Older Women: Getting Pregnant in Your Mid 30s and 40s
An increasing number of women are choosing to have children in their mid-30s or later, when the “biological clock” begins to loom large as a worry. “I met Mr. Right late” is one of the most frequent laments among women participating in our monthly infertility support group. “I haven’t met Mr. Right and want to preserve my fertility until I do” is a wish of many of our patients, who seek to preserve their fertility by freezing their eggs for use at a later age, when they have met their life partner and wish to have a baby. At Michigan Reproductive Medicine, we offer real hope and provide real solutions for many women choosing to have a child in their mid-30s or later.
Advancing female reproductive age creates a challenge to fertility. A woman’s opportunity to have a healthy child in large part depends on her ability to produce good eggs, and this ability declines as she moves into her mid-30s and beyond. Getting pregnant after age 40 is a challenge for women that may have no other impediment to conception. Ovary reserve refers to both egg quantity and egg quality. Many more of our patients are recognizing that having regular menstrual cycles and being in good physical health are encouraging, but don’t provide reassurance about ovary reserve.
Ovarian Reserve: Knowing Where you Stand
We can assess ovary reserve with several tests that determine your fertility potential. These tests mainly assess egg quantity. There are no reliable tests to assess egg quality short of observing their performance during In-vitro fertilization therapy. However, if egg quantity is very low, egg quality is likely similar with some exceptions.
Knowing your ovary reserve assists in selecting the optimal treatment to succeed in having a healthy baby.
Hormone Blood Tests to Assess Ovarian Reserve
Anti-Mullerian Hormone (AMH)
AMH is a hormone produced in the ovary by cells surrounding each egg that has just been activated coming out of long-term storage. Usually hundreds of eggs activate at one time. Over the next 6 months, like a wave that diminishes as it moves to the shore, most eggs wither and are lost while one egg prevails and is released (ovulated) at the end of its 6-month journey. The more eggs that are activated at one time, the higher the AMH blood level, which is generally good. In short, AMH is a long-term forecast of your ovary reserve.
How do I interpret the AMH test result?
Our doctors often compare AMH to the gas gauge in your car: you don’t want to be at “E” for empty. Usually ¼ tank to a full tank (4/4). Take the numerators in a range from 1 to 4 as normal. We require our egg donors ages 18-28 to have an AMH level of 2 or greater. AMH value less than 1 raises concern for diminished ovarian reserve. AMH levels greater than 4 often are related to the excessive egg activation caused by polycystic ovary syndrome.
If you present with infertility, an AMH value in the range of 1 to 4 is considered normal. A result less than 1 raises concern for diminished ovarian reserve as a potential cause of infertility. A value greater than 4 is commonly associated with infertility related to polycystic ovary syndrome- excessive number of activated eggs, but a problem of impaired ovulation.
If you are interested in fertility preservation by planned egg banking (freezing), but have not been trying to become pregnant (not proven infertile), then the above AMH normal range 1 to 4 does not imply infertility as it would for women demonstrating infertility. A study in 2017 measured AMH levels among women having children (proven fertile). Many fertile woman less than 35 years of age had AMH levels less than 1. Lower AMH levels reflect a lower number of eggs likely to be recruited for planned egg banking, but not lower egg quality. A woman may need to consider undergoing more than one cycle of egg harvesting in this situation in order to accumulate and store their desired number of eggs.
When is the best time to test AMH?
AMH can be tested at any time, regardless of whether you have regular menstrual cycles or not.
AMH is the best test to estimate how your ovaries will respond to fertility medications. It serves as the best test for our doctors to estimate the optimal dose of fertility medication for your fertility treatment plan.
Follicle Stimulating Hormone (FSH)
FSH is a hormone made in the pituitary gland of your brain, not your ovary. It does what its name suggests—stimulates a follicle and its egg within the ovary to grow in preparation for ovulation (release of the egg). You make the most FSH for the entire menstrual cycle month in the first three days of your menstrual period. That’s the time we like to obtain the blood test and discover the maximum FSH level. The follicles and the cells that surround the eggs within them should quickly respond to FSH and release estrogen into the blood stream. The estrogen signals the brain not to release too much FSH in order to avoid releasing more than one egg a month. In short, if your system is very efficient (good ovary reserve) your FSH level should be pretty low and your estrogen level should not be too high. If the eggs in the ovary are too few and not very responsive to FSH (diminished ovary reserve), then the brain will compensate by releasing abnormally high amounts of FSH pushing the ovary harder to release an egg.
What is the best time to test FSH?
FSH should be tested in the first three days of menstrual flow starting with any sign of menstrual bleeding.
How do I interpret the FSH test result?
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- If your ovary reserve is not diminished, then the peak FSH level during the first three days should be low, less than a value of 10.
- FSH value of 10 or greater raises concern for diminished ovary reserve.
- FSH value of 15 or greater raises great concern for substantial decline in fertility potential of your eggs.
- FSH value of 20 or greater suggests a very low fertility potential. The highest FSH value for which any of our patients have had a baby is 32, and that was the same as her age of 32 years! Even with abnormally elevated FSH levels, there may still be hope to succeed in having a baby with your own eggs. Our doctors are well recognized as an “FSH-friendly” physicians.
Drawbacks to FSH Testing
- FSH levels can vary from month to month: a result of “7” one month (normal) and “12” the next month (abnormal is greater than 10). The “high water mark” value likely tells the story. Therefore, it is better to check FSH levels during more than one month.
- It can be a “late bloomer” test. Although a true egg problem may be present, the FSH level can be normal for years and finally rise into the abnormal range.
- If ten different women have the same test result, for example an abnormally elevated result of “12”, they can have a broad range of abnormally diminished ovary reserve among them, from minor to major. That’s why our doctors present the wide value ranges of less than 10, less than 15, less than 20 or 20 and above to interpret the results.
Estradiol (E2)
Estradiol is the most potent form of estrogen in your body and is responsible for maintaining healthy eggs in your ovaries. FSH from the brain drives the release of estradiol from cells that surround eggs in the ovary. If a test reveals an abnormally elevated level of estradiol of a value of 100 or greater in the first three days of your period, this is a sign that FSH activity is also too high. This is true regardless of whether the FSH blood test value is normal (less than 10 at that time) and is a sign of diminished ovary reserve.
Ultrasound Evaluation to Assess Ovary Reserve
Antral Follicle count (AFC)
One of the best ways to assess ovary reserve is to count the number of resting follicles present inside both ovaries within the first three days of your menstrual period. Ideally, about 10-20 total follicles, each less than 10 mm in size should be seen. If the follicle count is lower than 8, this may be a sign of diminished ovary reserve. The number of resting antral follicles also provides an estimate for how many eggs may be recruited for fertility treatments with ovulation induction, whether for intrauterine insemination (IUI) or In-vitro fertilization (IVF) therapies. We expect our egg donors, ages 18-28 years, to have at least 16 resting antral follicles. Women with an excessive AFC of more than 12 resting antral follicles on each ovary and irregular menstrual cycles may have infertility related to polycystic ovary syndrome.
Please make an appointment with one of MRM’s fertility expert physicians to discover and follow the best fertility options available to begin building your family.
