Laplace Law Controls Pregnancy Intervals, Circadian Timers, and Mode of
Delivery Through Exponential Uterine Wall Tension and Hormonal Milieu: A
Hypothesis 1
Abstract
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.