Decelerations defined

If decelerations are associated with tachysystole consider terbutaline 0.

Decelerations defined

Decelerations defined

At term, the fetal adrenal glands weigh the same as those in the adult and are similar in size to the adjacent fetal kidney. Within the fetal adrenal gland, steroidogenic function and zonation are different from the adult. For example, significant amounts of cortisol are not produced in the fetal adrenal gland until the last trimester.

As a result, fetal cortisol levels increase during the last weeks of gestation Murphy, During this same period, levels of dehydroepiandrosterone sulfate DHEA-S production also are increasing significantly, leading to increases in maternal estrogens, particularly estriol.

The increase in adrenal activity occurs in contrast to fetal adrenocorticotropic hormone ACTH levels which do not increase until the stress of actual labor.

This substantial growth and increased steroid synthesis during latter gestation is at a time when fetal plasma ACTH levels appear to decline Winters and co-workers, Thus, many investigators have surmised that there must be growth and steroidogenesis stimuli for these glands in addition to ACTH.

Two observations have made it extremely likely that factors secreted by the placenta play a key role in the regulation of steroidogenesis during late gestation.


First, the fact that ACTH levels do not increase significantly during the last part of gestation makes it likely that growth and differentiation of the fetal adrenal glands are influenced by factors secreted by the placenta. Second, the fetal zone of the adrenal gland undergoes rapid involution immediately after birth when placenta-derived factors are no longer available.

Many believe that CRH of placental origin is one of the critical components that facilitates fetal adrenal hypertrophy and increased steroidogenesis late in gestation.

The ability of CRH to regulate the adrenal glands and of the adrenals to regulate placental production of CRH has led to the idea of a feed-forward endocrine cascade that occurs late in gestation Fig.

Placental CRH has been proposed to play several roles in the regulation of parturition. First, placental CRH may enhance fetal cortisol production, which would provide positive feedback on the placenta to produce more CRH. The resulting high level of CRH may modulate myometrial contractility.

Second, cortisol has been proposed to affect the myometrium indirectly by stimulating the membranes to increase prostaglandin synthesis.

Acceleration Lane | Definition of Acceleration Lane by Merriam-Webster

Third, CRH has been shown to stimulate fetal adrenal Csteroid synthesis, leading to increased substrate for placental aromatization. The resulting elevation in estrogens would shift the estrogen-to-progesterone ratio and promote the expression of a series of contractile proteins in the myometrium, leading to a loss of myometrial quiescence.

Prolactin Maternal plasma levels of prolactin increase markedly during the course of normal pregnancy. Paradoxically, after delivery, the plasma prolactin concentration decreases even in women who are breast feeding.

During early lactation, pulsatile bursts of prolactin secretion occur apparently in response to suckling. The physiological cause of the marked increase in prolactin prior to parturition is not entirely certain. It is known, however, that estrogen stimulation increases the number of anterior pituitary lactotrophs and may stimulate the release of prolactin from these cells Andersen, Thyroid-releasing hormone also acts to cause an increased prolactin level in pregnant compared with nonpregnant women, but the response decreases as pregnancy advances Andersen, ; Miyamoto, Serotonin also is believed to increase prolactin, and prolactin-inhibiting factor dopamine inhibits its secretion.

The principal function of maternal serum prolactin is to ensure lactation. Early in pregnancy, prolactin acts to initiate DNA synthesis and mitosis of glandular epithelial cells and the presecretory alveolar cells of the breast. Prolactin also increases the number of estrogen and prolactin receptors in these same cells.

Finally, prolactin promotes mammary alveolar cell RNA synthesis, galactopoiesis, and production of casein and lactalbumin, lactose, and lipids Andersen, Kauppila and co-workers found that a woman with an isolated prolactin deficiency failed to lactate after two pregnancies, establishing the absolute necessity of prolactin for lactation but not for successful pregnancy outcome.

Prolactin is present in amnionic fluid in high concentrations.For example, the sudden onset of recurrent, significant variable decelerations is more concerning in the context of a prior cesarean delivery, and late decelerations are more concerning in a patient with placental abruption, fetal growth restriction, or poorly controlled maternal diabetes.

The Clinical Coverage Guideline (CCG) is intended to supplement certain standard WellCare benefit plans and aid in administering benefits. Federal and state law, contract language, etc.

Decelerations defined

take precedence over the CCG (e.g., Centers for Medicare and Medicaid Services [CMS] National Coverage Determinations [NCDs], Local. Intrapartum Fetal Heart Rate Monitoring: Periodic or episodic decelerations; The duration of the acceleration is defined as the time from the initial change in heart rate from the baseline to the time of return to the FHR to baseline. Fetal Distress: Diagnosis, Conditions & Treatment.

Historically, the term fetal distress has been used to describe when the fetus does not receive adequate amounts of oxygen during pregnancy or is oftentimes detected through an abnormal fetal heart rate. However, while the term fetal distress is commonly used, it is not well defined.

Acceleration lane definition is - a speed change area or lane consisting of added pavement at the edge of through traffic lanes to permit vehicles to accelerate before merging with the through-traffic flow.

Heart rate-defined sustained attention (HRDSA) is a well-validated biological measure of attentional engagement that, in non-clinical infant populations, provides incremental information about attentional engagement beyond looking behaviors alone.

Transcervical Amnioinfusion - - American Family Physician