Assume a mom with good health insurance, access to first-world medical care, keeps her appointments, practices good health & nutrition habits, etc.
Under these circumstances, how many deliveries are likely to result in a second, un-known baby coming through the birth canal? One in a hundred? One in a thousand?
-Assume that, for whatever reason, all of the pre-natal care simply failed to pick up on the fact that there were two fetuses. The mom had no idea, the doc had no idea, etc.
The answer probably depends to some extent where you live. You mention ‘first-world’ medical care, but prenatal care in rural Alabama (not picking on Alabama) and in downtown Manhattan might be quite different.
Is it possible for someone to miss a second heartbeat or not see the second baby on a sonogram? Sure. Does it happen often by competent medical professionals? Not very often.
I have read recently suggestions that ultrasound does not usually have any significant medical benefit usually, it’s done for the delight and entertainment of the parent(s). As a result, suggestion is that some plans may refuse to cover it, making the parents pay. if this becomes the norm, that eliminates one avenue for determining the head count of the bundle of joy.
Ultrasound has taken all the fun out of asking pregnant women, “but have you picked names for twins?”
That’s silly. Ultrasounds can screen for Down syndrome, predict heart valve issues, and do all sorts of medical stuff besides “it’s a boy”. At my anatomy scan they measured the long bones, made sure all the organs were there and functioning, etc. I can’t imagine insurance eliminating paying for them (if only because my insurance company would surely prefer I terminate a pregnancy that could get very expensive.) Now, they don’t pay for “vanity” ultrasounds.
IIRC Downs tests can be done with a blood test before the pregnancy is too far along to be terminated.
the article IIRC was complaining about how many ultrasounds and some were definitely just “vanity” not medically necessary.
A family friend had “surprise” twins about twenty years ago. I think the twins’ heartbeats were in sync, so they “read” as a single heartbeat. One kid always managed to block the other in the ultrasounds. I don’t believe there was an issue with pre-natal care, but there were probably fewer ultrasounds done over the course of the pregnancy.
They do a blood test, yes, which is also a screener, but they also do an ultrasound looking for nuchal translucency. The diagnostic tests are all much more invasive (amnio or CVS.)
Sure, you have the option for vanity ultrasounds, but the ones your doctor has you get are anything but. Everybody gets the anatomy scan at 20 weeks; you can choose whether you want the genetic screening stuff, which was IIRC at 12 weeks. I have to have another one done at 28 to make sure the baby is growing correctly because it’s sharing space with a fibroid, which I assure you is also not a vanity ultrasound. Additionally, most people get one early on (ours was at 8 weeks) to get a firm date. There are a lot of medically very valid reasons for ultrasounds; everybody, essentially, at least gets the anatomy scan at 20 weeks.
As the father of twins, I can attest that is a plausible scenario, or at least it was when mine were born. One kid can block the other in an ultrasounds, although multiple ultrasounds would probably show the second baby at some point. Still, our gynecologist was always just a little concerned because she couldn’t be sure there wasn’t a* third* baby hiding in there.
My mother only found out she was pregnant with twins six days before the birth. This was in 1981. A friend of mine, of a similar background, was a complete surprise to her parents. Both mothers had standard ultrasounds carried out.
My Aunt had surprise twins. She was already the mother of three. When she gave birth to her 4th she told the doctor that she felt like she still had something inside of her. And sure enough, to the surprise to everyone another baby crowned.
She had access to top notch medical care in a large metro area. But this happened in 1967 so I’m not sure if that matters.
A friend of mine gave birth to twins about ten years ago. She didn’t know, until after the first was delivered, that the second was on the way. She had excellent medical care in a leading maternity hospital in a European capital city. And she was a paediatric nurse herself.
She opted not to have a lot of the diagnostic procedures on offer, as they have no therapeutic value and some - e.g. amniocentesis - have a small but non-trivial mordbidity.
Interestingly, the number of multiple births has doubled recently. Link.
Some due to infertility treatments (no surprise) but also some due to more older women getting pregnant.
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