Do unborn babies urinate/defecate in the womb? Plus: Was "here be dragons" ever really inscribed on maps?

August 18, 2006

Dear Cecil:

Do unborn babies pee and/or defecate in the womb?

That's two questions, so two answers. Number one: yes, and it's a good thing they do. Number two: yes, but you better hope they don't.

Fetal urination is normal. It's part of that "miracle of life" folderol the nature programs exalt just before they hit you with something you'd rather not know. Naturally, fetal urine isn't quite the same as yours or mine. It does contain urea, but much of the nitrogenous waste enters maternal circulation for mama to clean up. Fetal urine isn't yellow, either. Fetuses and newborns lack enzymes to convert bile pigments to urobilin, which colors the output of older children and adults.

Urine production begins late in the first trimester, about the same time the two-inch embryo becomes a fetus. In the second half of pregnancy, fetal urine is an important constituent of amniotic fluid. By the time the kid is about ready to pop out, he or she is passing roughly a liter a day. Where does it go? Seems kids learn the benefits of recycling early on — they swallow it. They'd better, too, lest polyhydramnios (a potentially dangerous buildup of fluid volume) result. When fetal urination is impaired, the opposite complication, oligohydramnios, usually occurs.

Fetal defecation isn't normal, but fetuses do accumulate a mass of greenish feces, called meconium, in their intestines. Unlike the adult version, meconium is sterile and odorless, though still pretty icky, and the sight of it in the newborn nursery starkly reminds a new parent — not infrequently dad, since mom at this point is often out of it — that his life has entered a dramatic new phase. (Nurses invariably offer to clean things up. Let 'em.) You may ask: There's nothing much to nosh on in there, so where's this stuff coming from? Various endogenous and swallowed sources: mucus, bile, intestinal epithelial cells, lanugo (fine body hairs that are normally shed before birth), and vernix caseosa (a lubricating sebaceous secretion of the skin).

Fetuses usually don't pass meconium until after birth, but doing so in the womb isn't rare. Around 12 percent of fetuses have meconium-stained amniotic fluid (MSAF), colored yellow or green by bile pigments in the meconium — an indication that junior couldn't wait. The more prolonged the pregnancy, the greater the risk. In postterm births (those occurring after 42 weeks), the rate of meconium staining is about a quarter to a half. Why is this a concern? Fetuses take amniotic fluid into their lungs, and in a minority of MSAF cases, passed meconium enters the airway before birth and afterward leads to respiratory symptoms collectively called meconium aspiration syndrome (MAS). MAS can be fatal, although the rate of deaths is falling in developed countries — in part due to better treatments, but mostly because labor is now more likely to be induced if pregnancy drags on.

What else are they doing in there for nine months without cable? Let's put it this way: fetuses manage to entertain themselves. For instance, in 1996 two doctors reported on their ultrasonic observation of a female fetus masturbating over a period of 20 minutes. Twenty minutes? Change the channel already, you pervs.

Dear Cecil:

It seems whenever somebody wants to create a map that looks antique, they'll put "Here be dragons" on it somewhere, possibly with a picture of said creature. But I've seen photos of real historical maps, and they've never included that phrase. My question to you, master, is this: have I not seen the right maps, or is this the cartographic equivalent of "The butler did it"?

Cecil replies:

Now, Daniel. As this column has previously established, in at least a couple detective stories the butler did do it. Likewise, there's one, though possibly only one, representation of the earth from the era of exploration on which one may find the phrase "here be dragons" — to be precise, the Latin equivalent, HC SVNT DRACONES. These words are inscribed on the Lenox Globe (circa 1503-'07), an engraved copper sphere owned by the New York Public Library and on display in the Edna Barnes Salomon Room — or so online sources claimed. Naturally we wanted confirmation, but our NYC-based operatives couldn't get off work in Jersey. Eventually, however, we reached Rebecca Federman, NYPL social-sciences bibliographer, who says (a) the globe is small (12.7 centimeters) and dark and you can't tell much from looking at it in the display case, but (b) photographs of the globe taken for research indicate the above words appear on the coast of Southeast Asia. Thanks, Rebecca. You want me to spell you for an hour at the reference desk, say the word.

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