Antithyroidal Antibodies With or Without Subclinical Hypothyroidism During Pregnancy in Infertile Women
Antithyroidal Antibodies With or Without Subclinical Hypothyroidism During Pregnancy in Infertile Women
One prospective observational study was carried out in 2009 aiming at identifying the
 fluctuations of the thyroid hormones in women with normal thyroid gland and in women with
 anti-TPO antibodies. Serum samples were collected periodically during and after pregnancy in
 previously infertile women. The samples were stored frozen at -80 °C. Now, the hormone
 measurements will be carried out.
Exclusion of thyroid disease has long been an integral part of a comprehensive infertility
 work-up, because thyroid function disorders are also associated with disturbances in the
 menstrual cycle and can cause complications during pregnancy. Subclinical hypothyroidism is
 the most frequent disease of the thyroid in women of reproductive age (affecting 5 to 10 %).
 For a long time, measurement of TSH concentration was the only screening parameter used to
 exclude thyroid disorders. Not only has the differentiation of normal thyroid function
 (euthyroidism) from the pathological range been controversial for some years but, recently,
 the role of an elevated anti-TPO antibody titre has also been identified as a significant and
 independent risk factor for miscarriages and for complications during late pregnancy, even in
 otherwise euthyroid women. This discovery implies that solely determining the TSH
 concentration is insufficient. The mechanism underlying the increased rate of complications
 during pregnancy is also unclear.

 The investigators therefore performed a double study to clarify the relative importance of
 the various possible parameters of thyroid function in the context of an infertility work-up:

 1. Prevalence study: Measurement of TSH and anti-TPO concentrations in 175 women who
 present with infertility at the Infertility Clinic at the Women's Hospital, University
 Hospital Basel. In addition, each participant underwent an ultrasound scan of the
 thyroid. Control group: 175 healthy women of reproductive age and with regular menstrual
 cycles, but not currently wishing to have children (recruited via posters in the
 university and Blood Donor Centre). This study has been finished in 2010. The data of
 the prevalence study were used to carry out the prospective sampling of the serum
 samples.

 2. Prospective measurement of fluctuations in thyroid function during pregnancy and
 post-partum in a group of euthyroid women and/or those with subclinical hypothyroidism
 (TSH > 4.5 mIU/l) with/without anti-TPO antibodies. Two different euthyroid groups were
 defined for the study: Euthyroidism I = TSH 0.3-2.5 mIU/l; Euthyroidism II = TSH 2.5-4.5
 mIU/l. Six groups, each with 16 women, divided according to TSH concentration and
 anti-TPO antibody status, will be required (total 96). All female participants with
 subclinical hypothyroidism (TSH concentration > 4.5 mIU/l, normal values of peripheral
 thyroid hormones) receive a T4 supplementation dose. Serum samples will be collected
 each week from the start of pregnancy up to the 12th week and stored frozen at -80 °C.
 Thereafter, a serum sample will be collected once a month (up to the 38th week) and
 stored frozen at -80 °C. Finally, one serum sample post-partum (4 to 6 weeks after
 delivery) and freeze it. A total of 96 women (16 in each group) were recruited to
 participate in this study.

 After conclusion of the observation period, levels of the following hormones will be measured
 in the total of 1120 serum samples: TSH, total and free l-thyroxine and fT4 index, total and
 free triiodothyronine, thyroid autoantibodies (TPO antibodies), hCG, 17β-oestradiol,
 progesterone, prolactin.
Inclusion Criteria:

 -  previous infertility with known thyroidal function (TSH, anti-TPO)

 Exclusion Criteria:

 -  other endocrine pathology, such as Addison, diabetes mellitus

 -  manifest thyroidal pathology, such as Graves disease

 -  contraindication against pregnancy

 -  after repeated miscarriage (3 or more)

 -  heavy smokers (20 cig per day or more)