Background Our hypothesis suggests another view regarding the following: Labor physiology. Labor progress. Labor dystocia. Objective To support the hypothesis. Study Design This study investigated the current evidence-based literature and research that may support the hypothesis. Results Intrinsic myometrial cell character ensures that parturition is an autonomic, intrinsic, and interactive repetitive contraction and relaxation cycle, secondary to myometrial tension changes that cause labor progression and protect the foetus against hypoxia. The progress during the first stage of labor and what is called cervical dilatation is the complete transformation of the cervix into the LUS, which has a clinical and radiological presentation. The clinical presentation is effacement, and dilatation. Radiologically, the cervix transforms into the LUS through an inverted inside-out TYVU and an inverted U pattern formation. In the second stage of labor, the cervix has completely transformed into the LUS which is a wedge-shaped birth canal that extends from the vaginal vault (cervicovaginal junction) into the physiologic retraction ring. All these changes reverse instantly after foetal delivery, and the cervix returns to its anatomical site and regains its full anatomical shape. Concomitant malfunctions of the inhibitory and stimulatory systems cause labor dystocia. Conclusion Labor dystocia is the failure of the complete transformation of the cervix into the lower uterine segment secondary to combined inhibitory and stimulatory system malfunction. Most of the cervical transformation into the LUS takes place during the third trimester and is completed during the first stage of labor. So, the treatment of labor dystocia should focus on the causes of the stimulatory system’s malfunction before the onset of labor. There is evidence to support the hypothesis, and it should be in the interest of obstetricians, physiologists, midwives, neonatologists, and those with a research interest in maternal and family welfare.
Background Spontaneous preterm birth is the leading global cause of neonatal death, and countless efforts have failed to establish a single effective treatment for preterm labor, partly because the mechanisms that regulate the uterus and the cervix during pregnancy are not well understood. When a post-term pregnancy truly exists, its cause is mostly unknown. Objective To support the hypothesis. Study Design: This study investigated the current evidence-based literature and research that may support the hypothesis, accompanied by 40-second 3D animations. Results Light-dark cycle modulation of interactive inhibitory and stimulatory systems divides gestation into five clinical phases: growth, maturation, transition, parturition, and involution. During the maturation phase (30–40 weeks), nocturnal synchronisation and synergy of the inhibitory and stimulatory systems, secondary to light-dark cycle modulation, make the cervix progressively transform into the lower uterine segment and lose its strength, eventually causing EUWT failure. The clock that measures the duration of pregnancy consists of two interacting timers, an interval timer measuring the overall length of gestation and a circadian timer that defines when a 24-hour cycle birth occurs. Pregnancy intervals 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 preterm labor focus on delaying or preventing EUWT failure. Stimulatory system malfunctions cause post-term pregnancy. Conclusion The creation, autonomic maintenance, and eventually autonomic EUWT termination make pregnancy an autonomic cycle with constant intervals and circadian timers where its malfunctions change the timing of birth and pregnancy duration. Laplace’s law measures EUWT, which might be the law of physics that controls pregnancy duration.
Background Despite a considerable body of literature gathered from the few species that have been studied, the mechanisms responsible for the maintenance of pregnancy and the initiation of parturition have not been fully elucidated. Failure to understand uterine function during pregnancy is a major shortcoming in healthcare. Objective To support the hypothesis. Study Design This study investigated the current evidence-based literature and research that may support the hypothesis, accompanied by 40-second 3D animations. Results The isthmus of the cervix does not seem to exist embryologically, anatomically, histologically, or functionally. The isthmus of the cervix may be a flaw in the concept of human parturition, which creates a block barrier that prevents understanding of uterine function. Mechanotransduction is the process by which cells sense physical forces and translate them into biochemical and biological responses. Uterine mechanotransduction has functional and molecular components, wherein intrinsic myometrial cell character (IMCC) is the molecular component and Exponential uterine wall tension (EUWT) is the functional component. IMCC enables the uterus to control its functions autonomically and intrinsically, secondary to changes in tension, where high tension induces relaxation and low tension induces contraction. EUWT is created and maintained by a complex interaction between the gestational sac, uterus, and cervix, for which the primary function is to maintain EUWT. EUWT mechano-transduction and progesterone/estrogen induce the stretch-dependent inhibitory system, and indirectly, they also induce the stimulatory system by inducing myometrial hyperplasia and hypertrophy. Pregnancy is mainly maintained through a stretch-dependent inhibitory system, in addition to direct myometrial relaxants. Contractions of the stimulatory system in the presence of the foetus create direct and indirect uterine-cervical interactions (DIDUCI). DIDUCI transforms the cervix into the lower uterine segment through TYVU pattern formation and causes EUWT failure. So, the functional components of the stimulatory system (DIDUCI) are the uterus corpus, fetus, cervix, and bony pelvic inlet. Conclusion Pregnancy is a state of balance between the two opposing and interactive inhibitory and stimulatory systems secondary to EUWT mechanotransduction and progesterone/estrogen stimulation. EUWT is measured using Laplace’s law, which might be the law of physics that controls uterine function during pregnancy.
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.
