Academic literature on the topic 'Active uterine contraction'

Normal labour is a process of spontaneous expulsion of the fetus, placenta, and membranes at term. This process is initiated by complex endocrine mechanisms that cause uterine contractions which lead to effacement and dilatation of the cervix and descent of the fetus, resulting in delivery. About 10% of women go into labour in the preterm period. The progress is dependent on uterine contractions (power), the size and presentation of the fetus (passenger), and the size of the pelvis (passage). For ease of management, the observed labour is artificially divided into three stages. The partogram is used to manage labour and is where maternal and fetal observations can be plotted in addition to cervical dilatation and descent of the presenting part. The value of active management is still debated but has been adapted in routine practice. More research is needed to decide the best management of labour to optimize the maternal and fetal outcomes.

Primary postpartum hemorrhage (PPH) is one of the leading causes of maternal morbidity and mortality worldwide. The most common cause of primary PPH is uterine atony. Various uterotonics have been used over the years for the prevention of PPH. Oxytocin, Ergometrine, Misoprostol, and Carboprost have been extensively studied. Recently, Carbetocin, an analog of Oxytocin has been added to the armamentarium of postpartum hemorrhage. However, the optimal route and dose of these drugs are still being studied. Oxytocin induces superior myometrial contractions when compared with Ergometrine, Carboprost and Misoprostol. The effect of Oxytocin is reduced in myometrium of women with Oxytocin-augmented labor; however, it is still superior to the other uterotonics. Although the value of universal use of uterotonics to reduce postpartum hemorrhage after vaginal birth has been well established, their value in cesarean section has received little attention. It has been assumed that the benefits of oxytocics observed at vaginal birth also apply to cesarean section. The route of Oxytocin has been studied by various researchers. Intravenous (IV) infusion of Oxytocin has been preferred during cesarean section as an IV line would have been already secured and it has faster plasma peak concentration as in comparison to the Intramuscular (IM) route. Though IV bolus Oxytocin has been associated with a faster peak plasma concentration of Oxytocin, faster uterine contraction; it also has been associated with sudden hypotension. Carbetocin is also another promising drug. It has been prioritized due to its heat stable and long-acting properties. It also reduces the need for infusions. It is still an expensive drug in many countries. Carbetocin is administered as 100 mcg IM/IV/IV infusion. The dose in elective cesarean may be less as shown in some studies. Misoprostol by oral route has been recommended by WHO at 400–600 mcg in places where Oxytocin cannot be administered. Syntometrine has lesser blood loss compared to Oxytocin alone.

The posterior pituitary produces arginine vasopressin, which has a key role in fluid homeostasis, and oxytocin, which stimulates uterine contraction during birth and ejection of milk during lactation. Cranial diabetes insipidus is the passage of large volumes of dilute urine due to vasopressin deficient synthesis and/or release. The most common cause is lesions of the neurohypophysis or the hypothalamic median eminence damaging the magnocellular neurons. MRI of the neurohypophysis is required to delineate the cause. Mild polyuria can be managed simply by ensuring adequate fluid intake; treatment with the long-acting vasopressin analogue, desmopressin is used for more severe cases. The syndrome of inappropriate antidiuresis is diagnosed when there is hyponatraemia with hypotonic plasma, inappropriate urine osmolality, and urinary sodium more than 20 mmol/litre, together with no evidence of volume overload or hypovolaemia, and normal renal, adrenal, and thyroid function.

The posterior pituitary produces arginine vasopressin, which has a key role in fluid homeostasis, and oxytocin, which stimulates uterine contraction during birth and ejection of milk during lactation. Cranial diabetes insipidus is the passage of large volumes (>3 litres/24 h) of dilute urine (osmolality<300 mOsm/kg) due to vasopressin deficiency, and most commonly occurs as a consequence of trauma or tumour affecting the posterior pituitary. Diagnosed by a water deprivation test revealing urine osmolality less than 300 mOsml/kg with concurrent plasma osmolality more than 290 mOsml/kg after dehydration, with urine osmolality rising to more than 750 mOsml/kg after desmopressin. MRI of the neurohypophysis is required to delineate the cause. Mild polyuria can be managed simply by ensuring adequate fluid intake; treatment with the long-acting vasopressin analogue, desmopressin (desamino, D-8 arginine vasopressin; DDAVP), is used for more severe cases....

Abstract Tocolytic agents are agents that inhibit uterine contraction and allow enough time for corticosteroids to help with lung maturation. They are administered in cases of premature labor between the 22nd and 34th weeks of gestational age. They are divided into betamimetics, calcium channel blockers, cyclooxygenase inhibitors, and magnesium sulfate. Betamimetics can be used for a short period of time; their prolonged use is not recommended due to extensive side effects, including maternal death. They are associated with pulmonary edema, tachycardia, arrhythmias, hyperglycemia, and hypokalemia. Calcium channel blockers are more beneficial than β-adrenergic agents for prolongation of pregnancy, neonatal morbidity, and maternal side effects. Magnesium sulfate is not effective in delaying labor, and it does not have an advantage over other tocolytic agents when it comes to neonatal and maternal outcomes, as it shown in a Cochrane review. However, evidence suggests that magnesium sulfate reduces the severity of cerebral palsy in surviving infants if administered when the birth is anticipated before 32 weeks of gestation. It does prolong the action of depolarizing and nondepolarizing muscle relaxant and can have serious side effects if overdosed.

Preterm labor is the leading cause of neonatal mortality and accounts for 70% of the total cost of neonatal health care. Premature softening of the cervix has been identified as one of the primary causes of preterm labor. As the biochemistry of the cervix is distinct between the proximal and distal portions, the objective of this study was to determine the viscoelastic properties of these portions in mid-pregnancy (Day 15–16) relative to virgin Long-Evans rats. This will serve to establish baseline data for future studies that will aim to induce preterm labor in this model. The cervix was divi

The cervix plays a critical role during pregnancy, acting as a mechanical barrier to keep the fetus inside the uterus until term. In a normal pregnancy, it is hypothesized that the cervix gradually softens until uterine contractions occur. At this point, the cervix dramatically ripens and dilates for delivery. Similar to other collagenous tissues, the extracellular matrix (ECM) is the load-bearing component of cervical tissue. It is composed mainly of a cross-linked network of fibril forming collagen, types I and III, embedded in a viscous proteoglycan ground substance. Studies conducted on an