Embryonic karyotype in recurrent miscarriage with parental karyotypic aberrations.

OBJECTIVE: To assesses chromosomal aberrations in the abortus in recurrent miscarriage, in the presence of parental chromosomal aberrations.

DESIGN: Retrospective comparative cohort study.

SETTING: Tertiary referral unit in university hospital.

PATIENT(S): One thousand one hundred eight patients with 3-16 miscarriages before 20 weeks gestation; 113 patients with and 995 without chromosomal aberrations.

INTERVENTION(S): Karyotyping by standard G-banding techniques of both parents, and of 205 abortuses collected at curettage.

MAIN OUTCOME MEASURE(S): The incidence of the euploidic and aneuploidic abortuses according to the parental karyotype.

RESULT(S): Two hundred three abortuses were successfully karyotyped. In 164 embryos of patients with no parental chromosomal aberrations, 23.2% (38/164) had chromosome aberrations. Of the 39 abortuses karyotyped in patients with chromosomal aberrations, 17 had normal karyotypes, 8 had balanced translocations, 2 had inversions identical to the parents, and 12 (30.8%) had abnormal karyotypes. This difference is not statistically significant (odd ratio 1.47, 95% confidence interval 0.63-3.39). Only 4 of the 39 karyotyped abortuses had an unbalanced translocation.

CONCLUSION(S): Parental karyotyping was not particularly predictive of a subsequent miscarriage as a result of chromosomal aberrations as 43.5% of abortuses were euploidic, and the parental aberration was only passed on to the abortus in 10% of cases.