Objective: Spontaneous preterm birth is the leading global cause of neonatal death, and countless efforts have failed to establish a single effective treatment for preterm labor. Labor dystocia is the major cause of primary cesarean delivery; however, its biological mechanisms during labor are poorly understood. When post-term pregnancy truly exists the cause is usually unknown. The objective of the study tries to identify the possible cause of these obstetric complications Design: Research Study Setting: Portiuncula University Hospital, Ireland Population: N/A Methods: This study investigated the current evidence-based literature that may support the hypothesis. Main Outcome Measures: N/A Results: Obstetric literature is replete with overwhelming evidence that malfunction of any exponential uterine wall tension (EUWT) component (stretch-dependent inhibitory system) terminates the pregnancy. Most of the current therapeutic preterm strategies are focused on preventing premature EUWT failure e.g. the cervical stitch. Progesterone treatment for preterm labor may be working by enhancing the stretch-dependent inhibitory system by modulating uterine wall plasticity and EUWT. Post-term pregnancy is due to the failure of the stimulatory system to transform the cervix into the lower uterine segment and to lose its resistance that terminating the pregnancy at full term. A combined malfunction of the two systems causes labor dystocia e.g rupture of fetal membranes with a long cervix. Conclusion: There is growing evidence to support the hypothesis that malfunction of the inhibitory system causes preterm labor, malfunction of the stimulatory system causes post-term pregnancy and labor dystocia is due to a combined malfunction of the two systems.
Objective: The clock that measures the duration of pregnancy consists of two interacting timers: an interval timer measuring the overall length of gestation, and a circadian timer defining when within a 24-hour cycle birth occurs, and they have not been definitively established or systematically studied and our objectives to study pregnancy interval and circadian timers. Design: Research Study Setting: Portiuncula University Hospital, Ireland Population: N/A Methods: This study investigated the current evidence-based literature and research that may support our proposed hypothesis, accompanied by a 40-second 3D animation. Main Outcome Measures: N/A Results: Gestation is divided into five clinical phases, growth, maturation, transition, parturition, and involution secondary to light-dark cycle modulation of the interactive inhibitory and stimulatory systems. During the maturation phase (30-37 weeks), the inhibitory system transiently wears off due to cortisol modulation. This occurs alongside the modulation of melatonin and oxytocin, and the latter induces contractions of the stimulatory system, resulting in nocturnal synchronization and synergy of the two systems and causing the cervix to lose its strength by transforming it into the lower uterine segment. Pregnancy interval and circadian timers are achieved by a single mechanism, that is, exponential uterine wall tension (EUWT) failure, secondary to the complete loss of cervical resistance nocturnally. Conclusion: The creation, autonomic maintenance, and eventually autonomic termination of the EUWT make gestation an autonomic cycle with constant intervals and circadian timers. There is evidence-based support for the hypothesis which will have an impact on obstetric practice and maternal and family welfare.
Objective: Labor is viewed as the result of a physiologic release from an inhibitory effect of pregnancy on the myometrium, rather than an active process mediated by contractile agonists. The contractile stimulators and relaxation mechanisms have not yet been well defined. The objective of the study is to identify the systems that control uterine function during pregnancy. Design: Research Study Setting: Portiuncula University Hospital, Ireland Population: N/A Methods: This study investigated the current evidence-based literature that may support the hypothesis, accompanied by a 40-second 3D animation. Main Outcome Measures: N/A Results: Uterine mechanotransduction has functional and molecular components, wherein the exponential uterine wall tension (EUWT) is the functional component, and the intrinsic myometrial cell character (IMCC) is the molecular component. IMCC enables the uterus to control its functions both autonomically and intrinsically, secondary to changes in tension. EUWT is measured by Laplace’s Law and is created and maintained by interaction among the gestational sac, uterus, and cervix, for which the primary function is to maintain the EUWT. Directly, EUWT mechanotransduction and progesterone/estrogen stimulation induce the inhibitory system and indirectly, they induce the stimulatory system by inducing myometrial hyperplasia and hypertrophy. The inhibitory system is the main system that maintains pregnancy through a stretch-dependent mechanism. The stimulatory system makes the cervix lose its strength through the YVU pattern formation by transforming it into the lower uterine segment, thus terminating the pregnancy. Conclusion: There is evidence-based support for the hypothesis which might be the first step in uncovering the human parturition’s mystery.
Objective Failures in understanding uterine functions during pregnancy are a major shortcoming of healthcare and can be attributed to many possible causes. Importantly, there might be flaws in the current concept of human parturition, which creates a genuine barrier to a greater understanding of the process. The objective of the study is to challenge the existence of the isthmus in view of the current evidence-based studies. Design: Research Study Setting: Portiuncula University Hospital, Ireland Population: N/A Methods: This study investigated the current evidence-based literature that may support our proposed hypothesis. Main Outcome Measures: N/A Results The isthmus of the cervix, both anatomically and functionally, does not seem to exist. There has been no convincing evidence to support its existence since Aschoff first proposed it in 1905. In fact, the embryological, anatomical, and histological characteristics of the cervix and the radiological evidence for cervical changes during pregnancy challenge its existence. The study makes it clear that there are two opposing and contradicting views about the isthmus. In the first view, the isthmus and its nebulous character must be accepted, and no evidence contradicting this concept in the human being could be found. The other view is that the isthmus, geographically and functionally, does not exist, and we have provided abundant evidence to support this view. Conclusion The anatomical and functional division of the cervix into isthmus and non-isthmus portions may be the main obstacle to understanding cervical function and parturition and they should be revised in light of this hypothesis.