BJOG mini-commentary on BJOG-22-0097
This manuscript by McCall et al reports that UK and France have very
different approaches to managing women with PAS. More women in France
received a uterus conserving approach. Major haemorrhage was more common
in the UK series. The authors speculate that this may be related to
treatment modality. The ACOG/SMFM committee opinion (Obstet Gynecol
2018;132:e259–75) recommends caesarean hysterectomy as the most
generally accepted approach. Does this report imply that we should stop
offering hysterectomies and recommend conservative treatment?
Before we make up our mind, it is important to consider what else was
different in the two cohorts. The case definitions used by UK OSS and
PACCRETA investigators were different. However, the authors of the
current report have included only those cases that satisfied a
harmonised definition. UK prevalence (1.7/10 000) was significantly
lower as compared to that from France (4.2/10 000). This raises the
question: Is UK under-reporting or is France over-reporting? Screening
studies may give some idea about the ‘true’ prevalence. A prevalence of
5.8/10 000 (Panaiotova et al, Ultrasound Obstet Gynecol 2019; 53:
101–106) was reported with screening for Caesarean scar pregnancies.
Coutinho et al (Ultrasound Obstet Gynecol 2021; 57: 91–96) reported a
prevalence of 3.8/10 000 with screening for PAS in late pregnancy. In
both these reports all women had either placenta previa or a low-lying
placenta. In contrast, placenta previa was present in 64% and 63% of
women from UK and France, respectively. In this light, one would expect
a higher, rather than lower prevalence of PAS as compared to the two
screening studies. One explanation could be increasing Caesarean section
rate and better awareness with time.
A systematic review reported high (>90%) sensitivity for
the detection of PAS using ultrasound in women at high risk of PAS
(D’Antonio et al, Ultrasound Obstet Gynecol 2013; 42: 509–517). The
prenatal detection was disappointingly low at < 50% in both
UK and France. Before we begin to berate ourselves, it is noteworthy
that these are 7-12 year-old data. The current study took place between
May 2010 - April 2011(UK) and November 2013 - October 2015(France).
What about the differences in median blood loss? Manual removal of the
placenta was attempted in fewer women in France. Even then, unplanned
hysterectomy was more common in the French group. The blood loss may be
lower with conservative management, but this advantage should be weighed
against the uncertainty about the possibility and timing of developing
major haemorrhage in the post-operative period. Moreover, it is possible
that the UK series had particularly severe cases as compared to the
French cohort given the significantly lower prevalence. A head-to-head
comparison of the two treatment modalities has never been reported. This
will necessitate a unified definition and accurate prenatal detection.
Such a study would be extremely challenging given the strong views of
women regarding fertility preservation and of physicians regarding
ongoing uncertainty with complications and personal experience. The jury
is still out on this one.