You would think.
And yet, here she is, going in for amnio on page 66:
"Amniotic fluid is ... bacteriostatic, meaning that bacteria will not grow when cultured in it, so amniotic fluid undoubtedly helps keep the womb a sterile place."
She was pregnant in 1997/8 and this book was published in 2001. By this point, we'd known for quite a while that all kinds of stuff (bacterial, specifically) grew in amniotic fluid and were a prime cause of preterm delivery and sepsis of the new born and so forth. We knew it well enough that people were trying all kinds of antibiotic protocols to deal with the problem. And failing, because it turned out those germs were often quite exotic and sometimes fungal. _That_ particular revelation is quite recent.
On the next page, p 67:
"by measuring the size of the head and the length of the long bones, sonographers can calculate the age of a fetus to within seventy-two hours"
It's crap like this that just makes me wonder about how much I can trust the rest of the information. Altho the stuff about really good birders being able to identify birds at night by sound when they're migrating 1000 feet overhead is so charming I think I'll just believe it anyway.
(Quotes from _Having Faith_.)