In vitro fertilization, IVF, is a fertility treatment that involves combining eggs and sperm outside the body and then placing the embryo in the uterus. The procedure was originally developed as a treatment option for women who had fallopian tube disorders. The number of babies born using IVF increased from one million between 1981 and 2003 to two million by 2005.
To investigate the association between the number of eggs produced and miscarriage rate following IVF treatment, the researchers analyzed data from 402,185 stimulated fresh IVF cycles collected between 1991 and June 2008 from the Human Fertilization and Embryology Authority’s list of assisted reproductive treatment in the United Kingdom. The researchers also analyzed 124,351 pregnancy outcomes.
According to the study, the number of eggs produced following ovarian stimulation in an IVF cycle was strongly associated with the rate of miscarriage. Women with a poor ovarian response — defined as women who produced four or less eggs — had a miscarriage rate of 20 percent. The rate fell to 15.5 percent among women who produced five to nine eggs and 13.8% for women who produced 10 to 14.
In other words, the number of eggs produced following ovarian stimulation in an IVF cycle correlates to the rate of miscarriage. Women who produce fewer eggs have a higher risk of miscarriage while women who produce more eggs have a lower risk.
Additionally, the researchers hypothesis that the increased risk of miscarriage following poor ovarian response after IVF is the result of a decline in the quality of the eggs.
States co-author Professor Arri Coomarasamy of the School of Clinical and Experimental Medicine at the University of Birmingham:
“It has always been a question to be answered, whether women with low ovarian reserve had high miscarriage risk. Our study which is largest to date has shown that women with low ovarian reserve indeed have a high risk of miscarriage. Even younger women with a low ovarian reserve have a high chance of miscarriage.”
The results of the study could help improve counseling for couples undergoing IVF treatment by increasing the awareness of the risk of miscarriage for women with poor ovarian response.
Another recent study suggested that women who conceive with the help of assisted reproductive therapies are at an increased risk for serious birth complications including stillbirth, preterm birth, low birth weight, and neonatal death.
Association between response to ovarian stimulation and miscarriage following IVF: an analysis of 124 351 IVF pregnancies: http://humrep.oxfordjournals.org/content/early/2014/03/19/humrep.deu053.abstract
Miscarriage risk increases for women who respond poorly to IVF ovarian stimulation: http://www.medicalnewstoday.com/releases/274325.php
IVF Ovarian Stimulation and Miscarriage Risk: http://www.freeimages.com/photo/723739