Miscarriage is the spontaneous loss of a pregnancy before the 20th week. About 10 to 20 % of known pregnancies end in miscarriage. Most miscarriages occur before the 12th week of pregnancy .
There are two types of miscarriage: sporadic and recurrent . Recurrent miscarriage affects about 1% of couples. By contrast, at least 25 % and probably as many as 50 % of all women experience one or more sporadic miscarriages usually due to random fetal chromosomal abnormalities[3-5] , the risk of which rises with increasing maternal age .
1. Mayo clinic website. http://www.mayoclinic.org/diseases-conditions/pregnancy-loss-miscarriage/basics/definition/con-20033827.
2. Rai R, et al. Lancet 2006;368:601-611.
3. Stirrat GM. Recurrent miscarriage. Lancet 1990; 336: 673–75.
4. Stephenson MD, Awartani KA, Robinson WP. Cytogenetic analysis of miscarriages from couples with recurrent miscarriage: a casecontrol study. Hum Reprod 2002; 17: 446–51.
5. Greenwold N, Jauniaux E. Collection of villous tissue under ultrasound guidance to improve the cytogenetic study of early pregnancy failure. Hum Reprod 2002; 17: 452–56.
6. Regan L, Rai R. Epidemiology and the medical causes of miscarriage. Baillieres Best Pract Res Clin Obstet Gynaecol 2000; 14: 839–54.