Sir,
We thank Drs Raber and Vierhapper for their interest in our paper published in Gynecological EndocrinologyCitation[1]. We are well aware of the work done by these authors in the field and have cited some of their publications in our own paper.
Drs Raber and Vierhapper write that we did not give any information on our patients. This is correct, since we wanted to prove whether thyroid-releasing hormone (TRH) testing in infertility patients overall is helpful or not. However, we excluded all patients with a known thyroid disease or positive antibody titers. This was not an intervention study as done by the authors themselves in 2003 Citation[2].
The authors claim that it might be helpful to perform TRH tests and several basal thyroid-stimulating hormone (TSH) measurements to optimize pregnancy chances in assisted reproductive technology cycles. However, as they state themselves, they cannot prove by the current literature or their own published data that basal measurement of TSH alone would be as beneficial as the combination of TSH measurement and TRH tests together. As outlined in our own paper, we suggest to lower the basal TSH level to below 2.5 mU/l in patients who undergo infertility treatment. Therefore, our two approaches may not be as far away from each other as it seems: both of us point to the necessity of an optimal thyroid situation. We, however, doubt the value of TRH testing in addition to basal TSH measurement – something which cannot be proved wrong at the moment by Drs Raber and Vierhapper.
The work done by the authors in 1986 was important Citation[3]. However, nowadays we have another generation of TSH tests. Therefore, results obtained 20 years ago cannot be compared with the situation today.
We look forward to future studies, which should be designed to compare subfertile patients with (1) basal TSH testing and subsequent l-thyroxine treatment, if necessary, to lower TSH to below 2.5 mU/l and (2) TRH testing and basal TSH measurement and subsequent treatment. Until such time, the different theories of neither Raber and Vierhapper nor ourselves can be proved wrong.
References
- Ludwig M, Banz C, Katalinic A, Jacobeit J W, Epe M, von zur A Mühlen, Schulte H M. The usefulness of thyrotropin-releasing hormone stimulation test in subfertile female patients. Gynecol Endocrinol 2007; 23: 226–230
- Raber W, Nowotny P, Vytiska-Binstorfer E, Vierhapper H. Thyroxine treatment modified in infertile women according to thyroxine-releasing hormone testing: 5 year follow-up of 283 women referred after exclusion of absolute causes of infertility. Hum Reprod 2003; 18: 707–714
- Raber W, Vierhapper H. Letter to the editor. Gynecol Endocrinol 2008; 24: 359–360