Abstract:
A prospective study was conducted during the period 2001 to 2003
at Omdurman maternity, Khartoum teaching and Khartoum North teaching
hospitals.
One hundred and twenty Sudanese pregnant women at different
stages of pregnancy were chosen for this study. Forty non-pregnant women
of the same age without endocrine disease were chosen as control. Thyroid
hormones total (T4 and T3) and free (FT4 and FT3) were measured. In
addition TSH, hCG and TG were also measured in both groups.
The Study group were divided according to the gestational age (weeks)
into three subgroups: - First trimester 5 – 12 weeks, second trimester 13 –
27 weeks and third trimester 28 – 40 weeks. Determination of serum
hormones concentration was carried out using a highly sensitive specific
RIA technique.
The results of this study showed that there was an increase in concentration
of total thyroid hormones (T4 and T3), but the increase did not proceed at
steady level during the different trimesters both hormones increase
significantly in all trimesters compared with control group and continued
thereafter, but at slower rate.
Mean serum free T4 increase significantly during the first trimester, while
the increase in T3 concentration was not significantly different compared
to non-pregnant women. Free T4 and free T3 decreased significantly
during second and third trimesters of pregnancy compared with non-
pregnant women.
Thyroid stimulating hormones (TSH) level remained within the normal
range throughout pregnancy period although pregnant women had
suppressed
Below normal range in the first trimester( 12.5%).
The concentration of human chorionic gonadotrphin hCG
increased highly significantly in the first trimester, but decreased sharply in
the second and third trimesters. Thyroglobulin increased in all three
trimesters of pregnancy compared to control group, however the greatest
elevation was detected during the first trimester.
The results of this study showed that the increase of hCG in the first
trimester has stimulating effect on thyroid gland, although TSH remains
within the normal range, this indicated that the increase of free thyroxine
hormone concentration during pregnancy may be due to the increase in
hCG only this indicated that the changes of thyroid hormones during p
pregnancy were physiological resulted from The pituitary gland has no
stimulating effect on thyroid gland during normal pregnancy.
