What Is the Pregnancy Rate at Age 37? Up to What Age Is Egg Freezing Possible? A Clinical Perspective
What Is the Pregnancy Rate at Age 37? Up to What Age Is Egg Freezing Possible? A Clinical Perspective
We have recently been receiving more inquiries from individuals asking, “At 37, do I still have time?”
It is well known that the likelihood of pregnancy declines with age. At the same time, many women in their late 30s still go on to have successful pregnancies and deliveries. For those around the age of 37, it is normal to wonder what the actual chances of conceiving are, and how long fertility can be maintained.
At our clinic, we increasingly hear questions such as:
● Is egg freezing still an option at my age?
● Is it still possible for me to become pregnant?
In this article, we outline the age-related changes in fertility and explain the timeline of the female body from a medical perspective, with a focus on pregnancy and childbirth around the age of 37.
How Fertility Changes with Age
The probability of natural conception gradually declines with age. It is estimated at approximately 18% per cycle at age 35 and around 5% at age 40. At age 37, the probability is about 11.5%.
Compared with women in their 20s and early 30s, the decline becomes more noticeable after the age of 35.
Source: Gynecology Lab “The Probability of Natural Conception Is Lower Than You May Expect”
In addition to lower conception rates, the likelihood of chromosomal abnormalities increases with age. This is associated with a higher incidence of conditions such as Down syndrome. The risk rises after age 35 and is estimated at approximately 4.4% at age 37.
Maternal Age and the Frequency of Chromosomal Abnormalities
表：Maternal Age, Risk of Down Syndrome (per birth/per 1,000 births), Risk of Any Chromosomal Abnormality (per birth/per 1,000 births)
Source: Ministry of Health, Labour and Welfare (2013), “Study Group on the Future of Support Programs for Infertility Treatment”
Age at First Childbirth: 16.6% in Women Aged 35–39
According to 2023 data, 16.7% of women who gave birth to their first child were aged 35–39, approximately one in six. For second births, the proportion in this age group rises to 26.9%.
While these figures may feel reassuring to some, it is important to recognize that fertility itself does decline after 35.
A woman’s eggs are formed before birth and do not increase in number over time. As a result, both the quantity and quality of eggs gradually decline with age.
Even when ovulation occurs, the likelihood of chromosomal abnormalities or miscarriage increases. These changes generally become more apparent after age 35, and the probability of natural conception in the 40s decreases to around 5%.
What Is “Advanced Maternal Age”?
In medical terms, a first pregnancy at age 35 or older is defined as “advanced maternal age.” While it has become more common to have children later in life, the biological risks associated with age remain unchanged.
After 35, the risks of chromosomal abnormalities and pregnancy-related complications gradually increase. For this reason, it is important to consider age when planning for pregnancy.
From a clinical perspective, there are two main areas to consider when preparing for pregnancy.
The first is to optimize overall physical condition and maintain hormonal balance. Hormonal balance plays a key role not only in conception but also in women’s general health. It is important to pay attention to signs that may reflect hormonal imbalance, such as irregular menstruation, premenstrual syndrome (PMS), sensitivity to cold, sleep disturbances, and skin concerns.
To support stable hormonal function, the following daily habits are recommended:
● A well-balanced diet
● Adequate sleep
● Regular, moderate physical activity
● Managing stress and allowing time for relaxation
As another aspect of preparation, there is also the option of oocyte cryopreservation (egg freezing)—retrieving and preserving eggs at a younger age, when fertility potential is relatively higher, in order to prepare for possible future fertility treatment. If assisted reproductive treatment is required later, the use of frozen oocytes may have a significant impact on treatment outcomes.
However, it is important to note that egg freezing has age-related considerations. In general, egg retrieval is recommended before the age of 40, and the use of frozen oocytes is typically considered up to around age 50.
What Is the Success Rate of Egg Freezing at Age 37?
The likelihood of achieving pregnancy after egg freezing depends on several factors, including:
● Age at the time of egg freezing
● Number of eggs preserved
● The technical expertise of the clinic performing the retrieval
These and other factors all play a role. In general, outcomes are more favorable when eggs are frozen at a younger age.
Frozen eggs are used after thawing. Looking at key indicators such as survival after thawing and subsequent fertilization rates:
● Post-thaw survival rate of frozen eggs: 80–95%
● Fertilization rate following sperm injection (ICSI): 60–80%
These are the typical ranges reported.
If viable, high-quality embryos are obtained, the next consideration is the likelihood of achieving a live birth. The following figures are expressed per 10 embryos.
Birth rate
(per 10 embryos after thawing and confirmation of good-quality embryos)
● ≤30 years: ~80%
● 31–34 years: ~75%
● 35–37 years: ~53%
● 38–40 years: ~30%
● ≥41 years: ≤20%
While relatively high success rates can be expected up to the early 30s, outcomes decline after age 35. In addition, a greater number of frozen eggs is associated with a higher likelihood of achieving pregnancy.
Reference: Grace Sugiyama Clinic SHIBUYA — Pregnancy and Live Birth Rates in Egg Freezing
If You Are Unsure, Start with an AMH Test
Some individuals may feel that egg freezing is a significant step. As an initial approach to preparing for future pregnancy, AMH testing can be considered.
AMH (Anti-Müllerian Hormone) is a type of female hormone measured through a blood test. It provides an estimate of how many eggs remain in the ovaries and is sometimes described as an indicator of “ovarian age.”
There is natural variation between individuals. Even among women of the same age, AMH levels can differ. Measuring your AMH level allows you to better understand your current fertility potential and ovarian status in a more objective way.
At Grace Sugiyama Clinic SHIBUYA, results are typically available within 30 to 60 minutes on the same day. For those who prefer, results can also be reviewed at a later visit. Rather than simply providing the results, physicians explain how to interpret the values. If you have any questions or concerns, you are encouraged to discuss them during your consultation.
The test itself can be performed at any point in the menstrual cycle. As it is a blood test, only a small sample is required. For individuals taking oral contraceptives, AMH levels may appear lower than usual; if a more accurate assessment is desired, it may be advisable to temporarily discontinue use for one month prior to testing.
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Is it still a viable option for you?
Many individuals around the age of 37 express concern that it may already be too late. However, fertility cannot be assessed based on age alone. Personal circumstances—such as partnership status and future reproductive plans—vary from one individual to another.
To make decisions that align with your circumstances, it can be helpful to first understand your current status through appropriate testing.
Whether you are considering pregnancy now or in the future, early awareness and preparation are important.