If you’ve been trying to conceive for a while, you’ve probably had some blood work done. If the answer was “everything looks normal,” you may have left with more questions than you came in with.
It’s reasonable to call that into question. Was the blood work done on the correct day of your cycle? Was the list of tests the doctor sent you for comprehensive enough? Even if not of the results were flagged outside of the normal range, are your levels still optimal for conception?
Why normal doesn’t always settle it
Lab reference ranges come from large groups of people, and they’re built to flag disease. They don’t tell you whether a number is ideal for getting pregnant.
Thyroid is the example I use most. The standard TSH range runs from about 0.3 to 4.0 mIU/L, and many fertility practitioners like to see it under 2.5 when someone is trying to conceive. A TSH of 3.5 gets called normal, and by the lab’s definition it is.
Your doctor was right to say so. Normal and optimal just answer different questions.
Why waiting costs you
Standard practice often means waiting until you’ve been trying for 12 months (6 months if you’re over the age of 35) before investigating. That’s a long stretch if you’re already tracking your cycle, taking a prenatal, and wondering what you’re missing.
I completely understand and appreciate spending our government health care dollars wisely - it’s true that 60% of couples TTC will be pregnant within 6 months, and up to 85% within 12 months. So we play an odds game for that investigation. Most people won’t need it.
But more than that, I also understand that if you are in that 15% not pregnant at the end of 1 year, you surely wish you had some testing done sooner to try to figure out why.
The 12 labs I ask about most
This set of tests provide a great look at your fertility-metrics and give us a good sense as to whether there are underlying hormonal conditions that might impact your ability to get pregnant, and to assess some metrics to reflect your overall state of health, nutritional status, inflammation levels, and more.
AMH (anti-Müllerian hormone): a marker of ovarian reserve, which is a rough measure of how many eggs you have left. It can be tested on any day of your cycle.
Day 3 FSH: another ovarian reserve marker. A higher number can mean your brain is working harder to get your ovaries to do their job of maturing and growing a follicle and egg.
Day 3 LH: reflects signalling from the pituitary gland. The ratio of FSH to LH is useful when PCOS is a possibility.
Day 3 estradiol (E2): estradiol suppresses FSH, so a high value early in your cycle can make FSH look better than it is. Reading the two together gives a clearer picture. Low estradiol levels also make me wonder about stress and nutrition.
7 Days Post-Ovulation Progesterone: shows whether you ovulated and how well the second half of your cycle is supported. It’s timed about a week after ovulation, which lands on day 21 only if you have a 28-day cycle.
Full thyroid panel: TSH, free T3, free T4, and thyroid antibodies (TPO and Anti-TG), rather than TSH alone. Subclinical thyroid issues are common and easy to miss. Elevated antibodies, even in the context of a normal TSH, can be problematic for fertility and risk of pregnancy loss.
Prolactin: high levels can interfere with ovulation.
Vitamin D: low levels are linked to poorer reproductive outcomes in research. It’s easy to test and straightforward to address. I like to look at levels to guide how we use a vitamin D supplement for fertility.
Ferritin: your iron stores. Iron status matters for energy, ovulation, and early pregnancy.
Fasting insulin and glucose: insulin resistance is common with PCOS and unexplained infertility, and a glucose number alone can look fine while insulin runs high. This is such a common finding in my office.
DHEA-S: an adrenal hormone that tends to run higher with PCOS and some adrenal conditions.
CRP: a general marker of inflammation that adds context to the rest of the picture.
How to ask your doctor
You can say something like: “I’d like to talk about some additional testing for fertility. Could we look at a full thyroid panel, ferritin, vitamin D, and fasting insulin?”
Some doctors will happily order a few of these. Others will want to wait, or refer you to a fertility clinic (which usually means more waiting!)
It’s helpful to know that naturopathic doctors in Ontario can order these tests for you directly.
What the numbers can and can’t tell you
One result rarely tells the whole story. I read labs together, alongside your cycle history, your symptoms, and whatever your fertility clinic has already done.
Even when everything comes back fine, you’ll know where you stand, and that’s one less thing to wonder about at 2 a.m.
If you want help with this…
Choosing which tests make sense for you, or making sense of results you already have, is what a Fertility Naturopathic Consultation is fore. We look at what’s been done, what’s missing, and what to do next.
Book a visit to talk about your fertility blood work → click here!
Prefer to start on your own? Download my free Fertility Lab Guide HERE.
This post is for education only and isn’t medical advice. Check with your regulated health care provider before changing your care.