الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
The ante natal care is a systemic examination of the woman and growing fetus from the time that conception is confirmed until the beginning of labor. During antepartum period, several tests are performed routinely to monitor fetal well-being and to detect possible problems. The electronic evaluation of antenatal fetal heart rate pattern is a widely accepted screening test of fetal well-being, non stress test is often used as a first choice for fetal health and survival assessment (1,2).
The non stress test (NST) still continue to be a valuable procedure for the assessment of fetal well-being. NST is a simple and noninvasive method of assessing fetal well being by observing the fetal heart rate(FHR) and it’s acceleration in response to fetal movement, the test is based on the knowledge that the fetus is normally active throughout pregnancy and that fetal activity will result in acceleration of the FHR when the normal fetus moves(3). It can be done at 28 weeks of gestation or later and takes from 10-45 min (4). The advantages of NST are relatively quick, non-expensive, easy to interpret, it can be done in outpatient setting and there are no known side effects (5).
The fetal heart rate monitoring by cardiotocography (CTG) is a tool of non stress test and a widely accepted as the primary method of antenatal fetal monitoring to assess the state of fetal oxygenation especially in high-risk pregnancies. It is important to understand how the development of the sympathetic and parasympathetic nervous systems of the fetus occurs in the intrauterine period. The sympathetic and parasympathetic controls of blood flow are matured at different times during fetal development, so that the sympathetic becomes active before the parasympathetic (6).
It is a simple test performed by trained midwives. Antenatal CTG is commonly used in conjunction with ultrasound assessment of fetal and placental Doppler in high risk pregnancy (7).
Components of cardiotocograph patterns of NST including a. the baseline fetal heart rate (FHR) which is the mean level of the FHR when it is stable, excluding accelerations and decelerations. It is determined over a time period of 5-10 minutes, expressed as beats per minute (b/m) and normal range is 110 -160 b/m. b. The baseline variability is the minor fluctuation in baseline FHR. It is assessed by estimating the difference in b/m between the highest peak and lowest trough of fluctuation in one minute segments of the trace. c. Accelerations are transient increases in FHR of 15bpm or more above the baseline and lasting 15 seconds and finally d. Decelerations are transient episodes of decrease of FHR below the baseline of more than 15 b/m lasting at least 15 seconds (8,9).
The non stress test is described as reactive (normal) if there are at least two or more fetal movements in 20 min with acceleration of the FHR by at least 15 beats/min, with long term variability of at least 10 beats/min and a baseline fetal heart rate within the normal range. It is described as nonreactive (abnormal) if there are no fetal movement or acceleration of the FHR with movement, poor to no long-term variability, baseline FHR may be within or outside the normal range. And it can be uncertain reactivity if there are fewer than two fetal movements in 20 minutes or acceleration of less than 15 beats/min, long term variability amplitude less than 10 beats/min and baseline fetal heart rate outside of normal limits (10).
Comfort is a state of physical and psychological wellbeing. Discomfort is operationally defined as the presence of behaviors considered to express a negative emotional and/or physical state that is capable of being observed by a trained rater unfamiliar with the usual behavior pattern of the patient..The main role of the nurse is ensuring women’s comfort during NST because it take 10-45 minutes. Position is one method to provide comfort and decrease pain. So the woman should be placed in position which provide comfort to her and not affect on physiological parameters which can affect on NST result (11,12).
Several factors can contribute to false-positive results and increase the time spent performing tests. One of them is the maternal position, maternal position surely influences the hemodynamics of the maternal and feto-placental circulation. A Varity of positions can be used during non stress test, such as semi fowler’s, lateral tilts, lateral recumbency, supine and semi fowler’s with tilts, it has been suggested that these positions optimize uterine perfusion and fetal heart rate patterns and prevent maternal hypotension (13).
Supine recumbent position is the common position used during NST although few researches showed that maternal supine recumbent position during NST can result in aorto-caval compression by the pregnant uterus, affecting placental perfusion and fetal oxygenation. Prolonged monitoring in this position should therefore be avoided and the lateral recumbent, half-sitting, and upright positions are preferable alternatives(14).
Nurses play an important role in non-stress test; prior to the NST, explain the testing procedure and asked women to empty bladder. Place the women in the appropriate position and apply the two external monitor belts. document the date and time of test, the reason for testing, and maternal vital signs. In addition she obtain a baseline fetal monitor strip over 10-45 min. During the test, observe for signs of fetal activity with a concurrent acceleration of fetal heart rate. Interpret the NST as reactive or nonreactive(15).
After NST procedure, assist the woman off the table. Discuss the results with the woman. Provide teaching about warning signs and symptoms. If serial NST are being done, schedule the next testing sessions(16).
Position is one of the main factors to be considered during non-stress test where the proper maternal position eliminates procedure related errors and prevent false interpretation. During NST the pregnant women are generally positioned in the supine position, because this position allows easy application of the test. However, the supine position causes aorto-caval compression which decrease blood supply to the fetus and lead to non reactive results. Thus, the current study is undertaken to determine the appropriate position can be used during the test.