Pregnancy, hCG, thyrotoxicosis and hyperemesis gravidarum

Transient non-autoimmune hyperthyroidism of early pregnancy

It is characterized by chemical and sometimes clinical hyperthyroidism, without evidence of thyroid autoimmunity that resolves spontaneously by 16 weeks gestation without significant obstetrical complications.

Relation between plasma adenosine and serum TSH levels in women with hyperemesis gravidarum

INTRODUCTION

This study investigated the relation between adenosine and thyroid function associated with hyperemesis gravidarum.

METHODS

We examined 84 Japanese singleton pregnant women with an average age of 33.0+/-5.8 years at 9-12 weeks gestation being managed at our hospital. The patients were divided into three groups according to the severity of emesis: (1) those with hyperemesis gravidarum (nausea and vomiting with weight loss >5%, n=13), (2) those with emesis (nausea and vomiting with weight loss <5%, n=31), and (3) those with no symptoms as a control (n=40).

RESULTS

The average serum TSH levels in the emesis and hyperemesis groups were significantly higher than that in the control group (P<0.05). The average plasma adenosine level in the hyperemesis group was significantly higher than those in the control pregnant and emesis groups (P<0.05). There were no significant differences in plasma adenosine levels between the control pregnant and emesis groups. The serum TSH level showed significant correlations with weight loss (%) and plasma adenosine levels (P<0.05).

CONCLUSIONS

Our findings support the possible role of adenosine in counteracting the further progression of hyperemesis gravidarum associated with gestational thyrotoxicosis.

[Hyperemesis in the first trimester of pregnancy: role of biological hyperthyroidism and fetal sex]

OBJECTIVES

Our objectives were to link hyperemesis gravidarum with biochemical hyperthyroidism and hormonal modification (HCG and estradiol) and to test the hypothesis that biological abnormalities (ionogram and liver enzyme) are more often reported in hyperemesis gravidarum with biochemical hyperthyroidism.

STUDY DESIGN

Thirty three patients admitted in "Hôpital Jeanne de Flandre" with hyperemesis gravidarum were studied prospectively.

RESULTS

Twenty-two patients (66.7%) had biochemical hyperthyroïdsm (suppressed thyroid stimulating hormone or increased triiodothyronine index or tetraiodothyronine index). Hyperthyroid patients were more likely than euthyroid patients to have abnormal electrolyte levels (16/22 [72.7%] vs 3/1 [27.3%], P < 0.02) or increased liver enzyme levels (8/22 [36.4%] vs 3/11 [27.3%]). The severity of hyperemesis was found to vary directly with the degree of hyperthyroidism. We report a female predominance among the offspring of mothers with hyperemesis gravidarum.

CONCLUSION

Our results are suggestive of the involvement of hyperthyroidism and fetal sex in the pathogenesis of hyperemesis gravidarum. Also these hypothesis are not clearly understood, human chorionic gonadotrophin occurred in the two mechanisms.

Evaluation and management of common thyroid disorders in women

Thyroid disorders are very common in women. Many important changes occur in thyroid physiologic characteristics during different phases of a woman's life. Thus it is important to understand these changes in managing thyroid disorders in women. These changes are especially important during pregnancy and in postmenopausal women because the consequences of thyroid diseases are quite different. This Clinical Opinion presents current understanding of pathophysiologic features and clinical management of various common thyroid disorders in women.