Thyrotropin releasing hormone-induced thyrotropin response was studied in healthy women during the course of normal pregnancy and in some women in the immediate postpartum period also. The plasma thyrotropin levels were significantly elevated, starting early in pregnancy, and remained so even in the early postpartum period. The sensitivity of the pituitary gland to exogenous thyrotropin releasing hormone administration remains unaltered during the course of normal pregnancy.
From the Departments of Endocrinology and Obstetrics and Gynaecology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Submitted for publication April 13, 1973.
We are grateful to Professor Russel Fraser of Royal Postgraduate Medical School, London for the supply of anti-human TSH guineapig serum, to MRC, London for supplying the Human TSH Standard and National Pituitary Agency, NIH, USA for the gift of TSH for labelling. TRH was generously donated by Messrs. Farbwerked Hoechst, AG Frankfurt, West Germany.