Introduction: The physiologic retention of water during pregnancy causes oedema in many organs. Optical review of Retinal Nerve Fiber Layer (RNFL), located in the undersurface of the retina, and is clinically useful in many diseases. Aim: This study assessed pregnancy induced oedema in retina by using the measurement of RNFL in pregnant women before and after delivery. Materials and Methods: In a prospective cohort study, 32 pregnant women with 28 weeks or more gestational age were compared during pregnancy and postpartum period. The RNFL thickness was measured by Optical Coherence Tomography (OCT). Results: The mean RNFL thickness was significantly more during pregnancy in comparison with the postpartum period, 107±9 µm versus 103±9 µm (p=0.013). Conclusion: RNFL thickness in diabetes and chronic hypertension or other chronic diseases might be misdiagnosed in pregnancy due to pregnancy induced increased thickness.