The Dentist’s Nitrous Oxide Gains Popularity during Labour and Delivery

Sarah Sutton had been in labour for more than 12 hours when she asked her nurse-midwife for some nitrous oxide. She knew the gas was an option at Charleston Birth Place, a freestanding birth centre in North Charleston. Her contractions, spaced about a minute or so apart, had become “excruciating.”

“I had it in my mind that it would take pain away,” Sutton said. “It didn’t.” Two hours later, her son was born. Sutton said her husband definitely noticed a difference after she inhaled the nitrous oxide. “It gave me something to focus on,” she said. “I could relax.”

The midwife birth centre and only one hospital in South Carolina offer nitrous oxide to pregnant women to ease labour pain.

The gas, commonly used in dentists’ offices, was widely available in hospitals for women in childbirth until powerful, pain-killing epidurals gained popularity. Now, “laughing gas” is making a comeback, offering an alternative to patients who need some relief but want to keep their labour as natural as possible.

Lesley Rathbun, a certified nurse-midwife and owner of Charleston Birth Place, said 25 percent of her patients use nitrous oxide during labour. Like Sutton, she said they don’t always know what to expect.

“Nitrous (oxide) does not really provide any pain relief at all,” Rathbun said. “It’s just an anti-anxiety agent.” Anxiety and pain are closely linked, she explained.

“The more anxious you are, the more pain you have. The nitrous oxide doesn’t eliminate labour pain, but it tends to help women relax during contractions. It’s probably the most studied substance in history because it’s been used since the 1700s,” she said. “There’s really a lot of evidence around the use of it.”

Michael Civitello sells the Porter Instrument machine called the Nitronox system, which is used at Charleston Birth Place. He said that four years ago, only three or four hospitals and birth centres in the country used nitrous oxide for labour pain management. Today, he estimated there are 150. It is already widely used in other countries, including theUK. “It’s a new market, not new technology,” he said.

Unlike the nitrous oxide machines commonly used in dentists’ offices, the FDA-approved Nitronox system is self-administered by the patient.

Patients in a dentist’s office generally inhale the gas continuously through a nasal cannula looped under their nose and around their ears. But the Nitronox system allows a pregnant patient to raise a mask to her face and inhale the gas during a contraction. She typically lowers the mask when the contraction is finished. There is no continuous flow.

The blend of nitrous oxide and oxygen in a dentist’s office may also be stronger than the blend used for labouring women.

Dentists can adjust the blend to a maximum 70 per cent nitrous oxide and 30 per cent oxygen for their patients. The blend administered through the Nitronox system does not change. It is always 50 per cent nitrous oxide and 50 per cent oxygen.

Rathbun said the machine cost about $5,000. Nitrous oxide is not covered by health insurance plans, so she charges patients $150 to use it.

Clarendon Health System in Manning offers it to pregnant patients for free. It is the only hospital that offers nitrous oxide to pregnant women in South Carolina.

Nurse-midwife Tom Chappell said the hospital bought the Nitronox system about ten months ago.

“Many women are anxious in labour. They want everything to go well,” he said. “(Nitrous oxide) helps them relax and decrease anxiety.”

The gas isn’t risk-free. Patients who have had middle-ear surgery or who have a vitamin B deficiency should not use nitrous oxide. It’s also possible to overdose on the gas, but only in very high concentrations.

Rathbun said some studies have suggested that dental hygienists are more likely to miscarry because of prolonged exposure to nitrous oxide, but this exposure doesn’t seem to pose a risk to patients who only occasionally use it.

Lynn Gottlieb delivered her son at Charleston Birth Place in 2013. She said nitrous oxide helped “take the edge off” during labour. “It did help me to focus on my breathing as you had to inhale and exhale through the mask with each contraction,” she said.

Rathbun called it a “no-brainer” for most moms. “It’s safe. It’s very effective,” she said. “It doesn’t completely replace an epidural. For women who are having really difficult labours, it will help them get further down the road, but it will at least delay that epidural so you’re not getting it way too early.” Lauren Sausser