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Background & Objective: Labor pain is one of the most severe pains that mothers experience. Intense pain leads to stress and has unfavorable effects on the mother and fetus. This research was done to determine the effect of using Entonox (N2O) self administration on reducing labor pain in the active phase of labor& delivery, Mode of delivery, and newborn's Apgar score.
Methods: One hundred and twenty primiparous women in 29 Bahman Hospital in Tabriz were included it this randomly single-blind research. In the active phase of delivery, Entonox and Oxygen gases were used. The severity of the mother's pain was asked and was scored according to analogue criterion.
Results: There was a significant difference in frequency of pain intensity in two groups of Entonox and Oxygen. The Mean score of pain intensity in Entonex user, in the first & second stage of labor was 5.93% and 5.82% respectively, while for the oxygen users it was 6.99% and 6.74% which was significant. 41.7% of the mothers in the Entonox group had a severe pain and 11.7% had a very severe pain, whereas in the Oxygen group 58.3% of the mothers had a severe pain and 25% of them had very severe pain (p< 0.001). Meanwhile we found no significant difference between modes of delivery progress of labor and newborn's Apgar
score.
Conclusion: According to research results, Entonox reduces the intensity of labor pain more than oxygen and is effective during the first and second phase of delivery.

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 Background & Objectives: Delivery is a process with pain so one of the midwives duties is to decrease the severity of pain during delivery so decrease in labor period has been much of a concern. Atropine and Hyosine are two common drugs in decreasing time of labor and decreasing the need for labor stimulation with oxytosine. The aim of this study was to investigate the effects of hyoscine and atropine in the progress and time of labor.

 Methods:�This study was double blind clinical trial on 200 primiparous women who had labor pain and were admitted in labor in Alavi hospital in 2008. Who were randomly divided into two groups .the case group infused 20 mg Hyoscine with Atropine in the onset of active phase of labor (4cm dilation, Ruptured membrane) and in the control group 2cc, Dextrose water was infused 0.05. Then, progression in dilatation and effacement, time of active labor, time of 2^nd and 3^rd stage of labor, fetal heart rate monitoring, infant APGAR score of the 1^st and 5^th minute were registered. The data were analyzed by SPSS software using descriptive and analytical statistics as chi- square.

 Results: The findings indicated that there was a significant difference in dilatation & effacement between two groups (5/2cm/h, 1/5cm/h) (p<0.05). Duration of active phase of labor was 105 min in case group and 251 min in control group (p<0.05), duration of stage 2 was 17 min in case group and 33 min in the control group (p<0.05). Total time of labor and deliver (121 min in case group, 274 min in control group).incidence of Tachycardia and bradycardia in FHR in 30 min after infusion 25%(15% Tachycardia and 10% bradycardia in case group) 20% (12% Tachycardia and 8% bradycardia in control group) and no difference in two group was seen.

 Conclusion:�According to the finding s of this study Hyoscine and Atropine are effective in the progression of labor and delivery.

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  Background & Objectives: Delivery is one of the most important events in a woman's life, and pain is an inevitable part of childbirth. The non-controlled pain leads to prolonged labor and multiple injuries to mother and fetus. This research was done to determine the effect of acupressure at the SP6 and LI4 points on the duration and pain of the labor in nulliparous women.

  Methods: This randomized controlled clinical trial was conducted on 84 nulliparous women who were attended hospital in Ardabil. The participants were divided into two intervention and control groups using randomized blocking. Pressure has been done on SP6- LI4 points in intervention group. Pain intensity was measured before and after the intervention using visual analog scales and length of active phase and second stage were recorded through vaginal exam in the checklist. Determination of the effect of pressure on the intensity of labor pain and delivery length performed using paired t-test, Student’s t-test and chi-square by SPSS v.16.

  Results: After the intervention the mean level of pain intensity in the intervention group was decreased. Also, there was a significant decrease in mean intensity of pain after each intervention in the intervention group with different dilations (4, 6, 8, and 10 cm) (p<0.001).The mean duration of active phase and second stage in intervention group was significantly less than the control group . (p<0.001, p=0.008).

  Conclusion: Since acupressure at the SP6- LI4 point in different dilatations leads to the reduction in labor pain intensity and delivery duration, therefore, this method can be used to reduce the pain and duration of labor.

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Background & objectives: In many medical studies, the response variable is measured repeatedly over time to evaluate the treatment effect that is known as longitudinal study. The analysis method for this type of data is repeated measures ANOVA that uses only one correlation structure and the results are not valid with inappropriate correlation structure. To avoid this problem, a convenient alternative is mixed models. So, the aim of this study was to compare of mixed and repeated measurement models for examination of the Entonox effect on the labor pain.

Methods: This experimental study was designed to compare the effect of Entonox and oxygen inhalation on pain relief between two groups. Data were analyzed using repeated measurement and mixed models with different correlation structures. Selection and comparison of proper correlation structures performed using Akaike information criterion, Bayesian information criterion and restricted log-likelihood. Data were analyzed using SPSS-22.

Results: Results of our study showed that all variables containing analgesia methods, labor duration of the first and second stages, and time were significant in these tests. In mixed model, heterogeneous first-order autoregressive, first-order autoregressive, heterogeneous Toeplitz and unstructured correlation structures were recognized as the best structures. Also, all variables were significant in these structures. Unstructured variance covariance matrix was recognized as the worst structure and labor duration of the first and second stages was not significant in this structure.

Conclusions: This study showed that the Entonox inhalation has a significant effect on pain relief in primiparous and it is confirmed by all of the models.