Rising C-section rates and cholesterol drugs for kids.

Health and medicine explained.
July 14 2008 2:02 PM

Your Health This Week

Are C-section rates rising because mothers are getting older? And why cholesterol drugs for kids are such a bad idea.

Cesarean section birth
Doctors perform a C-section

This week, Dr. Sydney Spiesel discusses a new explanation for the rising rate of birth by cesarean section, the recent recommendations about managing cholesterol in kids, and when it's safe to take a baby or a sick kid on a plane.

A good reason for more C-sections?

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Procedure: In recent years, the rate of cesarean section deliveries in the United States, Europe, and much of the developing world has been rising. Explanations include less tolerance for risk by both mothers and their doctors, more use of epidural anesthesia (which may increase the chance of a labor failing to progress), physicians' interest in scheduling deliveries at their convenience, and also the increasing autonomy of pregnant women, who are now able to choose C-section over vaginal delivery.

Question: These are all social causes not driven by medical necessity. And because C-sections have potentially serious side effects, there is a lot of interest in lowering the rate. But maybe, in fact, good medicine is often driving the increase. I know, I know; I was skeptical, too, but I found a recent paper from Scotland that caused me to think again.

Findings: The authors studied about 500,000 first pregnancies that went to term and were delivered by emergency C-section over a 25-year span between 1980 and 2005. They were particularly interested in how the age of the mother might affect the likelihood that a baby would be delivered surgically. In 1980, only about 8 percent of women delivering babies in Scotland were in their 30s or older. By contrast, by 2005, 24 percent of pregnant women were thirtysomethings, and the number of women over 40 delivering babies rose about 10 fold. And there was a direct relationship between maternal age and the likelihood of C-section. Fewer than 5 percent of Scottish 16-year-olds underwent emergency C-sections. The proportion rises steadily with each additional year of age, to more than 30 percent by age 40.

Explanation: Why should that be? It is possible that social differences between younger and older mothers played a small role. But the difference is likely a biological one resulting from the way women's bodies change. Looking at women from the same sample who delivered vaginally, the study's authors found that duration of labor increased with age, as did the probability that forceps or vacuum assistance would be required. About 15 percent of 16-year-old mothers required this kind of intervention, compared with three times as many 40-year-olds. In addition, the researchers found that as women age, the muscles of the uterus change, and contractions decrease in strength. All of these changes make successful vaginal delivery a little less likely for older women.

Conclusion: So much for social causes. Instead, it may well be that the increasing number of older women giving birth accounts for the rise in the C-section rate. If that's the case, then our strategies for discouraging C-sections, by presuming them to be elective, may be both wrong and dangerous.

Lowering cholesterol in children

Recommendations: The American Academy of Pediatrics' most recent set of recommendations involves the management of cholesterol levels in children for the sake of cardiovascular health. I'm skeptical of some of the conclusions. But first, the important guidelines are:

  • A healthy diet for all kids, and for chunky children between the ages of 1 and 2 with a family history of weight or cholesterol problems, reduced-fat milk. (The standard advice has been whole milk at least until age 2.) For older kids or adolescents with a weight problem or high levels of bad (LDL) cholesterol, nutritional counseling and more exercise.
  • Blood studies to look at cholesterol levels and similar markers of cardiovascular risk for children (even as young as two) and adolescents with, essentially, any degree of cardiovascular risk—heaviness, high blood pressure, diabetes, a suspect family history, or even a family history where the risk of cardiovascular disease in parents or grandparents is unknown. This edges toward all children.
  • The most controversial recommendation applies to children with significantly abnormal lab values or bad family histories. For these kids, the report urges medication, starting at 8 or sometimes even younger. Though other medications are mentioned, the authors focus on statins, the cholesterol-lowering drugs now used by innumerable adults.

Lack of evidence: The main problem is that the AAP's recommendations extrapolate heavily from theory and from adult practice without adequate grounding in research about kids. That is, they're not evidence-based. To be sure, it's common in medicine to make treatment recommendations and decisions before all the data are in, especially in pediatrics because it's hard and expensive to do research on children. But usually when we're in that position, we just take small risks for small numbers of very sick patients.

