Effects of combined oral contraceptive pills on thyroid function tests in Mosul City

Abstract

Background: There are very little studies to determine the effects of combined oralcontraceptive pills (COCPs) on thyroid function tests in hormonal contraceptiveusers at least in our locality.Objective: To evaluate the effects of COCPs on serum level of thyroid stimulatinghormone (TSH) , free triiodothyronine (FT٣) and free tetraiodothyronine (thyroxine)(FT٤) and in relation to the duration of their usage in Mosul City.Design: A case control study.Subject & Methods: This study was conducted during the period from September٢٠٠٨ to March ٢٠٠٩. A total of ٧٨ healthy married women , age range between ١٩-٣٥years, from those who were attending AL–Batool and AL-Khansa Family PlanningCenters in Mosul, who were taking Microgynon tablets which are one of monophasic,second generation combined oral contraceptive pills (COCPs) (contain ٠.٠٣ mg ofethinyl estradiol and ٠.١٥ mg levonorgestrel) (N=٤٨) for a period ranged between ٣months to ٥ years and these were considered the users group. Other ٤٠ healthymarried women who did not use any hormonal contraceptives and were drawn fromthe same population and matched for age, body mass index (BMI) with the usersgroup and they were considered as the non users groups. Blood samples (٥ml) wereobtained from COCPs users and non-user groups. The sera obtained from the bloodsamples were used for the estimation of serum TSH, FT٣, FT٤ using Menividusanalytic device.Results: This study revealed non significant differences in TSH , FT٣ and FT٤serum levels between COCPs users and non users and no correlationbetween serum TSH, FT٣ and FT٤ levels and duration of hormonal contraceptivesusage.Conclusion: This study supported that the free thyroid hormone tests are the tests ofchoice in assessing thyroid function of women taking COCPs and concluded thatCOCPs can be regarded as a safe drugs in women using these types of hormonal as faras thyroid function is concerned.