Midpelvic forceps and vacuum deliveries are more traumatic than cesarean section

Taking a decision in favor of cesarean section is considerably safer than attempting midpelvic operative vaginal delivery in terms of reducing severe birth trauma and obstetric trauma reports a study finding published June 5, 2017 in Canadian Medical Association Journal (CMAJ).

Midpelvic arrest in second stage of labor and operative interventions are a test of obstetrician’s skills and experience. In recent year, there has been a shift towards cesarean section, increasing the rates of cesarean section worldwide.

In 2014, a consensus statement by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine supported operative vaginal delivery over cesarean delivery to bring down the cesarean rate and improve maternal and neonatal outcome. Although, ACOG statement was not specific for midpelvic operative vaginal delivery but included it in more general sense.

Studies on the risk and benefits of these two procedures are lacking and not stratified by the station of fetal head in pelvis, which is an important decisive factor for maternal and fetal outcome.

The researcher team involved in the current study looked at data across a span of 10 years including 187,234 singleton births which included all mid pelvic live or stillbirths via forceps or vacuum and C-section deliveries between 37 and 41 weeks of gestation that resulted in a singleton live birth or stillbirth.

In all the cases, the head was engaged and the leading point of fetal head was as above station +2 cm but below 0 station.

It was seen that infants born by midpelvic operative vaginal delivery in women having dystocia, with prolonged second stage of labor has 81% more chances of severe morbidity and mortality as compared to when they were delivered by cesarean section. It included higher rates of birth asphyxia, meconium aspiration syndrome and intracranial hemorrhage.

Forceps delivery and vacuum delivery exposed the neonate to nearly 5 times the risk of birth trauma, but the rates were considerably high (9.5 times ) in sequential application.

Rates of obstetric trauma were also quite higher using forceps (5 times the risk), vacuum (2.7 times the risk) and sequential instruments (3 times the risk) as compared to delivery by cesarean section. In addition, significant more third and fourth degree perineal tear occurred in women who had midpelvic forceps (19%), midpelvic vacuum (12%), and 20% among women who delivered using a combination of midpelvic vacuum and forceps.

Rates of maternal morbidity and mortality did not differ much in the two groups, but midpelvic forceps and vacuum use was associated with significantly higher rates of post-partum hemorrhage.

In that subset of women in which the midpelvic forceps application was done for fetal distress, the composite maternal morbidity and mortality was 48% lower in vacuum group, but nearly 3 times higher rates of obstetric trauma and higher rates of PPH was observed.

The association between midpelvic operative vaginal delivery and composite severe perinatal morbidity and mortality were significantly stronger in those women who had dystocia but not prolonged second stage of labor. Similar outcomes were seen in women who had fetal distress but not prolonged second stage of labor. Midpelvic forceps and vacuum deliveries are more traumatic than cesarean section.

The study showed that encouraging higher rates of operative vaginal delivery to reduce the rate of cesarean delivery comes at the cost of increase in severe perinatal and maternal morbidity and mortality, especially neonatal birth trauma, severe postpartum hemorrhage and obstetric trauma.

"It is important to understand that similar to cesarean deliveries, midpelvic forceps and vacuum deliveries are invasive procedures with their own risks -- risks that we have now quantified and that should be communicated to women who may encounter them, especially when the risk is as high as one in five," says lead author, Giulia Muraca, a doctoral researcher at the School of Population and Public Health, University of British Columbia (UBC). "Women who are delivered by midpelvic forceps or midpelvic vacuum should be afforded the same standard of informed consent as women who consent to cesarean delivery. Ideally, this should take place prior to labour when women are considering their birth plans."

The full text of the journal article can be accessed here.

News from ACOG 2017: Most advanced wireless, tetherless maternal-fetal simulators Train Physicians at ACOG 2017.

Meet Victoria®and Super Tory®, who are world’s most advance maternal and fetal simulators.

Victoria is closest to real human expectant mother of all the simulators currently available. She was developed as a result of decades of obstetrical experience, her anatomical accurate features help improving patient’s safety through accurate and real life training.

Victoria and Super Tory will be showcased at the American College of Obstetricians and Gynecologists Annual Clinical and Scientific Meeting (ACOG) 2017 annual meeting in San Diego, California, May 6–9.

She looks like a real life expectant mother, her eyes can interact with care-giver, thus enabling neurological examination to evaluate eye movements as a warning sign for stroke, drug overdose, head trauma and cranial impairment.

