After 35, can you really afford to wait to do IVF? The differences in protocols for ages 35–39 and 40+ are bigger than you might imagine.

Many women first truly realize that “age affects fertility,” not on their 35th birthday, but when trying to conceive has not led to results for some time, or after receiving test results such as AMH and antral follicle count. Even among women trying to conceive at an advanced age, a 36-year-old and a 41-year-old do not necessarily face exactly the same issues.

At ages 35–39, there may still be some time and room to choose among options; after entering the 40s, as factors such as ovarian reserve, oocyte quality, and the risk of embryonic chromosomal abnormalities change, fertility planning often places greater emphasis on efficiency and time.

For families preparing to pursue IVF or Thailand third-generation IVF for overseas fertility treatment or cross-border childbirth, “advanced age” should not be treated simply as one uniform label. What truly matters is: Which age stage has been reached? How much ovarian reserve remains? When should testing be done? Should they keep trying, or enter an assisted reproductive cycle as soon as possible?

Today, Huanqiu Xinsheng will begin with age stratification and clearly explain several key issues that women of advanced age should consider when undergoing assisted reproduction.

01 | 35 Is a Line, but 40 May Be the Milestone That Deserves More Attention

Clinically, an age at expected delivery of ≥35 years is generally defined as advanced maternal age, making 35 an important cutoff in the management of women’s reproductive age. However, it is important to understand that fertility does not suddenly decline on a woman’s 35th birthday; rather, it changes gradually with increasing age.

The clinical guidelines referenced indicate that after women enter their 35th year, the risk of miscarriage increases with age, the incidence of infertility gradually rises, and pregnancy and live birth rates begin to decline significantly; related risks such as pregnancy comorbidities, complications, and birth defects also increase accordingly. Therefore, in practical management, “≥35 years” still needs to be broken down further.

35–39: Time Begins to Matter

Although this stage already falls within advanced maternal age, ovarian reserve and fertility can still vary greatly among individual women. Some women still have relatively good AMH, basal hormone levels, and antral follicle findings at 36; others already show a noticeable decline in ovarian reserve around age 35. Therefore, the most important thing at this stage is not to become anxious just because you see the words “advanced age,” but to learn your true fertility status as soon as possible and not wait repeatedly without understanding your ovarian status.

≥40: Greater Emphasis on Early Evaluation and Treatment Efficiency

After age 40, clinical management is usually more proactive. There are clear differences in pregnancy risk between women aged 35–39 and those aged 40 and above, so individualized fertility treatment plans should be developed according to different age stages. In other words: After 35, pay attention to time; after 40, it is even more important to avoid wasting time ineffectively.

This is also why, when two women with seemingly similar AMH levels both come to Thailand for consultation about Thailand third-generation IVF, if one is 36 and the other is 41, the doctor’s treatment approach may be completely different.

02 | For IVF at an Advanced Age, the First Step Is Not Choosing a Protocol, but Understanding the Ovarian “Foundation”

When many people consult about IVF, their first question is, “Doctor, what ovarian stimulation protocol is right for me?” In fact, before discussing ovarian stimulation, a more important step is to complete a fertility evaluation first. Age can only tell us a general trend; when actually creating a plan, it is also necessary to make a comprehensive assessment based on ovarian reserve, basal hormones, antral follicle count, and previous treatment history.

Ovarian Reserve Cannot Be Assessed by AMH Alone

AMH is important, but AMH is not the only indicator for assessing ovarian status. At present, no single indicator can fully define diminished ovarian reserve, so it is more advisable to combine factors such as age, hormone levels, anti-Müllerian hormone (AMH), and ultrasound antral follicle count (AFC) for a comprehensive evaluation.

This is also why some women ask, holding an AMH report, “My AMH is just over 1—can I still do it?” In fact, it is difficult to give an accurate answer based on this single number alone. Doctors usually also need to look at the menstrual cycle, basal FSH/LH/E2, AFC, previous ovarian stimulation response, previous number of oocytes retrieved, and embryo development. Inhibin B (INH B) and ovarian volume alone are not recommended as primary indicators for assessing ovarian reserve. So, rather than obsessing over one test number, it is better to give the complete report to a reproductive doctor for an overall assessment.

03 | When Should Women Aged 35–39 and Those Over 40 Get Tested?

This is a very important point.

35–39: If Not Pregnant After 6 Months of Trying, Seek Evaluation Soon

For women aged 35–39, if they have not used contraception and have been trying to conceive regularly for about 6 months without success, it is not advisable to continue waiting indefinitely. At this point, ovarian reserve evaluation and relatively complete infertility-related testing should be performed. Testing should not focus on the woman alone. If a couple is trying to conceive together, the man’s semen status, tubal factors, uterine and endometrial conditions, and other factors should also be considered together to identify the cause.

