Women with a history of elevated levels of follicle-stimulating hormone (FSH) may have worse odds of becoming pregnant using assisted reproductive technologies (ART), says a new study.1
The Hormone Link
It's well known that patients presenting with elevated levels of FSH prior to beginning in vitro fertilization (IVF) treatment are discouraged by their physicians from going ahead with therapy, since these increased hormone levels are tied closely with low odds of IVF success, wrote the study investigators led by Zev Rosenwaks, MD. Other studies have strongly suggested that.2,3
But while in some patients, FSH levels at the beginning of an IVF cycle may be normal, they may also have a history of higher FSH levels, which could be just as detrimental. To test that possibility, Rosenwaks and his team conducted a retrospective analysis of nearly 2,000 consecutive IVF cycles performed at the Center for Reproductive Medicine and Infertility at Weill-Cornell Medical Center in New York.
"We proposed to determine the impact of a patient's FSH history on IVF outcome and how to best counsel these couples at their initial visit before time and money has been spent in preparation for treatment," wrote Rosenwaks, director of the fertility clinic that was the study's focus, and his fellow researchers. "Such patients should be channeled to either adoption or oocyte [egg] donation and spared the time and expense on low-yield treatments."
Higher FSH Levels May be Detrimental
The study investigators collected information on IVF outcomes performed between 2001 and 2003 between those with a history of elevated FSH levels and those with a history of normal FSH levels. The patients were then separated by age: those under age 35, those ages 35 to 40, and those over age 40. All patients had had a normal FSH level at the start of their IVF cycle.
Rosenwaks and his team reported all patients had undergone routine IVF procedures using standard ovulation induction methods. Retrieved eggs were fertilized using either IVF or intracytoplasmic sperm injection (ICSI), a procedure in which a single sperm is injected into an egg in cases of male-factor infertility.4
After analyzing the entire patient data, Rosenwaks' group found that the total number of eggs retrieved per patient was lower in women who had a history of higher FSH levels compared to those with a history of normal hormone levels. This was true even after taking a patient's age into account.
Impact of Patient's Age
When the researchers broke down the data by age, those over age 40 with a history of elevated FSH had lower odds of both embryo implantation and pregnancy success due to poorer embryo quality. Those under 40 tended to have the same chances of embryo implantation and pregnancy as those in the general IVF population, Rosenwaks and his group noted. However, in women with a history of at least three instances of elevated FSH, no pregnancies had been achieved, regardless of age.
In conclusion, the investigators noted that younger patients with normal FSH levels at the start of an IVF cycle, but with a history of elevated FSH, are more likely to have fewer eggs collected for fertilization, "but does not translate to either lower pregnancy or implantation rates." Those over age 40 have poorer outcomes if they have a history of elevated FSH, even if their FSH levels are normal at the start of an IVF cycle. "As expected, age is an excellent predictor of IVF success; however, the combination of age greater than 40 years and prior elevations in FSH predicts a particularly poor outcome," they wrote.
Based on their findings, FSH testing should continue to be an important prognostic evaluation given to women prior to starting IVF, Rosenwaks' team wrote. "Certainly, women aged greater than 40 years with a history of elevated basal FSH levels should be counseled on their poor prognosis with IVF and directed toward more appropriate options, such as oocyte donation or adoption."
1. Roberts JE, Spandorfer S, Fasouliotis SJ, Kashyap S, Rosenwaks Z. Taking a basal follicle-stimulating hormone history is essential before initiating in vitro fertilization. Fertil Steril 2005 Jan;83(1):37-41.
2. Scott RT, Toner JP, Muasher SJ, Oehninger S, Robinson S, Rosenwaks Z. Follicle-stimulating hormone levels on cycle day 3 are predictive of in vitro fertilization outcome. Fertil Steril 1989 Apr;51(4):651-4.
3. Ebrahim A, Rienhardt G, Morris S, Kruger TF, Lombard CJ, Van der Merwe JP. Follicle stimulating hormone levels on cycle day 3 predict ovulation stimulation response. J Assist Reprod Genet 1993 Feb;10(2):130-6.
4. American Society for Reproductive Medicine (ASRM). Patient's Fact Sheet: Intracytoplasmic Sperm Injection (ICSI). Available at: http://www.asrm.org/Patients/FactSheets/ICSI-Fact.pdf. Accessed March 29, 2005.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include coverage of health news for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.