In Vitro is Chauvinist: The Sex Ratio of IVF Babies is Skewed Towards Males

Got to admit, I thought this was about eugenics and culture.

In vitro fertilization (IVF) accounts for up to five percent of babies born in developed countries, and the technique has yielded some five million people ever since Louise Brown was born in the UK on July 25, 1978. And that’s just humans; the technology has been a huge boon in breeding farm animals. Yet there are hints that the procedure can have some unwanted effects on the resultant embryos. One such indication is a skewed sex ratio.

Source: In vitro is chauvinist: The sex ratio of IVF babies is skewed towards males

Looks like the fix is just a change in culture medium. It will take some time for this to become mainstream for human IVF. It also looks like (from the abstract) that this extra bath doesn’t harm male embryos in any way, so it won’t require genetic testing of embryos to sort out the girls (extra $$$ and mandatory freeze).

The best part is that this fix will likely increase overall success rates as those female embryos that would have failed instead thrive. Even a small % increase in success means so much to people desperately trying for a child, regardless of gender.

Study: Pesticides May Be Killing Off Your Sperm

Men who consume the pesticide residue found in many fruits and vegetables may have nearly 50 percent lower sperm count, according to a paper published in the journal Human Reproduction. The study, conducted by a team of Harvard researchers, is the first to examine the link between pesticide consumption and reproductive health.

Source: Pesticides May Be Killing Off Your Sperm

They didn’t actually address pesticides directly. They asked each man what he ate, then went to a USDA database to estimate their pesticide consumption based on what fruits and vegetables they ate Different fruits and vegetables have different amounts of pesticides residues. No specific pesticide was measured or estimated, just pesticide residue in general.

The men were also selected in a biased fashion, as they were all a part of couples seeking fertility treatment.  The observed sperm count was 50 % lower with men estimated to have consumed the most pesticides, so it was a pretty pronounced effect. This finding is consistent with other studies that showed that agricultural workers who work directly with pesticides have a lower sperm count.  However the study size was small (~150 men), and they did not actually measure pesticide exposure or pesticide metabolites.