Background Failure to understand uterine function during pregnancy is a major shortcoming of healthcare. Objective To support the hypothesis and we would call it, Hegazy’s Hypothesis for Gestation. Study Design: The thesis of this hypothesis is derived from a study that was carried out in Australia and published in PLOS in 2010. Sokolowski P et al. 2010. Human Uterine Wall Tension Trajectories and the Onset of Parturition. PLoS ONE 5(6): e11037. Results Pregnancy is a state of balance between the two opposing and interactive inhibitory and stimulatory systems secondary to EUWT mechano-transduction and Progesterone/estrogen stimulation. Pregnancy is mainly maintained through a stretch-dependent inhibitory system. Contractions of the stimulatory system transform the cervix into the lower uterine segment causing EUWT failure, which terminates the pregnancy. Light-dark cycle modulation of interactive inhibitory and stimulatory systems divides gestation into five clinical phases. Pregnancy interval and circadian timers are achieved by a single mechanism, namely EUWT failure, secondary to the complete loss of cervical strength nocturnally. Inhibitory system malfunction causes preterm labor, and most of the current therapeutic modalities for pre-term labor are focusing on delaying or preventing EUWT failure. Stimulatory system malfunction causes post-term pregnancy, and the combined malfunction of the two systems causes labor dystocia. Conclusion EUWT creation, autonomic maintenance, and autonomic EUWT termination make pregnancy an autonomic cycle with constant intervals and circadian timers. EUWT malfunctions alter birth timing and/or mode of delivery. Laplace’s law and Pascal’s principle measure EUWT which might be the laws of physics that genetically pregnancy duration.