A simple intervention can make a big difference to IVF success
CHRISTOPH BURGSTEDT/SCIENTIFIC PHOTO LIBRARY
Men should ejaculate less than 48 hours before collecting eggs for in vitro fertilization to maximize the chances of it leading to an ongoing pregnancy, according to the first clinical study designed to test how different intervals of abstinence from ejaculation affect the success of the method. birth rate care.
Toward the end of an IVF cycle, a woman takes a “trigger” drug that encourages the developing eggs to mature. It is administered 36 hours before the collection and fertilization of eggs.
To ensure the healthiest sperm possible for fertilization, men are usually advised to ejaculate for a period of two to seven days before providing a sample to be used for IVF. “There is an optimal period between ejaculations when the sperm is in its best condition,” says David Miller from the University of Leeds, UK, who was not involved in the trial.
But two to seven days is a wide range. On the one hand, the longer sperm is stored in the testes, the longer they are exposed to various toxins, primarily oxygen free radicals, which are formed naturally during metabolic processes, as well as under the influence of external factors such as environmental pollution. This can lead to DNA damage and poor sperm quality, scientists say. Richard Paulson at the Keck School of Medicine of the University of Southern California, Los Angeles, who was also not involved in the study. But too short a period of time between ejaculations reduces the sperm count.
Until now, there has been no reliable clinical evidence that shortening the ejaculation interval leads to improved pregnancy outcomes, but there have been hints. For example, a 2024 meta-analysis found that the interval between ejaculations is less than four days. improving sperm quality in infertile men. Another study found that an interval of less than 4 hours decreased the number of sperm with DNA damage and improving sperm motility.
To test the idea directly, Yang Yu at the First Hospital of Jilin University in Changchun, China, and colleagues asked 226 men undergoing traditional IVF to ejaculate approximately 36 hours before obtaining the final sample. Another 227 people were asked to ejaculate within 48 hours to seven days.
The group with a shorter abstinence interval had a higher level of ongoing pregnancy rates – 46 percent compared to 36 percent. “The improvement in pregnancy rates is encouraging,” says Miller, “but of course it does not necessarily fully reflect the end result of treatment, which is the live birth rate.” However, he says that since the miscarriage rate was lower (though not statistically) in the shorter abstinence group, he would also expect more live births.
Paulson says that while the study makes interesting observations, it has limitations, such as the inclusion of both fresh and frozen embryos at IVF success rates may vary between the two. He also notes that the data shows a decrease in fertilization rates but an increase in ongoing pregnancies in the shorter abstinence group, suggesting that fewer couples conceived, but of those that did, more continued beyond the last 12 weeks, which requires more careful analysis. “These kinds of extraordinary claims will require extraordinary evidence and careful control of all possible factors,” he says.
Future research may also examine whether frequent ejaculation improves pregnancy outcomes in couples who have not undergone IVF. “This study is excellent evidence that shorter abstinence is a good way to get better sperm,” says Jackson Kirkman-Brown at the University of Birmingham, UK.
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