The effect of misoprostol with and without evening primrose oil on labor progress and neonatal Apgar score in post-term pregnancies: a clinical trial study

One of the possible causes of post-term pregnancies is the unripe cervix. The present study was performed with aim to compare the effect of misoprostol and evening primrose oil on labor progress and neonatal Apgar score in post-term pregnancies.

This double-blind randomized clinical trial study was conducted in 2018 on 130 pregnant women with post-term pregnancy. The samples were selected by convenience sampling method and randomly assigned to two groups: (evening primrose and misoprostol) and (placebo and misoprostol). To collect the data, a checklist of demographic and clinical information was used along with questions related to bishop score, duration of labor and neonatal Apgar score. Data analysis was done using SPSS statistical software (version 21) and chi-square test, Fisher exact test and independent t-test. P< 0.05 was considered statistically significant.

The mean bishop score in the evening primrose and misoprostol group significantly increased compared to the placebo and misoprostol group (p=0.0001). Also, the length of the latent phase of labor was shorter in the evening primrose and misoprostol group compared to the placebo and misoprostol group. However, based on the results of the chi-square test, there was no significant difference between the two groups in terms of first and fifth minutes Apgar scores (p>0.05).

The use of evening primrose oil vaginal capsule along with misoprostol, compared to misoprostol alone, while helping to prepare the cervix, will be effective in reducing the duration of the latent phase of labor and has no adverse effect on the neonatal Apgar score.