusion: Hypercalcemia may be the mechanism under-
From the Department of Obstetrics and Gynecology, Prince of Wales Hospital, Chinese University of Hong KDng, Shatin, Hong Kong. ~e would like to thank Dr. Louis Chow (Pathology Department, Prtn~e of Wales Hospital) for his assistance in reviewing the pathologic specimen.
VOL. 85, NO.5, PART 2, MAY 1995
Polyhydramnios, presumably reflecting fetal polyuria, is associated with congenital mesoblastic nephroma. We report a case of congenital mesoblastic nephroma associated with both polyhydramnios and hypercalce• mia. Based on a literature review, we believe that hypercalcemia is the underlying mechanism for the polyhydramnios. Case report A 26-year-old Chinese woman, graVida 2, para 1, presented at 33 weeks' gestation with a fundal height of 37 em. An ultrasound scan revealed normal fetal indices for the gesta• tion, and the four-quadrant amniotic fluid index (AFI) was only 10.2. Fetal morphology was considered to be normal. At 36 weeks, the fundal height was 45 cm, there was clinical evidence of polyhydramnios, and the AR was 20.0. A 5.4-em solid left renal tumor was detected in the fetus (Figure 1). The right fetal kidney was normal in size. Oral glucose tolerance test was also normal. At 38 weeks' gestation, the renal tumor increased in size to 7.6 em, and the AFI increased to 31.2. The patient began to have pressure symptoms from polyhydram• nios at 40 weeks' gestation; therefore, labor was induced. The maternal albumin-adjusted calcium before delivery was 10.6 mg/dL. A male infant weighing 4.385 kg was delivered vaginally. On examination, a large, finn, mobile mass was palpable in the left flank of the neonate's abdomen. Serial blood pressure measurements were nonnal. The initial neonatal albumin• adjusted serum calcium level was 12.6 mg/dL (normal range
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Flpre 1. Antenatal ultrasonogram of the fetull at 36 weeks. Transverse view through abdomen shows a lOUd mass that measures 5.4 an in diame• ter in the left rena1 fossa.
for cord blood and serum obtained 2 hours after delivery is 9.3-11.7 mg/dL and 8.8-11.3 mg/dL, respectively>. The albu• min-adjusted calcium level decreased spontaneously to 11.4 mg/dL at 18 hours and then further decreased to 10.3 mg/dL by 3 days (normal range for neonates at 24 hours is 7.8-10.0 mg/dL). The neonate tolerated feeding well, and there was no significant weight loss. A left nephrectomy on day 5 identified a solid tumor 10 x 8 x 8 em in the lower pole. Histology confirmed mesoblastic nephroma. The postoperative course was uncomplicated, and the calcium level returned to normal range.
Discussion Polyhydramnios in pregnancy can be idiopathic in origin because of underlying maternal causes or fetal anomalies. Of the latter, congenital mesoblastic nephroma associated with polyhydramnios has been reported,1 but not all cases were diagnosed antenatally by ultrasound scan.2-s Several causes, including polyuria and intestinal ob• struction, have been proposed to account for the poly• hydramnios associated with congenital mesoblastic nephroma. Polyuria is believed to be the more probable cause,1,2 but the exact mechanism remains unknown. In theory, an increase in fetal renal blood flow or a localized effect of the tumor could have accounted for the polyuria, especially because our patient's polyhy• dramnios increased with tumor size. However, fetal renal perfusion is not the only factor that could influ• ence the amniotic fluid volume as tubular reabsorption may playa more important role in the pathogenesis of polyhydramnios.6 On the other hand, any localized
816 Fung et aI
Congenita Mesoblastic Nephroma
effect of the renal tumor would have been compensated by the other kidney. Hypercalcemia has been shown to cause polyuria,7 and it may impair the ability of renal concentration by inhibiting active sodium chloride transport in Henle's loop, redistributing the medullary blood flow, and impairing vasopressin-facilitated water reabsorption in the collecting tubules. As a result, fetal hypercalcemia may cause polyuria in utero and then polyhydramnios. Impaired renal concentration leading to polyuria in the immediate neonatal period has been reported in cases of congenital mesoblastic nephroma, suggesting preex• isting fetal renal impairment before delivery.2 Serum calcium level was not mentioned in that report. We demonstrated neonatal hypercalcemia at delivery in this patient. Based on our experience and previously reported cases,8 we propose that fetal hypercalcemia may be the cause of polyhydramnios in congenital mesoblastic nephroma. The time of presentation and type of presenting symptoms of neonatal hypercalcemia may vary. There have been cases of presentation of neonatal hypercalce• mia as late as 2 weeks after delivery.s This phenomenon can be explained by the peculiar link between the physiology of maternal and fetal calcium during preg• nancy and after delivery. During pregnancy, the fetal calcium level is higher than the maternal level because of the presence of active transport. However, this mech• anism is removed immediately after delivery, which causes a decrease in neonatal calcium level. This de• crease may be further enhanced by adequate neonatal
