Letters to the Editor
Re: Kapoor S, Thomas JT, Petersen SG,Gardener GJ. Is the third
trimester repeatultrasound scan for placental localisation needed
ifthe placenta is low lying but clear of the os at themid-trimester
morphology scan? Aust N Z J ObstetGynaecol 2014; 54(5): 42832
Dear Editor,The study by Kapoor et al.1 conrms previous
similarstudies, showing that mothers with a placenta identied
ontransabdominal abdominal ultrasound in the secondtrimester as
within 20 mm of the internal cervical os are atrisk of placenta
praevia requiring abdominal delivery atterm and thus require
follow-up.Unfortunately in their introduction, the authors
misquote national guidelines from the RCOG2 andSOGC3 as
suggesting that such women do not requirefollow-up unless the
placenta reaches or covers theinternal cervical os. What both
guidelines actually advise isthat if the placenta is assessed on
transvaginal ultrasoundbetween 18 and 24 weeks, only those found to
reach orcover the internal cervical os remain at risk of praevia
atterm and require follow-up. This is based on studies byTaiale et
al.,4 Becker et al.,5 Smith et al.6 and Lauriaet al.7 amongst
others involving over 10 000 women intotal.Whilst this
(transvaginal assessment at 1814 weeks
gestation) is not currently routine practice in mostcentres, it
may become so as recent evidence about theuse of transvaginal
cervical length measurement at 1822 weeks gestation, with
progesterone treatment for thosewith a short cervix to reduce the
risk of preterm birth,8
begins to be incorporated into practice. Thus, an addedbenet of
routine transvaginal ultrasound at the secondtrimester morphology
scan should be to dramaticallyreduce the number of women requiring
follow-up for alow-lying placenta in the third trimester, along
with therestricted activities that many obstetricians continue
toadvise.FRANZCOG, FRCSC, FRCOG
David SOMERSETSouthern Alberta Centre for Maternal Fetal
Medicine,
Calgary, AB, CanadaE-mail: [email protected]
DOI: 10.1111/ajo.12310
References1 Kapoor S, Thomas JT, Petersen SG, Gardener GJ. Is
the thirdtrimester repeat ultrasound scan for placental
localisation
needed if the placenta is low lying but clear of the os at
themid-trimester morphology scan? Aust N Z J Obstet Gynaecol2014;
54(5): 428432.
2 RCOG Green-top Guideline No. 27, 2011. Placenta
praevia,placenta praevia accreta and vasa praevia: diagnosis
andmanagement. [Accessed 16 December 2014.] Available fromURL:
https://www.rcog.org.uk/globalassets/documents/guidelines/gtg27placentapraeviajanuary2011.pdf
3 SOGC Clinical Practice Guideline No. 189, 2007. Diagnosisand
Management of Placenta Previa. [Accessed 16 December2014.]
Available from URL:
http://sogc.org/wp-content/uploads/2013/01/189E-CPG-March2007.pdf
4 Taipale P, Hiilesmaa V, Ylostalo P.
Transvaginalultrasonography at 1823 weeks in predicting placenta
previa atdelivery. Ultrasound Obstet Gynecol 1998; 12: 422425.
5 Becker RH, Vonk R, Mende BC et al. The relevance ofplacental
location at 2023 gestational weeks for prediction ofplacenta previa
at delivery: evaluation of 8650 cases. UltrasoundObstet Gynecol
2001; 17: 496501.
6 Smith RS, Lauria MR, Comstock CH et al.
Transvaginalultrasonography for all placentas that appear to be
low-lying orover the internal cervical os. Ultrasound Obstet
Gynecol 1997; 9:2224.
7 Lauria MR, Smith RS, Treadwell MC et al. The use
ofsecond-trimester transvaginal sonography to predict
placentapraevia. Ultrasound Obstet Gynecol 1996; 8: 337340.
8 Hassan SS, Romero R, Vidyadhari D et al. Vaginalprogesterone
reduces the rate of preterm birth in women with asonographic short
cervix: a multicenter, randomized, double-blind, placebo-controlled
trial. Ultrasound Obstet Gynecol 2011;38 (1): 1831.
Re: Is the third trimester repeat ultrasound scan forplacental
localisation needed if the placenta is lowlying but clear of the os
at the mid-trimestermorphology scan?
