The purpose of the study was to determine if young women (age 35 or younger) with follicle stimulating hormone (FSH) levels between 8-10 mIu/mL have lower clinical pregnancy rates in their first in vitro fertilization cycle (IVF) compared to young women with FSH levels less than 8.METHODS:
Retrospective cohort study of young women undergoing their first IVF attempt between 1/1/2010 and 12/19/2016. All subjects had a day 2/3 FSH and estradiol drawn within one year of their IVF cycle. The probability of clinical pregnancy was compared between the two groups using Pearson’s chi-squared test at a 5% significance level. Logistic regression analysis was used to assess the effect of confounding factors. An ROC analysis was conducted to evaluate other potential cutoffs.RESULTS:
Three hundred fifty two women age 35 or younger with FSH levels less than 10 and normal estradiol levels met criteria. There were no significant differences in age, BMI, gravidity, or parity between groups. Stimulation outcomes were similar. Clinical pregnancy rates were lower in the FSH 8-10 group (28.3% versus 43.8%, P=.035) and remained significant when controlling for potential confounders via logistic regression analysis.CONCLUSION:
Young women with FSH levels between 8-10 had lower clinical pregnancy rates after IVF than those with FSH levels less than 8. An FSH level of 8 or greater may represent premature ovarian aging in young women. Anticipatory counseling and sooner referral to reproductive endocrinology and infertility may be warranted at a new threshold level in young women.