1–16 of 16
A man deposits seed in a womb and goes away, and then another cause takes it, and labours on it and makes a child. What a thing from such a material! Again, the child passes food down through the throat, and then another cause takes it and makes perception and motion, and in fine life and strength and other things…
From a female perspective, pregnancy is always a huge investment. Even more so if her species has a hemochorial placenta. Once that placenta is in place, she not only loses full control of her own hormones, she also risks hemorrhage when it comes out. So it makes sense that females want to screen embryos very, very…
Inside the uterus we have a thick layer of endometrial tissue, which contains only tiny blood vessels. The endometrium seals off our main blood supply from the newly implanted embryo. The growing placenta literally burrows through this layer, rips into arterial walls and re-wires them to channel blood straight to the…
Given the invasive nature of pregnancy, it’s perhaps not surprising that the primate womb has evolved to be wary of committing to it. Mammals whose placentae don’t breach the walls of the womb can simply abort or reabsorb unwanted foetuses at any stage of pregnancy. For primates, any such manoeuvre runs the risk of…
In most mammals, the mother’s blood supply remains safely isolated from the foetus. It passes its nutrients to the foetus through a filter, which the mother controls. The mother is a despot: she provides only what she chooses, which makes her largely invulnerable to paternal manipulation during pregnancy. In primates…
Careful and reproducible observations and measurements in the bbiosciences have similarly forced us to repeatedly refine our traditional ideas about what life itself is and when it begins. Is a human being first a life when it emerges from the birth canal? Does it have any legal rights is as a person before then? Or…
One of my favorite cases of embryological evidence for evolution is the furry human fetus. We are famously known as “naked apes” because, unlike other primates, we don’t have a thick coat of hair. But in fact for one brief period we do—as embryos. Around sixth months after conception, we become completely covered with…
Does that mean exercise should be a part of human pregnancies? Evidence suggests the answer is yes. The first benefit is a practical one, having to do with labor. Many women report that giving birth is both the most exhilarating experience of their lives and the most painful. But women who exercise regularly have a…
Researchers have isolated three toxic types. Their common characteristic: that you feel out of control over the bad stuff coming at you. As stress moves from moderate to severe, and from acute to chronic, this loss of control turns catastrophic and begins to affect baby. Here are the bad types of stress: • Too…
Of its several advantages, "birtn stress" has been found to be especially beneficial for a newborn's breathing. Compared with babies born by C'Section, vaginally delivered babies are quicker to take their first breaths; their blood oxygen levels rise more rapidly after birth; and they are less likely to suffer any of…
There are two main reasons for concern about exercising during pregnancy. One is that it may reduce the baby's oxygen supply, since exercise, like other sources of stress, reduces blood flow to the uterus. Another risk is overheating. As we have already seen, fetal development is highly sensitive to temperature, and…
Caffeine crosses the placenta and may even concentrate in the fetal circulation. Concern about its effect on fetal development stems from animal studies, where it has been found to be teratogenic when fed to pregnant rats in high doses; a dose equivalent to 150 cups of strong coffee per day causes malformations in…
Most women also realize that smoking is bad during pregnancy. Unfortunately, it can be a very hard habit to give up, even for the best-intentioned parent. Smoking is not as detrimental to fetal brain development as heavy alcohol drinking, but it acts on many other organ systems. like the heart and lungs, that…
Another experiment, however, proves that babies really do imprint on auditory experiences while still in the womb. In this case, mothers were asked to read a particular story aloud, twice a day, during the last six weeks of pregnancy. The story was by Dr. Seuss again, this time The Cat in the Hat, and it was estimated…
Initially, Almond doubted that the intrauterine conditions provided by a pregnant woman, even one sick with a virulent strain of the flu, could exert any lasting influence on her offspring. “When I started looking at the influenza pandemic, I was skeptical of the fetal origins hypothesis. I didn’t think I’d find any…
The notion of prenatal influences may conjure up frivolous attempts to enrich the fetus, like playing Mozart through headphones placed on a pregnant belly. In reality, the nine-month-long process of shaping and molding that goes on in the womb is far more visceral and consequential than that. Much of what a pregnant…