Obstructive sleep apnea (OSA) occurs when the upper airway narrows causing recurrent cessation of breathing during sleep, resulting in fragmented sleep and subsequent daytime sleepiness, fatigue and a reduction in quality of life (1). Excess body weight is a significant driver of OSA. Rates of obesity among pregnant Australian women have risen recently with current estimates of 50% either overweight (BMI>25-30) or obese (BMI>30) (2). A parallel increase in rates of OSA among pregnant women has been observed. (3).
OSA in pregnancy is associated with both maternal and fetal morbidity (4–7), however no dedicated screening tool has been validated for this setting. The STOP-BANG questionnaire is an established convenient and consistent prediction tool for OSA in non-pregnant adults (8).
To improve clinical care of patients attending our tertiary obstetric hospital we modified the STOP-BANG with additional questions on risk factors specifically associated with OSA in pregnancy such as polycystic ovarian syndrome (PCOS), and previous gestational complications such as pre-eclampsia and diabetes. Patients with moderate risk scores (3-4/7) were invited to a sleep clinic consultation, whereas those with high risk (≥5/7) were referred directly for an in-laboratory sleep study or polysomnography (PSG).
In the pilot phase of our project 25 patients have completed screening. Of those scoring five or more on our screening tool, the median age was 32 years (range 24-35 years). All patients had a BMI of >35kg/m2 and reported feeling tired. Observed loud snoring, enlarged neck circumference, and previous gestational complications were present in 71%. PCOS was reported in 57%, whereas only 14% reported medical treatment for hypertension. At present, our screening tool indicates that elevated BMI is the commonest objective OSA risk factor in pregnancy. Screening is ongoing and high-risk patients are currently undergoing PSGs, of which further results will be presented.