1.- Adam Zs, Toth-Pál E,PappZ,. Recurrence risk of Craneospinal Abnormalities 1.994.14th European Congress of Perinatal Medicine. Abstracts 188.

2.-  Allen LC,  Doran TA, Miskin M, et al. Ultrasound and amniotic fluid alpha-fetoprotein in the prenatal diagnosis of spina bifida.1.982; Obstet Gynecol 60:169-73.

3.-  Allen LH.  Complementos nutricionales para la embarazada.1994. Clinicas Obstet Gynecol; Vol 3:539-46.

4.-  Arbuckle TE, Sherman GJ, Corey PN, et al. Water nitrates and CNS birth defects. A population base case controlled study.1988, Arch Environ Herlth, 43:162-7.

5.-  Archiron R, Barkai G, Kestznelson MBM, Marchied. Fetal lateral ventricle choroid plexus cysts; The dilemma of amniocentesis; 1991.Obstet Gynecol 98(8):15-18.

6.-  Arnold G, Wilkins. Haug L. Toluene embriopathy syndrome. 1990, Am J Hum Genet; 47:A46.

7.-  Bar-Hava I, Bronstein M, Ornoi A, Ben-Rafael Z. First trimester sonographic diagnosis of acrania 1993. Harefuah, 124(11):685-7.

8.-  Barr M Jr, Hanson JW, Currey K, Sharp S, Tiriello H, Schmickel Rd, Wilson GN. Holoprosencephaly in infants of diabetic mothers. 1983; J Pediatric, 102(4):565-68.

9.-  Becerra JE, Khoury MJ, Cordero JF, et al. Diabetes Mellitus during Pregnancy and the Risks for Specifics birth defects: A population based case control Study. 1990; Pediatrics: 85:1.

10.- Becker R, Narssisa F, Hoffbauer H,. Ultrashall diagnostic in der Schvangeranberatung: Moglichkeiten auspruch. Wirklichleit. 1995,7:77-82.

11.- Beekhuis JR, Van Lith JMM, de Wolf THM, Mantingh A. Increased maternal serum alphafetoprotein and human chorionic gonadotropin in compromised pregnancies other than for neural tube defects or Down syndrome. 1992; Prenat Diagn 12:643-7.

12.- Benacerraf BR, Harlow B, Frigoletto ID, Are choroids plexus cysts a indication for amniocentesis. 1990 Am J Gynecol Obstet; 162,1.001.

13.- Benson CB, Fetal Anormalies of the Central Nervous System. 1997, Ultrasound Women’s Imaging. Harvard Medical School and Brigham and women’s Hospital.

14.- Blum M, Cassis-Martinez R,. Diagnóstico Ecosonográfico de las Malformaciones Congénitas I: Meningomieloceles. 1981. Rev Ecuat Med Perinat 1:85.

15.- Boehm FH,. Tratamiento del defecto del tubo neural no anticipado en el embarazo tardío. 1984. Clinic Gynecol y Obstet. Vol 1:101.

16.- Bonilla F. Diagnóstico con Ultrasonidos en Obstetricia y Ginecología. 1974 ed. Científico Médica.

17.- Bordarier C, Aircardi J, Dandy Walker sindrome and genesis of the cerebella vermis: diagnostic problems and genetic counseling. 1990, Dev Med Child Neurol 32:285-94.

18.- Brown NA, Fabro S,. El valor de la experimentación animal en teratogenecidad para predecir el riesgo en humanos. 1983. Clinic Obstet y Gynecol. Vol 2:563.

19.- Bromley B, Friggoletto Jr FD, Benacerraf BR,. Mild fetal lateral cerebral ventriculomegaly; Clinical course and outcome 1991, AJ Obstet Gynecol 164:863.

20.- Bronhtein M, et al. Early transvaginal sonographic diagnosis of alobar holoprosencephaly. 1991; Prenatal Diagn 11:459-62.

21.- Bruyere H, Favre B, Douvier S,. De novo interticial proximal delation of 14q and prenatal diagnosis of holoprosencephaly. Prenat Diagn 16:1059.

