The Principles of Clinical Cytogenetics - Extra Materials - Springer

Cytogenetics of Spontaneous Abortion 325
Table 2
Chromosomal Abnormalities and Gestational Age
Gestational age No. of Abnormal Percent
(weeks) cases cases abnormal
2 23 18 78.0%
3 374 258 69.0%
4 203 125 61.6%
5 139 85 62.2%
6 302 211 69.9%
7 56 27 48.2%
Total weeks 2–7 1097 724 66.0%
8 36 8 22.2%
9 42 6 14.3%
10 14 7 50.0%
11 8 1 12.5%
12 8 3 37.5%
Total weeks 8–12 108 25 23%
Total 1205 749 62.2%
Source: Adapted from ref. 14.
Table 3
Abnormal Development and Gestational Age
4 weeks or less 5–8 weeks 9–12 weeks
Study Normal Abnormal Normal Abnormal Normal Abnormal
Milamo 0 48 21 40 71 10
Miller and Poland 10 73 51 71 121 56
Total 10 (8%) 121 (92%) 72 (39%) 111 (61%) 192 (74%) 66 (26%)
Source: Adapted from ref. 14.
Table 4
Chromosomal Abnormalities in Induced Abortuses
Developmental age No. of cases Abnormal cases (%)
3–4 weeks 108 10 (9.3%)
5–6 weeks 570 37 (6.5%)
7–8 weeks 389 25 (6.4%)
9–10 weeks 130 7 (5.4%)
Source: Ref. 15.
The likelihood of detecting congenital anomalies in therapeutic terminations is variable and might
be a reflection of the thoroughness of the examination and the skill of the examiner. However, identification
of anomalous development could have considerable impact on future reproduction, and it is
the opinion of the author that careful anatomic evaluation of aborted products of conception should
be considered regardless of the whether the pregnancy is aborted spontaneously or induced.