The secret life of sperm: may aid contraception and male fertility

Swimming Sperm

Scientists have discovered something about sperm that makes perfect sense: they don’t start swimming until they are closer to the egg.

Because sperm only have limited resources, they need to maximise their chances of fertilising the egg.

Internal pH

University of California researchers have found that sperm increases its internal pH — its acidity or alkalinity — due to pores on its surface that allow it to jettison protons.

Dr Yuriy Kirichok, who led the research, said: “The concentration of protons inside the sperm cell is 1,000 times higher than outside.

“If you just open a pore, protons will go outside – we identify the molecule that lets them out.”

A substance called anandamide, present in the female reproductive tract and in particularly high levels near the egg, seems to be the trigger for this release, which in turn allows the sperm’s tail to begin moving, and the vigorous swimming to begin.

Cannabis

This may also explain why men who regularly use cannabis/marijuana experience greater levels of infertility.

Contraception and Fertility

It seems fair that, as scientists learn more about sperm, it could aid in two ways.

Firstly, it could be used to create effective male contraceptives.

Secondly, it could be another explanation for male infertility. Sperm’s motility is already measured. Research such as this could help to improve motility, or to ensure that sperm doesn’t use up its resources too early.

Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, said: “Although it seems obvious that sperm have to swim in order to find and fertilise an egg inside the female body, or in the dish during IVF, we are only just uncovering some of the molecular details that the sperm use when swimming”

Via

Women not confident about contraception, put other worries before unwanted pregnancy

Four in five women are concerned about the current method of contraception used for birth control, yet two in five have stayed with their chosen method for five or more years.

That’s according to a new survey carried out in the US by Schering-Plough, which also found that well over half of women using a hormonal contraceptive had increased stress levels when having sex if they’ve not used their birth control product correctly.

Women using birth control say they worry more about their own or their partner’s satisfaction (29%) and body image (24%) than pregnancy (10%) or contracting a sexually-transmitted disease (8%).

Of women aged 18 to 34 who currently use birth control, four in five use contraception primarily to prevent pregnancy. However, 93 percent of women aged 18 to 34 (both on and off birth control) do not know that half of unintended pregnancies in the United States occur with couples that used some method of birth control.

Sixty-two percent of women indicated they discuss birth control with a potential partner. Women of all ages who currently use, or have previously used hormonal contraceptives, reported that a physician’s recommendation was among the top five attributes that are most important to them in choosing a birth control method.

Nearly a quarter of 18-34 year-old women said that a daily method of birth control would be most convenient for them, though 46 percent of women in the same age group who currently use a hormonal contraceptive have more difficulty remembering to use their current method correctly when their daily routine is interrupted.

“The findings from this survey signal that while we may be living at a time when women have many contraceptive options and are empowered to make their own informed decisions, many are either dissatisfied with or have concerns about their method,” says clinical professor of obstetrics and gynecology at Yale University School of Medicine, Dr. Minkin. “Overall, this is a wake-up call for women to evaluate how happy they really are with their current method and recognise that they don’t have to settle for the status quo when it comes to birth control options.”

“Morning after pill” could encourage teen sex

Concerns have been raised by the Family and Youth Concern organisation that giving out the “morning after pill” to under 16s can encourage them to have sex.

“It inevitably results in young men putting pressure on vulnerable girls to have sex by telling them that if they are worried about getting pregnant, they can always go to the school nurse and get the morning-after pill without anyone needing to know,” he said.

He cited a number of studies, 23 from 10 countries, that suggests that increased access to the pill has not made any difference to unintended pregnancy or the abortion rate.

Others in Suffolk, where a number of schools now give the morning after pill to girls as young as 13 in complete confidence, disagree.

Emrys Green, chairman of the Bury St Edmunds Youth Council, said, “I think it’s a good thing the morning-after pill can be given out in schools. At least it gives young girls a choice to live their lives and not their parents’ lives.

“It’s their choice whether they want to involve them or not. Just because the morning-after pill is available it doesn’t mean girls will have sex before they’re ready. If they wanted the morning-after pill that bad, they would go to the doctor anyway.”

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Research suggests natural family planning as effective as contraceptive pill

Natural family planning methods are often a desired method of preventing, or indeed planning, a pregnancy, but they are often seen as less effective than using a chemical contraceptive pill for the same purpose. However, good news for those (including myself) that believe avoiding pills and using a more natural method is preferable, particularly given the potential short- and long-term effects of taking oral contraception.

New research published in Europe’s leading reproductive medical journal “Human Reproduction” suggests that the symptothermal method (STM) was at least, if not more, effective than the contraceptive pill.

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