22.- Bureau YA,  Fraser W, Fouquet B. Prenatal diagnosis of trisomy 9 mosaic presenting as case of Dandy Walker malformation. 1993; Prenatal Diagn 13:79-85.

23.- Clark SL, Devore GR, Sabey PL, Prenatal Diagnosis of the fetal choroid plexus 1.988. Obstet Gynecol 72:585-7.

24.- Clewel WH, Manco-Johnson ML, Manchester DK,. Diagnóstico y tratamiento de la Hidrocefalia fetal 1.986, Clinic Obstet Gynecol; Vol 3:655.

25.- Campbell RL, Dayton DH, Sohal Gs. Neural tube defects a review of human and animal studies on the etiology of neural tube defects. 1.986, Teratology; 34:171-87.

26.- Campbell S, Holt EM, Johnson FD, &May P: Anencephaly: early ultrasound diagnosis and active management. 1.972; Lancet ii, 1126-1227.

27.-Campbell S. Early Diagnosis of neural tube defects by ultrasound. 1.977. Clin Obstet Gynecol 20:351-59.

28.- Campbell S, Pryse-Davies J, Coltart TM et al. Ultrasound in the diagnosis of spine bifida 1.975; Lancet I, 1065-66.

29.- Carrera JM, The Decalogue of prenatal ultrasonographic diagnosis. 1.996; Prenatal and Neonatal Medicine. Vol 1(2):107-8.

30.- Cassís-Martínez R,. Diagnóstico Ecosográfico de las malformaciones Fetales 1981 I Congreso Internacional de Ecografía, Gquil-Ecuador.

31.- Cassís-Martínez R. Blum M,. Diagnóstico Ecosonográfico de las malformaciones Congénitas III: Hidrocefalia 1.982. Rev Ecuat Med Perinat Vol 2(4):244-46.

32.- Cassís-Martínez R, Blum M. Detection of fetal anomalies (1.980-1.991). 1.992, Ultrasound Obstet Gynecol, Vol 2 Supplem 1:78.

33.- Cassís-Martínez R, Arosemena I Durán G;. Central Nervous System: Anomalies in a period of 17 year. 1.997. Ultrasound in Medicine and Biology Vol:23, Surl 1:6208.

34.- Cassís-Martínes R, Arosemena I,. Incidence of Central Nervous System Anomalies in a private Unit of Prenatal Diagnosis in Guayaquil-Ecuador. 1.994. 14th European Congress of Perinatal Medicine (Helsinky-Finland) Abstract 192.

35.- Cowles T, Furman P, Wilkins J. Prenatal Diagnosis of Dandy Walker malformation in a family displaying X-linked inheritance. 1.993; Prenatal Diagn 13:87-91.

36.- Chen,Chin-Ping, Liu Fen, Lan, Chung. Chi. Prenatal diagnosis of supernumerary der (22) (11,22) associated with Dandy Walker malformation in a fetus. 1.996; Prenatal Diagn 16:1137-40.

37.- Chevernak FA, Berkowitz RL, Romero R, et al., The diagnosis of fetal hydrocephalus 1.983. A J Obstet Gynecol 147:703.

38.- Chin DH, Miller EL, Worthy LM, Towers CV. Sonographically detected fetal choroids plexus cysts: frecuency and association with aneuploidy?. 1.991; J Ultras Med 10:255-8.

39.- Chitkara V, Cagwell C, Norton K, Wilkins IA, Mehalek K, Berkowitz RI. Choroid plexus cysts in the fetus: a benign anatomic variant or pathology entity? Report of 41 cases and review of the literature. 1.988. Gynecol Obstet, 72:185-9.

40.- Cochrane D, Aronyk K, Sawatshy B, et al. The effects of labor and delivery on espinal function and ambulation in patients with meningomyelocele. 1.991. Child Nerv Syst; 7:312-15.

41.- Coerdt W, Miller K, Holzgreve W, Rauskold R, Schwinger E, Rehder H, Neural tube defects in chromosomally normal and abnormal human embryos. 1.997. Ultrasound Obstet Gynecol 10(6) 410-15.

42.- Colby L, Langhleine T, Lee G, Diagnosis of human malformation by ultrasound 1982. J Clin Ultras 10:37.

