During IVF, certain habits, substances, and activities can lower your chances of a successful cycle. Some of these are well-established, like avoiding alcohol, while others are less obvious, like the type of pain reliever you reach for. Here’s what the evidence says about the specific things worth steering clear of at each stage of treatment.
Alcohol, Even in Small Amounts
Alcohol is one of the clearest modifiable risk factors during IVF. A study published in Obstetrics & Gynecology found that women who consumed as few as four alcoholic drinks per week had 16% lower odds of a live birth compared to those who drank less. When both partners drank at that level, the odds of a live birth dropped by 21%.
The effects went beyond pregnancy rates. Women and men drinking more than four drinks per week had 48% greater odds of complete fertilization failure, meaning none of the retrieved eggs successfully fertilized. Even one to seven drinks per week was associated with 18% greater odds of failed implantation. The takeaway is straightforward: cutting out alcohol before and during your cycle removes a real, measurable obstacle to success.
High-Impact Exercise During Stimulation
The two weeks of hormone injections that stimulate egg development cause your ovaries to enlarge significantly. Enlarged ovaries are more vulnerable to torsion, a painful twisting of the ovary on its blood supply that can become a medical emergency. Most fertility clinics advise against high-impact or strenuous exercise during this window.
That doesn’t mean you need to stop moving entirely. Walking, light time on a treadmill, and gentle activity are fine and can help manage the stress of treatment. What you want to avoid are things like CrossFit, jumping, sudden movements, and deep twisting poses in yoga. Some doctors suggest staying active through about day 5 or 6 of stimulation and then scaling back further as your ovaries reach their largest size before retrieval.
Strict Bed Rest After Embryo Transfer
It feels intuitive to lie completely still after an embryo transfer, but the data suggests this doesn’t help and may even hurt. A systematic review and meta-analysis in JBRA Assisted Reproduction compared outcomes between patients prescribed bed rest and those who resumed normal light activity. The bed rest group had a live birth rate of 43.6%, while the group that got up and moved had a rate of 52.5%. While that difference didn’t reach statistical significance, the trend pointed in the wrong direction for bed rest.
The researchers concluded there is no evidence to recommend bed rest after transfer. Gentle, normal activity is the better approach. You don’t need to run a marathon, but you also don’t need to spend days on the couch worrying that standing up will prevent implantation.
Ibuprofen and Other NSAIDs
If you need pain relief during your cycle, especially after egg retrieval, avoid ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs like naproxen or aspirin). These medications work by blocking enzymes called cyclooxygenases, which play a role in producing prostaglandins. Prostaglandins are involved in several reproductive processes, including implantation.
Research published in Human Reproduction found that ibuprofen decreased cell growth and increased cell death in early fetal ovarian tissue. While most formal guidelines focus on restricting NSAIDs later in pregnancy, the evidence suggests caution from the very start. Acetaminophen (Tylenol) is the typical alternative recommended by fertility clinics when you need something for pain or headaches during treatment.
Caffeine Beyond Very Low Levels
The caffeine threshold during IVF appears to be lower than many people expect. One study of couples undergoing assisted reproduction found that women with usual caffeine intakes above 50 milligrams per day had nearly four times the odds of not achieving a live birth compared to women consuming under 2 milligrams daily. Even intakes between 2 and 50 milligrams per day tripled the odds of not having a live birth.
For context, a standard 8-ounce cup of brewed coffee contains roughly 95 milligrams of caffeine. A cup of black tea has about 47 milligrams, and a can of cola around 34 milligrams. If you can’t cut caffeine entirely, keeping intake well below one cup of coffee per day is a reasonable target based on the available data.
High-Mercury Fish
Mercury is a neurotoxin that accumulates in certain large, long-lived fish species. The FDA advises women who are pregnant or trying to become pregnant to completely avoid shark, swordfish, king mackerel, and tilefish because of their high mercury content. Since IVF is an active attempt at pregnancy, the same guidance applies during your cycle.
You don’t need to avoid fish entirely. Up to 12 ounces (about two meals) per week of lower-mercury options like salmon, shrimp, pollock, and catfish is considered safe. Albacore tuna falls in the middle and should be limited to about 6 ounces (one meal) per week, since it contains more mercury than canned light tuna.
Plastics and Endocrine Disruptors
Bisphenol A (BPA) is a chemical found in hard plastics, food can linings, and some dental sealants. It mimics estrogen in the body and can interfere with egg development. A large scoping review in Human Reproduction Update found that over half of human studies showed associations between higher urinary BPA levels and reduced egg counts or lower egg yields in IVF patients. In laboratory studies, 96% found at least one harmful effect of BPA on egg health, including disrupted cell division and abnormal chromosome alignment.
What makes this tricky is that products labeled “BPA-free” often substitute closely related chemicals like BPS or BPF. The same review found that 94% of studies on these alternatives also documented harmful effects on egg health. The substitutes appear to be just as problematic as the original. Practical steps include avoiding microwaving food in plastic containers, choosing glass or stainless steel for food storage, and reducing canned food consumption during your cycle. These steps won’t eliminate exposure entirely, since bisphenols are widespread in the environment, but they can meaningfully reduce your daily dose.
Sexual Intercourse at Key Points
Most fertility clinics advise abstaining from intercourse during two specific windows. The first is late in the stimulation phase, as your ovaries become significantly enlarged. At that point, intercourse carries a small risk of rupturing an ovarian cyst or triggering ovarian torsion. Your doctor will typically let you know when to stop, usually several days before retrieval.
The second window is after embryo transfer. Clinics generally recommend “pelvic rest” for five to seven days following the transfer to give the embryo the best chance to implant into the uterine wall. After that point, your clinic will let you know when it’s safe to resume based on your pregnancy test results.
Hot Tubs, Saunas, and Excessive Heat
Raising your core body temperature more than 2°C (about 3.6°F) above your baseline can pose risks to an early pregnancy. Hot tubs and saunas are the most common culprits because they can push your body temperature above 38.9°C (102°F) relatively quickly, especially if you stay in for more than 10 to 15 minutes. Animal research consistently shows that elevated maternal temperature during critical developmental windows can cause harm, regardless of the heat source.
During the post-transfer period, when implantation may be occurring, avoiding hot tubs, saunas, and very hot baths is a straightforward precaution. Warm showers and baths that don’t leave you feeling overheated are fine. The concern is sustained, significant elevation of core temperature, not everyday warmth.