This experimental study aims to evaluate whether the application of obstetric lubricant gel during vaginal delivery can significantly reduce the duration of the second stage of labor, preserve perineal integrity, and decrease the need for episiotomies. The study hypothesis is that lubricant gel facilitates fetal passage through the birth canal by reducing friction, shortening the expulsion phase and reducing maternal-neonatal complications. Two groups will be included: with and without gel application. Follow-up will span from admission of the pregnant woman until immediate postpartum discharge.

This is a single-blind, randomized, parallel-group, controlled clinical trial comparing obstetric lubricant gel application versus standard care during the second stage of labor. The intervention consists of a single 50 mL application of water-based, sterile lubricant gel (e.g., Gynotal®, Dianatal®, or equivalent) into the vaginal canal (anterior and posterior walls) at the onset of the second stage of labor (complete cervical dilation with confirmed cephalic presentation). The control group receives standard obstetric care without lubrication. The primary outcome is duration of the second stage of labor in minutes. Secondary outcomes include perineal integrity (tears, episiotomy), maternal complications (infections, adverse reactions), neonatal Apgar scores at 1 and 5 minutes, and need for instrumental delivery. The study will be conducted at Hospital Materno Infantil, Tegucigalpa, Honduras, with a target enrollment of 160 participants (80 per group). Randomization will be performed using simple block allocation. Statistical analysis will include ANCOVA for the primary outcome, logistic regression for binary secondary outcomes, and appropriate non-parametric tests if assumptions are violated. A Data Safety Monitoring Board (DSMB) will oversee safety every 6 months or after every 20 inclusions.

Inclusion Criteria:

• Signed informed consent form
• Willingness to comply with study procedures
• Age between 18 and 40 years
• Term pregnancy (37-41.6 weeks) with active labor
• Diagnosis of spontaneous labor and planned vaginal delivery
• Fetus in cephalic presentation
• Agreement to comply with lifestyle restrictions during the study

Exclusion Criteria:

• Multiple pregnancy
• Previous cesarean section
• High-risk pregnancy (preeclampsia, uncontrolled gestational diabetes, etc.)
• Presence of fever or active infection
• Contraindication for vaginal delivery
• Refusal to sign informed consent
• Premature rupture of membranes >18 hours without labor
• Known allergy to lubricant gel components
• Participation in another clinical trial in the last 3 months

Individual participant data (anonymized) will be shared for scientific purposes related to maternal-perinatal health. The final dataset will be deposited in the Central American Clinical Data Repository (RCDC) under CC-BY-NC 4.0 license. Only de-identified datasets will be shared, with prior ethics committee approval. Participants may opt in/out during informed consent.

In this single-blind trial, the outcomes assessor is masked to group allocation. The outcomes assessor (the individual responsible for measuring and recording the primary and secondary outcomes, including duration of the second stage of labor, perineal integrity assessment, and Apgar scores) will not have access to the randomization list and will be unaware of whether the participant received the lubricant gel or standard care. This masking is maintained to minimize measurement and ascertainment bias in evaluating study endpoints. The statistician performing the final data analysis will also be blinded to group allocation. Participants and clinical care providers are not blinded due to the nature of the intervention.