43.- Crane JP, Lefebre ML, Winsborn RC, et al. A randomized trial prenatal ultrasonographic screening: impact of the detection, managment and outcome of anomalous fetuses. The Radius Study Group. 1.994; Am J Obstet Gynecol 171:392-399.

44.- Cuckle HS, Wald NJ, Cukle PM, Prenatal screening and diagnosis of neural tube defects in England and Wales in. 1.985., 1.989. Prenatal Diagn: 9:393-400.

45.- David A, Nombalais MF, Rival JM, Verloes A. Nosology of fetal hypokinesia sequence based on CNS abnormalities: Is there an AaseSmith  syndrome?. 1.996, Clin Genet; 50(4)251-4.

46.- De la Fuente P, Bajo Arenas J, Olaizola Lodio JI. Diagnóstico prenatal de Malformaciones Congénitas. 1.984 Interamericana.

47.- Dempsey PJ, Koch HJ,. The in utero diagnosis of the Dandy Walker syndrome diferentation from extra-axial posterior fossa cyst. 1.981: Journal of Clinic Ultras  9:403-5.

48.- Dorsh MN, Scragg RKR, McMichel AJ, et al. Congenital malformations and maternal drinking water supply in rural South Australia: a case control study. 1.984, J. Epidemiol; 119:473-86.

49.- Chow BH, Loh SF, Yan YL, Ang HK, Yeo GS. Holoprosencephaly and chromosomal anomalies. 1.996 Singapore Med J 37(4):394-7.

50.- Earnhart CB et al, Alcohol teratogenicity in the human. A detailed assessment of specifity, critical period, and threshold. 1.987. Am J Obstet Gynecol 156:33-39.

51.- Eskes TK, Open or closed? A world of difference: a hystori of hemocysteine research. 1.998. NutrRev 56:8,236-44.

52.- Estroff J, Parad RB, Bames PD, et al; posterior fossa arachnoid cyst: an in utero mimicker of Dandy Walker malformation. 1.995; J Ultras Med 14:787.

53.- Estroff J, Scott M, Benacerraf B. Dandy Walker variant prenatal sonographic features and clinical outcome. 1.992; Radiology 185:755-58.

54.- EUROCAT Working Group. Prevalece of neural tube defects in 20 regions of Europe and the impact of prenatal diagnosis. 1.980-86. 1.991 J Epidemiol Commnity Health; 45:52-58.

55.- Fakhry J, Schechter A, Tenner MS, et al. Cysts of the choroid plexus in neonates Documentation and review of the literature. 1.985. J Ultras Med 4:561-4.

56.- Filly RA: Ultrasound evaluation of the fetal neural axis. In Callen PW(ed) Ultrasonography in Obstetric and Gynecology. 1.994; WB Saunders Co. Philadelphia, pag 189.

57.- Fink IJ, Chinn DH, Callen PW: A potential pitfall in the ultrasonographic diagnosis of fetal encephalocele. 1.983, J Ultras Med 2:313.

58.- Fiske C, Filly RA & Callan PA,. Sonographic measurement of lateral ventricle width in early dilatation. 1.981. J Clin Ultras 9:303-7.

59.- Freeman RK, Mc Quown DS, Secrist LJ, et al. The diagnosis of fetal hydrocephalus before viability. 1.997. Obstet Gynecol 49:109-12.

60.- Fried PA. Prenatal exposure to tabacco and marijuana: Effects during pregnancy, infancy and early chidhood.1.993 Clin Obstet Gynecol, 36:319-336.

61.- Fried PA, Watkinson B.12 and 24 months neural behavioural follow-up of children prenatally exposed marijuana, cigarettes and alcohol. 1.988. Neuritoxol Tearatol, 10:305-13.

62.- Gabrielly S, Reece AR, Pilu G, Perolo A, Rizzo N, Bovicelly L, Hobbins JC. The significance of prenatally choroid plexus cyst. 1.989. Am J Obstet Gynecol 160:1207-10.

63.- Ghavani M, Levy HL, Erbe RW,. Prevención del daño fetal mediante control diabético de la hiperfeninemia maternal. 1.986, Clinic y Gynecol Vol 3:739.

