Data Collection
All women signed an informed consent agreeing to their participation,
along with the PCPNDT (Pre-Conception and Pre-Natal Diagnostic
Techniques Act 1994) form. 15
At the growth scan, the biparietal diameter (BPD), head circumference
(HC), abdominal circumference (AC), and femur length (FL) measurements
were taken using standard reference planes. Estimated fetal weight (EFW)
was calculated using the Hadlock formula.
The umbilical artery, middle cerebral artery (MCA), and ductus venosus
pulsatility indices (PI) were recorded, along with the amniotic fluid
index (AFI) according to standard protocol.
Hadlock EFW chart 16 was used to calculate EFW and
growth centile as these charts are the ones used locally.
If a woman had scans on multiple occasions during the third trimester,
then the last scan closest to delivery, was included.
All fetuses ≤ 10th percentile were identified. Fetuses
≤ 3rd percentile were labelled as FGR and
> 3rd percentile and ≤
10th percentile were labelled Small for Gestational
Age ( SGA). Appropriately grown fetuses (AGA) were those between the
10th and 90th percentile, and Large
for gestational age (LGA) > 90thpercentile. The latter were excluded from the analysis.
The final birth weight at delivery was obtained and plotted on Fenton’s
gender birth weight chart17 considered as the
reference chartfor assessing SGA/FGR/AGA by local neonatologists, both
in the study hospital and the tertiary care hospitals.
All patients were managed according to local obstetric protocol. If
fetal Doppler suggested impending demise, only then were the obstetric
units alerted by a phone call. Delivery was performed according to
obstetric indications.
Outcomes were collected from the delivery records or by a telephonic
interview if the woman did not deliver in the study hospital. Neonatal
admission data were taken from the hospital records or from the patient.
All study stillbirths had a pre-structured questionnaire filled and an
internal review to ascertain cause and assign a CODAC
code18(Causes of Death and Associated Conditions )
All the scans were performed on GE Voluson S8 ultrasound system (GE
Healthcare; Zipf, Austria). Data was entered into an obstetric database
Astraia GmbH from which the appropriate parameters were extracted.