A 21-year-old white female with short stature, cubitus valgus, multiple cutaneous nevi, and no other major features of the Turner syndrome is described. She had normal secondary sex development and menses. She recently completed a normal pregnancy with delivery of a normal male infant. Postpartum endocrine studies were normal. All cells examined from blood, skin, uterus, and both ovaries had a 45, X karyotype. She is the sixth reported monosomy X patient to achieve pregnancy. A literature review indicates increased fetal wastage (22 of 46 pregnancies) and increased chromosomal errors in the offspring (8 of 26 liveborn infants) of patients with a 45,X cell line. Three cases of trisomy 21 occurred in these infants. Amnioccntesis and prenatal diagnostic studies are indicated for women with a 45,X chromosome constitution. The pathogenesis of the Turner syndrome is considered in relation to these findings.