A doctor at the Alma Res fertility clinic in Rome prepares eggs and sperm¹ for an attempt at artificial insemination, June 7.

Having sex every day improves the quality of men's sperm and is recommended for couples trying to conceive, according to new research.

Until now doctors have debated whether or not men should refrain from sex for a few days before attempting to conceive with their partner to improve the chance of pregnancy².

But a new study by Dr David Greening of Sydney IVF, an Australian center for infertility³ and in vitro fertilisation (IVF) treatment, suggests abstinence is not the right approach.

He studied 118 men with above-average sperm DNA⁴ damage and found the quality of their sperm increased significantly after they were told to ejaculate daily for seven days.

On average, their DNA fragmentation index -- a measure of sperm damage -- fell to 26 percent from 34 percent, Greening told the European Society of Human Reproduction and Embryology in Amsterdam on Tuesday.

Frequent sex does decrease semen volume but for most men this is not a problem.

"It seems safe to conclude that couples with relatively⁵ normal semen parameters⁶ should have sex daily for up to a week before the ovulation date," he said in a statement.

"In the context of assisted reproduction, this simple treatment may assist in improving sperm quality and ultimately achieving a pregnancy."

Greening said it was likely frequent ejaculation improved the quality of sperm by reducing the length of time they were exposed to potentially damaging molecules⁷ called reactive oxygen species in the testicular ducts.

最新研究显示，每天一次性生活可以改善男性精子质量，研究人员建议打算生育的夫妇可以试试。

直到如今，医生们还在争论这个话题：男性和伴侣打算怀孕之前是否需要禁欲几天以提高怀孕几率。

“悉尼体外受精”研究中心的大卫•格里宁博士开展了此项新研究，结果显示禁欲做法欠妥。该中心是澳大利亚一家研究不孕不育与体外受精疗法的机构。

格里宁对118位男性进行了研究，这些男性的精子DNA受损程度高于平均水平。研究结果发现，在要求被调查者连续七天射精之后，他们的精子质量显著改善。

格里宁于本周二在阿姆斯特丹举行的“欧洲人类生殖及胚胎学会”会议上表示，平均来看，被调查者的“DNA碎片指数”（衡量精子受损程度的指标）从34%降至26%。

频繁性事的确会降低精子数量，但对大多数男性而言这不会构成问题。

格里宁在声明中称：“有把握这样说，精液参数相对正常的夫妇应该在排卵日前一周时间内每天过性生活。”

“在人工助孕时，这种简单的方法可能有助于改善精子质量，并最终有助怀孕。”

格里宁表示，频繁性事可以通过减短精子接触输精管中活性氧的时间来改善精子质量。这种被称为活性氧的分子有可能损害精子。

Vocabulary:

conceive：to become pregnant with（怀孕）

in vitro fertilisation (IVF)：In vitro fertilisation (IVF) is a process by which egg cells are fertilized⁸ by sperm outside the womb, in vitro.（体外受精）