Parulekar SV

Obesity during pregnancy is on the rise, and so are the conditions that go with obesity. Obstructive sleep apnea (OSA)  is one such condition. It is characterized by repetitive episodes of obstruction of the upper airway during sleep, leading to absence or severe reduction in airflow despite respiratory effort. The gravida experiences hypoxemia and recurrent arousal from sleep. Its prevalence is directly proportional to maternal age and weight independent of each other. Physiological changes of pregnancy like reduced diameter of the oropharynx, nasal obstruction due to mucosal edema and increase in Mallampati grade lead to increased resistance of the upper airway and greater negative intra-pharyngeal pressure, which in turn lead to snoring and obstructed breathing in sleep. The increase in the circulating blood volume causes adverse effect on the upper airway function in recumbency (sleep) and risk of OSA. The true incidence of OSA in pregnancy is not known, but is probably much more than what is believed, because women tend to report it less often. Questionnaires are not found to be very useful to detect which gravidas suffer from it. An objective test is more likely to detect OSA. A full-night, attended, in-laboratory polysomnogram is the best method of diagnosing OSA. An unattended, home sleep apnea testing is more convenient, but is not cleared for use in pregnancy by American Academy of Sleep Medicine. When apnea hypopnea index (average number of apneas plus hypopneas per hour slept) is 5 to 15, 15-30, and more than 30 events per hour, OSA is said to be mild, moderate and severe respectively. It must be kept in mind that OSA is not the only cause of disturbance of sleep in pregnancy, and there are causes related to pregnancy, e.g. leg cramps, fetal movements, urge for urination and dyspepsia. If OSA is not treated, risk of complications like fatigue, excessive daytime sleepiness, lack of attention, systemic hypertension, cerebrovascular disease, cardiac arrhythmias, ischemic heart disease, cardiomyopathy, pulmonary embolism,  insulin resistance, gestational diabetes, preeclampsia, gestational hypertension, fetal growth restricition, effect on neurological growth, preterm labor and fetal death. Pregnancy may exacerbate OSA. Thus treating OSA during pregnancy is important. All gravidas with moderate or severe disease are treated. The treatment includes use of oral mandibular repositioning appliances, continuous positive airway pressure and behavior modification. Modafinil, which is used to treat OSA, is a category C drug. It is also found in the breast milk. Hence its use is not recommended in pregnancy and lactation.  Upper airway surgery like uvulopalatopharyngoplasty is not recommended in pregnancy. Complications listed above need to be watched for and managed aggressively. Continuous pulse oximetry is used in labor and after childbirth. Any hypoxemia is evaluated and treated energetically, maintaining oxygen saturation at least 96%. Regional anesthesia for labor pain management is preferred to opioids. As the awareness of this condition during pregnancy increases, more and more cases will come to light. We hope to create this awareness in our readers through this editorial.