64.- Golden JA, Cheenoff. Multiples sites of anterior neural tube closure in Human: Evidence from anterior neural tube defects (anencephaly). 1.995. Pediatric, 4:506-10.

65.- Goldstein RB, Filly RA,: Prenatal diagnosis of anencephaly: Spectrum of sonographic appearance and distinction from the amniotic band syndrome. 1.988, AJR 151:1547.

66.- Goldstein RB, Filly RA, Callen PW: Sonographic of anencephaly: pitfall in early diagnosis. 1.989 J Clin Ultrasound 17:397.

67.- Green NDE, Copp AJ. El inositol previene defectos del tubo neural. 1.997. Nature Medice; 3:60-65. Tomado de SIIC. (sociedad iberoamericana de información científica).

68.- Hansmann M,. Prenatal Ultrasound Diagnosis. 1.979. Ferdinand Enke Publish, Stuutgart, Pag. 154.

69.- Harrison LA, Pretorius DH, Budorick NE: Abnormal spinal curvature in the fetus. 1.992 J, Ultras Med; 11(9):473-79.

70.- Hautman GD, Sherman SJ, Utter GO, et al. Acrania. 1.995 J Ultras Med 14:552.

71.- Hendricks SK, Cyr DR, Nyberg DA: Exencephaly clinical and ultrasonic correlation to anencephaly. 1.988. Obstet Gynecol 72:898.

72.- Herberg BS, kay HH, Bowie, Bowie JD, Fetal Choroid plexus lesions; relationship of antenatal sonographic appearance to clinical outcome. 1.989. J: Ultras Med 8:77-82.

73.- Hobbins JC, Grannum PA, Berkowitz RL et al. Ultrasound in the diagnosis of congenital abnormalities. 1.979. A. Obstet Gynecol; 134:331-38.

74.- Hooher JG, Lucas M, Richars BA, et al. Is maternal alpha-fetoprotein screening still of value in a low risk area for neural tube defects?. 1.984. Prenat Diagn 4:29-33.

75.- Howard RJ, Tuck SM, Long J, Thomas VA, The signicance of choroid plexus cyst in fetuses at 18-20 weeks. An indication for amniocentesis?. 1.992. Prenatal Diagn 12:685-88.

76.- Johnson A, Losure TA, Weiner S. Early Diagnosis of fetal anencephaly. 1.985. J Ultrasound Med 13:503.

77.- Johnson ML, Dunne MG, Mack LA et al. Evaluation of fetal intracranial anatomy by static and real time ultrasound. 1.980. J clin Ultras 8:311-18.

78.- Johnson VP, Swayze VW II, Sato Y, Andreasen NC. Fetal alcohol syndrome: craniofacial and central nervous system manifestations. 1.996, Am J Med Genet; 61(4):329-39.

79.- Kapur RP, Shaw CM, Shepard TH. Brain Hemorrhages in cocaine exposed human fetuses. 1.991; teratology 44:11-18.

80.- Kelly TE, Teratogenicity of Anticonvulsivants Drugs; II: A prospective Study. 1.984. Am J Med Gent, 19:435-43.

81.- Kennedy D, Chitayat D, Winsor Ej, Silver M, Toi A. Prenatally diagnosed neural tube defects; ultrasound chromosome and autopsy or postnatal findings in 212 cases. 1.998. Am J Genet 77:4,317-21.

82.- Keogan MT, Deatkine AB, Hertzberg B, Cerebellar verniam defect: antenatal sonographic appearance and clinical significance. 1.994, J Ultras Med 13:607-611.

83.- King JA, Gardner V, Chen H, Blackburn W. Neu-Laxova syndrome: pathological evaluation of a fetus and review of the literature. 1.995; Pediatr Pathol Lab Med, 15(1):57-79.

84.- King JC, Fabro S,. Consumo de alcohol y de tabaco sobre el embarazo. 1.983. Clinic Obstet y Gynecol Vol 2:525.

85.- Kirkinen P, Joppila P, Valkeakari T, et al. Ultrasonic evaluation of the Dandy Walker syndrome. 1.982. Obstet Gynecol 59:188.