≥40: Fertility Evaluation Can Be Done Directly

After age 40, the situation is different. Women aged ≥40 may consider undergoing fertility evaluation immediately, with a focus on ovarian reserve while also completing other necessary infertility-related tests. In other words, if a woman is already 41 or 42, she does not necessarily need to try naturally for six months or even a year before getting tested. For this age group, time itself is one of the important variables affecting fertility outcomes.

For families planning overseas fertility treatment or cross-border childbirth, Huanqiu Xinsheng also usually recommends completing as many basic tests as possible in your home country first, then sending the test materials to a Thai doctor for evaluation in advance. This allows a clearer understanding of the general treatment direction, cycle arrangements, and time costs before formally traveling to Thailand, and can reduce the situation of discovering only after arriving in Thailand that many additional tests are needed.

04 | If AMH Is Low, Is There a Way to “Restore” the Ovaries?

This is one of the easiest misconceptions for women of advanced age to fall into. After seeing AMH decline, many people’s first reaction is: “Is there any medication that can raise AMH?” But what truly deserves attention is not simply making a number on a report look better, but how many follicles the ovaries can actually recruit, how many mature oocytes can be obtained, and whether embryos with developmental potential can ultimately be formed. For women of advanced age with diminished ovarian reserve, there is currently no so-called specific treatment.

Two possible adjunct interventions are mentioned:

DHEA (dehydroepiandrosterone) may improve ovarian response, the number of oocytes retrieved, and related outcomes in some patients with diminished ovarian reserve, but the available evidence remains insufficient.

Growth hormone (GH) may also improve ovarian response in some women with poor ovarian response, but it likewise should not be understood as a “universal solution” suitable for all women of advanced age.

Therefore, whether DHEA, growth hormone, or other adjunct medications, it is not advisable to purchase and use them on your own. Whether they are needed, when to use them, and for how long should be decided by a reproductive doctor based on the individual’s situation.

05 | Women Aged 35–39 May Try IUI First; Why Is IVF More Often Favored After 40?

Age not only affects fertility but also directly influences the choice of treatment path. For women under 40, some eligible individuals may consider trying IUI first, but it is important to fully understand that the probability of successful pregnancy gradually declines with increasing age. For patients aged ≥40, continuing with IUI is not recommended; instead, IVF is more often favored directly to improve the efficiency of achieving a chance at pregnancy. The core idea behind this is actually easy to understand: the older the patient, the more important it is to calculate the “time cost.” If one treatment is unsuccessful, what is lost is not just one cycle, but also several months of reproductive time.

Therefore, for women over 40, doctors usually pay more attention to how to maximize the informational value and efficiency of each treatment cycle under limited time and ovarian reserve conditions. At the same time, reasonable expectations must be established. As age continues to increase, even after entering an IVF cycle, cumulative pregnancy and live birth rates will still decline, and the risk of miscarriage will increase. The source also specifically emphasizes that this should be fully communicated early in IVF treatment. Therefore, IVF is not “insurance” that offsets the effects of age, but an assisted reproductive technology that helps improve treatment efficiency.

06 | Ovarian Stimulation in Women of Advanced Age Is Not “More Medication, More Eggs”

After entering an IVF cycle, many people pay particular attention to ovarian stimulation medication dosage. Especially for women with lower AMH and fewer antral follicles, it is easy to have the intuition: “I have few eggs—if I increase the dosage, can I retrieve more?” In fact, the core of ovarian stimulation is not to increase medication indefinitely, but to help the existing follicles achieve relatively synchronized and reasonable growth based on ovarian reserve and previous response.

Different women may use a long protocol, antagonist protocol, or other individualized ovarian stimulation strategies. The use of r-LH in different protocols is also differentiated: for individuals aged ≥35 using a long protocol, adding r-LH may be considered under specific LH level conditions; for women aged ≥35 using an antagonist protocol, there is currently insufficient evidence to prove that routinely adding r-LH improves pregnancy outcomes.

This precisely shows that: ovarian stimulation at an advanced age is not about applying a template, but about dynamic adjustment. Doctors will decide subsequent dosage and trigger shot timing based on information such as follicle size, hormone changes, and ovarian response after medication. This is also a very important part of the overseas medical accompaniment process. When accompanying clients in Thailand, Huanqiu Xinsheng assists with appointments, translation and communication, coordination of testing processes, and treatment arrangements, so clients can better understand why the doctor arranges each step, rather than only knowing “how many injections to take today.”

07 | If You Are Older, Do You Necessarily Need ICSI?

Not necessarily. ICSI, or intracytoplasmic sperm injection, is a technique in which a single sperm is injected into an oocyte to achieve assisted fertilization. However, a common misconception needs to be specifically corrected: ICSI is not required simply because a woman is older. Using ICSI solely because of advanced age cannot improve the final outcomes of assisted reproduction in women of advanced age; the choice between IVF and ICSI is not determined by the woman’s age alone.

