Assessment of Ovarian Reserve
Current reproductive function can be subdivided into whether it is
apparently normal, absent, or compromised. When there is evidence of
ongoing ovarian function, there are difficulties in the accurate
assessment of whether there is damage, although measures of ovarian
reserve can provide some data and are summarized in table 1. Measurement
of Follicle Stimulating Hormone (FSH) in the early follicular phase
shows significant inter-cycle variation and is a late indicator of
reduced ovarian reserve. A high result, i.e. over 10 IU/L, even if not
present on a repeated sample, remains an important indicator of at least
some loss of ovarian reserve. Low Anti-Müllerian hormone (AMH),
traditionally used to predict poor response to ovarian stimulation, is
increasingly used to indicate diminished ovarian reserve and correlates
well with antral follicle count.(35) It is important to realize that low
AMH is not predictive of the inability to conceive in regular cycling
women who are actively trying to become pregnant.(36,37) Recent data
show the value of AMH in prediction of natural menopause, but its
accuracy falls sharply with decreasing age.(38) While AMH can
distinguish categories of gonadotoxic risk in AYA cancer survivors its
use in predicting duration of future fertility is unclear (39,40).
Furthermore, concurrent treatment with exogenous hormones, either as
replacement or as contraception, makes FSH levels uninterpretable and
may suppress AMH by up to 30%.(41) As such, there are few reliable
measure of ovarian reserve that can aid in predicting future fecundity
in AYA survivors. The ideal variable would progressively decrease in a
linear manner and allow for a window of time after crossing a threshold
when oocyte preservation might be attempted after cancer treatment. It
may be more helpful to trend measures such as AMH over time.
Additionally, due weight should be given to predicted fertility risk
based on therapy received.(42) Conversely, it is also essential to
discuss the need for contraception when patients are at risk of
unplanned and unwanted pregnancy.