86.- Kollias S, Ball W, Prenger E,. Cystic malformation of the posterior fossa: differential diagnosis clarified trought embriology analysis. 1.993; Radiographics 13:1211-31.

87.- Kruslin B, Jukic S, Kos M, Simic G, Cviko A,. Congenital anomalies of the central nervous system at autopsy in Croatia in the period before and after the Chernobyl accident 1.998;52;2,103.

88.- Kupesik S, Kurjak A, Babic M. M., New data in early cerebral circulation. 1.997. Prenatal and Neonatal Medicine Vol 2(1):56-7.

89.- Landom MB, Gabbe SG. Diabetes Mellitus and pregnancy. 1.990. Obstetrics and Gynecology Clinics of North America 19:6333.

90.- Luthy DA, Wardinsky T, Shurtleff DB, et al. Cesarean section before the onset of labor and subsequent motor function in infants with meningomyelocele diagnosed antenatally. 1.991, N Engl 324:662-66.

91.- Mahony BS, Filly RA, Callen PW, et al: The amniotic band syndrome: antenatal sonographic diagnosis and potential pitfall. 1.985; Am J Obstet Gynecol 152:63.

92.- Mahony BS, Callen P, Filly R, Hoddick W,. The fetal cisterna Magna. 1.984; Radiology 153:773-76.

93.- Martínez T, Morales C, Andina D, Gonzalez R, López M, Usandizaga JM. Diagnóstico prenatal del síndrome de Meckel Gruber. Presentación de un caso. 1.994; Progresos en Diagnóstico Prenatal Vol 6(3):219-22.

94.- Méndez JD, Palomar-Morales M, Revilla G, Islas S. Teratogenesis y Diabetes Mellitus. 1.998. SIIC.

95.- Mennuti MT,. Teratología y asesoría genética en la embarazada diabética. 1.985 Clinic Obstet Gynecol; Vol 3:611.

96.- Mills JL, McPartlin JM, Kirke PN, et al. Homocysteine metabolism in pregnancies complicated by neural-tube defects. 1.995. Lancet; 345:149-51.

97.- Milunsky A, Alpert E. Results and benefits of a maternal serum alpha-fetoprotein screening program. 1.984. JAMA 252;1438-42.

98.- Montagne I, Fox R,. Selective serum testing for neural tube defects. 1.997. J Obstet Gynecol Vol 17 S1:833.

99.- Montero JJ, Blanco G, Cavero A, Hervas JL, González JM, De Miguel JR, Martínez T, Loidi B. Quistes del plexo coroideos: significado y actitud ante su hallazgo. 1.994. Progresos en diagnóstico Prenatal Vol 6(3):197-202.

100.- Nadel AS, Green JK, Holmes LB, et al. Absence of need for amniocentesis in patients with elevated levels of maternal serum alpha-protein and normal ultrasonographic examinations. 1.990; N. Engl J Med 323;557-61.

101.- Nicolaides KH, Campbell S, Gabbe SG, et al,. Ultrasound screening for spina bifida; cranial and cerebellar sign. 1.986 Lancet 7:72.

102.- Nyberg DA,. Mack LA,. The spinal and neural tube defects. Diagnostic ultrasound of fetal anomalies: Text and Atlas. 1.990; Year Book Medic Pub., pag 146.

103.- Nyberg DA,. The Dandy Walker malformation: prenatal sonographic diagnosis and its clinical significance. 1.988; J Ultras Med 7:65-71.

104.- Ober C, Simpson JL. Diabetes sacarina: prevención de anormalidades mediante intervención metabólica materna. 1.986. Clinic Obstet y Gynecol. Vol 3:711.

105.- Oltra MF, Ariza N, Donaue G, Villaroya E, Barbal A, Fagoaga R. Teratoma sacrocoxigeo en gestación gemelar: a propósito de un caso 1. 1.996. Clinic e Invest Ginel y Obstet, 23(6):210-12.

106.- Oltra MF, Fernández R, Ariza NE, Villaroya E, Fagoaga R. Holoprosencefalia alobar, diagnóstico ecográfico prenatal. 1.996. Clinic e Invest Gynecol y Obstet 23(10):427.