Victoria simulates shoulder dystocia, breech, and C-section deliveries with a level of fidelity that truly suspends disbelief. Participants immerse themselves deeper and faster as they engage in problem solving and collaborative teamwork. What’s more, Victoria captures participants’ performance through an array of hidden sensors. This means you can easily track progress on the way to success.

Besides being a childbirth simulator, she can also be used by trainers to practice other obstetrics scenarios like early pregnancy complications, post-partum hemorrhage and management of high risk pregnancy.

Her condition deteriorates due to blood loss during PPH, obstetricians can practice fundal massage with uterus that contracts and shrink in response. She is also fitted with three replaceable episiotomy modules, and obstetricians can practice midline, mediolateral and fourth degree perineal tear repair.  

Victoria give births to a High-fidelity, full-term baby of realistic size and weight,it has smooth skin, articulate joints, full body endoskeleton, programmable heart and respiratory sounds , cyanosis and 1 minute Apgar score.

Super Tory is also world’s most advanced neonatal simulator. Like a real neonate, it gasps for breadth imitating a real newborn in respiratory distress.  The lungs are controlled electronically and appear realistic when the mannequin responds to mechanical ventilation.

Simply pressing a button puts the baby in acute respiratory distress and his entire body also reacts to the situation.

Pediatrician and other care giver can stabilize Tory using real instruments in NICU.

Gaumard executive vice president John Eggert said, "Every specialist gets to participate in Super Tory's treatment."

"Super Tory allows healthcare providers to prepare for high risk/low frequency complications with anatomical and physiological accuracy never before seen in neonatal simulation," Mr. Eggert adds. "It's the first neonatal simulator to offer heart and lung interaction as well as motion in a mobile platform."

"Super Tory can be assessed for early onset sepsis, hyperbilirubinemia, pneumonia with pneumothorax and other conditions using real vital signs monitors.  Critical metrics such as ECG-derived respiration rate, pre- and post-ductal SpO2, and NIBP can be evaluated in real time.  And Super Tory can be paced and defibrillated using real energy, just as in a clinical live situation. His facial expressions change and you can track his chest wall motion and programmable arm and leg movements."

Super Tory weighs eight pounds and 21 inches and is fitted with an internal, rechargeable battery with life of nearly 8 hours. It remains fully functional while in transit from labor room to NICU.

Gaumard® Scientific Company has designed, manufactured and marketed simulators for health care education for more than 60 years. Users worldwide recognize Gaumard products for their innovation in simulation.

Victoria Video 

Super Tory Video 

The dilemma of cervical ripening --Should it be oral or vaginal; should it be misoprostol or dinoprostone? A systemic review and network meta-analysis.

Induction of labor is considered  when the benefit of the procedure is surpasses the benefit of continuation of pregnancy. The rate of induction of singleton pregnancies in US in 2012 was 23.3%, almost more than double a decade ago. 

A primed and favorable cervix is a prerequisite for successful induction of labour.

Numerous methods are in use for cervical ripening to induce labour, that includes Foley’s catheter( Mechanical Method) to pharmacological methods including  the use of prostaglandins, oxytocin, and mifepristone.  Prostaglandin E₂, also known as dinoprostone, is the only prostaglandin that has been approved by the US Food and Drug Administration (FDA) for cervical ripening in labour induction.

Misoprostol, a prostaglandin E₁ analogue is often used as an off-label drug for inducing labour. Its use is fraught with many complications from uterine hyper stimulation, rupture and adverse FHR.

Many studies and reviews comparing the safety and efficacy of different methods have been conducted but the best agent and route is still unanswered.

The three most common agents widely in use are dinoprostone, Foley catheter and misoprostol (oral and vaginal). There are many RCTs comparing these different modalities but no large single trial has compared them all  head to head.

The study conducted by W Chen et al. is a systemic review and network meta-analysis of all the available RCTs comparing the five most commonly used methods,  published in the February issue of  BJOG: An International Journal of Obstetrics & Gynaecology .

The study aims at providing a comprehensive summary of the existing evidence to further inform clinical practice and aid in the design of future trials.

Network meta-analysis, in the context of a systematic review, is a meta-analysis in which multiple treatments (that is, three or more) are being compared using both direct comparisons of interventions within randomized controlled trials and indirect comparisons across trials based on a common comparator.

The selection criteria was including all the (RCTs) of cervical ripening during the induction of labour, evaluating rates of failure to achieve vaginal delivery within 24 hours, incidence of uterine hyperstimulation with fetal heart rate (FHR) changes, and rates of caesarean section. Studies including women with prelabour rupture of membranes were excluded.

