Looking for The Lactivist? She's retired. But you CAN still find Jen blogging. These days, she's runs A Flexible Life. Join her for life, recipes, projects and the occasional rant.
Monday, June 26, 2006Ok, so among the many questions and statements revolving around home birth is the issue of "what if X happens." You know how it goes... "if we hadn't been in the hospital, my baby would have DIED." This phrase gets applied on everything from nuchal cord to failure to progress to TRUE emergencies like full placental abruption.
One of the popular ones is shoulder dystocia...where the shoulders of the baby get trapped behind the pubic bone, prohibiting delivery. Now, there are a variety of ways to handle this problem, especially in the hospital. So, I thought I'd do a little write-up on what they are... Note that the "Gaskin Manuever" is the most common resolution in home births but is rarely practiced in the hospital because most hospital moms have epidurals and thus, cannot be properly moved into the position.
So, here we go...
More Info on the following procedures, including diagrams
Basically, it says that if you are on your back, your pubic bone does get in the way, but if you push your knees back to your chest (sound familiar?) that it "raises" the pubic bone up and lets the baby slide under it. Of course they seem to miss that simply being on the back closes up the pelvis by about 30% and that if you WEREN'T on your back, you wouldn't NEED to push your knees up to your chest.
It involves sharply flexing the legs upon the maternal abdomen. By doing this, the symphysis pubis is rotated cephalad and the sacrum is straightened. In a high percentage of cases this by itself suffices to free the impacted anterior shoulder.
It goes on to note that this position needs to be "assisted" with suprapubic pressure...that basically means making a fist and pushing on the abdomen where the shoulder would be to "force" it through.
Sounds...umm...painful? And very likely to lead to broken clavicals on baby? Also, the "success rate" of this working is about 40%.
Other methods that are discussed for anyone that's curious...
The Wood's Screw Manuver
Basically, this one rotates the baby in order to "corkscrew" the shoulders out of the body. Often, it involves the doctor sliding his hand INTO the birth canal to locate the baby's lower arm which is then slid up across the chest and delivered next to the head. This then allows for the "relatively easy" delivery of the baby.
Of course it would likely require a VERY generous episiotimy (baby's head AND a doctors hand in there?? eeeeee!) and has a 12% humeral fracture rate in the baby. Of course that is cited as a "small price to pay for the "safe" delivery of the baby."
These are said to be the two most common ways that OBs resolve shoulder dystocia.
On to the others...
In this cephalic replacement maneuver -- now generally referred to as the Zavanelli maneuver -- the head must first be rotated back to its pre-restitution position -- that is, occiput anterior -- and then flexed. Constant firm pressure is applied while pushing the head back into the vagina. Tocolytic agents or uterine-relaxing general anesthesia may be administered to facilitate this process. Cesarean section must be performed immediately after replacement of the head.
It's reported as having a 90% success rate in that it lets the doctor do the c-section to deliver the baby. It doesn't say what happens to the other 10%.... It gets worse...Looking at overall stats for Zavanelli babies...(there were 59 of them in the study)
Apgar scores at 5 minutes were less than 6 in 61% of these babies and were less than 3 in 27%. Four babies in his series had seizures in the nursery, two had permanent neurologic injury, five experienced a permanent Erb palsy, and two died. Three percent of the mothers experienced ruptured uterus and 5% suffered uterine lacerations.
Symphysiotomy (Known to Jen as the "Holy CRAP!" maneuver)
The theory is that by transecting the firm ligaments joining the left and right symphyseal bones, an additional 2-3cm in pelvic circumference can be gained. In most cases this will allow the anterior shoulder to be delivered beneath the symphysis.
Basically, for every 1cm of "joint separation" you gain about 8cm of pelvic space...Apart from the extreme "holy crap!" of the fact that they're basically splaying your legs and cutting your ligaments, it requires five days of a cath to drain the bladder, a patient remaining immobile on her side (often with legs tied together) for a full three days and obvious injury risk to the bladder and urethra.
Thankfully, it says that this manuever is rare in 1st world countries and is really only used or suggested when all other options have been exhausted in a third-world country without access to c-section. Still...gives me the heebie-jeebies.
Gaskin Maneuver (All-Fours)
The average time needed to move the mother into this position and to complete delivery was reported to be 2-3 minutes. Unfortunately, there was no detailed description of fetal and maternal outcome in this report. Also, reports about this procedure have generally been in the midwifery literature, involving a patient population less likely to have epidural anesthesia and thus more likely to be fully mobile.
However, from a study involving the Gaskin maneuver that was published in the Journal of Reproductive Medicine, the following is noted:
Overall, the maternal complication associated with the use of the “Gaskin Maneuver” was 1.2 percent (one case of postpartum hemorrhage, transfusion not required), and the neonatal complication rate was 4.9 percent. . . None of these patients required any additional maneuvers. . . Not only was the Gaskin Maneuver instrumental in relieving shoulder impact in every instance, it is also a non-invasive procedure requiring only a change of maternal position.”
The study that I quote above says that the maneuver was successful in all instances in which it was tried, making for an obviously much higher outcome than an 82% success rate. ;) However, most of the other references that I can find for the Gaskin Maneuver leave the rate at around 80-85%. Whichever number is true, it's still LOADS higher than the rate of ANY of the more common obstetrical techniques.
From Ina May's own site...the following information is quoted...
...32 [shoulder dystocias] were managed by having the mother assume the all-fours position, with no mortality, no birth injuries, and with excellent Apgar scores. All the babies for whom follow-up was possible (29 of 35) were developmentally normal (ages 9 months to 15 years). These statistics compare favorably with the reported mortality rates of 21% to 29% and morbidity rates of 16% to 48%. In addition, despite frequent recommendations that any maneuvers to deliver the shoulders be preceded by a generous episiotomy or proctoepisiotomy, 23 of the babies were delivered over an intact perineum, and there were no 3rd or 4th-degree lacerations. Finally, though some authors recommend the time-consuming step of administering general anesthesia to the mother before attempting alternative maneuvers, these babies were all delivered without anesthesia.
The reason given by that first link (an OB reference site) for this maneuver not being more commonly practiced in the obstetrics world?
Since the all-fours maneuver involves a gravid woman at the end of her pregnancy, exhausted by a long labor, often with an epidural in place, being moved quickly out of her delivery position onto all fours on her bed or on the floor, the practicality of this maneuver for a general obstetrical population is open to question.
So What Usually Gets Done?
Here's what ACOG recommends, in order, for handling shoulder dystocia...
ACOG, in its bulletin on shoulder dystocia, proposed the following sequence of maneuvers for reducing a shoulder dystocia:
1) Call for help - assistants, anesthesiology, pediatrician. Initiate gentle traction of the fetal head at this time. Drain the bladder if distended.
2) Generous episiotomy.
3) Suprapubic pressure with normal downward traction on fetal head.
4) McRoberts maneuver.
Then, if these maneuvers fail,
5) Wood's screw maneuver.
6) Attempt delivery of posterior arm.
Now here's what makes me really, really sad.... and before you read this, keep in mind the 82% success rate of the Gaskin maneuver alone...
McFarland (1996) reported that the use of two maneuvers alone -- McRoberts and suprapubic pressure -- resulted in the resolution of 58% of 276 cases of shoulder dystocia in his series. He found that the addition of the Wood's Screw maneuver and delivery of the posterior arm were sufficient to resolve the shoulder dystocia in all remaining cases.
Now...what was that question people had again about OBs and them not practicing "evidence-based" medicine? ;)