I met this emi­nent repro­duc­tive endocri­nol­o­gist from Europe at a con­fer­ence and we were dis­cussing low egg reserve and he ver­bal­ized what repro­duc­tive endocri­nol­o­gists always knew but in a very clear state­ment ” you can­not cre­ate a repro­duc­tive poten­tial for a woman, a good repro­duc­tive endocri­nol­o­gist can take a woman and get her to the max­i­mum of her ovar­ian poten­tial  and IVF suc­cess” This issue comes often into dis­cus­sions of suc­cess rates of fer­til­ity treat­ment in gen­eral, fer­til­ity preser­va­tion, egg freez­ing, ovar­ian tis­sue freez­ing and any other topic related to the suc­cess of achiev­ing and main­tain­ing a preg­nancy, even if the cause for sub-fertility is related to the male partner.

Ovar­ian reserve is defined as the num­ber and qual­ity of eggs remain­ing in the ovary. It cor­re­sponds to fer­til­ity poten­tial in women. Many sci­en­tists were fas­ci­nated with the ovary and were inter­ested in pre­dict­ing the num­ber of eggs at a given age. One such model is shown here.

It was real­ized how­ever, that there are con­sid­er­able indi­vid­ual vari­a­tions among women of the same age due (between the orange and green lines in the fig­ure) to genetic and other fac­tors. In other words tools other than age are always needed to bet­ter pre­dict ovar­ian reserve, fer­til­ity poten­tial and suc­cess of treat­ment. A large group of tests were devel­oped. Will dis­cuss the most infor­ma­tive ones here.

FSH (fol­li­cle stim­u­lat­ing hor­mone). A hor­mone that is pro­duced by the mas­ter gland in the brain and con­trols the devel­op­ment of fol­li­cles (the units that con­tain the eggs) in the ovary. As the num­ber of fol­li­cles decrease, FSH increases. Lev­els on the sec­ond or third day of the cycle reach­ing 12-15mIU/mL or higher were found to asso­ci­ated with reduced chance for suc­cess­ful fer­til­ity treatment.

Ultra­sound scan for antral fol­li­cle count. Ultra­sound scan early after menses can iden­tify small fol­li­cles within the ovaries. This gives an imme­di­ate impres­sion of ovar­ian reserve. Low num­bers e.g. < 10 in both ovaries indi­cate low reserve.

Antim­ul­ler­ian hor­mone (AMH). Its a hor­mone pro­duced by the cells sur­round­ing the egg. It can be tested at any day of the cycle. Lev­els < 1ng/mL gen­er­ally indi­cates low reserve.

Two pre­cau­tion­ary notes; 1. Abnor­mal value of these or other tests does not auto­mat­i­cally indi­cate that a woman should be pre­vented from try­ing using her own eggs. The pre­dic­tive abil­ity of these tests is mod­est and not absolute (these tests can make mis­takes) 2. The­ses tests inter­act with other fac­tors as age. Younger women with high FSH have higher suc­cess rates than older women with sim­i­lar value. The results of these tests should be care­fully inter­preted by a repro­duc­tive endocri­nol­o­gist. Gen­er­ally women should not be denied treat­ment based on the test result alone. These tests have low abil­ity to pre­dict the occur­rence of pregnancy.

Egg qual­ity. In short it means the egg has fin­ished reduc­tion divi­sion with appro­pri­ate num­ber (23) and struc­ture of its chro­mo­somes. Tests for ovar­ian reserve can­not directly pre­dict the qual­ity of indi­vid­ual eggs or embryos. Age is a bet­ter pre­dic­tor of egg qual­ity. Inva­sive tests were devel­oped to detect the num­ber and struc­ture of chro­mo­somes in the egg (nor­mal 23) or embryo cells (nor­mal 46). So far there is no proof that any of these tests is 100% accu­rate nor there is proof that they improve out­comes of fer­til­ity treatment.

What are the ben­e­fits of test­ing for ovar­ian reserve?

1. For women: to have some insight into the chances for suc­cess of their fer­til­ity treatment

2. For their repro­duc­tive endocri­nol­o­gists: to be able to tai­lor fer­til­ity treat­ments to improve suc­cess rates. Low ovar­ian reserve may require mod­i­fi­ca­tion of fer­til­ity med­ica­tion to improved response.

3. In fer­til­ity preser­va­tion: the suc­cess of preser­va­tion is espe­cially related to egg reserve. In the major­ity of cases, freez­ing of eggs and embryos for preser­va­tion of fer­til­ity. For exam­ple, women with low egg reserve will pro­duce small num­ber of mature eggs after stim­u­la­tion. Because some of the eggs will not sur­vive thaw­ing, they will end with small num­ber of embryos avail­able for trans­fer. Some physi­cians pre­fer to restrict egg freez­ing or ovar­ian tis­sue freez­ing to women younger than 40 with nor­mal reserve.

4. In women exposed to chemother­apy: expo­sure to cyclophos­phamide and other agents markedly reduce egg reserve. Eval­u­a­tion of ovar­ian reserve may reflect fer­til­ity poten­tial after can­cer treat­ment. Very young women exposed to less toxic treat­ments may pre­serve their future fer­til­ity after can­cer treat­ment. Mark­ers of ovar­ian reserve are how­ever, may not accu­rately reflect dam­age caused by chemother­apy. Women with nor­mal ovar­ian reserve after chemother­apy com­monly exhibit low response to fer­til­ity medications.

Read more about ovar­ian reserve and low response to ovar­ian stim­u­la­tion in my review