Obstetrics & Gynecology
hydration. Therefore, the underlying mechanism caus• ing hypercalcemia may be masked by the physiologic changes during immediate neonatal period. Neonatal calcium may in fact return to the normal range for a varying period. Thus, the symptoms of neonatal hyper• calcemia may not be present for some time until the calcium level rises again. The severity of hypercalcemic symptoms depends on the serum calcium level. In severe cases, there can be a catastrophic presentation characterized by abdominal pain, intractable vomiting, profound weakness, dehy• dration, and rapid deterioration of renal function, lead• ing to coma and death. This may explain some of the unexpected deaths (six of six) reported in association with congenital mesoblastic nephroma and polyhy• dramnios when surgery was delayed.2-5 In these cases, the serum calcium level was not monitored. On the other hand, in the absence of polyhydramnios, the neonatal outcome of congenital mesoblastic nephroma was much better. There was only one death due to sepsis among 51 cases. 9 Therefore, in the absence of polyhydramnios and perhaps hypercalcemia, the neo• natal outcome appears to be better. Based on our case and the literature review, we believe that hypercalcemia may be the mechanism underlying polyuria and polyhydramnios in cases of congenital mesoblastic nephroma. Therefore, we pro• pose that the fetal renal tract be carefully evaluated in all patients with polyhydramnios. Prompt identification and surgical treatment of the renal tumor could help to avoid the potential detrimental effects of neonatal hy• percalcemia.
COARCTATION OF THE ABDOMINAL AORTA IN PREGNANCY: DIAGNOSIS BY MAGNETIC RESONANCE IMAGING
Donna Dizon-Townson, MD, Kevin P. Magee, MD, Diane M. Twickler, MD, and Susan M. Cox, MD Background: Coarctation of the aorta is rare, affecting one per 2000-3000 women. Abdominal coarctation is more com• monly identified in women than in men, but only two cases have been reported in pregnancy. Case: A 26-year-old woman was diagnosed with hypertenFrom the Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas.
VOL. 85, NO.5, PART 2, MAY 1995
References 1. Ohmichi M, Keiichi T, Nagatoshi 5, Shinkichi K, Toshimichi H, Osamu T. Hydramnios associated with congenital mesoblastic nephroma: Case report. Obstet Gynecol 1989;74:469-71. 2. Perlamn M, Potashnik G, Wise S. Hydramnion and fetal renal anomalies. Am J Obstet GynecoI1976;125:966-8. 3. Lason OM. Congenital mesoblastic nephroma. Am J Dis Child 1978;132:318-9. 4. Favara BE, Johnson W, Ito J. Renal tumors in the neonatal period. Cancer 1968;22:845-55. 5. Hans H. Wilms' tumor in a newborn infant. J Pediatr 1949;35:381-4. 6. Marl G, Kirshon B, Abuhamad A. Fetal renal artery flow velocity wavefonns in normal pregnancies and pregnancies complicated by polyhydramnios and oligohydramnios. Obstet Gynecol 1993;81: 560-4.
7. Goldfarb 5, Agus ZS. Mechanism of the polyuria of hypercalcaemia. Am J Nephrol 1984;4:69-76. 8. Jayabose 5, Iqbal K, Newman L, et al. Hypercalcaemia in childhood renal tumors. Cancer 1988;61:788-91. 9. Howell CG, Othersen HB, Kiviat NE, Norkool P, Beckwith JB, D' Angio GJ. Therapy and outcome in 51 children with mesoblastic nephroma: A report of the National Wilms' Tumor Study. J Pediatr Surg 1982;17:826-31. Address reprint requests to: Tak Yuen Fung, MD
Department of Obstetrics and Gynecology Prince of Wales Hospital Chinese University of Hong Kong Shotin Hong Kong Received May 13, 1994. Received in revised form July 19, 1994. Accepted July 26, 1994.
Copyright to 1995 by The American College of Obstetricians and Gynecologists.
sion at 15 years of age. Her blood pressure was controlled adequately with beta-blockers. During her pregnancy, she was found to have coarctation of the abdominal aorta by magnetic resonance imaging. Conclusion: Magnetic resonance imaging is a safe, reliable means by which to confirm clinically suspected coarctation of the aorta during pregnancy. (Obstet Gynecol 1995;85: 817-9)
Coarctation of the aorta is a congenital vascular defect identified in approximately one per 2000-3000 women.! 2 Only 2% of these cases involve the abdominal aorta. Maternal mortality approaches 4%, and deaths are usually related to aortic rupture or dissection. 3 The subset of women with coarctation of the aorta who are at greatest risk for morbidity and mortality have signif• icant underlying hypertension. A review of the English-language literature revealed only two cases in which abdominal coarctation of the
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