Your Advil bottle might be working against you
10 fertility facts we should've been taught in sex ed
Taking Advil for cramps is fine. Taking it mid-cycle when you’re trying to conceive could be why you’re not.
I didn’t know this until recently, and I was stunned. I had spent years rotating through ibuprofen for headaches, injuries, and the occasional hangover. Nobody, not my doctors or the internet, ever mentioned that NSAIDs (nonsteroidal anti-inflammatory drug) can delay or prevent ovulation entirely. You can bleed on schedule, feel like you had a normal cycle, and never actually release an egg.
I learned this from Dr. Natalie Crawford, a reproductive endocrinologist whose work I have been deep in this year. Below are ten facts from her that we all deserve to know about our reproductive health. Most of them I wish we’d learned in middle school sex ed class.
1. You can have semen without sperm
The fluid is one thing, the cells inside it are another. Around 1% of all men, and roughly 10% of infertile men, have azoospermia, meaning they produce normal-looking semen with no measurable sperm in it at all. Even when sperm are present, count, motility, or concentration can be low. The volume is not the test, the cells are.
2. Cervical mucus is doing real work
It is not a hygiene issue. Cervical mucus is the medium that helps sperm survive and travel through the female reproductive tract to reach the egg. That is why it changes throughout your cycle and gets thinner and stretchier around ovulation. Your body is literally rolling out a runway.
3. Ovulation is your fifth vital sign
Ovulation does more than make babies. It’s the only time your body produces meaningful progesterone, and a successful ovulation means your hypothalamus, pituitary, and ovaries are all communicating correctly. The progesterone and estrogen that come with an ovulatory cycle protect bone density, brain function, breast tissue, and cardiovascular health. As Canadian endocrinology professor Dr. Jerilynn Prior puts it, women benefit from 35 to 40 years of ovulatory cycles not just for fertility but to prevent osteoporosis, stroke, dementia, heart disease, and breast cancer.
Here’s the catch: you can bleed on a predictable schedule and still not ovulate. Anovulatory cycles look normal from the outside, which is why cycle length is step one, but ovulation tracking is the real read. If your cycle is irregular, very short, very long, or absent altogether, that’s actionable information. Ask your OB or REI to actually look at it instead of writing off variation as normal.
4. Your fertility window is shorter than you think
Once an egg is released, it can be fertilized for about 24 hours. Sperm can survive in the female reproductive tract for up to 5 days, though most last 2 to 3. That makes the fertility window about six days each cycle, with the highest probability of conception in the two days before ovulation and the day of ovulation itself.
5. You had the most eggs you’ll ever have before you were born
Peak egg count happens around 20 weeks gestation, while you are still in your mother. At that point you have somewhere around 6 to 7 million eggs. By the time you are born, that number is already down to 1 to 2 million. From there you lose eggs every single day for the rest of your reproductive life. Your mother's health during her pregnancy with you affected the reserve you started with. Yours during a pregnancy will affect your daughter's.
6. You need acute inflammation to ovulate, and NSAIDs block it
Chronic inflammation is bad, but acute inflammation is necessary. When a follicle ruptures to release an egg, that rupture is an inflammatory event. NSAIDs (ibuprofen, naproxen, aspirin) suppress that response, which can delay ovulation or prevent it from happening that cycle. In one prospective controlled study, ibuprofen delayed ovulation in 85 percent of women who took it during their fertile window. You can still bleed and feel like you had a normal cycle when no egg was released. Dr. Crawford's guidance for women trying to conceive is to confine NSAIDs to your period only, when ovulation is not on the table.
7. Stress can cancel ovulation entirely
Major lifestyle changes, acute stress, sleep loss, undereating, and overtraining can all delay ovulation or trigger an anovulatory cycle where no egg is released at all. The clinical name for the more severe version of this is functional hypothalamic amenorrhea, and it accounts for roughly a third of cases of secondary amenorrhea in reproductive-age women. This is not woo. It is your hypothalamus deciding the conditions are unsafe for reproduction and pulling the brake. Sleep, food, and stress management are not just lifestyle accessories when you are trying to conceive. They’re inputs.
8. IVF does not drain your egg reserve
Every cycle, your body recruits a cohort of eggs, and only one (usually) matures and gets released. The rest die off that month regardless. IVF stimulation rescues the cohort that would have died anyway. It does not dip into your lifetime reserve.
9. IVF is not an insurance policy
Success rates are real, and they decline with age. Treating IVF as a backup plan you can lean on at 42 is one of the most expensive misunderstandings in modern fertility. It’s better framed as an investment in your fertility journey, not a guaranteed rescue.
10. The reason IVF isn’t covered by insurance isn’t just financial
Some countries cover it. The US largely does not, and the reason is partly logistical and partly ideological. Embryos created in IVF that go unused raise questions that are legal, religious, and personal. Are they considered life? Who decides what happens to them? Donation, destruction, and indefinite storage all carry weight. Women I’ve talked with in online communities bring up the existential side of this frequently. That’s your DNA sitting in a freezer somewhere. There’s no version of this conversation that’s purely clinical.
Dr. Natalie Crawford is a reproductive endocrinologist who has had four pregnancy losses of her own and who uses her platform to push for honest, evidence-based fertility education and reform. She is one of my newly acquired heroes in the women’s health space, and her work is some of the clearest I’ve come across.
If you want the full conversation with Dr. Crawford that covers this post’s topics (along with many others) listen here:
None of this is just about getting pregnant. Cycle health is health. Your hormones are telling you something about your bones, brain, immune system, energy, and mood every single month. That matters whether you are trying to conceive, trying not to, or just trying to understand what your body is doing. We have spent generations treating periods as something to manage and ovulation as something to track only when a baby is on the table. Both are worth more than that.
If anything in this post made you think “I wish I knew this sooner,” tell me in the comments, and share it with the women in your life who would’ve wanted to know.
Yeah I stopped taking advil and started taking advice instead. But it still doesn't work
all of this! being personally victimized by #7 was eye opening. also as a big aspirin girlie #6 hit hard