Clinical Evidence Concise
A Publication of BMJ Publishing Group
Am Fam Physician. 2008 Oct 15;78(8):977-978.
Recurrent miscarriage is the spontaneous loss of three or more consecutive pregnancies in the first trimester, with the same biological father. It affects 1 to 2 percent of women, in one half of whom there is no identifiable cause.
Overall, 75 percent of affected women will have a successful subsequent pregnancy, but this rate falls for older mothers and with increasing number of miscarriages.
Antiphospholipid syndrome, with anti-cardiolipin or lupus anticoagulant antibodies, is present in 15 percent of women with recurrent first- and second-trimester miscarriage.
We do not know whether bed rest, early scanning, lifestyle adaptation (to stop smoking, reduce alcohol consumption, and lose weight), low-dose aspirin, human chorionic gonadotropin therapy, trophoblastic membrane infusion, or vitamin supplementation increases the likelihood of a successful pregnancy in women with unexplained, recurrent miscarriage.
We also do not know whether estrogen supplementation increases the live birthrate in women with unexplained recurrent miscarriage, but it may increase the miscarriage rate and cause fetal abnormalities.
We do not know whether progesterone supplementation or corticosteroids reduce miscarriage rates compared with placebo in women with unexplained recurrent miscarriage.
Paternal white cell immunization and intravenous immune globulin treatment do not seem likely to improve live birth-rates compared with placebo in women with unexplained, recurrent miscarriage.
We do not know whether low-dose aspirin, alone or combined with heparin, can increase the live birthrate compared with placebo in women with antiphospholipid syndrome.
Prednisolone plus aspirin may not increase live birthrates in women with antiphospholipid syndrome, and increases the risk of adverse effects compared with placebo.
What are the effects of treatments for unexplained recurrent miscarriage?
Human chorionic gonadotropin
Lifestyle adaptation (e.g., smoking cessation, reducing alcohol consumption, losing weight)
Trophoblastic membrane infusion
Unlikely to be beneficial
Intravenous immune globulin treatment
Paternal white cell immunization
Likely to be ineffective or harmful
What are the effects of treatments for recurrent miscarriage caused by antiphospholipid syndrome?
Aspirin (low-dose) plus heparin
Likely to be ineffective or harmful
Recurrent miscarriage is usually defined as three or more consecutive, spontaneous miscarriages occurring in the first trimester, with the same biological father. A successful birth may or may not follow. About one half of recurrent miscarriages are unexplained. Antiphospholipid syndrome is one of the known causes of first- and second-trimester recurrent miscarriage. Antiphospholipid syndrome is defined as the presence of anticardiolipin antibodies or lupus anticoagulant antibodies, in association with three or more consecutive fetal losses before 10 weeks of gestation, one or more unexplained intrauterine deaths after 10 weeks of gestation, or one or more premature births before 34 weeks of gestation due to severe preeclampsia or impaired fetal growth. This review covers unexplained recurrent miscarriages and first- and second-trimester recurrent miscarriages in women with antiphospholipid syndrome.
In Western populations, recurrent miscarriage affects 1 to 2 percent of women of childbearing age, and about one half of these are unexplained. Antiphospholipid antibodies are present in 15 percent of women with recurrent miscarriage.
Increasing maternal age and number of previous miscarriages increase the risk of further miscarriages. No separate risk factors for antiphospholipid syndrome are known.
On average, the live birthrate for women with unexplained recurrent miscarriage is 75 percent in a subsequent pregnancy, with a miscarriage rate of 20 percent up to nine weeks, and a 5 percent miscarriage rate after this period. However, prognosis varies depending on maternal age and number of previous miscarriages. The chance of a successful subsequent pregnancy after three previous unexplained miscarriages varies from about 54 percent in a 45-year-old woman to about 90 percent in a 20-year-old woman. A 30-year-old woman with two previous unexplained miscarriages has about an 84 percent chance of a successful subsequent pregnancy, whereas for a woman of the same age with five previous unexplained miscarriages, the success rate drops to about 71 percent.
search date: April 2007
Adapted with permission from Duckitt K, Qureshi A. Recurrent miscarriage. Clin Evid Handbook. June 2008:486–487. Please visit http://www.clinicalevidence.bmj.com for full text and references.
This is one in a series of chapters excerpted from the Clinical Evidence Handbook, published by the BMJ Publishing Group, London, U.K. The medical information contained herein is the most accurate available at the date of publication. More updated and comprehensive information on this topic may be available in future print editions of the Clinical Evidence Handbook, as well as online at http://www.clinicalevidence.bmj.com (subscription required). Those who receive a complimentary print copy of the Clinical Evidence Handbook from United Health Foundation can gain complimentary online access by registering on the Web site using the ISBN number of their book.
Want to use this article elsewhere? Get Permissions