Spontaneous pregnancy in a 45,X/46,X,r (X) Turner's mosaic patient

Patients with a karyotype including a ring X chromosome account for 2% to 11% of patients with Turner's syndrome. Some of these patients are sexually developed and fertile. However, most of these patients required therapeutic intervention for infertility. We report a normal pregnancy in a patient with Turner's syndrome whose karyotype is a mosaicism of 45,X/46,X,r (X), with no therapeutic intervention for infertility. A 28-year-old woman who had been diagnosed at age 18 years as having a Turner's mosaic was referred to Oita Medical University Hospital for intrauterine growth restriction (IUGR) and threatened premature labor at 35 weeks 0 day of gestation. G-banding investigation for chromosomal analysis of the lymphocyte revealed a mosaic karyotype consisting of 50% 45,X, 50% 46,X,r (X) (Fig. 1). Menarche started at age 12 years and her cycle had been regular (27–30 days) without particular treatment. She married at age 28 years and has never used contraception. She became pregnant without any treatment, and her prenatal course had been uneventful until 23 weeks. Intrauterine growth restriction was noted at 24 weeks' gestation, and threatened premature labor was diagnosed at 33 weeks' gestation. On admission her height was 128 cm and she weighed 34.5 kg. She did not have the typical features of Turner's syndrome such as webbing of the neck, low hair line, and short fourth metacarpals. She showed good breast development and normal puberty. The pelvic examination revealed normal external genitalia, uterus, vagina and adnexa. The cervix was long, posterior, hard, and not dilated. Fetal heart beats were regular and estimated fetal body weight was 1734 g (−2.2 SD). Hemanalysis and hormone analyses were almost within normal limits. After admission, amniocentesis was carried out for karyotyping, which prenatally predicted a normal 46,XX child. Uterine contraction was controlled by ritodrine HCl. At 37 weeks and 1 day of gestation, a cesarean section was performed because of cephalopelvic disproportion. She delivered a normal female infant weighing 2240 g, and Apgar scores of 8 and 10 at 1 and 5 min, respectively. No congenital malformation was noted. Breast feeding was established and menstruation resumed as normal. Turner's syndrome associated with a ring X chromosome, r (X), has been reported infrequently since Lindsten et al. described the first patient (1). In mosaic Turner's syndrome, the case of mosaicism of 45,X/46,X,r (X) is rare and there has been few reports of pregnancy in this type of Turner's syndrome (2). Our case conceived easily without therapeutic intervention for infertility. Boyar et al. reported a secondary amenorrhea patient with 46,X,r (X) who was unable to conceive while she was menstruating regularly (3). Blumenthal et al. reported a patient with 45,X/46,X,r (X) karyotype whose conception occurred while on hormone replacement therapy (4). A review of the literature reveals a myriad of theories to account for the variability of ovarian function in Turner's syndrome, however, as yet, there are insufficient data to yield any conclusions (4). In general, patients with Turner's syndrome who proceed with pregnancy are at high-risk for abortion, still-birth and malformed children. Kawagoe et al. summarized the reports of 75 women with Turner's syndrome who had conceived at least once; overall, there were 167 pregnancies. The outcome was 51 abortions, 10 still-births, 75 alive well, 25 congenital or chromosomal abnormalities, and for the remaining nine pregnancies no information is available (5). In the same way, Tarani et al. summarized the reports of 74 women with Turner's syndrome who had conceived at least once: there were 160 pregnancies. The outcome was 47 abortions, 11 still-births, 94 live new-borns, and for the remaining nine pregnancies no information is available. Among the live new-borns, 62 were healthy and 32 had malformations (Down's syndrome, Turner's syndrome, etc.) (6). Turner's syndrome is a genetic condition occurring in approximately one in 2000 females. To our knowledge, there are no detailed reports about precautions. But according to Pasqualini-Adamo, only 2% of patients with Turner's syndrome have spontaneous pregnancies. The remaining 98% of fertile patients with Turner's syndrome who wish to avoid a risk pregnancy can proceed with artificial fertilization techniques, with the help of available oocyte donors (7). This issue deserves more further study. Address for correspondence: Isao Miyakawa Department of Obstetrics and Gynecology Oita Medical University Hasama-machi Oita, 879–5593 Japan