Obgyno Wino Podcast Episode 27 - Vaginal Breech Birth - Interview with Rixa Freeze and David Hayes
Updated: Sep 29, 2019
"That new principles of treatment have not been expressed and that each writer has simply perpetuated the teachings of his predecessor is clearly evident from the perusal of the textbooks published during the past twenty or thirty years. On no important point does the treatment ever appear to be questioned, and the paucity of new ideas is everywhere remarkable." - John Burns, 1934
This is a very, very special episode. I had the privilege of interviewing Rixa Freeze, PhD, and David Hayes, MD about vaginal breech birth (VBB). Queue the shock and awe! "What do I have to. learn about breech?! It's a done deal! They did that one study, and the data speaks for itself!" Well, I'm not going to try to convince you otherwise. But perhaps a closer look at the data will make you less inclined to rush to the OR when you find a bum delivering itself on your shift. Check out Rixa's nonprofit Breech Without Borders and her personal website to learn more.
The Term Breech trial changed the practice of obstetrics worldwide since its publication in 2001. It was methodologically flawed.
RCTs performed in countries in which vaginal breech birth is still a normal practice have found no difference in neonatal or maternal outcomes.
Large analyses of the further RCT-derived data has shown that the only consistent "bad" outcome is low APGARs in favor of cesarean delivery.
Prenatal, intrapartum, and postpartum risks to and benefits for mom, baby, and future pregnancies of having a cesarean delivery need to be weighed against the prenatal, intrapartum, and postpartum risks to and benefits for mom, baby, and future pregnancies of having breech delivery.
If you are attending a vaginal breech birth, take a hands off approach. Avoid supine maternal position (unless it's comfortable for her). Only intervene if you think it's necessary. Consider the mechanism of deviation from the norm to guide your intervention.
The Term Breech Trial (TBT)
- RCT Published in 2001 that drastically changed the way we deliver breech fetuses (link)
- c-section rose in popularity around the world as many countries accepted this RCT as the study to end all studies on the topic
- 121 centers across 26 countries
- 2088 women with frank or complete breech singleton enrolled
- they were randomly assigned to planned c-section or planned vaginal birth
- followed until 6 weeks postpartum
Outcomes of the TBT
- statistically significant differences in neonatal morbidity, favoring c-section over vaginal delivery for breech fetuses
a. 0.6% birth trauma (ICH, fractures, other injuries) in planned planned CS versus 1.4% with planned vaginal breech birth (VBB)
b. neonatal seizures: 0.1% versus 0.7%
c. neonatal hypotonia: 0.2% versus 1.8%
d. low APGARs: 0.8% versus 3.0%
e. NICU admission: 1.5% versus 3.0%
- composite for serious neonatal morbidity: 1.4% for planned CS versus 3.8% for VBB
- perinatal/neonatal mortality was also significantly different between the groups, even in centers with high national perinatal mortality rates: 3 deaths in the CS group (0.6%) versus 10 deaths in the VBB group (1.9%)
- no significant differences in maternal morbidity or mortality, apart from a higher risk of early postpartum depression in the c-section group
Criticisms of the Term Breech Trial
- high rate of randomization during labor (50% of primary CS group)
- twins and cephalic births were accidentally included
- not all patients have an experienced OB present
- continuous external fetal monitoring was rare
- pelvimetry was not performed routinely
- many centers did not have access to ultrasound (to confirm head flexion, for example)
- suboptimal labor management in some hospitals
- of the 16 perinatal deaths documented, 2 sets of twins, 2 growth restricted fetuses, 1 congenitally malformed fetus, 1 case of spina bifida, and 1 was in cephalic presentation (stillborn before randomization)...in others words, not attributable to mode of delivery (link here)
- Long-term outcomes of TBT babies were far more favorable
If c-section is so much safer than VBB, how have outcomes improved since the change in practice?
- not much if at all; reduction in neonatal mortality dropped by only 16% in Scotland (still low absolute risk)
PREMODA: Is breech safer in the hands of experienced practitioners?
- Observational prospective study with an intent-to-treat analysis published in 2006 (link)
- 8105 women enrolled (recall: TBT had n= 2088) in 74 maternity units across France and Belgium, where vaginal delivery is still considered standard of care for breech fetuses
- they were randomly assigned to planned c-section or planned vaginal birth
- no significant difference in neonatal or maternal morbidity or mortality between the groups apart from lower APGAR scores in the planned VBB group
Many other studies followed the TBT, including national registry studies from around the world...the TBT now looks a lot less conclusive
What about other studies long-term outcomes after planned VBB compared to planned primary CS?
- a few studies have found increased risk of cognitive impairment, cerebral palsy, low test scores, or neurodevelopmental delay, leaning towards primary CS (Andersen, MacKay, Molkenboer, Krebs, Xu, Jensen)
- also higher risk of childhood asthma and obesity in newborns delivered by c-section (Let me PubMed that for you...)
- two studies favored CS due to higher rates or urinary incontinence and perineal lacerations
- 15 found no difference, 20 favored pVBB (I'm not linking every single one...email me if interested)
- higher risk of severe acute maternal morbidity (SAMM; 6.4/1000 in planned elective CS versus 3.9/100 in planned VBB)
- also a higher likelihood of repeat c-section (and associated surgical risks), abnormal placentation, uterine rupture, and placental abruption (link)
And let's not forget about dangers to future pregnancies...
