Alterations in Thyroid Hormone Economy in Patients With Hydatidiform Mole

Abstract

A B S T R A C T Studies of several aspects of thyroid hormone economy have been conducted in 11 patients before and after removal of a molar pregnancy. Before evacuation of the mole, all patients demonstrated moderately to greatly elevated values for thyroidal 'I uptake, absolute iodine uptake, and serum protein-bound-I. Values for serum PBI and serum thyroxine (T4) concentration were consistently and often greatly increased, averaging more than twice those found in normal pregnancy and three times those in normal controls. On the other hand, the maximum binding capacity of the T4-binding globulin (TBG) was variably affected, and ranged between the values found in normal controls and those found in normal pregnancy. Values for the absolute concentration of free T4 in serum were, on the average, only moderately elevated, since the proportion of free To was moderately low, although not as low as in normal pregnancy. Sera of patients with molar pregnancy contained high levels of thyroid stimulating activity, as assessed in the McKenzie mouse bioassay system. The stimulator displayed a more prolonged duration of action than that of TSH and did not reveal a major immunological cross-reactivity with either human or bovine TSH, differing in the latter respect from the chorionic thyrotropin of normal human placenta. Abnormalities in iodine metabolism were rapidly ameliorated after removal of the molar pregnancy, and this was Despite the foregoing evidence of thyroid hyperfunction and hypersecretion of T4, patients with molar pregnancy were neither goitrous nor overtly thyrotoxic. They did display, however, high values of the urinary pigment/creatinine ratio, a possible indication of the presence of a hypermetabolic state.It is concluded that in patients with molar pregnancy, thyroid function and T4 secretion are stimulated, often greatly so, by an unusual thyroid stimulator which is demonstrable in the blood and which is probably of molar origin. The nature of the stimulator, as well as the reasons for both the variability of the increase in TBG which occurs in molar pregnancy and the lack of frank thyrotoxicosis, remain to be clarified.

Trophoblastic Hyperthyroidism and Its Perioperative Concerns

“…The maximum binding capacity of the T 4 -binding globulin(TBG) was variably affected and ranged between the values found in normal controls and those found in the normal pregnancy. Values for the absolute of free T 4 in the serum were only moderately elevated since the proportion of free T 4 was moderately low, although not as low as in normal pregnancy [47].…”

“…The first such case was reported in 2008 [46].Rarely the thyroid stimulation can have potentially life threatening consequences [3]. The prevalence of thyrotoxicosis in patients with trophoblastic tumors was reported to be close to 50% in some older studies [7,47]. But nowadays with the ability of early detection of the disease, the incidence is much lower.…”

“…Pronounced increase in urinary P/C ratio occurs in patients with molar pregnancy suggesting that they are hypermetabolic [47]. I uptake and absolute iodine uptake(AIU) in the patients [53] 6.…”

“…Several patients of trophoblastic tumors demonstrated thyroid hyperfunction or marked increases in serum PBI but failed to display signs or symptoms of frank thyrotoxicosis [47]. …”

Thyroid-Stimulating Activity and Chorionic Gonadotropin

“…For instance, increased thyroid function and occasionally overt hyperthyroidism have been observed in women with trophoblastic diseases (1)(2)(3)(4)(5)(6) and in men with testicular tumors that secrete chorionic gonadotropin (hCG) (7,8). These clinical observations have stimulated attempts to isolate and characterize the substance with TSA secreted by trophoblastic tissues.…”