The aim of the investigation was to study fertility in Danish women diagnosed with Turner syndrome (TS), and to describe their offspring. In total, 410 women in the fertile age were registered in the Danish Cytogenetic Central Register with TS between January 1973 and December 1993. Their karyotype were as follows: 49% with 45,X, 23% with mosaicism and a structural abnormality of the second X, 19% with 45,X/46,XX mosaicism, and 9% with 46,XX and a structural abnormality of the second X. Thirty-three women, one with 45,X, 27 with mosaicism and 5 with 46,XX and a structural abnormality of the second X, gave birth to 64 children. Two women had become pregnant after in vitro fertilization, including a woman with 45,X after an egg donation. Thus, 31 women(7.6%) had achieved at least one spontaneous pregnancy, but 48% of the fertile women registered with 45,X/46,XX had 45,X in less than 10% of the analysed cells. Twenty-five of the 64 children had a chromosome analyzed. Six of the 25 examined children, including three siblings, had chromosomal aberrations. No case of Down's syndrome was present, and only two children had malformations. Fertility in women registered with TS is higher than earlier reported. However, only women with 45,X/46,XX mosaicism or 46,XX and structural abnormality of the second X, gave birth to live children after spontaneous pregnancies.