Laplace Law Controls Pregnancy Intervals, Circadian Timers, and Mode of
Delivery Through Exponential Uterine Wall Tension and Hormonal Milieu: A
Hypothesis 2
Abstract
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.