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Precum is fertile in some men, but not fertile in others. The discrepancy here is not understood, but it likely just comes down to individual plumbing.
In the study1 we discuss below, if a man had fertile precum, it was fertile in every sample, but if a man didn’t have fertile precum in one sample, there were no live sperm in any sample. (At least that’s the gist of it.)
Thus, it would appear that some men can use the withdrawal method of birth control their whole lives without it resulting in a pregnancy, while others will get everyone pregnant, every time, with just the tip.
One of the only studies on how fertile pre-ejaculate fluid is in men was published in 2011 by a fertility clinic. This study found that many men secrete fresh sperm, in the millions, into their pre-ejaculate fluid.
There was some speculation that this was just ‘old’ sperm left over from a previous ejaculation. The researchers pointed out this was unlikely, because the men had passed urine many times since their last ejaculation — which washes out the urethra — and yet live sperm still turned up.1
Twenty-seven volunteer men were used in the research, with 40 samples in total taken. The men were asked to masturbate, then just before they ejaculated, to dip their penis onto a petri dish.
The petri dish was then rushed next door to the microscope, where an analysis was done. Air quickly dries out semen, and kills sperm, so time was of the essence.
How fertile is precum?
- Eleven of the 27 men (41 per cent) produced samples that contained live sperm
- Out of these 11 men, 10 produced samples that had a reasonable proportion of motile sperm
- Live sperm was found in either all or none of the samples from each man, with each man producing up to five samples. The total number of sperm per sample was low, but the concentration and movement could be similar to normal semen — so the authors said the chance of pregnancy ‘would not be zero’
- It was never the case that a man had some samples containing no sperm and some that did – a man either had sperm in his samples, or he never did
Does the withdrawal method work for avoiding pregnancy?
This is a tough question, because unless a man has had fertility testing, he has no way of knowing if his precum has live sperm in it. This means that any erect penis should have a condom on it when it goes near a vagina, if there is a risk of an unwanted pregnancy.
What it does tell us is that couples who have used the pull-out method for years without an unplanned pregnancy may well have a male partner whose precum carries no sperm. But precum is only part of the story: most withdrawal ‘failures’ come down to timing and not pulling out in time, not just sperm in pre-ejaculate. In typical real-world use, withdrawal fails for about 22 in 100 couples over a year, compared with about 4 in 100 when the timing is perfect every time.2
Frequently asked questions
Can you get pregnant from precum?
Yes, potentially. Around 4 in 10 men in one study had live sperm in their pre-ejaculate. The total amount was small, but the sperm could be normal and moving, so the pregnancy risk is not zero.1
Does the withdrawal (pull-out) method work?
It can, but it is one of the less reliable methods. With perfect timing every time it fails for about 4 in 100 couples a year; in typical real-world use, about 22 in 100. If avoiding pregnancy really matters, use it alongside another method or a condom.2
This article is general information and not a substitute for personalised medical advice. If you are relying on withdrawal for contraception, please discuss your options with an experienced practitioner.
- Killick SR, Leary C, Trussell J, Guthrie KA. Sperm content of pre-ejaculatory fluid. Human Fertility. 2011;14(1):48–52.
- Trussell J. Contraceptive failure in the United States. Contraception. 2011;83(5):397–404.
