2.3 Interventions
Researchers applied a checklist to confirm eligibility criteria. If the
parturient were eligible, she received information about the study and
was invited to participate voluntarily. A Free and Informed Consent Form
was requested according to the 466/12 Resolution of the National Health
Council.
This research was approved by the Research Ethics Committee of the
Federal University of Pernambuco under the registration numbers
2.885.560 and CAEE: 81405717.7.0000.5208 and is also registered in the
Brazilian Clinical Trials Registry (ReBEC) under the identifier
RBR-556d22. The description of this article followed the international
standards recommended by the CONSORT Statement: Updated Guidelines
for Reporting Parallel Group Randomised Trials [13].
The study sample for the primary outcome (episiotomy) was calculated
considering the results of a meta-analysis [2] that obtained a RR of
0,51 and a control group incidence of 71% through the Open-epiversion 3.0 software, considering alpha and beta errors of 0,05 and
0,20, respectively. A 20% loss to follow-up was anticipated. 95%
confidence level and 80% power were considered. Therefore, 62 pregnant
women were necessary, 31 in the intervention group and 31 in the control
group.
Randomization was carried out by placing each patient’s name in opaque
envelopes that corresponded to either the intervention or the control
group and were prepared by an independent researcher not directly
involved in the study. The parturients were followed in three moments:
right after randomization, one hour and 24 hours after delivery.
In this initial follow-up performed during prepartum and in the delivery
room the duration of the second stage of labor and the maternal pushings
were measured. Then, the following data were collected: personal and
socioeconomic (age, marital status, schooling, family income, and
occupation), clinical and obstetric data (weight, height, Body Mass
Index – BMI, Systolic Blood Pressure and Diastolic Blood Pressure),
postpartum hemorrhage, perineal laceration, episiotomy, gestational age,
parity, route of delivery, instrumental delivery, pain, anxiety,
maternal fatigue, and satisfaction. Finally, the following neonatal data
were collected in the obstetric center or at the joint accommodation:
newborn admission to intensive care, hypoxic-ischemic encephalopathy,
5-minute Apgar, and neonatal resuscitation.
After the diagnosis by the hospital team about the complete deletion of
the cervix (10 centimeters) and effacement, the volunteer in the
intervention group received guidance about the breathing pattern
associated with expulsive efforts, based on the spontaneous pushing
physiology: pursed lips breathing associated with open glottis in tidal
volume, controlled by the woman, along with abdominal muscle efforts and
perineal relaxation. The team also used communication strategies
providing positive feedback and information about labor evolution and
the possible sensations (Figure 1).
The control group followed the usual routine of the service team, with
the use of directed pushing, regardless of maternal desire, initiated
right after uterine contraction, by guiding the woman to perform a deep
inspiration, initiating the effort with closed glottis for 10 seconds or
more. The entire pushing protocols are described in Figure 1.