Background: Determining symptoms of menopause in older users of hormonal injectable contraceptives may be challenging, owing to method-induced amenorrhoea, suppression of follicle-stimulating hormone (FSH) and vasomotor symptoms.
Objective: To investigate menopausal symptoms in women aged 40 - 49 using injectable contraceptives depot-medroxyprogesterone acetate (DMPA), norethisterone enanthate (NET-EN) or combined oral contraceptives (COCs), compared with non-users of hormonal contraception.
Methods: Women using DMPA (N = 127), NET-EN (N = 102), COCs (N = 106) and 161 non-hormonal contraceptive user controls were recruited. Baseline visit serum FSH was measured and information was collected on vasomotor symptoms and menstrual regularity.
Results: There was no difference in reporting of vasomotor symptoms between the groups. There was no evidence of a difference in FSH level between non-users (mean FSH 26.7 IU/ml, SD 28.7) and DMPA users (mean FSH 23.1 IU/ml, SD 27.8) (p = 0.64). However, the NET-EN (mean FSH 11.0 IU/ml, SD 10.9) (p = 0.003) and COC groups (mean FSH 12.5 IU/ml, SD 18.7) (p = 0.001) had significantly lower FSH levels compared with the non-user group.
Conclusion: The lower FSH levels found in the NET-EN and COC users compared with controls may indicate a greater degree of suppression of FSH levels in these two methods, compared with DMPA. Measuring FSH levels may therefore be informative of menopausal status in DMPA users but not in NET-EN or COC users. Vasomotor symptoms may assist in assessing menopausal status in DMPA, NET-EN and COC users.