This Article Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by YLIKORKALA, O. Articles by REINILÄ, M. Search for Related Content PubMed PubMed Citation Articles by YLIKORKALA, O. Articles by REINILÄ, M.

Serial Prolactin and Thyrotropin Responses to Thyrotropin-Releasing Hormone throughout Normal Human Pregnancy

Departments of Obstetrics and Gynecology and Clinical Chemistry, University of Oulu SF 90220 Oulu 22, Finland

Address all correspondence and requests for reprints to: Dr. Olavi Ylikorkala, Department of Obstetrics and Gynecology, University of Oulu, SF 90220 Oulu 22, Finland.

In order to determine whether or not the pituitary responsiveness to TRH changes in pregnancy, 9 healthy pregnant women were given serially 200 µg TRH iv between 9-15, 26-29, and 35-38 gestational weeks as well as 3-5 days postpartum. Serum PRL and TSH were measured before and 20 and 60 min after the TRH administration. In addition, serum 17β-estradiol (E2) and progesterone (P) were measured before and 60 min after TRH. The mean (and SD) basal PRL concentration in the nonpregnant state was 7.6 ± 4.9 ng/ml; mean values were significantly higher during pregnancy and postpartum (35.9 ± 16.0 ng/ml in the first trimester, 176.6 ± 33.7 ng/ml in the second trimester, 210.0 ± 25.3 ng/ml in the third trimester, and 197.3 ± 65.6 ng/ml in the postpartum period). Basal serum TSH levels ranged from 3.6-14.2 µU/ml in pregnancy. The mean value was not significantly different from that in the nonpregnant control subjects. The mean serum PRL and TSH responses to TRH were similar in the different trimesters and in the puerperium, and were relatively smaller than the nonpregnant response. Thus, there is no increase in secretory reserve of the pituitary occurring with advancing gestational age. Baseline serum PRL displayed a significant correlation with the levels of E2 and P, while the baseline TSH or the PRL and TSH responses to TRH did not correlate with the sex steroid levels. E2 and P concentrations were unaffected by TRH itself or by the transient hyperprolactinemia induced by TRH. (J Clin Endocrinol Metab 48: 288, 1979)

Received July 17, 1978.

This article has been cited by other articles:

				D. Glinoer The Regulation of Thyroid Function in Pregnancy: Pathways of Endocrine Adaptation from Physiology to Pathology Endocr. Rev., June 1, 1997; 18(3): 404 - 433. [Abstract] [Full Text]