effect of combined oral contraceptive pills on pituitary-thyroid axis

Thyroid hormones, thyroxine binding globulin [T.B.G] and thyrotropin [T.S.H] were studied in 39 women receiving combined oral contraceptive pills [C.O.C] and 18 normal controls not receiving pills and of matched age and weight. Statistical analysis of the results revealed a significant elevation of T.B.G and T[3] levels inpatients as compared controls and insignificant elevation of T[4], T.S.H and reverse T[3] levels in patients as compared to controls. F.T[4] was highly significantly low in patients as compared to controls. F.T[3] was insignificantly low in patients as compared to controls. We concluded that chemical changes in thyroid functions can occur in women receiving C.O.C without clinical manifestations and we have to depend on F.T[3] concentration and T.S.H in evaluating thyroid functions in cases receiving C.O.C pills or other oestrogen containing drugs