It’s no biblical Second Coming, but the sperm of a man who ejeculates twice in a short period of time might work miracles for couples looking to get pregnant, a somewhat recent and admittedly small study suggests.

The preliminary research, actually presented earlier this June at the annual meeting of the European Society of Human Reproduction and Embryology (ESHRE 2015), found that a method of artificial fertility known as intrauterine insemination (IUI) was much more successful when the second of a husband’s sperm samples, collected within an hour of the first sample, was used to impregnate their wife — to the point where IUI’s success rate jumped threefold over previously documented levels, from 6 to 21 percent in the 73 couples studied in 2014. That increased rate is comparable with the success achieved by in vitro fertilization (IVF), which, while a more popular fertility treatment with a success rate ranging from 50 to 10 percent depending on age, is much more expensive and less accessible to the average person.

The Rebound Effect

In an interview with the Daily Mail this past November, lead researcher Dr. Gulam Bahadur, an infertility specialist at North Middlesex Hospital in the UK, offered cautious enthusiasm about the study’s findings. “Though this is a relatively small study, we believe it is a big step forward and could make a major difference to pregnancy rates,” he told the Daily Mail. “It would be reasonable to assume the same effect would apply to men trying to conceive naturally.”

That’s because IUI involves collected sperm being directly, if artificially, introduced to a woman’s egg(s) right as she’s ovulating, whereas IVF arranges the meet-cute between egg and sperm outside of the body, with the embryo hopefully derived from that interaction later inserted into the woman’s uterus. In other words, IUI is much more like the natural version than IVF ever could be.

The team’s results may also poke a hole in the common assumption that sperm works best on the rainy day principle of only using it when you absolutely have to. “There is a great deal of misinformation out there,” Dr. Jackson Kirkman-Brown, a reproductive expert at the University of Birmingham, told the Daily Mail. “People still think that if you want to have a baby, you should save up sperm when, in fact, not having sex is very bad for men because it affects sperm quality. The fresher the sperm, the better its condition.”

We should be careful not to extrapolate too much from Bahadur’s findings, however. The husbands’ sperm quality was already characterized as subpar prior to the procedure, meaning there’s no way to tell how much more potent a second romp in the sack might be over the first for men with normal fertility. More crucially, the “consecutive ejeculate” was only part of the magic formula that increased IUI success rates. The team also shifted to a different class of drugs aimed at stimulating the women’s fertility cycles, from the widely popular clomid (clomiphene citrate) to human Menopausal Gonadotropin (hMG) — a switch similarly associated with improved fertility outcomes.

Fun as it might be to tell your partner that having sex as many times as you can within the span of a hour can help with conception, the more immediate benefit of this research, should it hold up, will surely be for couples already struggling with their fertility and their finances. In the U.S., the average cost of one IUI treatment is $865 compared to $8,158 for IVF, according to the National Infertility Association, or RESOLVE.

Source: Bahadur G, Ilahibuccus A, Almossawi R, et al. Improving pregnancy rates in intrauterine insemination procedure. ESHRE 2015. 2015.