A 25-year-old woman, gravida 4 para 2, at 37 weeks gestation was evaluated and treated for preeclampsia. Overnight, the patient had a witnessed apneic episode with maternal oxygen desaturation and concurrent fetal heart rate deceleration. She subsequently delivered an infant that was small for gestational age. This is the first case described with confirmed obstructive sleep apnea by formal polysomnography and witnessed maternal desaturation with fetal heart rate decelerations. Recognizing obstructive sleep apnea (OSA) early in gestation will help dictate treatment options and may prevent adverse maternal fetal outcomes. Continuous positive airway pressure (CPAP) seems to be a safe treatment with minimal adverse effects. Questioning of patients at the first prenatal visit and monitoring for increased snoring during gestation may help detect early signs and symptoms of OSA. Treatment of OSA with CPAP might improve perinatal outcomes.