The Effect of Evening Primrose Oil on Cervical Ripening

Comparison of the Effects of Evening Primrose Oil and Cervical Strip on Induction of Cervical Ripening and Birth Outcomes in Nulliparous Patients with Post-Term Pregnancies: A Clinical Trial Study

Status

Recruiting

Phases

Phase 3

Study type

Interventional

Source

IRCT

Registry ID

IRCT20251218068375N1

Enrollment

Registered

2026-02-17

Start date

2026-03-21

Completion date

Unknown

Last updated

2026-06-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Childbirth.

Interventions

Intervention 1: Intervention group: Insertion of 500 mg vaginal capsules of evening primrose oil (Barij Essence Company, official packaging) by the researcher and evaluation for 5 days. Intervention 2

Eligibility

Sex/Gender

Female

Age

18 Years to 40 Years

Inclusion criteria

Inclusion criteria: Week 40 of pregnancy (from LMP or NT) First pregnancy Willingness to participate in the study Age over 18 years A healthy pregnant woman without underlying conditions. Women without contraindications for the use of evening primrose oil There is no contraindication for natural childbirth. Singleton pregnancy Normal fetal heart rate pattern, absence of uterine contractions, healthy fetal membranes.

Exclusion criteria

Exclusion criteria: Rupture of fetal membranes during cervical preparation Causing potential side effects from the medication, such as headaches Individuals with a history of epilepsy

Design outcomes

Primary

Measure	Time frame
Bishop score average. Timepoint: Once daily for a maximum of 5 consecutive days. Method of measurement: Vaginal examination and assessment of the Bishop score.	—

Countries

Iran (Islamic Republic of)

Contacts

Public ContactZahra Rahmani

Mazandaran University of Medical Sciences

z.rahmani1972@gmail.com+98 11 3335 0670

Outcome results

None listed

Source: IRCT (via WHO ICTRP) · Data processed: Jun 11, 2026