107.- Papp C., Adam Z, TóTh-P al E, Risk of recurrence of craniospinal anomalies. 1.997, J Matern Fetal Med 6(1):53-7.

108.-Parson RB., Waring RH, Ramsden DB, Williams AC. In vitro effects of the cysteine metabolites hemocysteic acid, hemocysteine and cysteic acid upon human neuronal cell lines. 1.998. Neurotoxicology; 19:4-5;599-603.

109.- Petrikovsky BM., Kaplan GP, Size disparity  of the cloroid  plexuses of the lateral ventricles: Prenatal diagnosis and neonatal outcome. 1.996. Prenatal Diagn, 16:670-72.

110.- Pillu G., Romero R, Gabrielli S, et al : Prenatal diagnosis of cerebrospinal anomalies. In Fleischer AC, Manning FA, Jeanty P, Romero R (Eds). 1.996. Sonographic in Obstetrics and Gynecology-Priciples & Practice, 5th Edit, Stamford, CT Appleton & Lance p 375.

111.- Pillu G., Goldstein I, Reece E, Perolo A, Foschini MP, Hobbins JC, Bovocelli L,. Sonographic of fetal Dandy Walker malformation: a reappraisal. 1.992; Ultras Obstet Gynecol 151-57.

112.- Platt LD., Carlson DE, Medearis AL, Walla CA,. Fetal choroid plexus Cysts in the second trimester of pregnancy: a causes of concern. 1.991. Am J Obstet Gynecol, 164:1652-6.

113.- Pollar A, Gruber W, Birnbacher R, Zwiauer K. Richlinien zur Pravention von Neuralrohrdefekten durch perikonzeptionelle Folsauresubstitution. 1.998. Perinatal Medizin; 10:73.74.

114.- Porto M, Murata Y, Warnike LA, Keegan KA Jr. Fetal choroid plexus cysts and independent risk factor for chromosomal anomalies. 1.993. J Clin Ultra 21:103-8.

115.- Raybaud C,. Cystic malformations of the posterior fossa abnormalities  associated with development of the roof of the fourth ventricle and adjoint meningeal structures. 1.982. J Eouroradiol 9:103-33.

116.- Remington J, Klein J. Infectious Diseases of the fetus and Newborn Infant. 1.990 WB. Saunders, Co.

117.- Ricketts NEM., Lowe EM, Patel NB, Prenatal diagnosis of choroid plexus cysts. 1.987. Lancet 1:213-14.

118.- Robin NH, Ko LM, Heeger S, Muise Kl, Judge N, Bangert BA., Syntelencephalt in a infant of a diabetic mother. 1.996. Am J Med Genet, 66(4):433-37.

119.- Robinson HP., the role of ultrasound in the prenatal Diagnosis of neural tube defects: In Prenatal Diagnosis. 1.979.S. Schwinger E., Enke Pub Suttgart Pag:179.

120.- Robinson HP., Hood VD Adam AH et al. Diagnosis Ultrasound: early detection of fetal neural tube defects. 1.980; Obstetric Gynecol 56:705-10.

121.- Rose NC, Menutti MT, Complementos Periconcepcionales  de folato y defectos del tubo neural. 1.994. Clinica Obstet Gynecol; Vol 3:555-68.

122.- Rosenquist TH, Ratashak SA, Selhub J., Hemocysteine  induces congenital defects of the heart and neural tube: effect of folic  acid. 1.996. Proc Natl Acad Sci USA, 93(26)15227-32.

123.- Rottem S., Bronshtein M, Thaler I, et al. First trimester transvaginal sonographic diagnosis of fetal anomalies. 1.990; Lancet 1:444-5.

124.- Rinke U, Koletzko B, Pravention von Neuralrohedefekten durch Folsáure-zufuhr in der Fruhshwangerschaft. 1.994, Deutsches Arzteblatt 91:A30-A37.

125.- Rubin P. Prescribing in Pregnancy. 1.990. The practitioner 234:556-560.

126.- Russ PD, Pretorius DH, Johnson MJ, Dandy Walker syndrome: A review of fifteen cases evaluated by prenatal sonographic. 1.989. A J Obstet Gynecol 161:401.