Risk: This time, the AAP's recommendations potentially reach many, many children and adolescents. And contrary to the bland reassurances of this report, we don't yet have a good enough idea of the safety or long-term consequences of dramatically cutting back on the use of full-fat dairy products in young children. The very cholesterol that threatens to clog my arteries is critical to making new cells in them. The same goes for the idea of using statins in children—relatively small and short-term studies have been done in kids, but in a significant way, we really don't yet know the risks. Though using these medications is probably a good idea for the small number of children known to be at high risk for heart disease, it's seriously premature to expand that group until we've learned a lot more.

Questions: There are many other questions to ask about this subject: For instance, how often does well-intentioned dietary advice to kids (or even grandmotherly nudging) lead to eating disorders later on? What kind of advice about physical activity will lead to the best lifelong results? How can gym teachers and coaches make exercise appeal to all children? How can we get more affordable, tasty, low-calorie food into schools? How can we overcome the genetic propensity to become overweight? Is it possible to change entrenched habits?

Conclusion: Until we have a better grip on the answers to these questions, broad recommendations of the sort in this report aren't a good idea. I'd give it an A for good intentions but at best a C-minus for content.

Flying kids

Question: When is it safe to take a baby on a plane? That's a question frequently asked of pediatricians, and until recently, we each answered it differently, based on what we know about infants and our knowledge of (or guess about) the differences between an airline cabin and a sea-level bedroom. Now, as a result of a recent paper that brings together a diverse body of research findings and explains the significance of some obscure studies, we can stop guessing.

Worry No. 1: On a plane, the dense packing of passengers and recirculation of air gives rise to fears of germs migrating like crazy. Stop worrying. Disease transmission isn't much of a risk aloft because cabin air actually recirculates frequently and rapidly and, in the process, passes through filters that strain out particles like germs.

Worry No. 2: The real health issue involves cabin pressure. On a plane, air pressure is at a level comparable to the top of a 5,000- to 8,000-foot mountain, which brings the oxygen level to about three-quarters of the amount available at sea level. Young infants have a little more difficulty in maintaining a good oxygen level in the blood than older kids or adults. So, how does flying affect them?

Findings: Full-term babies (and even premature ones) who don't have respiratory problems seem to be at no special risk when flying. This conclusion is based on observation of the millions of kids who have flown without immediate or long-term trouble and on laboratory studies of children exposed to lowered air pressure.

But there are groups of kids to watch out for:

  • Babies in the first week of life. It's prudent to wait a week to ensure good health.
  • Children with chronic lung disease. Mostly, theseare babies who needed a lot of mechanical ventilator support as premies. They usually see a respiratory specialist, who should be consulted about special requirements for flying. For instance, theymay need supplemental oxygen in flight, which must be arranged in advance. Sometimes children with lung problems can be tested before the flight by exposure (with a parent) to a lower oxygen concentration in a sealed box.
  • Children with asthma. Acute exacerbation can sometimes occur while flying, so always carry medications on board. (If you put them in your luggage, you won't have them, and your bags will invariably get lost.) To avoid boarding hassles with overzealous security staff, ask your doctor for a prescription to take with you on the plane.
  • Children with diabetes. Parents whose children use insulin should also carry this medication and a prescription in their hand luggage. Any bottles left in checked luggage could freeze during the flight and then no longer be effective.
  • Children withcystic fibrosis. Talk to a specialist to see if there is concern about flying. One problem for these patients is that the low humidity of air inside a plane can worsen the thickening of mucus inside the lungs, but usually kids with CF don't have trouble flying.
  • Children withheart disease or clotting problems. Most pediatric patients with these medical problems have no trouble flying, but, again, it's a good idea to check with your doctor.
  • Children with sickle cell disease. Though patients with this condition are somewhat more likely to have problems at higher altitudes, limited research suggests that flying is probably OK. Still, it's a good idea for patients to drink a lot of fluids and to move around during the flight. Talk to your doctor about whether aspirin might be a good idea on the day of.
  • Children with middle-ear problems. The decreased cabin pressure exacerbates this condition, more often in children than in adults. The trouble ranges from ear pain to (very rarely) deafness or a torn eardrum. Decongestants before flying don't seem to help. Doctors disagree about whether a recent ear infection is reason to postpone a trip. Unfortunately, the paper doesn't really answer this question. What advice do I give? I used to think that flying with an ear infection was a bad idea, but I've pretty much changed my mind. Is that because I now consider the risk of problems to be so low (which I do) or because I value vacations so highly?

Sydney Spiesel is a pediatrician in Woodbridge, Conn., and clinical professor of pediatrics at Yale University's School of Medicine.

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