Monday, December 20, 2004

Study fails to find link between fertility medications and ovarian cancer

A study performed bt the National Cancer Institute studied over 12,000 women at five fertility clinics. These women received infertility treatment between 1965 and 1988. About 2/3 of them did not use fertility medications and about 1/3 did.

Importantly, the study controlled for other factors that are already known to increase the risk of ovarian cancer. The results showed that taking fertility medication did not result in a higher risk of ovarian cancer overall.

Looking at the results more closely, women who used clomiphene citrate (Clomid) had a lower risk of ovarian cancer than the general population but women using injectable gonadotropins had a slightly higher risk.

The primary risk occurred in women who failed to acheive pregnancy whether they took fertility medications or not. Earlier studies failed to take this important factor into account.

Since it takes many years for ovarian cancer to develop, it is still important to follow these women over a longer period of time. For the time being, the results are very reassuring.

Friday, December 10, 2004

Laptop use and infertility


A study published recently in the journal Human Reproduction suggested that men who sit with their laptops in their lap may be at higher risk for infertility. The premise is the age old concern about heat exposure to the testicles.

The study looked at 29 healthy men. After attaching temperature sensors to the skin over each testicle, a laptop was placed in their lap for 60 minutes. In one session, the laptop was not turned on. In another session, the laptop was turned on 15 minutes beforehand.

The results showed that the external scrotal temperatures increased by about two degrees when the laptop was off and from 2.5 to 3 degrees when it was on.

IMPORTANT NOTE!

Although the study was reported in the media as showing a link between laptop use and infertility, the researchers did not study whether there was a correlation between the increase in scrotal temperature and abnormal results on a semen analysis. The men were also not assessed to see if they had more difficulty acheving a pregnancy.

They inferred that since increased scotal temperature from other causes has in SOME past studies been correlated with sperm abnormalities or infertility that this should apply to laptop use as well. However, this is not necessarily true! Unlike, for example, a varicocele (dilated veins in the scrotum) which is present 24 hours a day for years, the laptop increase is, at best, intermittent.

The quality of evidence in this study is very weak. There is no need for alarm just yet. On the other hand, it would seem to be a no brainer to put the laptop on a desk or tray instead and not worry about it.