Objective: We assessed
longitudinal patterns of maternal C-peptide concentration to examine
the hypothesis of beta-cell regeneration in type 1
diabetes pregnancy.
<p>Research Design
& Methods: C-peptide was measured on maternal serum samples from 127
participants (12, 24, 34 weeks) and cord blood during the continuous glucose
monitoring in type 1 diabetes pregnancy trial (CONCEPTT). C-peptide was
measured using a highly sensitive direct and solid-phase competitive electrochemiluminescent
immunoassay. </p>
<p>Results: Three discrete
patterns of maternal C-peptide trajectory were identified: Pattern 1 undetectable
throughout pregnancy, n=74 (58%, maternal C-peptide <3 pmol/l); Pattern 2 detectable
at baseline, n=22 (17%, maternal C-peptide 7-272 pmol/l at baseline); Pattern 3
undetectable maternal C-peptide at 12 and 24 weeks which first became
detectable at 34 weeks, n=31 (24%; maternal C-peptide 4-26 pmol/l at 34 weeks).
Baseline characteristics and third trimester glucose profiles of women with pattern
1 and pattern 3 C-peptide trajectories were similar but women in pattern 3 had
suboptimal glycemia (50% time above range) at 24 weeks gestation. Offspring of
women with pattern 3 C-peptide trajectories had elevated cord blood C-peptide
(geometric mean 1319 vs 718 pmol/l; p=0.007), increased rates of
large-for-gestational-age (90% vs 60%; p=0.002)
neonatal hypoglycemia (42% vs 14%; p=0.001), and neonatal intensive care
admission (45% vs 23%; p=0.023) compared to pattern 1 offspring. </p>
<p>Conclusion: First maternal
C-peptide appearance at 34 weeks was associated with mid-trimester
hyperglycemia, elevated cord blood C-peptide and high rates of neonatal
complications. This suggests transfer of C-peptide from fetal to maternal serum
and is inconsistent with pregnancy-related beta-cell regeneration.</p>
Comment on: Meier JJ, Lin JC, Butler AE, Galasso R, Martinez DS, Butler PC (2006) Direct evidence of attempted beta cell regeneration in an 89-year-old patient with recent-onset type 1 diabetes. Diabetologia 49:1838–1844
