The right time to try IVF depends on your age, how long you’ve been trying to conceive, and whether you have a specific diagnosis that makes IVF the most effective path. For most couples under 35, fertility specialists recommend trying for a full year before pursuing treatment. For those over 35, that window shrinks to six months, and for women over 40, an evaluation is recommended before you even start trying on your own.
Age Is the Biggest Factor in Timing
Egg quality and quantity decline steadily through a woman’s 30s, then drop sharply after 40. That biological reality shapes every guideline around when to escalate treatment. The American College of Obstetricians and Gynecologists recommends the following timeline for seeking a fertility evaluation:
- Under 35: After 12 months of regular unprotected intercourse without a pregnancy
- 35 to 39: After 6 months
- 40 and older: Before attempting to conceive, so you have a realistic picture of your options
These timelines aren’t just about patience. Each month of delay at older ages means a measurable decline in the number of eggs your ovaries can produce in response to fertility medications. A woman who starts IVF at 38 will typically have better outcomes than the same woman at 40, even though the gap is only two years. If you’re in your late 30s and your gut says something isn’t working, trust that instinct and get evaluated sooner rather than later.
Conditions That Point Directly to IVF
Some diagnoses skip the usual stepwise approach and make IVF the first recommendation. These include blocked or absent fallopian tubes, since there’s no other way to bring egg and sperm together. Severe male factor infertility, where sperm counts or motility are very low or sperm must be surgically retrieved, also calls for IVF with laboratory-assisted fertilization.
Endometriosis that hasn’t responded to surgery or medication is another common reason. Advanced endometriosis (stages III and IV) is associated with roughly a 20% reduction in clinical pregnancy rates with IVF compared to patients without it, but IVF still offers the best odds when other treatments have failed. The main concern for women with endometriosis is protecting ovarian reserve from surgical damage, which is why many specialists recommend moving to IVF rather than pursuing repeated surgeries.
Genetic conditions that cause recurrent miscarriage or carry risks of abnormalities in offspring also warrant IVF, because embryos can be tested before transfer. And unexplained infertility, the frustrating diagnosis that means nothing obviously wrong has been found, often ends up at IVF after simpler treatments haven’t worked.
When to Move On From IUI
Intrauterine insemination with ovarian stimulation is generally the first-line treatment for unexplained infertility. It’s less invasive, less expensive, and works well enough for some couples. But the per-cycle success rate is significantly lower than IVF, and most fertility specialists recommend transitioning to IVF after three to four unsuccessful IUI cycles.
Continuing IUI beyond that point rarely changes the outcome. If three or four medicated IUI cycles haven’t resulted in pregnancy, the odds of the fifth or sixth cycle working are low. At that point, the time and money spent on additional IUI attempts could be better invested in an IVF cycle with substantially higher success rates per attempt. For women over 38 or those with diminished ovarian reserve, some specialists skip IUI entirely and recommend going straight to IVF to avoid losing valuable time.
What Your Ovarian Reserve Tests Mean
Before or early in any fertility workup, your doctor will check your ovarian reserve, essentially measuring how many eggs you have left and how well your ovaries respond to stimulation. Two key tests drive this assessment: AMH (a blood test measuring a hormone produced by your follicles) and antral follicle count (an ultrasound that counts the small follicles visible on your ovaries).
An AMH level below 0.7 ng/ml signals that your ovaries may respond poorly to the medications used in IVF. Levels below 0.2 ng/ml make achieving a clinical pregnancy through IVF significantly harder, with higher rates of cycle cancellation because too few eggs develop. Elevated FSH levels on day 3 of your cycle point in the same direction. In one study, women whose cycles were cancelled due to poor response had average FSH levels of 13.3 IU/l, compared to 10.5 IU/l in women who successfully reached egg retrieval.
These numbers don’t mean IVF is impossible, but they do mean urgency matters. If your ovarian reserve is already low, waiting another six months to “try naturally” means fewer eggs to work with when you do start treatment. Low AMH is one of the clearest signals to move to IVF quickly rather than spending time on less aggressive approaches.
The Financial Reality
Cost plays a real role in timing for many people. A single IVF cycle in the United States runs between $12,000 and $18,000, which typically covers consultations, monitoring, egg retrieval, lab fertilization, and embryo transfer. Medications add another $3,000 to $5,000 on top of that. Many people need more than one cycle.
Some states mandate insurance coverage for fertility treatment, but many don’t, and even mandated coverage varies widely in what it includes. If cost is a barrier, it’s worth checking your insurance plan’s specifics, asking your clinic about financing programs, and factoring in the cumulative cost of multiple IUI cycles that may not work. Three or four IUI cycles with medications and monitoring can approach the cost of a single IVF cycle, with lower cumulative success rates.
Preparing Your Body Before a Cycle
Once you’ve decided to pursue IVF, most specialists recommend two to three months of preparation. Egg development takes roughly 90 days from the earliest stage to ovulation, so lifestyle changes made now affect egg quality in your upcoming cycle. This preparation window includes optimizing your weight if needed, quitting smoking, limiting alcohol, and starting supplements like CoQ10 (typically 200 to 600 mg per day), which supports the energy production inside developing eggs.
This doesn’t mean you need to overhaul your entire life. Focus on the basics: consistent sleep, moderate exercise, a diet rich in whole foods, and managing stress where you can. Your fertility clinic will give you a specific protocol for the weeks leading up to your cycle, including which medications to start and when.
Signs You Shouldn’t Wait
Certain situations call for acting quickly rather than following the standard timelines. You should consider moving to IVF sooner if you have a known diagnosis like blocked tubes or severe male factor infertility, if your ovarian reserve testing shows low AMH or elevated FSH, if you’re 38 or older and have been trying for even a few months, if you’ve had two or more miscarriages, or if you’ve already completed three to four IUI cycles without success.
The common thread is that time works against fertility in almost every scenario. The biggest regret fertility patients report isn’t starting treatment. It’s waiting too long to start.