INSERM. France: An observational study carried out in France by Jennifer
Zeitlin and her team (Inserm Unit 1153, Obstetrical, Perinatal, and
Pediatric Epidemiology Research Team, EPOPé), on over 14,000 women,
shows that only 21% of infants with foetal growth restriction (FGR) had
been suspected of having FGR during pregnancy, despite national
recommendations that invite women to have an ultrasound scan during the
third trimester of pregnancy.
The study shows that nearly half of the
infants with suspected FGR were of normal weight at birth (false
positives). Moreover, suspected FGR during pregnancy was associated with
an increased risk of planned pre-labour caesarean delivery or induced
labour, independent of the existence or otherwise of low birthweight.
The results of this study, published in
BJOG: An International Journal of Obstetrics and Gynaecology,
emphasise the need to reflect on the reasons for the poor performance
of FGR screening, and also raise questions about the potential
iatrogenic effects of screening on the false positives.
Foetal
growth restriction (FGR) is an obstetric pathology that causes
considerable perinatal morbidity and death. It appears as a change in
foetal growth that can be detected during pregnancy, mainly by
estimating foetal weight from ultrasound measurements. In France, the
third trimester ultrasound recommended for all pregnant women serves to
monitor foetal growth and identify foetuses with FGR. Antenatal
detection of FGR enables monitoring of the pregnancy to be adapted to
prevent risks of foetal and neonatal death, as well as risks of
neurological sequelae for the infant.
Few studies to date had assessed the performance and impact of FGR screening on the general population.
The
aim of the researchers was to estimate the percentage of infants for
whom FGR had been suspected antenatally, and to measure the effect of
this suspicion on medical decision-making, by analysing a representative
sample of births in France in 2010. To do this, they estimated
the number of low birthweight (below the 10th percentile for
gestational age) infants born and, of these, the proportion of infants
who had been suspected of having FGR antenatally.
The study showed that only 21% of low birthweight infants had been
suspected of having FGR during pregnancy. Furthermore, half of the
infants suspected of having FGR during pregnancy were of normal
birthweight (≥ 10th percentile). Antenatal suspicion of FGR was
associated with an increased probability of having a planned pre-labour
caesarean delivery or an induced labour, independent of the existence or
otherwise of low birthweight. Similar results were obtained for the
subgroup of women who showed no complications during pregnancy.
For Jennifer Zeitlin and her team:
“The
results of this study emphasise the need for a reflection on the reasons
for the poor performance of FGR screening in France. They also raise
questions about risks from carrying out unnecessary medical
interventions, where suspected FGR during pregnancy has not been
confirmed at birth.”