References for: Causes, evaluation, and treatment.

Medscape Women’s Health 1998 May;3(3):2 (ISSN: 1521-2076) Bick RL; Madden J; Heller KB; Toofanian A

Thrombosis Clinical Center, Department of Medicine (Hematology & Oncology), Presbyterian Hospital of Dallas, Tex., USA.

Impact and Implications of Chromosomal Abnormalities

Cytogenetic Studies of Abortuses

In determining the cause of fetal loss, it is useful to conduct a chromosome study on the abortus. Chromosome analysis is indicated in the case of a stillbirth or neonatal death because chromosomal anomalies are found in approximately 6% of these cases.[8] Tissues for cytogenetic studies should be obtained using sterile technique, and they should be delivered immediately to the cytogenetics laboratory in transport medium provided by the laboratory. If such medium is not available, a laboratory technician can provide information regarding the suitability of sterile saline or other solutions, although culture success is compromised. To avoid this problem, it is important to have tubes of frozen, unexpired transport medium onsite.

Tissue specimens that have been frozen or placed in formalin may not be cultured. Tissues suitable for cytogenetic study include placental villi, chorion, amnion, skin, or internal organs such as liver, lung, kidney, or spleen. For early gestation, the entire abortus may be submitted. For later gestation, blood in a sodium heparin tube is also suitable. Submitting several specimen types increases the culture success rate which, even in laboratories with the most experienced staff, is usually no more than 85%.

Cytogenetic Studies of Parents

When a couple has had 2 or more spontaneous abortions or a child with a structural chromosomal anomaly, chromosomal analysis on both partners should be considered. Analysis requires a 5mL to 10mL blood sample in a tube with sodium heparin.

The chance of a balanced chromosome rearrangement in 1 partner of a couple with 2 or more spontaneous abortions is about 7%.[5] Determining the presence of such a rearrangement in a parent is useful because it provides: (1) an explanation for the miscarriages; (2) information about the risk for a live-born child with potentially serious anomalies, as well as the risk for future miscarriages; (3) availability of prenatal diagnosis in a future pregnancy; and (4) information for members of the extended family who may be at risk and may wish to undergo chromosome testing.