CHEST
Dr. Seema Amin
The increased prevalence in pregnancy can be explained by physiologic changes impacting the upper airway such as increases in maternal blood volume and reductions in oncotic pressure, as well as increases in circulating levels of estrogen and progesterone. OSA in pregnancy is associated with adverse perinatal outcomes such as hypertensive disorders of pregnancy, gestational diabetes, severe maternal morbidity abnormalities in fetal growth, preterm birth, and congenital abnormalities in the offspring.2,3 Despite this evidence, guidelines on the screening, diagnosis, and treatment of OSA in pregnancy have only recently been published and will be reviewed here.1
CHEST
Dr. Ghada Bourjeily
The obstetric subcommittee of the Society of Anesthesia and Sleep Medicine that produced these guidelines had expertise in obstetric anesthesiology, sleep medicine and sleep research, high-risk obstetrics, and obstetric medicine. The guideline aimed to answer 3 questions: 1) Who should be screened in pregnancy for OSA, 2) how to make a diagnosis of OSA in pregnancy and the postpartum period, and 3) what is the treatment for OSA in pregnancy and the postpartum period. Although the estimated number of annual pregnancies in the US declined between 2010 to 2019, these clinical questions remain critical considering the obesity epidemic, the ability to conceive despite advanced maternal age and chronic illnesses with the use of fertility treatments, and the crisis of severe maternal morbidity and mortality. As sleep disordered breathing (SDB) has been associated with many conditions linked to maternal mortality, better management of SDB in this population is key.
Screening for OSA in the pregnant population
The guideline does not support universal screening of all people who are pregnant, but rather suggests that people who are pregnant and at high risk for OSA, such as those with a body mass index (BMI) ≥30 kg/m2 and those with hypertensive disorders of pregnancy, or diabetes, in the index pregnancy or a prior pregnancy, be screened for OSA in the first or second trimester.1 Screening for OSA in pregnancy in limited populations is recommended due to the lower yield of universal screening and its potential burden on the health care system. Furthermore, screening for OSA in early pregnancy is suggested given the practical challenges of arranging testing, initiating, and allowing time for patients to become acclimated to therapy in later stages of pregnancy. However, even when timing of diagnosis may not allow for appropriate treatment of OSA during pregnancy, knowing a person’s OSA status before delivery is beneficial, particularly for patients at risk for Cesarean delivery who may require intubation and exposure to sedative medications, as well as those receiving epidural anesthesia, as OSA is a risk factor for respiratory depression.
Although screening was thought to be beneficial in specific populations, there is insufficient evidence to recommend any one screening tool. The guideline made recommendations against the use of the Berlin questionnaire, STOP-BANG questionnaire, Epworth Sleepiness Scale, or the ASA checklist.1 These screening tools were developed and validated in nonpregnant patient populations and their pooled sensitivity and specificity to detect OSA in pregnancy is low. Individual components of these screening tools, such as prepregnancy BMI, frequency and volume of snoring, hypertension, and neck circumference ≥16 inches have, however, been associated with OSA status.
Pregnancy-specific OSA screening tools have been proposed.4,5 The guideline suggests these pregnancy-specific tools may be considered for screening for OSA in pregnancy but still require external validation, especially in high-risk populations. The committee agreed that individuals with BMI >30kg/m2, hypertension, diabetes, and those with a history of difficult intubation or Mallampati score III or IV are considered at risk for OSA in pregnancy.