Therefore, the actual choice of fertilization method requires comprehensive consideration of the man’s semen status, previous fertilization history, number of oocytes, laboratory judgment, and other factors.

This is also why, when undergoing Thailand third-generation IVF, it cannot be simply understood as: advanced age = ICSI = definitely higher success rate. Every technique in assisted reproduction has its own indications, and stacking more techniques does not necessarily mean better results.

08 | For Third-Generation IVF at an Advanced Age, Why Do Many People Focus on PGT?

With increasing age, in addition to declining ovarian reserve, another issue that cannot be ignored is the increased risk of embryonic chromosomal abnormalities. A more commonly used term in clinical communication now is PGT-A (preimplantation genetic testing for aneuploidy). For women who are older, have recurrent implantation failure, or have a history of recurrent miscarriage, relevant embryonic genetic screening may be considered after fully understanding the pros and cons. This is also a key area many families consult about when choosing Thailand third-generation IVF.

The basic logic of PGT-A is not to “make poor embryos better,” but to obtain more chromosomal-level information from already formed, testable embryos through genetic testing, providing reference for subsequent embryo selection. However, it is likewise not an all-purpose technology. This type of testing has limitations, and patients need to be fully informed of the possible benefits, errors, and related risks before making an informed choice. Especially when ovarian reserve is low and the number of blastocysts ultimately formed is limited, whether to perform testing should be discussed comprehensively in light of age, number of embryos, previous miscarriage history, and family needs, rather than mechanically applying the same plan just because the words “advanced age” are seen.

09 | Does Transferring More Embryos Definitely Mean a Higher Success Rate?

This is another common misconception. After undergoing multiple egg retrievals, some women of advanced age cherish every embryo very much and therefore have thoughts like: “Since there are two, let’s transfer them together—at least the chance is greater.” But embryo transfer cannot only calculate the “chance of getting pregnant”; it must also calculate the risks that multiple pregnancy brings to the mother and fetus.

For women aged 35–37 with a relatively good prognosis, elective single embryo transfer may be prioritized to reduce the risk of multiple pregnancy and related maternal and neonatal complications; for women with a poorer prognosis or older age, the number of embryos to transfer needs to be evaluated according to the specific situation.

Therefore, the truly ideal treatment goal is not: “the more transferred at once, the better.” Rather, it is to achieve as much as possible: a healthy, safe singleton live birth.

10 | After Transfer, Why Is Luteal Support Still Needed?

Completion of embryo transfer does not mean the entire treatment process is over. Luteal support after transfer is also a very important part of an assisted reproductive cycle. Common methods include intramuscular progesterone injection, vaginal medication, and oral progesterone.

At present, there is insufficient evidence to prove that different routes of administration have clear statistically significant differences in live birth rate, clinical pregnancy rate, ongoing pregnancy rate, or miscarriage rate; therefore, clinical selection can be based on the treatment plan and the patient’s situation. The experience of use also differs among methods; for example, intramuscular injection may cause local induration, redness, and swelling.

Therefore, after transfer, do not stop medication, reduce the dose, or change the route of administration on your own. It is more important to complete luteal support and subsequent HCG and other tests according to the doctor’s arrangements.

11 | What Really Needs to Be Managed in IVF at an Advanced Age Is Not Only “Whether Pregnancy Can Be Achieved”

Many families focus all their attention on: How many eggs were retrieved? How many blastocysts were cultured? How many embryos were screened? How is the HCG doubling? These are of course all important. But for women of advanced age, the ultimate goal of assisted reproduction has never been just seeing “two lines.” What truly needs to be managed is the entire pathway from: fertility evaluation → ovarian stimulation → egg retrieval → fertilization → embryo culture → genetic testing → embryo transfer → pregnancy management → delivery.

Especially when multiple pregnancy occurs in women of advanced age, even greater attention must be paid to maternal and neonatal risks. The source also specifically discusses the management of twin pregnancy at an advanced age after assisted reproduction, emphasizing that individualized assessment should be based on factors such as age, previous pregnancy history, and genetic risk.

Therefore, a truly scientific assisted reproductive strategy is not simply pursuing the “success” of a single transfer, but going as far as possible toward a final healthy delivery under safe conditions.

Final Thoughts: After 35, the Greatest Fear Is Not Age, but Not Knowing How Much Time You Have Left

This article was compiled and created by Huanqiu Xinsheng for assisted reproductive health education and sharing of overseas medical information. It is not intended as individualized diagnosis or treatment advice. For specific testing, medication, ovarian stimulation, embryo testing, and transfer plans, please rely on the plan developed by a professional reproductive doctor based on your individual situation.