en Health Health Original Research Original Research Neural tube defects (NTD) are one of the most important malformations of newborns. The aim of this research is to determine the rates of NTD, anencephaly and spina bifida cystica and the relations of these abnormalities to the factors including sex, race, ethnicity, maternal age and familial marriage in the south-east of the Caspian Sea border. A three-year descriptive-analytic and cross-sectional study was carried out on 19545 newborns deliverd in Dezyani hospital in Gorgan during 1998-2000. From the total sample population (19545), the NTD rate was 3.12 per 1000 deliveries. In males the rate was 2.49 per 1000, in females 3.79 per 1000, and the female to male ratio was l.44: l. The rate of anencephaly and spina bifida was l.25 per 1000 and l.74 per 1000 respectively. In regard to different races the NTD rate was 7.48 per 1000,9.5 per 1000, and 2.35 per 1000 among Turkmans, Sistanis and Parses, respectively. It can be concluded that there is a higher rate of NTD in this region that may be due to the race-ethnicity and the ecological variations. neural tube defects, anencephaly, spina bifida cystica, Iran. 199 203 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-189&slc_lang=en&sid=1 MJ GOLALIPOUR mjgolalipour@yahoo.com 20031947532846003929 20031947532846003929 Yes From the Department of Embryology and Histology Golestan University of Medical Sciences, Gorgan, I.R. Iran MA VAKILI 20031947532846003930 20031947532846003930 No the Department of Health Golestan University of Medical Sciences, Gorgan, I.R. Iran B ARYA 20031947532846003931 20031947532846003931 No the Department of Surgery, Golestan University of Medical Sciences, Gorgan, I.R. Iran