Obstructive sleep apnea (OSA) is a sleep-related breathing disorder characterized by repeated episodes of partial or complete upper airway collapse during sleep. This collapse leads to temporary pauses in breathing, fragmented rest, drops in blood oxygen levels, and surges in blood pressure. OSA is increasingly prevalent during pregnancy, potentially affecting a significant portion of expectant mothers as gestation advances. Recognizing and managing sleep apnea is an important part of prenatal care due to serious potential complications for both the mother and the developing fetus.
Identifying Sleep Apnea During Pregnancy
The symptoms of obstructive sleep apnea in pregnant individuals are often confused with the common discomforts of pregnancy, leading to underdiagnosis. The most frequent sign is loud, habitual snoring, especially if it is new or has worsened significantly since becoming pregnant. A partner may also witness distinct pauses in breathing, followed by gasping or choking sounds as the sleeper’s airway reopens.
Excessive daytime sleepiness that is disproportionate to the usual fatigue of pregnancy is another common indicator. Other symptoms include morning headaches and frequent nighttime urination (nocturia). Healthcare providers use screening tools, such as the STOP-BANG questionnaire, during prenatal visits to assess risk. If high risk is identified, the definitive diagnosis is confirmed through a formal sleep study (polysomnography), which monitors breathing patterns, oxygen levels, and other vital signs.
Physiological Changes That Increase Risk
Pregnancy creates a unique environment that significantly increases the risk of developing or worsening obstructive sleep apnea. Hormonal changes play a substantial role, as elevated estrogen levels cause mucosal swelling and congestion in the nasal passages and upper airway. This swelling narrows the breathing path, making the airway more susceptible to collapse during sleep.
Weight gain during pregnancy, particularly in the neck circumference, also contributes by increasing fat deposits around the pharynx. Mechanical pressure from the growing uterus, especially in the third trimester, pushes the diaphragm upwards, reducing the functional residual capacity of the lungs. This decreased lung volume increases the collapsibility of the upper airway.
Fluid retention (edema) is common and can accumulate in the tissues of the throat and neck. This tissue swelling further decreases the diameter of the upper airway, increasing resistance to airflow. These combined anatomical and fluid changes make airway obstruction more likely, especially when lying on the back.
Maternal and Fetal Health Consequences
Untreated obstructive sleep apnea is linked to serious adverse outcomes for both the mother and the developing baby. Repeated episodes of reduced oxygen and interrupted sleep lead to chronic intermittent hypoxia, triggering systemic inflammation and increased sympathetic nervous system activity. This physiological stress drives many of the associated complications.
A major maternal risk is the development of hypertensive disorders, including gestational hypertension and preeclampsia. OSA increases the risk of preeclampsia by more than two times, a condition involving high blood pressure and damage to other organ systems. Sleep apnea is also strongly associated with gestational diabetes, which affects blood sugar regulation. Furthermore, mothers with untreated OSA have a higher likelihood of requiring a C-section delivery.
The consequences extend directly to the fetus, as the mother’s chronic oxygen deprivation can compromise placental blood flow. This can lead to fetal complications, such as intrauterine growth restriction (IUGR), where the baby does not grow as expected. Untreated maternal sleep apnea is also associated with an increased risk of preterm birth and low birth weight. Early detection and appropriate treatment are important to mitigate these risks.
Safe Management During Gestation
The most effective treatment for obstructive sleep apnea during pregnancy is Continuous Positive Airway Pressure (CPAP) therapy. This device delivers a steady stream of pressurized air through a mask, acting as a pneumatic splint to keep the airway open during sleep. CPAP is a safe intervention throughout gestation, and its use can help reduce the risk of conditions like gestational hypertension and preeclampsia.
Positional therapy is another strategy, encouraging the pregnant individual to sleep on their side, particularly the left side. Side sleeping minimizes vena cava compression, optimizing blood flow, and reduces gravitational pressure on the upper airway. Special positioning pillows can be used to help maintain this posture throughout the night.
Lifestyle adjustments also support management, but they must be guided by a physician. While excessive gestational weight gain increases risk, weight management efforts must be balanced with the nutritional needs of pregnancy. Avoiding sedating medications that relax the throat muscles is also advised. Effective care involves close monitoring and collaboration between the obstetrician and a sleep specialist to ensure optimal outcomes.