---

Background: Studies in different species indicate that a variety of different inhibitors may influence myometrium during pregnancy and withdrawal of one or more of them leads to the onset of labor pain. Hence, this study was done to investigate the association between parathyroid hormone-related peptide1-34 (PTH-rp1-34) and labor pain. Materials and Methods: This study was a case-control one. Plasma PTH-rp1-34, PTH, total calcium, phosphorous, magnesium, and alkaline phosphatase concentrations were quantified for 152 normal pregnant women at term (76 women at the onset of labor pain, as the case group and 76 women without labor pain, as the control group). The subjects had no pregnancy related complications. Results: The mean of plasma PTHrp concentrations in the group with labor pain (12.36±0.60 ng/ml) did not differ from that in the group without labor pain (13.57±0.63 ng/ml). The means of plasma PTHrp concentration amounts in the group with labor pain and the group without labor pain were 28.92±1.66 pg/ml and 31.88±1.64 pg/ml, respectively and there was no significant difference between the two groups. There were no significant difference in plasma calcium, phosphorus, magnesium, and alkaline phosphatase concentrations in the two groups too. Conclusion: In this study, the endocrinal role of PTHrp and the onset of labor pain was not confirmed.

---

Background: Labor pain, which is a natural, unique and multi- factorial pain, is considereds a major part of women's anxiety at reproductive ages. There are two pharmacological and non-pharmacological approaches for reducing this pain. Since the pharmacological approach involves side effects, lots of attention has recently been given to the non-pharmacological methods. One of these methods, is use inc birth ball the, which includes sitting and rocking on the birth ball. The purpose of this study was to evaluate the effects of using birth ball on labor pain, the duration of active phase and contractions of physiologic labor. Materials and Methods: In this randomized control-clinical trial, sixty primiparous women (18-35 year old) were selected and randomly assighed into birth ball and control groups. The severity of pain was measured through Visual Analogue Scale (VAS) and the pain score, interval between contractions and duration of active phase were compared between the two groups. Results: The average pain score in the birth ball group was significantly lower than the control group (p<0.05). In terms of interval between the contractions, duration of active phase and uterine contractions, there were no significant differences between the two groups. Conclusion: Although use of birth ball did not have any effects on the duration of active phase, uterine contractions and interval between uterine contractions, this complementary therapy reduced the severity of pain during the active phase of delivery. Therefore, this safe method is suggested to be used during normal vaginal delivery and physiologic labor. Also, conducting a study, which examines the effects of using a combination of complementary methods, is recommended