Context Hospitalized infants undergo repeated invasive procedures. It is unknown
whether cumulative experiences with pain lead to anticipatory pain behaviors
Objectives To determine whether newborns who are born to mothers with diabetes
and undergo repeated pain learn to anticipate pain and exhibit more pain during
a painful procedure than normal infants.
Design, Setting, and Participants Prospective cohort study of 21 full-term newborns born to mothers with
diabetes and 21 born to mothers with uneventful pregnancies, at a university
teaching hospital between August 1999 and October 2000. Infants of diabetic
mothers underwent repeated heel lances in the first 24 to 36 hours of life
for monitoring of blood glucose concentrations. Pain responses of all infants
undergoing a venipuncture on the dorsum of the hand to obtain blood for the
newborn screening test after the first day of life were compared. In addition,
from September through November 2001, 12 infants of diabetic mothers and 12
normal infants were compared for pain reactions to intramuscular vitamin K
injection after birth.
Main Outcome Measures Percentages of time observed grimacing and crying and visual analog
scale (VAS) scores.
Results Raters were blinded to exposure group. Median baseline scores for grimacing,
crying time, and VAS did not differ significantly between groups (P = .27, P = .32, and P = .32, respectively). Median scores (interquartile range) for grimacing
during skin cleansing were higher in infants of diabetic mothers (22.2% [77.5%]
vs 0% [15%]; P = .03). The VAS scores for both groups
were zero, but the distribution of the scores was significantly different
(86% of normal infants vs 52% of infants of diabetic mothers had scores of
zero) (P = .04). During venipuncture, infants of
diabetic mothers had higher median scores for grimacing (81.7% [32.5%] vs
40% [73.4%]; P = .01), VAS (69% [27.5%] vs 5% [60.5%]; P = .002), and crying (40.2% [77%] vs 0% [54.8%]; P = .03) compared with normal infants. There were no differences
between groups on any pain measure in response to intramuscular injection.
Conclusions Newborns who had diabetic mothers and were exposed to repeated heel
lances in the first 24 to 36 hours of life learned to anticipate pain and
exhibited more intense pain responses during venipuncture than normal infants.