A Study on Fetal Wellbeing through the Non-Reactive Non-Stress Test in the Patients Referred to Motazedi Hospital, Kermanshah, Iran

Since 1975, the non-stres stest (NST) has been applying as a first step to assess fetal well being. Over past decades, antepartum fetal heart rate testing has become an integral part in high-risk pregnancy management. During this time, the contraction stress test has given way to the non-stress test for primary fetal surveillance due to its proven reliability and its low false negative rate [1-4]. The main feature of normality to interprete the testis FHR accelerations, i.e., reactive tracing. Accelerations, which resemble aspike-like or transitory increase above baseline as a result of sympathetic nervous system stimulation, have been shown to be reassuring both antepartum and intrapartum [1,2,5-7], and indicate a non-acidotic fetus [1,8].


Introduction
Since 1975, the non-stres stest (NST) has been applying as a first step to assess fetal well being. Over past decades, antepartum fetal heart rate testing has become an integral part in high-risk pregnancy management. During this time, the contraction stress test has given way to the non-stress test for primary fetal surveillance due to its proven reliability and its low false negative rate [1][2][3][4]. The main feature of normality to interprete the testis FHR accelerations, i.e., reactive tracing. Accelerations, which resemble aspike-like or transitory increase above baseline as a result of sympathetic nervous system stimulation, have been shown to be reassuring both antepartum and intrapartum [1,2,[5][6][7], and indicate a non-acidotic fetus [1,8].
The suggested optimum number of accelerations varies in the literature from one to five over a period of 20 or 30 minutes [9][10][11]. In contrast, the absence of accelerations (non-reactive tracing) is considered suspicious, and management of a nonreactive NST first requires extension of the recording time to 40-50 minutes. Clinical evaluations performed on shorter time intervals may be misleading [1,12,13]. However, this investigation was conducted to make an appropriate evaluation for the non-reactive NST applicability in order to predict fetal healthy, necessity of an operation special method during parturition, consideration of essential schemes and so on.

Material and Methods
To determine a pregnancy outcome, fetal characteristics and their status through the non-reactive NST, which was performed on 323 pregnant patients with a gestationalageover28weeks, referred to Motazedi hospital, Kermanshah, Iran, abipartite form was prepared that the first part was completed at the beginning of hospitalization to consider a maternal age, a gestational age, the history of a previous or a background disease, a reason for performing the test, and the amniotic fluid volume (AFV), and the second one while patient-releasing for gestational finalization, a manner of labour, a fetal distresss (meconium passing, tachycardia, bradycardia), infant weight, an infant Apgar, perinatal mortality and hospitalization at the neonatal intensive care unit (NICU). The patients were between 15-46 years old (mean=25.33, STD=5.573, (Figure 1)) and the gestational age was between 37-42 weeks (mean=38.49, STD=2.007, ( Figure  2)). Data analysis was statistically performed using the program SPSS (version 16 for Windows; SPSS Inc. Chicago, IL).

Reason of performing NST
Out of 323 women, 53 individuals (16.4%) as a result of post dating, 113 persons (35%) because of decreased fetal movement, 126 (39%) for pain, eleven (3.4%) due to a vaginal discharge (suspect in membrane rupture), two (0.6%) due to hemorrhage, eleven(3.4%) as a consequence of decreasing the AFV in the sonogram, two (0.6%) because of a preceding weak NST, two (0.6%) as a result of the diabetes, and three (0.9%) due to fetal wellbeing screening referred to Motazedi hospital, Kermanshah, Iran (Table 1).
Fetal distress during labor 32 cases (9.9%) striked by the meconiumstain and 107 ones (33.1%) by the tachycardia or bradycardia during the labor.

Methods of termination of pregnancy
All cases were finalized the pregnancy. Two out of them (0.6%) had an instrumental delivery, 42(13%) through a normal vaginal delivery (NVD), and 279 (86.4%) by means of cesarean (Figure 3), out of which 56 specimens (20.07%) had a history of cesarean section (repeat CD) ( Table 2).

Discussion
The NST is the first step to evaluate fetal healthiness. 1% has been considered as a pseudo-negative measure in which fetal fatality occurs during a following weeks in conducting the reactive NST [14]. In order to demonstrate a fetal distress, a profile biophysical test is usually conducted after the non-reactive NST; in our study, nonetheless, it had not been directed on the instances and they just labored following a non reactive NST due to a complain of pain or decreased fetal movement. Morever, 33.1% led to a fetal distress (tachycardia or bradycardia), and 86.4% delivered by the cesarean section; whereas, Lohana et al. [14] reported that 46.66% did by the cesarean section and in 8.33% a fetal distress was there as one of cesarean. Verma and Shrimali [15] and Eden et al. [16], however, assigned 63.15% and 37.7% to the fetal distress.
The meconium staining of liquor has variously been announced in publications. Schifrin et al. [17] and Patil and Gharegrat [18] recorded 39.1% and 34%; whereas Bano et al. [19] and Lohana et al. [14] reported 42.8% and 33.3%, respectively. 10% in the present study might be related to a more immediate intervention, cesarean and time wasting to perform complementary tests. In as much as this phenomenon could lead to the meconium aspiration syndrome, the number of 10% could be considered significant. First minute/below seven Apgar was registered as 4.2% where as this type of number were done as 6% and 53.3% in Verma and Shrimali [15] and Lohana et al. [14], respectively. Fifth minute/below seven Apgar in the present research is 0.9%; the numbers of Lohana et al. [14] and Bano et al. [19] were, respectively, 60% and 42.8%. Result data showed that hospitalization of the infants at the NICU is 5.3%, where as it is 28.5% in Bano et al. [19]. The sample sizes in Lohana et al. [14] and Bano [19] were 15 and 12, respectively; whereas it is 323 in the present study. This difference might be responsible for the egregious differences of statistical data.