The article on fetal pain entitled, "Fetal plasma cortisol and
beta-endorphin response to intrauterine needling" by Xenophon
Giannakoulopoulus BSc. et al, out of the Department of Chemical Pathology,
Institute of Obstetrics and Gynaecology, Royal Postgraduate Medical
School, Queen Charlotte's and Chelsea Hospital, London W6 OXG, UK, appears
in volume 344, n. 8915, pp 77-81 of "The Lancet". Correspondence is
directed to Professor Nicholas M Fisk, Centre for Fetal Care at the same
In brief, the investigators wished to find out whether the fetus mounts
a hormonal response to potentialy painful procedures, such as
intrauterine surgery. Previously they had noticed that during the
placement of a catheter for a fetal transfusion, the fetus would respond
with vigorous body and breathing movements. They noted that such
movements were present when the catheter placement required abdominal
puncture but not when there was direct cannulation of the umbilical cord
(the umbilical cord is without nerves and therefore cannot cause pain).
Measuring a stress hormonal response during these procedures would
support the hypothesis that the fetus was experiencing pain.
They studied subjects between 20 and 34 weeks gestational age that were
undergoing clinically indicated fetal blood sampling. They excluded
infants with conditions that they would expect to cause hormonal
elevations, such as severe anaemia, bradycardia and hypoxemia. 31
subjects were eventualy found to meet the criteria. About half had
umbilical vein sampling (no nerves, no possibility of pain) and half had
hepatic vein sampling (required intra-abdominal puncture with the
possibility of pain). No difference was found in the plasma levels
measured. However, the investigators felt that perhaps the amount of
time it took to obtain the samples was insufficient to mount a hormonal
response. Therefore, in a second set of 17 subjects that were
undergoing transfusions they resampled the blood after the transfusion
was completed. This produced a distinct difference between the
hormonal levels in the hepatic vein cannulated group and the umbilical
vein cannulated group. The group that had undergone hepatic vein
cannulation (and therefore had a relatively huge needle stuck in their
bellies) had a marked rise in their plasma cortisol and beta-endorphin
levels. This response is consistent with an acute stress, such as pain.
The umbilical vein group had no elevation in hormones.
The authors concluded that their study provides further evidence that
the fetus can experience pain. They noted that the youngest subject
that they studied was 23 weeks gestational age and that this subject's
response was as vigorous as the older subject's. They suggested that
physicians consider modifying their clinical practices accordingly,
providing for analgesia when performing fetal procedures. In a final
note they added:
"This applies not just to diagnostic and therapeutic procedures on the
fetus, but possibly also to termination of pregnancy, especially by
surgical techniques involving dismemberment."
Thomas R Jackson, M.D.