Circadian thyrotropin variations are preserved in normal pregnant women.
Serum thyrotropin (TSH) concentration circadian rhythm is abolished in many endocrine and non-endocrine diseases. In the present study we have measured serum TSH concentration over 24 h every 2 h in second and third trimester pregnant women. During the 24-h period, serum free thyroxine and free triiodothyronine concentrations did not change significantly. In contrast, serum TSH concentrations demonstrated significant circadian variations both in the second and third trimester pregnant women (p < 0.02 and p < 0.005, respectively). In summary, second and third trimester pregnancy is associated with a normal circadian TSH rhythm.
Roti
E
E
Centro per lo Studio, Prevenzione, Diagnosi e Cura delle Tireopatie, University of Parma, Italy.
Bartalena
L
L
Minelli
R
R
Salvi
M
M
Gardini
E
E
Pistolesi
A
A
Martino
E
E
Braverman
L E
LE
D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000097:blood*; D011263:Pregnancy Trimester, Third / Q000097:blood*; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine