Timing Sex

May 27th, 2010 § 9 comments § permalink

If you’re trying to get pregnant, something useful to know is how often to have sex.  Sperm counts peak at two to three days after ejaculation, meaning, after you have sex (or masturbate,) the swimmers will be most abundant two to three days later.  Sperm live for about 48 hours in the female reproductive tract, so the optimum timing is sex every other day.

However, don’t freak out if you have an especially romantic weekend with a little extra frequent activity, or get caught up and miss a few days.  Stressing out about sex is counter productive, as stress itself can result in poorer sperm quality.

I’m often asked when during the month (or cycle) a couple should try to conceive.  Studies show that conception usually happens up to six days before, and ending on, ovulation.  The big problem is that all tests for ovulation show the event after it happens.  So a good plan is start having sex every other day after menstruation ends, and keep going until the next menstruation.

So, soldier on.  Have sex every other day.  Doctors orders.


May 24th, 2010 § Comments Off on Lube § permalink

Just about everything outside the female reproductive tract kills sperm, including lubricants.  But sometimes lubricant is desirable during sex.  In 2008, an independent lab at the Cleveland Clinic headed by Ashok Agarwal published in the journal of Fertility and Sterility a comparison of different lubricants and how they degrade sperm movement and the DNA that the sperm contains.  Of Pre-Seed, FemGlide, Astroglide, and Replens, Pre-Seed was the one that didn’t seem to have much negative effect on sperm motion and DNA.  So, if you’re going to use lubricant during sex and you want to conceive, Pre-Seed seems to be a good choice.  (I have absolutely no relationship, financial or otherwise, to the company that makes it.)

How Long is the Sperm Factory?

May 18th, 2010 § Comments Off on How Long is the Sperm Factory? § permalink

It’s useful to know how long it takes to make sperm in the testis.  Based on the brilliant work of Charles Leblond and Yves Clermont in the 1950s and 1960s studying how testes looked under the microscope, scientists guessed that it took about two and a half months to make a human sperm.  But Leblond and Clermont were looking at specimens that weren’t actively making sperm.

In 2006, Paul Turek did a clever experiment.  He gave men radioactive water (not enough to be dangerous, of course,) and waited until their sperm became radioactive. In most men, it took about 60 days.  From the moment a sperm sets out on the testis assembly line, it looks like it takes about two months before it reaches the end.

So if you’re taking a medication like clomiphene that works on the sperm factory, expect it to take about two months to begin to work.

Tighty Whities and Hot Testes

May 12th, 2010 § 3 comments § permalink

If you’re trying to conceive, do you need to change your underwear from boxers to briefs?

No doubt heat kills sperm.  The testes live outside of the abdomen for a good reason.  They need to be cool, about 4 degrees C cooler than body temperature.  Testes that don’t descend, a condition called “cryptorchidism,” have real problems making sperm.  Ovaries obviously don’t have this sensitivity to heat; they’re perfectly happy living in the abdomen.

The real question is: how much heat kills sperm?  Crossing your legs increases your scrotal temperature by about 1 degree C, and it’s difficult to imagine that every man who crosses his legs is going to have a hard time impregnating his wife.  Form fitting underwear, or briefs, raise it by a similar amount.  Putting a laptop on your lap increases your scrotal temperature by about 1.5 degrees C or so.

So you probably shouldn’t worry about wearing boxers or briefs, but stay away from cooking your testes in a jacuzzi or sauna while you’re trying to conceive.  Save that for stress reduction after the baby’s born.