127.- Seller MJ., Futher evidence for an intermittent pattern of neural tube closure in humans. 1.995. J Med Genet 32(3):205-7.

128.- Shepard TH., Consejo a las mujeres gestantes expuestas durante el embarazo a agentes potencialmente peligrosos. 1.983; Clinic Pbtet y Gynecol Vol 2:577.

129.- Shields LE, Uhrich SB, Easterling TR, Cyr Dr, Mark LA,. Isolated fetal choroid plexus cysts and karyotypes: Is it necessary?. 1.966. J Ultras Med 15:389-93.

130.- Shurtleff DB, Luthy DA, Nyberg Da, et al. Meningomyelocele: management  in utero and postpartum 1.994. Ciba Found Symp, 181:270-80.

131.- Steen MT, Boddie Am, Fisher AJ, Macmahon M, Saxe D, Sullivan KM, Dembure PP, Elsas LJ. Neural tube defects associates with low concentrations of cobalamin (vit B12) in amniotic fluid 1.998. Prenat Diagn; 18:6;545-55.

132.- Steinbicker V, Rosh C. Monitoringssystem angegorener Fehlbildungen. 1.998. Perinatal Medizin 10:45-48.

133.- Smithells RW, Seller MJ, Harris R, et al. Further experience of vitamin supplementation for prevention of neural tube defects recurrences. 1.983. Lancet; 1:1027-1031.

134.- Stmpf DA, Cranford RE, Elias S, et al: The infant with anencephaly. 1.990; New Engl J Med 322:669.

135.- Tan YY, Yeo GSH. The effect of prenatal diagnosis of fetal anomalies on perinatal Mortality. 1.994. 14th European Congress of Perinatal Medicine. Abstract 23.

136.-  Toutan C, Lippman S. Fetal solvent syndrome. 1.979, Lancet 1:1356.

137.- Wald NJ, Hackshaw AD, Stone R, Sourial NA; Blood folic acid and vitamin B 12 in relation to neural tube defects. 1.996. Br J Obstet Gynecol 103(4):319-24.

138.- Vargas RMC, Malformaciones del Sistema Nervioso Central. 1.997; Monografía. Hosp. Inf Ramón Sarda. Buenos Aires.

139.- Vergani P, Ghidini A, Sirtori M, et al. Antenatal diagnosis of fetal acrania. 1.987, J Ultrasound Med 6:715.

140.- Vergel RG, Sánchez LR, Heredero BL, et al. Primary prevention of neural tube defects with folic acid  supplementation: Cuban experience. 1.990; Prenat Diagn; 10:149-52.

141.- Vintzileos AM, Ingardia CJ, Nochimson DJ,. Congenital Hydrocephalus: a review and protocol for perinatal management. 1.983, Obstet Gynecol 62:539.

142.- Wald NJ, Bower C. Folic Acid, pernicious anemia and prevention of neural tube defects. 1.994. Lancet 343:307-308.

143.- Wald N, Cuckle H, Nanchahal K. Amniotic fluid acetycholinesterase measurement in the prenatal diagnosis of neural tube defects. Second report of the Collaborative Acetylcholinesterase Study. 1.989, Prenat Diagn, 9:813-29.

144.- Wasserman CR, Shaw GM, Gould JB, Syme SL, Socioeconomic status, neighborhood social conditions and tube defects. 1.998. Am I Public Health, 88(11): 1674-80.

145.- Watson WJ, Chescheir NC, Katz VL, Seeds JW,. The rol ultrasound in evaluation of patients with elevated maternal serum alpha-fetoproteina review. 1.991; Obstet & Gynecol 78(1):123-8.

146.- Wenstron KD, Understanding How neural tube defects ocurr-and can be prevented. 1.996. Medcape Women Health; 1:12.

147.- Werler MM, Shapiro S, Mitchel AA. Periconceptional folic acid exposure and risk of occurren neural tube defects. 1.993. JAMA; 269:1.257-61.

148.- Windham GC, Edmonds LD. Cuurents trends in the incidence of neural tube defects. 1.992. Pediatrics; 70:333-37.