Ovulation induction is seldom reported to cause pituitary abnormality and the physiological enlargement of the pituitary gland during pregnancy is asymptomatic. We report a woman who became pregnant after ovulation induction. She had symptomatic pituitary enlargement with a pituitary height of 2 cm on cranial magnetic resonance imaging (MRI) in the second trimester. Her symptoms (headache and blurred vision) improved greatly after delivery but she had absence of lactation. The height of the pituitary gland decreased to 1 cm on the second cranial MRI 40 days after delivery and her third cranial MRI only revealed a mild central bulge in the pituitary gland eight months after delivery. This article shows that the abnormal enlargement of the pituitary gland during pregnancy might remit spontaneously after delivery and these patients might have higher risk of postpartum hypopituitarism. Neurological symptoms and signs should be closely monitored during pregnancy and neurosurgery may not be necessary. Endocrine surveys should be performed regularly after delivery to detect hypopituitarism as early as possible.