photo of Lenore Goldfarb
recurrent miscarriage

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

Relationship to Spontaneous Abortion

Chromosomal anomalies are known to be the single most common cause of spontaneous abortion. Historically, 50% of spontaneously expelled abortuses have been thought to be chromosomally abnormal.[1]However, this is probably an underestimate in light of recent improvements in tissue culture techniques, coupled with earlier diagnosis of miscarriage.[2] In spontaneous abortions, the majority of chromosomal anomalies (95%) are numerical. About 60% are trisomies, trisomy 16 being the most common (see Fig. 2).[1] A further 20% are found to have 45,X (Turner’s syndrome).[1]Interestingly, approximately 99% of fetuses with 45,X are expelled spontaneously.[3] Another 15% have polyploidy, especially triploidy (see Fig. 3).[1]


Karyotype of 69,XXY (triploidy), common finding in spontaneous abortion. Risk for chromosomal anomaly in subsequent pregnancy is not increased significantly.

Figure 3. Karyotype of 69,XXY (triploidy), common finding in spontaneous abortion. Risk for chromosomal anomaly in subsequent pregnancy is not increased significantly.

In the case of a numerical chromosomal anomaly in a fetus, parental chromosomes are usually normal, so karyotype analysis of the parents is not indicated. The recurrence risk for a chromosomal anomaly following the diagnosis of trisomy in a pregnancy is thought to be about 1%.[1,4]

After diagnosis of a numerical chromosomal anomaly, couples should be counseled about the 1% risk for recurrence of a numerical anomaly, and prenatal diagnosis of the fetus may be considered for any future pregnancies. On the other hand, if a structural chromosomal anomaly is found in a fetus, parental karyotypes are indicated. The presence of a balanced chromosomal rearrangement in a parent would result in an increased recurrence risk for structural chromosomal defects in future pregnancies.

print this page back


If you value this service, kindly consider a donation to the Canadian Breastfeeding Foundation (registered charity). Earmark the donation for the International Breastfeeding Centre (Newman Breastfeeding Clinic) and/or the Goldfarb Breastfeeding Program.

Donate online: canadahelps.org

Donate by mail: Canadian Breastfeeding Foundation, 5890 Monkland Ave, Suite 16, Montreal, Quebec, Canada H4A 1G2.


© 2002-2019 Lenore Goldfarb, PhD, CCC, IBCLC, ALC and contributing authors to AskLenore.info. All rights reserved.


Disclaimer: The information provided on this website is for general informational purposes only and does not constitute medical advice. You should not rely on this information as a substitute for, nor does it replace, professional medical advice, diagnosis, or treatment. If you have any specific questions or concerns about any health issue, you should consult with a qualified healthcare provider.
The AskLenore administration is not affiliated with, nor sponsored by, nor do we sell or receive any commissions or incentives from, any of the products or services that we link to on this website. Therefore, we are not responsible for the accuracy, quality, availability, or suitability of said products or services. You should always do your own research and due diligence before purchasing or using any product or service that we link to on this website.
The views and opinions expressed on the message boards are those of the authors and do not necessarily reflect the official policy or position of asklenore.info. Any content provided by our users are of their opinion and are not intended to malign any religion, ethnic group, club, organization, company, individual or anyone or anything.

top