Low Power Laser for Spontaneous Perineal Laceration

Scenario: spontaneous perineal laceration is an injury to the tissue in the perineum region, which can occur during vaginal delivery. The lesion can be classified into four degrees, according to the structures affected, with degrees one and two being more common. Some consequences may arise due to lacerations, such as perineal pain, genito-pelvic pain, in addition to infection, and dehiscence of the lesion, which may last up to one year after delivery. A laser is a form of non-ionizing radiation and when used in the repair process it is capable of generating analgesic, anti-inflammatory, and healing effects. Low-level laser treatment has been used in several areas, promoting cellular and vascular responses capable of accelerating the repair of injured tissue, in addition to pain relief and consequently capable of improving patients' quality of life. Objective: To determine the effects of low-power laser on the acceleration of the healing process and pain relief in primiparous women who had a spontaneous perineal tear, grade one and two, during normal delivery. Methods: a pilot randomized clinical trial will be carried out. Two groups will be divided randomly, one group will receive the application of the laser, and the second group the laser "sham". Data collection will be carried out at the LAbor and delivery rooms of the Instituto de Medicina Integral Prof. Fernando Figueira (IMIP). Primiparous women who had a spontaneous perineal tear, grades one and two, over 18 years of age or younger who are in charge, with a full-term pregnancy, single fetus, cephalic presentation, and who have been admitted to labor at the ANC will be included, excluding patients who are transferred to another sector, those that evolve to a cesarean section or need episiotomy or curettage and, in addition, the presence of infection during childbirth assistance, postpartum hemorrhage and suspected or diagnosed COVID-19. The laser will be applied at three predetermined moments: six hours, 24, and 48 hours after delivery. To evaluate the healing process a REEDA scale and a Peri-rule will be used. The assessment of pain intensity will be through the Visual Analogue Scale (VAS). Ethical Aspects: the research will be submitted to the IMIP Research Ethics Committee and data collection will begin after its approval. All data will be kept confidential and confidential, the participant will be asked to sign the Informed Consent Form before beginning any procedure.

In primiparous women with spontaneous perineal laceration, grade 1 and 2, during normal delivery submitted to the application of low power laser versus "sham" laser:

1. Describe the biological characteristics (age, weight, height, BMI), sociodemographic (marital status, race, years studied, family income, social occupational);
2. Describe the characteristics related to life habits (smoking, activity physical, pelvic physiotherapy during pregnancy, Pilates during pregnancy, yoga during pregnancy);
3. Describe the previous gynecological and obstetric characteristics (number of pregnancies, type of previous births, number of abortions, suture in childbirth current) and obstetric (prenatal consultations, number of prenatal consultations, gestational age, gestational weight gain, use of oxytocin, use of analgesia, blood flow guidance, position during the second period of childbirth, hours labor, instrumental delivery, birth weight, head circumference of the newborn, shoulder dystocia, perineal laceration, the severity of lacerations, laceration extension, postpartum perineal pain);
4. Compare the parameters of REEDA, such as redness, edema, bruising, secretion and approximation of the edges at each intervention and in the range of seven and 42 days after laser application;
5. Compare the frequency of perineal pain and genito-pelvic pain at each intervention and between seven and 42 days after laser application;
6. Compare the measurement of the extent of perineal laceration, using Peri-Rule, the each intervention and in the interval of seven and 42 days after the application of the laser.

Initially, the study will be carried out with 30 women (pilot study) for later the sample calculation will be carried out. A pilot study will be carried out, as, during the search in the database, no studies were found that address the use of low-level laser in spontaneous perineal lacerations, so that sample calculation was carried out.

Randomization for the intervention and control groups will be performed according to a list of random numbers drawn up for that purpose by an employee who does not was involved with data collection, to ensure confidentiality in the allocation. From this list, sealed and opaque envelopes will be prepared, numbered sequentially, with each number, according to the randomization table, corresponds to the patient's allocation to the intervention or control group.

For statistical analysis of the data, the domain statistical program will be used public Epi-info version 7, or higher versions. Tables will be distributed frequency distribution for categorical variables, calculating the mean and deviation standard of quantitative variables. Then, contingency tables will be used to determine the association of the independent variable (laser application) with the independent variables (REEDA scale, perineal pain, genito-pelvic pain). For determination of the strength of association will be calculated as a measure of the risk (RR) and its 95% confidence interval. All p values will be two-tailed and in all stages of the analysis will be considered a level of significance 5%.

Eligibility Criteria:
Inclusion Criteria:

* Deliveries Assisted at the labor and delivery rooms (low risk)
* Spontaneous perineal laceration (grades 1 and 2)
* Primipara
* Full-term pregnancy (37 to 41 weeks and six days)
* Women over the age of 18 or under who are the presence of a responsible party
* cephalic presentation
* Single fetus
* Admitted in labor

Exclusion Criteria:

* Transfer to another sector;
* Performing an episiotomy;
* Evolution to cesarean section;
* Need for curettage;
* Instrumental delivery (use of forceps and vacuum);
* A patient who had the child referred to another sector;
* Shoulder dystocia;
* Change in skin sensitivity;
* Presence of infection during childbirth care;
* Postpartum hemorrhage;
* Suspected or diagnosed with COVID-19