The study results showed that frequent vaginal saline lavage did not increase the chance of maternal or neonatal complications, while the aseptic procedure significantly reduced the rate of infection. This finding could be meaningful when comparing the safety and effectiveness of different induction methods.
Labor induction has been an important obstetric intervention procedure worldwide . Successful induction of labor can increase the chance of natural delivery, reduce the time from intervention to delivery, and minimize the adverse effects of prolonged pregnancy . The main goal of labor induction is to ripen the cervix that is accessed by the bishop score. There are many cervical ripening methods including pharmacological, mechanical, and the combined or subsequent use of the two methods.
The pharmacological methods focus on the administration of cervix ripening medicines orally, via IV, or intracervical . Some ripening medicines include oxytocin, dinoprostone, misoprostol, mifepristone, and relaxin. Intracervically administered agents include different forms of prostaglandins gels such as PGE1, PGE2, etc. Pharmacological cervical ripening is quick and effective, but there are some associated harmful side effects and complications .
Excessive uterine activity is a serious complication from the use of pharmacological agents, and it can sometimes lead to hyperstimulation or even uterine rupture. The use of pharmacological agents can also cause tachysystole and fetal heart rate abnormalities. As a result, continuous monitoring of uterine activities and fetal conditions are highly encouraged after administration, which would increase the overall cost of delivery . The ideal method of cervix ripening should not increase the chance of hyperstimulation.
Mechanical induction of labor has been a popular method that intracervically introduces a device to locally stimulate the cervical ripening. Some mechanical devices are transcervical balloon catheters with or without Extra Amnionic Saline Infusion (EASI), Foley Catheters, hygroscopic cervical dilators, Leminaria tents, etc. Mechanical labor induction is shown to have similar effects on the overall cesarean delivery rates comparing to pharmacological methods, and it is relatively simple to apply .
The transcervical balloon catheter gently stretches and ripens the cervix by triggering local inflammatory reactions to release natural prostaglandins , and it is associated with less pain and better maternal experience . In addition to the mentioned benefits, the double balloon catheter mimics the physiology of the labor setting closely by pressuring both inner and outer cervical muscles, leading to more effective natural ripening .
Although mechanical devices induce cervical ripening without causing uterine contractions, the main argument against the usages is that the procedure lead to longer labor duration , and it introduces a foreign device into the cervix, bringing in local organisms that may cause maternal and neonatal infections, despite undertaking standard aseptic measures .
It is clinically important to explore an effective way to reduce the introduction of living organisms through the cervix. Most of the induction related maternal infections are caused by vaginal bacteria introduced to the uterus through the cervical canal .
Theoretically, excessive aseptic treatment of vagina could be effective in preventing infectious organisms from ascending to the cervix. Roeckner et al has conducted a systematic review and concluded that vaginal aseptic preparation immediately before cesarean section surgery could significantly reduce the risk of endometritis, postoperative wound infections and fever . Scholz et al has conducted a retrospective study of 3,637 patients and concluded that a surgical site infection bundle could significantly reduce the rate of infection for Cesarean Delivery patients .
Another question of debate is what antiseptic agents could be used in the aseptic preparation. Prophylactic antibody is not the ideal choice, because it may lead to microbial antibiotic resistance , and that the rates of asthma and childhood obesity increase with maternal usages of antibiotics . In our study, a simple and low cost saline solution was used for frequent vaginal douching before and during the course of mechanical labor induction by double balloon catheter.
Our study results showed that frequent saline lavage of the vagina can significantly reduce the infection rate by killing the infectious organisms introduced to the cervix by mechanical induction devices. This simple and preventative method avoids using antibiotics prophylactically. The procedure is mild and does not cause any irritation or allergic reactions. The clinical implication of the study is that infection could be reduced during mechanical labor induction with excessive aseptic vaginal preparation.
The conducted study had its limitations. Due to the intended intervention nature, the procedure operators were not blinded, and the bishop score examined might be biased. The vagina was not swabbed before or after the lavage procedure for culture studies to compare the difference in bacteria existence. The vaginal saline lavage with syringes caused some spills and cleanup was needed after each application. Aseptic saline lavage every 4 hours could be labor intensive and it require obstetricians or nurses to closely follow the timeline by setting the alarms.