The aim of our study was to determine the need forrepeat
ultrasound scan for placental localisation in thethird trimester
when the placenta was reported to be lowlying at the morphology
scan. We did not differentiatebetween the modality of scanning
given the currentclinical practice in the community was
mostlytransabdominal scanning (TAS) at the 1820 weekmorphology
scan.We regret the perceived lack of clarity in our paper with
regard to the national guidelines of the SOGC andRCOG. We agree
that the SOGC recommends follow-upthird trimester scan when the
placental edge reaches oroverlaps the internal os clearly stating
the modality astransvaginal scan (TVS) between 18 and 24 weeks
ofgestation.1 However, the RCOG guideline recommends
2015 The Royal Australian and New Zealand College of
Obstetricians and Gynaecologists 193
Australian and New Zealand Journal of Obstetrics and Gynaecology
2015; 55: 193197
Th e Australian and New Zealand Journal of Obstetrics and
Gynaecology
follow-up if the placenta covers or overlaps the cervical osat
20 weeks of gestation, without indicating the modalityof scan
although TVS is stated as the preferred modality.2
The evidence supporting the RCOG guideline includespapers, which
have mixed TAS and TVS data.3,4 TheNICE guideline on antenatal care
provides similarrecommendations, but again does not specify the
modalityas TVS or TAS at the mid-trimester scan.5
The introduction in our paper dealt with the differencesbetween
the current Australian practices and theinternational guidelines
with regard to the need for afollow-up third trimester scan for
placental localisation.6
Some recent observational studies, with predominantlyTAS,
suggest omitting a follow-up scan for asymptomaticwomen with
placenta close to but not covering the os.7,8
However, other recent reports, including ours, indicate theneed
to continue follow-up scans for women with placenta< 2 cm from
the os on TAS.6,9
Shveta KAPOOR1, Joseph T. THOMAS2,Scott G. PETERSEN2 and Glenn
J. GARDENER2
1Mater Mothers Hospital,2Department of Maternal Fetal Medicine,
Mater Health
Services, South Brisbane, Queensland, AustraliaE-mail:
[email protected]
DOI: 10.1111/ajo.12352
References1 Diagnosis and Management of Placenta Previa. SOGC
ClinicalPractice Guideline No. 189, March 2007.
2 Placenta praevia, placenta accreta and vasa praevia:
diagnosisand management. RCOG Green Top Guideline No. 27.
Jan2011.
3 Becker RH, Vonk R, Mende BC et al. The relevance ofplacental
location at 2023 gestational weeks for prediction ofplacenta previa
at delivery: evaluation of 8650 cases. UltrasoundObstet Gynecol
2001; 17: 496501.
4 Dashe JS, McIntire DD, Ramus RM et al. Persistence ofplacenta
previa according to gestational age at ultrasounddetection. Obstet
Gynecol 2002; 99 (5 Pt 1): 692697.
5 Antenatal care. NICE guidelines [CG62] March 2008.6 Kapoor S,
Thomas JT, Petersen SG, Gardener GJ. Is the thirdtrimester repeat
ultrasound scan for placental localisationneeded if the placenta is
low lying but clear of the os at themidtrimester morphology scan?
Aust N Z J Obstet Gynaecol2014 Oct; 54 (5): 428432.
7 Robinson AJ, Muller PR, Allan R et al. Precise
mid-trimesterplacenta localisation: does it predict adverse
outcomes? Aust NZ J Obstet Gynaecol 2012; 52: 156160.
8 Blouin D, Rioux C. Routine third trimester control
ultrasoundexamination for low-lying or marginal placentas diagnosed
atmid-pregnancy: is this indicated? J Obstet Gynaecol Can 2012;34
(5): 425428.
9 Copland JA, Craw SM, Herbison P. Low-lying placenta: whoshould
be recalled for a follow-up scan? J Med Imaging RadiatOncol 2012;
56: 158162.
Regarding Improving VBAC rates: The combinedimpact of two
management strategies
Please allow me to comment on a recent paper inANZJOG, Improving
VBAC rates: the combined impactof two management strategies.1
The authors report on a series of 396 VBAC (VaginalBirth after
Caesarean) candidates who attended adedicated clinic. The stated
goal of this clinic was, asmandated by NSW Health under Towards
NormalBirth, to increase VBAC rates. The authors convinced57% of
candidates to attempt VBAC, although about 10%of them changed their
mind, and only 160 actuallyunderwent VBAC. Of those 160, only 75
managed anspontaneous vaginal delivery, and both
instrumentaldelivery rate (17.5%) and emergency caesarean
deliveryrate (35.6%) were high.And there were two deaths one
postdates stillbirth and
one due to a ruptured uterus. I do not think it can bedisputed
that VBAC caused the death of those two babiesand that it
endangered the life of at least one motherrather seriously.The
authors do point out that we must be mindful that
pursuing increased VBAC rates. . .might have signicantcosts such
as increased uterine rupture rates., but they donot mention those
two deaths in the abstract, nor are theyfeatured in the
conclusions. Quite on the contrary. Theyconclude: A dedicated NBAC
clinic and more consistentapproach to labour management can help
improve VBACrates, and Further targeted counselling towards
womenwith previous malpresentation and/or East Asian descentmay
further improve VBAC attempt rates. Yes, let us tryand talk more
people into VBAC then.I wonder though how that is going to be
possible while
maintaining valid informed consent, in particular in viewof the
ndings of this study. Are you going to disclosethose deaths?
Without informed consent, our interventionsmay be politically
correct and they may well comply withNSW Health policy directives,
but they will be illegal.What on earth are we doing this for? Why
all this
misguided effort? Why are well-trained and
competentobstetricians risking the lives of their patients,
andultimately their own careers? Do caesarean delivery rates(or
rather, compliance with ill-advised bureaucratictargets) matter
more now than perinatal deaths?Of course we will all wake up from
this bad dream.
Barristers and judges are going to make us wake up,sooner or
later.
Hans Peter DIETZObstetrics and Gynaecology, Sydney Medical
School Nepean,
Nepean Hospital, Penrith, New South Wales, AustraliaE-mail:
[email protected]
DOI: 10.1111/ajo.12317
194 2015 The Royal Australian and New Zealand College of
Obstetricians and Gynaecologists
Letters to the Editor
