It happens every day on every labor and delivery unit in America. Something goes wonky on the fetal heart monitor (too slow, too fast, too flat) and the nurse straps an oxygen mask to mom's face, turns her to a new position and increases her IV fluids.
Pretty soon, baby's heart rate is back to normal and everyone heaves a sigh of relief. (If the heart rate doesn't go back to normal, that's a game changer that often results in a C-section.)
But according to an opinion piece published in the American Journal of Obstetrics and Gynecology in 2014, the supplemental oxygen given to resuscitate babies in the uterus is unnecessary and potentially harmful. Since giving oxygen is among the most common interventions done on a labor unit, let's break down why it's given, what it does and whether or not you should turn it down.
When do nurses administer oxygen?
Baby's heart rate is traced and evaluated along with your contraction pattern. Nurses, midwives and doctors look for specific heart rate patterns that indicate that Baby's A-OK. If heart patterns hint that Baby isn't feeling so hot, or that Baby's in trouble, then something needs to be done about it.
Mind you, just because the heart rate looks different does NOT mean the baby is actually in trouble, and in most cases, he's not. Just in case though, if his heart rate is too slow, too fast, or too "flat," (which means it doesn't vary much from one beat to the next), the nurse will probably follow the standards of care prescribed by the hospital to make the heart beat look better on the monitor.
The nurse will do something called intrauterine resuscitation; she'll change your position, infuse IV fluids and give you oxygen. In most cases, this procedure does the trick, and soon the baby looks better.
What does oxygen during labor do?
The idea is that giving you extra oxygen increases oxygen delivery to your baby. It can change the heart rate sometimes, but this is most likely due to a combination of interventions.
Many clinicians argue that unless you're hypoxic (low oxygen levels in your blood), there's no need to give you extra. You only have so many oxygen receptors in your blood, and once they're full—they're full! Unless you have a condition that inhibits your ability to take in or use oxygen on your own, like asthma or anemia, you'll inhale all you and your baby need through the air.
Bottom line: Extra oxygen probably doesn't do anything at all.
Why do it, then?
Because hospital standards tell nurses to do it, and if something happens and there's a bad outcome, it had better be on the chart that the nurse gave oxygen.
"So many things we do in obstetrics are based on hospital custom and/or culture and not backed by research," says Chris Beard, Certified Nurse Midwife at Kaiser Sunnyside Hospital in Portland, Oregon.
Beard isn't exactly convinced it does any good, but she hasn't seen it have any negative consequences, either. "It's possible that 02 will eventually be discarded, but for now, it's the standard of care, so we use it," she says, adding that the hospital "won't have a leg to stand on with lawyers" if something bad happens, and the medical professional didn't follow procedure.
What are the risks of supplementation of oxygen?
Maureen Hamel, M.D., OB-GYN resident at Women and Infant's Hospital in Rhode Island and author of the paper published in the American Journal of Obstetrics and Gynecology (see above), says that only two randomized trials have investigated the use of maternal oxygen supplementation in laboring women, and researchers haven't found it likely to benefit the baby.
What's more, she argues that supplementation with oxygen may have negative effects.
"We know that oxygen can cause free radicals to develop, and free radicals have been proven to be harmful in other settings (like if Baby is born prematurely or suffers certain injuries later in life)," says Dr. Hamel. Still, there's no evidence supporting the notion that supplemental oxygen creates enough free radicals to cause harm. Right now, the risk is theoretical.
Should you say no?
If your nurse offers you a whiff of oxygen, so be it. You can always say no, but this mild intervention is done so routinely, with no evidence that it causes any harm.
Do you need that oxygen? Probably not. But I've strapped the 02 on hundreds of patients, and I've never seen a single mother or baby suffer any negative side effects.