Forceps more likely to hurt mothers and babies than C-sections

Obstetric forceps

I’ve been writing recently about the moral panic surrounding C-sections.

A moral panic is a widespread fear, most often an irrational one, that someone or something is a threat to the values, safety, and interests of a community or society at large.

The handwringing about the high US C-section rate of 32% is a widespread fear, generally irrational that C-sections are a threat to the safety of women and babies.

[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]More babies and mothers were injured by attempting to avoid C-section than by C-sections themselves.[/pullquote]

The World Health Organization’s “optimal” C-section rate of less than 15% is Exhibit A in the moral panic. The WHO continues to cling to this fabricated figure despite:

Acknowledgement there is not and has never been any evidence that 15% is the optimal rate
Best studies to date demonstrate a minimal rate compatible with low perinatal and maternal mortality of 19%
International data that shows that C-section rates of over 42% are compatible with excellent outcomes

Exhibit B is the recommendation to reduce the C-section rate by promoting operative vaginal delivery (forceps and vacuum) instead. One of the reasons why the US C-section rate has increased is because operative vaginal delivery has fallen out of favor. The recommendation to revert to operative vaginal delivery makes no sense because the risk of severe perinatal injury and severe maternal injury are increased by operative vaginal delivery compared to C-section.

The 2017 paper Perinatal and maternal morbidity and mortality among term singletons following midcavity operative vaginal delivery versus caesarean delivery is yet more evidence of the harmful effect of operative vaginal birth.

What is operative vaginal delivery?

It is a procedure (using forceps or obstetric vacuum) used to deliver a baby during the pushing phase of labor. It is used for two main reasons: the baby doesn’t fit (dystocia) or fetal distress. The station of the baby’s head determines whether an operative vaginal delivery is midcavity, low or outlet.

…At midcavity station the leading part of the fetal skull is between 0 and 2 cm below the spines, at low cavity it is >2 cm below the ischial spines but not on the pelvic floor, and at outlet station the leading part of the fetal skull is on the pelvic floor and visible.12 Operative vaginal deliveries at midcavity require the greatest operator skill and experience; consequently, it is at midcavity station that the decision between operative vaginal delivery and caesarean delivery presents a serious challenge…

This study involves midcavity operative vaginal delivery and looks at severe perinatal and maternal morbidity.

Severe perinatal morbidity/mortality included convulsions, assisted ventilation by endotracheal intubation, 5-minute Apgar score <4, severe birth trauma (intracranial haemorrhage, skull fracture, severe injury to the central or peripheral nervous systems, long bone injury, subaponeurotic haemorrhage, and injury to liver or spleen), stillbirth and neonatal death. Severe maternal morbidity included severe postpartum haemorrhage (requiring transfusion), shock, sepsis, obstetric embolism, cardiac compli- cations and acute renal failure. Secondary outcomes included respiratory distress in the infant (including hya- line membrane disease, idiopathic respiratory distress syndrome, transient tachypnoea of the newborn and other neonatal respiratory distress), postpartum haemorrhage, as well as birth and obstetric trauma. Birth trauma included intracranial haemorrhage, injury to the central or peripheral nervous systems, injury to the scalp or the skeleton, and other birth injury. Obstetric trauma included severe perineal lacerations (third- and fourth-degree), cervical and high vaginal laceration, pelvic haematoma, obstetric injury to the pelvic organs, pelvic joints or ligaments, and other obstetric trauma.

They used an intention-to-treat analysis:

Women who had a failed operative vaginal delivery (and eventually delivered by caesarean) were included in the operative vaginal delivery group. This ensured a clinically appropriate comparison of the different modes of delivery using an intention-to-treat framework.

What did they find?

Among deliveries with dystocia, attempted midcavity operative vaginal delivery was associated with higher rates of severe perinatal morbidity/mortality compared with caesarean delivery (forceps ARR 2.11, 95% CI 1.46–3.07; vacuum ARR 2.71, 95% CI 1.49–3.15; sequential ARR 4.68, 95% CI 3.33–6.58). Rates of severe maternal morbidity/mortality were also higher following midcavity operative vaginal delivery (forceps ARR 1.57, 95% CI 1.05–2.36; vacuum ARR 2.29, 95% CI 1.57–3.36). Among deliveries with fetal distress, there were significant increases in severe perinatal morbidity/mortality following attempted midcavity vacuum (ARR 1.28, 95% CI 1.04–1.61) and in severe maternal morbidity following attempted midcavity forceps delivery (ARR 2.34, 95% CI 1.54–3.56).

The results are expressed in this table:


I graphed the overall results for severe perinatal and maternal morbidity:


It’s easy to see that operative vaginal delivery increases the risk of both severe perinatal and severe maternal outcome. The greatest risk is sequential application: for example the vacuum is tried but doesn’t work and then forceps are tried.

The authors explain:

…[A]ttempted midcavity operative vaginal delivery was associated with an increased risk of severe perinatal morbidity/mortality compared with caesarean delivery. The magnitude of the increased risk varied by indication for delivery, being significantly larger in the dystocia group relative to the fetal distress group. This difference in the effect of attempted operative vaginal delivery by indication appears to reflect the greater fetal jeopardy associated with fetal distress and the consequent higher baseline rate of adverse outcomes even in the caesarean delivery group. We also found substantially greater risk of birth and obstetric trauma following operative vaginal delivery compared with caesarean delivery, with 2.8- to 8.5- fold higher rates depending on indication and instrument.

And for mothers:

The increase in severe maternal morbidity following midcavity forceps delivery was primarily due to the increased rate of severe postpartum haemorrhage…

Third- and fourth-degree perineal laceration rates in our study were high following midcavity operative vaginal delivery. Similar high rates have been reported in other recent studies of operative vaginal delivery… With rates of obstetric anal sphincter injury as high as 23.0% following attempted midcavity forceps deliveries, it is imperative that the risks and relevant long-term quality-of-life implications for pelvic floor health of attempted midcavity operative vaginal delivery be discussed with women both in the antenatal period, as well as during labour (as currently done with regard to the surgical risks associated with caesarean delivery).

Every midcavity operative delivery was attempted in the express effort to avoid a C-section because of the purportedly harmful consequences of C-sections. Yet the “cure” turned out to be worse than the “disease.” More babies and mothers were injured by attempting to avoid C-section than by C-sections themselves.

The bottom line is that attempting to lower the C-section rate by substituting midcavity operative vaginal birth is bizarre because operative vaginal delivery is harmful.

There is nothing wrong with a high C-section rate. It is completely compatible with excellent perinatal and maternal outcomes. The current handwringing about C-section rates is the result of moral panic, generally irrational, and we should get over it.