Meanwhile, other studies have shown first-time mothers' pregnancies tend to last even longer—288 days. Whether she is truly "overdue" or not, going past 280 days ramps up the stress for expectant parents. Punctuality is a virtue in our society. Show up 15 minutes late to class, and you get sent to the principal's office. Clock in an hour late for work, and you might get fired.
For overdue mothers, the threat is medical. Some doctors start talking to patients about induction or Caesarean section just a day or two after the due date. The Swedish survey suggests some pregnant women might find themselves being induced before they're even actually overdue.
If there is no life-threatening medical problem, having the flexibility to go two weeks past the due date could make a huge difference. According to Pregnancy.org, around 80 percent of babies are born between the 38- and 42-week marks.
Medical science doesn't know exactly what causes labor. Some think it starts when the mother's body releases oxytocin. In fact, the drug Pitocin, which is used to induce labor, is synthetic oxytocin. A few new theories speculate that the baby's body starts labor by releasing hormones. While what causes labor remains a mystery, there are plenty of folk remedies that promise to speed it up. These include taking a long walk, eating spicy food and having sex—which sounds like the kind of date that could have caused the pregnancy in the first place!
To preempt her own worries about a punctual birth, my wife always told interested parties her due date, but was sure to add that she had no expectation of meeting it. And she was right—she blew right past it.
Then on the 286th day of her pregnancy—officially six days late, yet two days earlier than the average for first-time moms—she went into labor after watching an episode of Mad Men. A few weeks later, halfway through the opening credits of another Mad Men episode, one of our friends went into labor too. I think we may have something here. If you know a pregnant woman who is at 280 days, tell her to wait three days and then turn on her TV.