French advice on nonfrank breech birth: apply counter-pressure to the emerging foot/feet

I'm wading through obstetrical literature of the 1980s & 1990s to discover information relating to type of breech presentation and the associated risks/outcomes.

In a 1981 article by J. Dubois, Some present aspects of the problems of breech presentation and delivery, he gives advice on attending nonfrank vaginal breech births. From p. 489:

#6. The nonfrank breech. We have already seen how it can pose some particular problems. If one decides to attempt a vaginal breech birth, one should take, at a minimum, 3 precautions: keep the membranes intact until full dilation; be on guard for cord presentation or cord prolapse; at the moment of expulsion, slow the emergence of the foot/feet for at least a little while by pressing one hand against the vulva.

By implication, the last precaution refers specifically to breeches emerging feet-first, aka footling breech, and perhaps also to a complete breech with the foot/feet slightly in front of the buttocks. The French obstetrical nomenclature doesn't generally have a specific term for footling, just nonfrank (siège complet) and frank (siège décomplété).

The last part struck me, as it echoes a technique proposed by Russian obstetrician Tsovianov, the Tsovianov II. This maneuver converts a footling breech into a complete breech.

Antonín Doležal. Porodnické operace. 2007

Dubois' recommendations do not mention the goal of converting leg position, but that could be a side result of counter-pressure against the feet. This technique could provide additional time for the cervix to dilate, if not already fully dilated.

Severe acute maternal morbidity (SAMM)

Severe acute maternal morbidity (SAMM) is a maternal life-threatening event shortly before or after childbirth, often referred to as a "near miss."

Mantel et al (1998) describe a near miss as "a patient with an acute organ system dysfunction, which if not treated appropriately, could result in death." In other words, "A very ill pregnant or recently delivered woman who would have died had it not been that luck and good care was on her side."

In 2010, van Dillen et al published a study about severe acute maternal morbidity in The Netherlands. Following all pregnant women nationwide, they found that SAMM occurred 6.4 times per 1000 after elective cesarean section, compared to 3.9/1000 after planned vaginal birth. The risk of SAMM after a cesarean section persisted into the next pregnancy. The authors report: "Women with a previous CS were at increased risk for SAMM in their present pregnancy."

I created an infographic that represents those findings. Whenever a woman faces the possibility of a cesarean section, the short- and long-term risk to herself should be part of the discussion.

Can we predict the likelihood of a successful vaginal breech birth?

How likely is a woman to have a cesarean when she is in labor with a breech baby? Is there any way to predict her chances of a vaginal birth based on how dilation and estimated fetal weight?

A teaching hospital in Liverpool compiled data on all singleton term and near-term breech babies born in their unit between 1988 and 1991. Nwosu et al (1993) calculated the likelihood of having an in-labor cesarean based on both estimated fetal weight and cervical dilation at admission. They explain:

Recently Chadha et al (1992) have shown that women admitted in labour with breech presentation at a low cervical dilatation (less than 3 cm) are more likely to be delivered by caesarean section. This is in agreement with our study. Using our results for all vaginal and emergency caesarean deliveries, we are able to tabulate the likelihood of caesarean section corresponding to various values of cervical dilatation on presentation and estimated fetal weight. These results are presented as Fig. 1 (Callygram), which could assist the clinician on the labour ward in counselling the woman, and in the choice of the best mode of delivery. It must be stressed that the tabulated (percentage) probabilities of caesarean section for given values of cervical dilatation and fetal weight are derived from our sample which has not specifically addressed the question of augmentation of labour [this unit did not induce or augment] and intrapartum external cephalic version (with or without tocolytics).

As you can see, the likelihood of a successful vaginal birth increases significantly with higher cervical dilation at hospital admission. EFW also plays a role, but that difference nearly disappears at both extremes of cervical dilation.

Cervical dilation at admission depends on how long the mother waits to go in, so this is a tricky thing to use as a predictive measure. There is no automatic set point at which women go to hospital (or, at home, call their midwife). A woman's likelihood of a vaginal breech birth also varies widely by hospital and by provider. But this does suggest that a rapidly progressing labor is a strong positive indicator of a successful vaginal breech birth.