Does Stress Stop You Getting Pregnant? What Was Measured

On the best-designed evidence, mostly no -- and this is one of the few places in fertility medicine where the honest answer is also the kinder one. Fourteen prospective studies covering 3,583 women undergoing a cycle of fertility treatment were pooled to ask whether how anxious or depressed a woman was beforehand predicted whether she conceived. It did not.

The pooled effect was a standardised mean difference of -0.04, with a 95% confidence interval of -0.11 to 0.03: a result centred on nothing. The authors wrote that their findings should reassure women and doctors that distress caused by fertility problems, or by other life events happening alongside treatment, will not compromise the chance of becoming pregnant.

That is not the end of the story, because the answer depends heavily on how stress is measured. The rest of this page is about that split, because it is where almost all the confusion on this subject comes from.

Because they are not measuring the same thing. Studies that ask people how stressed they feel have mostly found nothing. Studies that measure a chemical in saliva have sometimes found something. Both kinds are called stress research.

On the questionnaire side: 339 women in the United Kingdom, aged 18 to 40 and trying to conceive, kept daily diaries for up to six cycles. Of the 339, 207 (61%) conceived, 69 (20%) did not and 63 (19%) withdrew. After adjusting for age, parity, how long they had already been trying, smoking, caffeine and intercourse frequency, no meaningful association appeared between any questionnaire measure of stress, anxiety or depression and the chance of conceiving. The one thing that did stand out was in the opposite direction: women reporting more social support conceived more readily.

On the biomarker side, in the same UK study population of 274 women, salivary alpha-amylase -- a marker of sympathetic nervous activation -- was associated with a lower daily probability of conception across the fertile window in the first cycle. It is worth being precise about how strong that was: on time-to-pregnancy the fecundability odds ratio was 0.85 with a 95% confidence interval of 0.67 to 1.09, which does not exclude no effect. The significant finding was on day-by-day conception probability, not on how long women took to conceive.

A larger American study then enrolled 501 couples before they started trying, of whom 373 had complete data. Women in the highest third of salivary alpha-amylase had a 29% reduction in fecundability compared with the lowest third (odds ratio 0.71, 95% CI 0.51 to 1.00), which translated into a relative risk of infertility of 2.07 (95% CI 1.04 to 4.11). Salivary cortisol showed no association with fecundability in that study or in the earlier one.

That last detail matters more than it looks. Cortisol is the hormone named in almost every article written about stress and fertility. In the two studies that actually measured it against conception, it did nothing.

There are associations, and they come from studies that cannot tell you which way the arrow points.

The largest measured Danish men from the general population, median age 19, who completed a four-item stress questionnaire and gave a semen and blood sample. Within that cohort (n = 1,215), men scoring above an intermediate stress level had poorer semen quality in a dose-response pattern: those at the highest level had 38% lower sperm concentration (95% CI 3% to 61%) and 15% lower semen volume (95% CI 1% to 27%) than men at the intermediate level. No association was found with LH, FSH, testosterone or inhibin B. The authors' own conclusion is conditional -- if the association is causal, stress may contribute to suboptimal semen quality.

A smaller American study of 193 men separated three kinds of stress and found they behaved differently. Perceived stress and stressful life events were associated with semen parameters; men reporting two or more stressful life events in the past year had a lower share of motile sperm than men reporting none, though their sperm concentration was similar. Job strain was not associated with any semen parameter at all.

Both studies measured men once. A man with a poor semen result who is worried about it will score higher on a stress questionnaire for that reason alone, and no cross-sectional design can separate those two. What a semen analysis actually measures is set out in the guide to reading a semen analysis, and the exposures with much firmer numbers are compared in what lifestyle changes have actually been measured.

Nobody has shown that it raises the chance of a baby. Cochrane reviewed psychological and educational interventions for subfertile men and women and found 39 randomised studies involving 4,925 participants undergoing assisted reproduction. It declined to pool them, judging that a combined figure would not be clinically meaningful, because every study carried a high risk of bias on at least one domain.

Only two of the 39 reported live birth and one reported ongoing pregnancy, all three with substantial dropout. Cochrane's stated conclusion is that the effects on distress and on live birth or ongoing pregnancy are uncertain, at very low certainty evidence, and that existing trials were generally poorly designed and executed.

So the case for getting help with distress does not rest on pregnancy rates, and it does not need to. Roughly one in five couples seeking fertility treatment has clinically relevant anxiety, depression or distress -- that is Cochrane's own background figure. Treating it is worth doing because living that way is hard, not because it is a fertility intervention.

Practically, four things follow.

1. Stop treating your own stress level as a cause of not conceiving. The best-designed evidence does not support it, and that belief adds a layer of self-blame to a situation that has enough of them.
2. Do not let it displace the work-up. Stress is not a diagnosis, and time spent trying to relax instead of being investigated is time in which age and the actual cause both continue.
3. Get help with distress on its own terms, from a counsellor, a therapist, or a clinic that offers psychosocial support. Ask whether your clinic has someone; many Indian clinics do not, and it is a reasonable question to ask before choosing one.
4. If a clinic tells you that relaxing will improve your odds, or sells you a therapy on that basis, treat it as a claim that has been tested and found uncertain.

If the difficulty is between you and your partner rather than inside your own head, that is a different problem with different answers -- see keeping a relationship going through treatment and what couples actually feel during IVF.

Stated plainly, because the opposite of each of these is printed widely:

• That stress lowers IVF success rates. The pooled prospective evidence in 3,583 women found no association with pregnancy after a treatment cycle.
• That reducing stress improves the chance of a live birth. Cochrane rates that uncertain at very low certainty across 39 studies and 4,925 participants.
• That cortisol is the mechanism. Salivary cortisol showed no association with fecundability in either study that measured it.
• That stress causes poor semen quality. The male evidence is cross-sectional and cannot establish direction; the authors of the largest study say so in their own conclusion.
• That psychological stress causes the oxidative stress that damages sperm DNA. These are two different uses of the same word, and no source retrieved for this page connects them.
• That yoga, meditation or acupuncture improve fertility outcomes. They may well help you feel better, which is a different and sufficient reason to do them.

One limitation runs the other way and should be said too. The meta-analysis that produced the reassuring headline found evidence of moderate publication bias in the literature it drew on. And the biomarker studies did find something. The honest summary is not that stress is irrelevant -- it is that the effect, if there is one, is smaller than the fear of it.

Being told to relax is one of the more infuriating things said to people trying to conceive, and the evidence is on your side rather than on the side of whoever said it.