Trials were excluded if they included the following cases: women with pregnancies less than  28 weeks of gestational age; non-cephalic presentations; multiple pregnancies; and women with previous caesarean sections, combination interventions, non-relevant outlook and conference papers, posters  and abstracts.

A total of 96 RCTs met the selection criteria resulting it a total of 17387 study subjects.

The interventions included in this review were Foley catheter, vaginal misoprostol, oral misoprostol, vaginal dinoprostone, and intracervical dinoprostone.

The primary outcome chosen for network metaanalysis were vaginal delivery not achieved in 24 hours; uterine hyperstimulation with FHR changes; and caesarean section.

The meta-analysis compared five different modalities of cervical ripening for induction of labour. It was seen that:

The rank probabilities of reducing the number of vaginal delivery not achieved in 24 hours according to different interventions from best to worst are vaginal misoprostol (100%), vaginal dinoprostone (95%), Foley catheter (59%), oral misoprostol and intracervical dinoprostone

The rank probabilities of not causing hyper stimulation with FHR changes from best to worst are Foleys catheter (90%), intracervical dinoprostone, oral misoprostol, vaginal dinoprostone, and vaginal misoprostol (99%).

The rank probabilities of different intervention in decreasing the rate of caesarean sections, from best to worst are oral misoprostol (83%), vaginal misoprostol (80%), vaginal dinoprostone, intracervical dinoprostone and Foley’s catheter.

Thus it was seen that although vaginal misoprostol was the most effective intervention for achieving vaginal delivery within 24 hours, but it came at the cost of highest rate of uterine hyperstimulation with FHR changes. Vaginal dinoprostone was second best vaginal delivery withi 24 hours.

Foley catheter was found to be the least likely to cause hyperstimulation, but is worse than both vaginal misoprostol and vaginal dinoprostone in achieving vaginal delivery within 24 hours.

Compared to Vaginal misoprostol, oral misoprostol had lesser incidences of uterine hyperstimulation but at the expense of slightly decreased number of vaginal deliveries in 24 hours, but this difference was not statistically significant.

In most countries misoprostol is not legalized to be used for induction of labor, because of the concerns of hyperstimulation. The study shows that oral misoprostol is safe in comparison to vaginal misoprostol and it also performed better than vaginal dinoprostone.The other advantage of misoprostol is it is effective, cheap, does not requires cold storage; the dose can be measured and precise as compared to vaginal route. It is the first drug of choice in developing countries.

Foley catheter has similar effect as oral misoprostol in achieving vaginal delivery.  It is inferior to prostaglandins in decreasing the C section rates but superior to use of Oxytocin alone. It may be highly indicated in women with high risk of Fetal hypoxaemia like postdate pregnancies, sickle-cell disease, pre-eclampsia, or intrauterine growth restriction, due to it’s least effect on hyperstimulation . It also has advantages in terms of cost and storage conditions, less stringent monitoring of uterine contraction and no medical intervention until it is expelled in labor.The drawback is high rate of chorioamnionitis, but metaanalysis was not performed due to lack of reporting of this data in most trials.  

Conclusion:

 

Vaginal misoprostol followed by vaginal dinoprostone are most effective methods for induction of labor beyond 28 weeks of gestation with intact membranes, in terms of achieving vaginal delivery. However they are also associated with  uterine hyper stimulation and adverse FHR requiring close monitoring.

Mechanical stimulation by Foley catheter was least effective method for vaginal delivery, along with oral misoprostol and intracervical dinoprostone, but caused the least uterine hyper stimulation and adverse FHR.

Oral misoprostol was the best method in terms of overall safety, least likelihood of uterine hyperstimulation and adverse FHR and reducing the likelihood of cesarean section than vaginal misoprostol. 

References:

 

Chen W, Xue J, Peprah MK, Wen SW, Walker M, Gao Y, Tang Y. A systematic review and network meta-analysis comparing the use of Foley catheters, misoprostol, and dinoprostone for cervical ripening in the induction of labour. BJOG 2016;123:346–354.

Hemming, K. and Price, M. (2016), Is it oral or vaginal; and should it be misoprostol or dinoprostone for cervical ripening? How to interpret a network meta-analysis. BJOG: An International Journal of Obstetrics & Gynaecology, 123: 355. doi: 10.1111/1471-0528.13533

http://www.improvingmedicalstatistics.com/meta_network.htm