Can Stressful Times Lead to Fewer Baby Boys?

This means that natural selection weeds out the fetuses that it deems unlikely to survive and reproduce, leading to a more robust population, one that is likely to survive whatever stressor might be around during that time. The fragility of the male fetus isn’t a problem during the good times and for whatever reason, the birth ratio is skewed towards males. As more instances of altered birth ratios come to light, we might realize that choosing a blue or pink color scheme is less like a coin toss and more a reflection of our world around us.