Influence of two different combination of oral contraceptive on some serum electrolytes in women

Sunday O. Ita, Confidence W. Ihua, Titilope H. Olatunbosun, Mary O. Nteh


Background: The wide spread use of hormonal contraceptives by women necessitates the assessment of their influence on various biochemical parameters. The objective of this study was to investigate the influence of two different combinations of oral contraceptives on some serum electrolytes in women on oral contraceptives.

Methods: The study involved 50 volunteer female undergraduate students of University of Port Harcourt (20-30 years of age), who were not on contraceptives served as control (group I). Group II consisted of 30 women who were on combined oral contraceptives (methyloestranolone 5 mg and methyloestradiol 0.3 mg), and group III consisted of 40 women who were on norgesterol-estradiol (1 mg and 50 µg respectively). These were apparently healthy women attending the Family Planning Unit of the University of Port Harcourt Teaching Hospital who were within the same age group as control.

Results: The combined oral contraceptive therapy (methyloestranolone 5 mg and methyloestradiol 0.3 mg) in group II significantly reduced serum sodium and chloride ions levels (p <0.05) while it significantly increased serum potassium and bicarbonate ion levels (p <0.05) compared with the control group. Low estrogen combined contraceptives; norgesterol-estradiol (group III) significantly reduced sodium and chloride ions compared with the control group (p <0.05) but significantly raised values of these ions higher than those of group II (p<0.05); whereas it did not alter potassium level significantly compared to group II, low estrogen contraceptives caused significant increase compared to the control group (p <0.05). Low estrogen combined contraceptives (group III) significantly increased and decreased bicarbonate compared with groups I and II respectively.

Conclusions: The results of this study provide evidence that oral contraceptive, though useful in preventing pregnancies could result in derangement of normal homeostatic processes by interfering with electrolyte balance.


Oral contraceptive, Serum, Electrolytes, Women

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