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

[Hyperemesis gravidarum and pregnancy outcomes]

OBJECTIVES

The aim of this study was to determine the impact of hyperemesis gravidarum (HG) on pregnancy.

METHODS

For this purpose, we conducted a retrospective cohort study between January 1st, 2006 and July 31st, 2009 in the level-3 maternity of the South Reunion teaching hospital, Saint-Pierre. Perinatal outcomes (gestational diabetes mellitus, hypertensive disorders of pregnancy, caesarean section, IUGR<10th percentile, low birth weight<2500 g, preterm birth<37 weeks, perinatal death) were compared among the women hospitalized for HG (exposed group) and a non-exposed group randomly selected from the South Reunion birth register. Finally, we also investigated the interactions between HG and maternal weight gain to assess whether HG might change perinatal outcomes according to weight gain.

RESULTS

During the study period, 215 women hospitalized for HG delivered (cumulative incidence rate of HG 14.1‰ among total deliveries), of which 197 were included in the exposed group. The low gestational weight gain (<7 kg), used as a criterion to define severe HG, was significantly more likely in the exposed group (30.5% versus 16.1%, P<0.0001). There was no significant association between HG and the various perinatal outcomes tested. The risk of delivering a low birth weight neonate was twofold (adjusted RR: 2.0, 95%CI: 1.0-3.1), that for a small-for-gestational age infant was more likely (adjusted RR: 1.7, 95% CI: 1.1-2.4), both only in case of severe HG.

CONCLUSION

Severe HG, defined for women with a gestational weight gain of less than 7 kg, is a poor prognostic factor for fetal growth.

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.

Thyroid function and human reproductive health

Via its interaction in several pathways, normal thyroid function is important to maintain normal reproduction. In both genders, changes in SHBG and sex steroids are a consistent feature associated with hyper- and hypothyroidism and were already reported many years ago. Male reproduction is adversely affected by both thyrotoxicosis and hypothyroidism. Erectile abnormalities have been reported. Thyrotoxicosis induces abnormalities in sperm motility, whereas hypothyroidism is associated with abnormalities in sperm morphology; the latter normalize when euthyroidism is reached. In females, thyrotoxicosis and hypothyroidism can cause menstrual disturbances. Thyrotoxicosis is associated mainly with hypomenorrhea and polymenorrhea, whereas hypothyroidism is associated mainly with oligomenorrhea. Thyroid dysfunction has also been linked to reduced fertility. Controlled ovarian hyperstimulation leads to important increases in estradiol, which in turn may have an adverse effect on thyroid hormones and TSH. When autoimmune thyroid disease is present, the impact of controlled ovarian hyperstimulation may become more severe, depending on preexisting thyroid abnormalities. Autoimmune thyroid disease is present in 5-20% of unselected pregnant women. Isolated hypothyroxinemia has been described in approximately 2% of pregnancies, without serum TSH elevation and in the absence of thyroid autoantibodies. Overt hypothyroidism has been associated with increased rates of spontaneous abortion, premature delivery and/or low birth weight, fetal distress in labor, and perhaps gestation-induced hypertension and placental abruption. The links between such obstetrical complications and subclinical hypothyroidism are less evident. Thyrotoxicosis during pregnancy is due to Graves' disease and gestational transient thyrotoxicosis. All antithyroid drugs cross the placenta and may potentially affect fetal thyroid function.

[Thyroid and pregnancy]

Screening for thyroid dysfunction is recommended among certain groups of women, who plan a pregnancy, for example women with history of hyperthyroid or hypothyroid disease, with type 1 diabetes or other autoimmune disorders or women with previous therapeutic head or neck irradiation, in the case of infertility. Management of thyroid disease during pregnancy requires special consideration because pregnancy induces major changes in thyroid function, and maternal thyroid disease can have adverse affects on the pregnancy and the foetus. Under ideal conditions there is a cooperation among several healthcare professionals, such as endocrinologists, nuclear medicine physicians, gynaecologists, neonatologists and if necessary surgeons. This article surveys the physiological and pathological changes of thyroid, their diagnosis and therapy in the case of women in childbearing age, women with unfulfilled desire to have children, pregnant women, as well as women after delivery.

Approche psychosomatique des vomissements incoercibles du premier trimestre

Vomiting of pregnancy is a physiological symptom of the first trimester and is a frequent reason for consultation in emergency as well as hospitalization in the severe forms (Hyperemesis gravidarum). Though strong the aversion usually developed against the hospitalized patients for H. gravidarum may be, it is important to understand the distress of these women with a symptom difficult to endure, which often reflects a psychical conflict with respect to their pregnancy. The gynecologist must be the somatic doctor who deals with the symptom and its sometimes disastrous clinical consequences, whereas the psychologist or the psychiatrist plays a fundamental role in this pathology. Indeed, he will lead the patient to work on how she feels her pregnancy, to give it a place in her personal history and to understand her contradictory feelings with regard to this pregnancy.

[Specific follow-up for pregnant patients with a thyroid dysfunction]

Association between thyroidian disease and pregnancy is a frequent event. Thyroidian hormones are mandatory for foetal development especially at the level of brain structures. Any shortage of thyroidian hormone can severely and irreversibly alter neurological development. On the other hand it is also clear that an excess of thyroidian hormone can jeopardize the embryo then the foetus. In case of maternal hyperthyroidism, strict guidelines relying mainly on foetal thyroid monitoring echographic scanning will allow in most cases the delivery of a healthy euthyroid newborn. Hypothyroidia, providing an adequate substitution, has no significant impact on pregnancy. Biological monitoring is the key of monitoring. Iodine deficiency is a matter of concern when considering neurodevelopmental outcome, however it is still an unsolved issue in France. A multidisciplinary team will sometimes be necessary for taking care of pregnant patients with active Graves' disease.