The Effect of Topical Magnesium Sulfate on Dilatation, Effacement and Duration of Labor in Primiparous Women: A randomized controlled clinical trial

Document Type : Original Article


1 Associate Professor, Department of Obstetrics and Gynecology, Faculty of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran.

2 Gynecologist and obstetrician, Faculty of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran.



Introduction: Considering the excruciating process of labor as well as anxiety and fear of natural childbirth, it is necessary to find an appropriate substance for expedite progression of labor and shortening labor duration in pregnant women. This study was performed with aim to determine the effect of topical magnesium sulfate on effacement, dilatation, and labor duration in primiparous women.
Methods: This randomized controlled clinical trial study was conducted in 2022 on 98 primiparous women with full-term pregnancy that had referred to Qazvin Kosar Hospital for delivery. Patients were randomly divided into intervention and control groups. After diagnosis of active phase, in the intervention group, 10 cc of magnesium sulfate 50% and in the control group, the same amount of distilled water was poured on the cervix during vaginal examination. The amount of effacement and dilatation at the beginning of the active phase and then every 2 hours, as well as mother's age, gestational age, number of pregnancies, BMI, type of delivery, duration of labor, Apgar score, weight of the baby, duration of contractions and intervals of contractions were recorded in the checklist. Data analysis was done using SPSS software (version 16) and Fisher's exact, Chi-square, t-test and Mann-Whitney tests. P<0.05 was considered statistically significant.
Results: Duration and intervals of contractions in first and second examination were not significantly different in the intervention and control groups (P>0.05). Mean effacement in the intervention group at the start of active phase was 55.61±3.80 and after two hours was 70.21±4.19, which was statistically significant (P=0.021(. Mean dilatation in the intervention group at the start of active phase was 4.57±0.57 cm and two hours after was 7.31±0.71 cm, which was statistically significant (p=0.043(. Mean effacement and dilatation in the control group at the start of active phase and two hours later was not statistically significant (P>0.05).
Conclusion: Topical magnesium sulfate is effective on improving dilatation and effacement during labor and help speed up delivery.


  1. Cunningham FG, Gant NF, Leveno KJ, Gilstrap LC, Hauth JC, Wenstrom KD. Williams Obstetrics. 21nd New York: McGraw-Hill; 2001.
  2. World Health Organization. WHO recommendations on intrapartum care for a positive childbirth experience. World Health Organization; 2018.
  3. Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, et al. Obstetricia de Williams. McGraw Hill Brasil; 2016.
  4. Kjærgaard H, Olsen J, Ottesen B, Dykes AK. Incidence and outcomes of dystocia in the active phase of labor in term nulliparous women with spontaneous labor onset. Acta obstetricia et gynecologica Scandinavica 2009; 88(4):402-7.
  5. Roberts L, Gulliver B, Fisher J, Cloyes KG. The coping with labor algorithm: an alternate pain assessment tool for the laboring woman. Journal of Midwifery & Women's Health 2010; 55(2):107-16.
  6. Stager L. Supporting women during labor and birth. Midwifery today with international midwife 2009; (92):12-5.
  7. Shahali S, Kashanian M. Effect of Acupressure at the Sanyinjiao Point (SP6) on the Process of Active Phase of Labor in Nulliparas Women. J Babol Univ Med Sci 2010; 12(3):7-11
  8. Hidalgo-Lopezosa P, Hidalgo-Maestre M, Rodríguez-Borrego MA. Labor stimulation with oxytocin: effects on obstetrical and neonatal outcomes. Revista latino-americana de enfermagem 2016; 24.
  9. Vogel JP, West HM, Dowswell T. Titrated oral misoprostol for augmenting labour to improve maternal and neonatal outcomes. Cochrane Database of Systematic Reviews 2013(9).
  10. Teimoori B, Esmaeilpoor M, Ashkezari AK, Farzaneh F. Comparison of induction abortion in the first trimester using misoprostol alone and misoprostol with estrogen priming. Blood vessels 2019; 7:8.
  11. Rameez MF, Lankeshwara D, Dias T, Khatri M, Lohana R. Preterm delivery: current concepts. Sri Lanka Journal of Obstetrics and Gynaecology 2013; 35(1): pp.22-28
  12. Khoddam R. Pocket guide to Iran generic drugs. Tehran: Dibaj 2007; 642.
  13. Heydari A, Kariman N, Naeji Z, Ahmadi F. The effects of topical magnesium sulfate on progression of effacement, dilatation and duration of labor in nulliparous women. The Iranian Journal of Obstetrics, Gynecology and Infertility 2019; 22(8):44-51.
  14. Heydari A, Kariman N, Naeje Z, Ahmadi F. Effect of Topical Application of Magnesium Sulfate on the Intensity of Labor Pain: Double Blind Clinical Trial. The Iranian Journal of Obstetrics, Gynecology and Infertility 2018; 21(5):58-65.
  15. Dalbye R, Bernitz S, Olsen IC, Zhang J, Eggebø TM, Rozsa D, et al. The Labor Progression Study: The use of oxytocin augmentation during labor following Zhang's guideline and the WHO partograph in a cluster randomized trial. Acta obstetricia et gynecologica Scandinavica 2019; 98(9):1187-94.
  16. Razavi M, Farzaneh F. Comparison of the three methods of syntocinon, misoprostol, transcervical catheter plus syntocinon in labor induction. Zahedan Journal of Research in Medical Sciences 2020; 22(2).