Q: I'm pregnant with my second child. In my first pregnancy, I had labor induced when I was 14 days past my due date. Am I going to have to go through that again? -- Mary P. Greenville, S.C.
A: Maybe (see below). But first, some great pregnancy facts! The longest pregnancy was reported by a doctor at Los Angeles Methodist Hospital in 1945: 25-year-old Beulah Hunter supposedly gave birth to a 6 pound, 15 ounce baby girl after carrying her for 375 days -- 95 days longer than the 280 that women are told is "normal." While it seems unlikely the claim is accurate, it does make you wonder, because finally researchers have figured out the length of a normal pregnancy can vary by as much as 37 days!
They discovered that 268 days (or 38 weeks and 2 days) is average for a full-term birth. And it's not abnormal for it to take much longer. It's interesting to note that only 4 percent of women deliver at 280 days, and 30 percent do not deliver within 10 days of their estimated due date.
Whether the length of your pregnancy is normal but simply longer-running than most is something only you and your doctor can determine. But one thing the researchers found was that while "full term" varies from woman to woman, for any one mom, the length of her pregnancy is pretty consistent from child to child.
Q: I'm fascinated by the new 3-D printers; I can't wait to manufacture things at home for myself and the kids. But I hear they may be a health hazard. What's that about? -- John P., Minneapolis
A: We also love technology that makes life simpler and easier. Who doesn't? But you're right, at-home 3-D printers come with some pretty serious risks. Remember "Na-Nu, Na-Nu," the friendly Orkan greeting that extraterrestrial visitor Mork (Robin Williams) used when meeting Earthlings? Well 3D printers come with a similar, "Nano Nano" greeting, but the meaning isn't so friendly.
At-home 3-D printers (available from $400 to $1,300) that let you manufacture your own cup and saucer or screwdriver can release from 20 to 200 billion toxic nanoparticles as they "print" objects. A recent test ranked them all as "high emitters." And some studies indicate that the emissions are related to total and cardio-respiratory mortality, hospital admissions for stroke and asthma symptoms.
The way 3-D printers work is that they heat up a thermoplastic feedstock (the equivalent of an inkjet cartridge) and then extrude the plastic in layers to create your desired object. The lower-temperature models use PLA (polylactic acid) feedstock and may be safer than the higher temperature ones that use ABS (acrylonitrile butadiene styrene) feedstock.
But industrial 3-D printers that are already used to make everything from scientific equipment to molds of teeth operate in a tightly controlled and filtered environment. At-home models are freestanding and don't come with exhaust ventilation or filtration accessories. So you and your kids could breathe in harmful mini-particles of plastic and associated chemicals.
Our tip? Hold off on buying that desktop 3-D printer until more tests are done to ensure it's safe for in-home use. And if you do have one already, make sure it's in a garage or shed that's very well-ventilated and install an air filter. Don't let the kids use it, and consider wearing a ventilator when you're around it.
(Mehmet Oz, M.D. is host of "The Dr. Oz Show," and Mike Roizen, M.D. is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. Email your health and wellness questions to Dr. Oz and Dr. Roizen at firstname.lastname@example.org.)