Obstructive Sleep Apnea in Pregnancy
Obstructive Sleep Apnea (OSA) is more prevalent in pregnant women especially those with complicated pregnancies than in nonpregnant women of reproductive age. The prevalence of OSA during pregnancy is estimated to be 4% to 27%, compared with approximately 0.7% to 6.5% in nonpregnant women. In pregnant females. Yet, OSA can be easily missed during pregnancy because some symptoms of sleep apnea like excessive daytime sleepiness, easily fatigue, fragmented sleep, trips to the bathroom during sleep, etc. can be mistaken as those due to pregnancy. However, it is imperative not to dismiss breathing-related sleep concerns as temporary pregnancy changes.
What is Obstructive Sleep Apnea?
Obstructive Sleep Apnea (OSA) is a chronic, serious, and most common sleep disorder. It occurs when the throat muscles relax during sleep, causing complete or almost complete airways collapse, cutting off airflow intermittently.
How does Pregnancy Affect Breathing During Sleep
Pregnancy can change breathing during sleep, especially as pregnancy progresses. Hormonal changes increase respiratory drive, while the growing uterus reduces lung reserve and can make breathing feel more noticeable when lying down.
Common sleep-related changes during pregnancy include:
More nasal congestion/snoring: Pregnancy-related swelling of the nasal passages can narrow the upper airway.
Faster or deeper breathing: Progesterone naturally stimulates ventilation, so breathing may feel different even without lung disease.
More shortness of breath when lying flat: This is more common later in pregnancy.
More awakenings and fragmented sleep: Reflux, frequent urination, fetal movement, and breathing discomfort can all contribute.
Higher risk of obstructive sleep apnea (OSA). Risk increases with pregnancy-related weight gain, pre-existing obesity, hypertension, and particularly preeclampsia. Symptoms include loud habitual snoring, witnessed pauses or gasping, morning headaches, and marked daytime sleepiness.
Why OSA Deserves Attention During Pregnancy
OSA during pregnancy has been associated with several complications affecting the mom or baby. These include:
Mom:
- Hypertensive disorders of pregnancy.
- Gestational diabetes
- Severe maternal morbidity
Fetal:
- Abnormal fetal growth
- Preterm birth
- Congenital malformations
Why is screening for OSA important during pregnancy?
Due to higher prevalence, difficult to recognize symptoms and higher morbidity in pregnancy, screening for OSA is important per American College of Chest Physicians. Screening using standard tools or pregnancy specific tools help identify patients who may need further evaluation with sleep studies.
What Happens if OSA Is Suspected?
What Happens if the Sleep Study Is Positive for Obstructive Sleep Apnea?
If sleep study comes back positive for sleep apnea, treatment decisions are based on the apnea-hypopnea index (AHI), symptoms, sequelae, comorbidities, additional risk factors, patient’s preference, insurance, etc.
Understanding Apnea-Hypopnea Index (AHI):
AHI is a sum of apnea and hypopnea events per hour. An apnea event is when breathing during sleep stops for at least 10 seconds due to complete collapse of the airway leading to absence of airflow. While a hypopnea event is 30% reduction in airflow accompanied by 3-4% oxygen drop caused by partial collapse of airways.
How do we treat OSA in pregnancy?
Auto-Continuous Positive Airway Pressure (APAP) is a preferred treatment.
AHI between 5 and 15, treatment is recommended when OSA is accompanied by symptoms, comorbidities like stroke, diabetes, high-blood pressure, etc, preferably with Auto-CPAP.
For an AHI greater than 15, PAP therapy is recommended regardless of symptoms or comorbidities.
What to do when sleepy despite using APAP?
If despite using APAP, there is residual sleepiness, scheduled naps are useful whenever possible. Stimulants are not the first line of treatment.
Should there be a Reassessment for OSA After Delivery?
Postpartum women who were diagnosed with OSA during pregnancy should be reassessed for sleep-disordered breathing. Pregnancy-related changes that can contribute to OSA may improve after delivery. Reassessment can help determine whether sleep apnea is still present and whether continued treatment is required.
