Pregnant women who have even mild sleep apnea should be treated for their sleep-disordered breathing given what is known about associated risks for hypertensive disorders of pregnancy and gestational diabetes, Carolyn M. D’Ambrosio, MS, MD, FCCP, said at the virtual annual meeting of the Associated Professional Sleep Societies.
“This is the current standard of care,” Dr. D’Ambrosio said. “Although guidelines on this issue are not hard and fast, I’d say that knowing what we know about the risk of adverse [maternal] outcomes, we should all try to treat these problems as soon as they’re identified” and then repeat polysomnography or home sleep testing 3-6 months post partum to “be sure the sleep-disordered breathing has resolved.”
Estimates of obstructive sleep apnea (OSA) prevalence range from approximately 9% in the first trimester to 20% in the third trimester. Yet recognizing the significance of OSA in pregnant women and identifying women for testing remains a major challenge. “Most women won’t [report sleep problems] because it’s pretty much common folklore that you don’t sleep well when you’re pregnant,” said Dr. D’Ambrosio, associate professor of medicine at Harvard Medical School, Boston, and current past-chair of the Women’s Lung Health Network for CHEST.
Many obstetricians and obstetrics providers, meanwhile, do not adequately screen. Typical screening tools like the Epworth Sleepiness Scale have low sensitivity and specificity during pregnancy, which means that inquiries about sleepiness, snoring, and disruptions in sleep are important, as is attention to potential risks for OSA posed by obesity, chronic hypertension, and neck circumference.
Only about a quarter of women in the United States snore during pregnancy, she noted. Snoring prevalence does increase as pregnancy progresses, reaching up to almost 50% in during the third trimester in some studies.
A four-variable screening tool reported almost 10 years ago for pregnant women is reliable for gauging risk, Dr. D’Ambrosio said. The model considers self-reported frequent snoring (more than three times/week), chronic hypertension, advanced maternal age, and a pregestational body mass index of at least 30 kg/m2. “If these [factors] are present, the patient is at significant risk for OSA and should be strongly considered for testing,” she said.
Home sleep apnea testing (HSAT) is validated for pregnant women but “it can underestimate,” she said. “If you get a negative result and [have clinical suspicion], then don’t stop there.”
And considering that the prevalence of OSA – at all levels of severity – increases as pregnancy progresses, it’s important to continue talking about sleep with patients who have frequent snoring, for instance, but negative sleep test results early in pregnancy. “They could develop [OSA] as time goes on,” she said.
Associated risk factors
Independent associations between sleep-disordered breathing and adverse maternal outcomes were demonstrated in a prospective cohort study published several years ago of 3,705 women who underwent HSAT in early and mid-pregnancy. The adjusted odds ratios for preeclampsia when sleep-disordered breathing (an apnea-hypopnea index of ≥5) was present early in pregnancy and in mid-pregnancy were 1.94 and 1.95, respectively.
For hypertensive disorders of pregnancy more broadly, the ORs were 1.46 and 1.73, and for gestational diabetes, the ORs were 3.47 and 2.79.
“Faced with the question about why it’s important to diagnosis and treat OSA [during pregnancy] since the pregnancy will be over in a few months, I go to this study,” Dr. D’Ambrosio said. “Waiting until the end of pregnancy is not safe. There are increased risks of very serious conditions if sleep apnea is there and it’s not treated.”
Another study demonstrating a link between OSA and maternal outcomes looked over 1.5 million deliveries in the United States and found a significantly higher prevalence of gestational diabetes (OR, 2.08), gestational hypertension (OR, 1.77), preeclampsia (OR, 2.07), and eclampsia (OR, 2.70) in pregnant women with OSA than without, after adjusting for maternal obesity. Associations remained significant after adjusting for a more comprehensive list of covariates.
Multiple potential casual pathways are at play, Dr. D’Ambrosio said. Short sleep duration decreases leptin and increases ghrelin levels, for instance, and sleep fragmentation activates the HPA axis and increases cortisol. Intermittent hypoxemia affects sympathetic activity, and intrathoracic pressure swings cause increased oxidative stress and systemic inflammation.
The resulting endothelial dysfunction, glucose dysfunction, and dyslipidemia can drive the adverse maternal outcomes documented in these studies, she said, noting that the adverse outcomes can have long-term cardiovascular consequences.
Continuous positive airway pressure therapy is well tolerated in pregnancy, and given pregnancy’s continual weight change, auto-titrating CPAP may be the best option, she said.
There is “some limited data that treatment improves maternal outcomes, and we’re still working on trying to get better data and more solid recommendations,” Dr. D’Ambrosio said. There currently are no guidelines covering the diagnosis and management of OSA during pregnancy.
“We’ve come a long way ... but we still have more to do,” she said. “We have a long way to go to getting [OSA in pregnant women] well recognized, with screening techniques and diagnosis.”
Asked after the meeting about Dr. D’Ambrosio’s messages, Anita Rajagopal, MD, said that OSA screening during pregnancy needs to be improved through more collaboration “with our ob.gyn. and primary care colleagues.”
Too often, she said, “the signs and symptoms of OSA in pregnancy are written off as ‘just harmless snoring’ while in fact the patient has treatable sleep disordered breathing with potential adverse effects.” Dr. Rajagopal is department medical director for sleep medicine at Community Physician Network and medical director of the Community Health Network Sleep-Wake Disorders Center, both in Indianapolis.
Dr. D’Ambrosio reported that she has no potential conflicts of interest related to the material she presented, and Dr. Rajagopal stated she has no potential conflicts of interest.