- there's also a higher risk of placenta accreta spectrum, especially as number of c-sections increases (and we all know that c-section rates are higher in subsequent pregnancies after the first), and this is a highly morbid condition (look at me and me)
- Van Dillen et al found that incidence of severe acute maternal morbidity and mortality (SAMM) was significantly higher in future pregnancies regardless of future mode of delivery
- you must also consider the risk of placenta previa, uterine rupture, and other less studied factors such as detriments to maternal wellbeing (e.g. postpartum depression), the trauma for many women of being strapped crucifixion style to an OR bed, and possible difficulties in maternal bonding with her newborn, which are anecdotally important nonetheless
"...for every infant saved by a caesarean section, one woman will experience a uterine rupture during a subsequent pregnancy...” - Gerard Wisser (author of this and this...this, too, if you speak Dutch)
How many c-sections needs to be performed to prevent bad outcomes in mom and baby?
- According to the TBT itself, 104 c-sections have to be performed to save one baby (from a complication of VBB)
- The numbers are even sillier when you look at larger RCTs:
- Vlemmix et al additionally found that 338 c-sections had to be performed to prevent 2 birth traumas (intracranial bleeding, cephalic hematoma, fractures, brachial plexus or facial nerve lesions) or 12 cases of low APGARs
PEARL: All of this is to say that if a patient has a fetus in breech presentation, prenatal, intrapartum, and postpartum risks to and benefits for mom, baby, and future pregnancies of having a cesarean delivery need to be weighed against the prenatal, intrapartum, and postpartum risks to and benefits for mom, baby, and future pregnancies of having breech delivery.
The Mechanics of Breech Vaginal Delivery
- respect physiology
- most fetuses will be in Frank breech or complete breech
- a foot in the vagina likely suggests that the fetus was in complete breech and that a foot dropped after the cervix opened
- higher risk of umbilical cord prolapse (UCP), but without pressure on the cord...does it matter?
"What do I do?"
- if you have no idea, then do nothing (you can disrupt the normal physiology of the process)
- invite the patient to get on all fours, as this position has been found to facilitate the normal physiologic process better than supine (this has been published on 12 separate occasions so far...shall I PubMed this for me?)
- most patients will assume this position (or whatever other position feels right) on her own, and an epidural may interfere with critical repositioning efforts by your patient
- having said that: an epidural is her choice. You can educate her that moving with the surges can help to facilitate a VBB
- allow rump to deliver. Remember that most vaginal deliveries - breech or otherwise - require zero assistance
- the position of the sacrum relative to the pelvis should be noted
- as the rump descends, the sacrum will generally move to sacrum anterior
- the rump will continue to descend, symmetrically in most cases
- arms will deliver, then baby will be hanging by just head, which also eventually deliver without assistance
- baby kicking, good cap refill, and cord pulsations will reassure you of fetal status
- for this entire time, you will likely have to do NOTHING
PEARL: Despite what you learned, unlike pizzas, (most) babies require no assistance to be birthed.
When should I help?
- per David Hayes, ask yourself:
"Is there a deviation?" If not, do nothing. If yes, go to question 2
"What's the cause?" - The most likely hold up will be a shoulder dystocia (generally anterior shoulder stuck on the pubic symphysis)
"Is the deviation interfering with the birth?" - It might be slower than you'd like, but with time mom or baby will likely figure out how to facilitate birth
"Do I need to intervene?" Consider fetal condition, time elapsed from initial rumping (should delivery within 12 minutes), morbidity from the intervention versus risk of doing nothing; consider maternal movement and position changes
How do I intervene?
For shoulder dystocia
> if sacrum rotates completely to sacrum posterior, use prayer hands technique to disengage head, rotate 180 degrees, then allow to proceed
> if sacrum rotates incompletely or only one arm delivers or if descent stops altogether, arm(s) is likely trapped behind the hand and stuck on something bony; use prayer hands to rotate the baby all the way to sacrum posterior in direction that baby is facing, then rotate in opposite direction back to sacrum anterior, then allow to proceed
> an alternative is the Louwen maneuver, in which you hold the baby by the shoulder girdles, rotate 180 degrees, then rotate in opposite direction back to sacrum anterior, then allow to proceed
For head extension
> prayer hands allows you to assist with head flexion through the Mauriceau-Smellie-Veit maneuver thereafter
For impacted shoulders impacted and urgency to deliver
> Loveset maneuvers can be used to disimpact shoulder(s) in order to expedite delivery (Note: this is the only intervention that includes traction on the newborn):
Grasping the newborn bilaterally by the shoulder girdles, apply traction on the newborn and deviate the body to drive the posterior shoulder towards the perineum
Rotate the torso to release the anterior shoulder. If you are unsure of the direction of rotation, remember that rotating the sacrum posteriorly if more difficult due to interference with the sacral promontory.
Once anterior shoulder is free, sweep the arm down. Then, rotate the torso in the opposite direction back to sacrum anterior, deviating the torso away from the perineum if necessary, to release the posterior shoulder.
See a video here.
- once the head is in the vagina, gravity will assist in gradually delivering the head (assuming she's on all fours)
- you still don't have to intervene, though assisting with head flexion by applying gentle pressure to the newborn's chest ("Louwen's nudge") or by creating space by lifting the patient's buttocks to help expel the head can expedite this process if necessary.
Note: This is by no means a comprehensive course on VBB. Please attend one of Rixa and David's breech workshops to learn more.