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Does Low Egg Count Predict Infertility?

The answer is no. Fertility is a functional diagnosis. If your numbers are high but you don’t get pregnant, then you may have infertility. If your numbers are low but you do get pregnant, you don’t have infertility. The caveat to this however, is that for women, as we age, our fertility declines. Unlike men, who make new sperm every 60-90 days for the duration of their life (unless they are exposed to physical, genetic, or chemical testicular injury), women do not make new eggs. Therefore with age, our egg numbers and egg quality decline leading to a drop in fertility and an increase in miscarriage rates.

pregnancy rate
Reproductive Ageing: Guidelines for First Line Physicians for Investigation of Infertility Problems (CFAS, 2004)

The attached graph is an old but still relevant graph reflecting decreasing monthly pregnancy rates with age (blue) and increasing miscarriage rates with age (red).

Anti-mullerian hormone (AMH) can be measured in the blood and reflects egg reserve. Studies have correlated this measure to number of eggs retrieved at egg retrieval (either for egg freezing or IVF) and with age of onset of menopause (see study). A recent article in the Journal of the American Medical Association confirmed that for women who had not yet tried to conceive and had random AMH levels drawn, conception rates over 6 months ( 70%) were not different for women who had low AMH levels compared to higher AMH levels. Since fertility is a functional diagnosis, this makes sense.

So why are people and companies promoting random “fertility assessments”, home AMH tests, and other assessments which may increase anxiety but not predict fertility? These days we have become accustomed to tracking everything: diet, fitness, steps. We want to be informed because knowledge is power. Also these days we can take proactive measures such as egg freezing to try to preserve our fertility until we are ready and close the “fertility gender gap“.

Egg number does not predict fertility. However, egg age does predict fertility. Even fewer eggs at a younger age saved may have a higher potential for pregnancy than more eggs available at an older age. For example, from worldwide data we know that 10 eggs frozen before age 35 have a 60% or better chance of baby. Ten eggs available at age 40 may have only a 30-40% chance of baby. If a younger woman has a low egg count for age on one observation, we do not know if that egg count will remain stable over time  until she reaches the age at which that egg count is expected or if the egg count will drop precipitously. The only way to know this is to assess two points in time. What is known is that over time fertility, egg quality and egg count will decrease for all women.

Therefore, I suspect the promotion of such home testing etc is not necessarily to scare women into aggressive action but to provide knowledge so that they act according to what they value most. For some who may be ready to conceive, knowledge may encourage them to try sooner than they would have. For others, they may decide that since they don’t know what will happen over time, egg freezing may be important for them. Others may realize that they are just fine as they are but if they do start trying to conceive and things don’t happen in a reasonable timeframe, they may be more proactive about pursing evaluation sooner than later.

One thing is for sure, whatever the circumstances are, getting pregnant for women will be easier sooner than later. And we believe knowledge is power. Visit us at www.genesis-fertility.com to explore your options.

 

 

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