by Rita Rubin
If you're trying to figure out your chances of having a C-section, look in your wallet. If you have a health insurance card, research shows that you're more likely to deliver by cesarean than a woman who's uninsured or covered by Medicaid, the state/federal program for low-income Americans. And your driver's license yields more information than all those diplomas hanging in your obstetrician's office -- that is, if you were honest about your age and weight when you applied for your license!
If you were over your ideal weight before you conceived, or you gained more than 40 pounds while pregnant, you're more likely to deliver by cesarean. Those extra pounds raise your risk of developing diabetes or high blood pressure, which in turn increases your chance of having a C-section. Even if you avoid those complications, it's important to remember that the more weight you gain, the bigger your baby might be -- and bigger babies tend to be harder to push out. Studies by researchers at the National Institutes of Health and elsewhere also suggest that the heavier you are, the longer your labor might be.
And even if you're a rail, simply being closer to your 40th than your 30th birthday raises your chance of delivering by cesarean, especially if it's your first baby. If you're one of those so-called "mature" pregnant women (don't you love those terms?) preparing to deliver your first baby, you're in good company. Growing numbers of women who delayed childbearing because of graduate school, career advancement, infertility, or late and second marriages are now tossing hair dye along with diapers into their shopping carts. Just look at these numbers from the National Center for Health Statistics, part of the federal Centers for Disease Control and Prevention:
The majority of pregnant women over 35, or even over 40, deliver healthy babies. But there's no getting around the fact that the older you are, the more likely you are to deliver your baby by C-section. For example, Harvard researchers found that 43 percent of first-time mothers age 40 and older who delivered at Boston's Brigham and Women's Hospital in 1998 had cesareans, compared to only 12 percent of those under 35. One reason for that disparity is pretty simple: The older you get, the more likely you are to experience pregnancy complications that predispose you to a cesarean. They include:
But even if you don't have any of the above risk factors, you should be aware that simply being a first-time mother who's at least 35 years old increases your chance of having a C-section. Part of that may be physiological; part of it may be cultural. A San Francisco study of 8,500 first-time moms who delivered full-term, head-down babies found that the older they were, the longer they labored. Their cervixes dilated more slowly, and it took longer for them to push their babies out. Not surprisingly, then, the older they were, the more likely they were to receive oxytocin (frequently referred to by one of its brand names, Pitocin) to ramp up their labor. But it's not like your uterus suddenly heads south when you hit 35. Here's a cheery thought: The study found that the chance that your uterus has lost its oomph actually begins to increase when you're in your early 20s -- long before you begin to entertain thoughts of Botox or bifocals.