Extremely light periods, so long as they occur at the right time, are not dangerous and really are not a medical problem.
This condition is most often seen among women taking low dose birth control pills. The birth control pills usually act by blocking the normal ovarian function (production of various hormones and ovulation), and then substituting the hormones (estrogen and progestin) found in the BCPs.
Usually, the result of this exchange is that the circulating estrogen levels are about the same as if the woman were not taking BCPs. In some women, however, the estrogen levels are significantly lower than before they started taking the BCPs. In this case, they will notice their menstrual periods getting lighter and lighter (over 3 to 6 months), and possibly even disappearing altogether.
This is not dangerous, has no impact on future fertility, and will resolve spontaneously if the BCPs are stopped. Stopping the BCPs is not necessary, however, because there are other safe alternatives. If the periods are simply very light (1-2 days), you can ignore the problem because this situation poses no threat to the patient.
If periods have totally stopped:
- Rule out pregnancy.
- You may stop the BCPs and expect normal menstrual flows to resume promptly. However, you will lose the contraceptive benefits of BCPs.
- You may change to a different BCP with different hormone in it. This will often lead to recognizable periods because the different hormone is metabolized differently.
- You may add estrogen (Premarin .625 mg or Estrace 1 mg) to each BCP to increase the estrogen stimulation of the uterine lining, increasing its’ thickness and leading to heavier periods. After the desired effect has been achieved (recognizable periods), the extra estrogen can be stopped.
- You may safely reassure the patient and allow her to not have periods while taking the BCPs. As long as she otherwise feels well, the absence of periods while taking BCPs is not known to have any adverse effects and some women prefer to avoid monthly flows.