In some operational settings, it may be desirable to avoid menstrual flows completely.

Depending on the tactical situation, changing sanitary pads or tampons can be difficult, distracting or dangerous. Women with significant menstrual symptoms (cramps, malaise, depression) may find it easier to complete their mission if menstruation is avoided altogether.

The Simple Explanation

With most BCPs, women take them for 3 weeks and then stop the BCPs for a week. During the “off week,” they have their menstrual period. The reason they have a menstrual flow at that particular time is because they stopped taking the BCPs. In other words, the menstrual flow is really a hormone withdrawal bleed. If they didn’t stop taking their BCPs, they wouldn’t have had a period.

Using this principle, a woman can go directly from one pack of pills into the next, skipping the “week off.” She won’t have a period because she never experiences a hormone drop. At the end of the second pack of pills, she can again go directly into the third pack of pills, skipping the “week off’ and skipping a menstrual flow.

This way of taking BCPs is safe and just as effective in preventing pregnancy as taking them the normal way. The only drawback is that she loses the regular, monthly feedback of a menstrual flow, reassuring her that she is not pregnant. In practice, the BCPs are so powerfully effective that effectiveness is not really an issue. Should a woman become pregnant despite the use of BCPs (rare), she will have other symptoms suggesting the pregnancy, including breast tenderness, fatigue, nausea and bloating.

In theory, women could use continuous BCPs indefinitely and never have a period so long as she continued taking the pills. Actually, there are two limiting factors to this approach. First, most women taking continuous BCPs will eventually experience some spotting or breakthrough bleeding. If it is mild and occasional, it is generally ignored. If it is daily or heavy, you can:

Stop the BCPs for 3 days, provoking a period (withdrawal flow), and then resume continuous BCPs until the spotting once again becomes annoying.

Add a small amount of estrogen (Premarin 0.625/day, Estrace 1.0/day, etc.) to each BCP until the spotting stops. This additional estrogen will stimulate the uterine lining to become a little thicker and less fragile.

Add any non-steroidal anti-inflammatory agents (NSAID) with significant anti-prostaglandin activity. This will reduce the force of the normal, physiologic uterine contractions and reduce or eliminate the spotting.

Compexities

As with most things, there are a few complexities.

Not all birth control pills lend themselves to this approach. The multiphasic pills, with different amounts of hormone in different pills, do not always create as stable a hormonal environment as do the monophasic BCPs, which have a constant amount of hormone in each pill.

This system relies on complete suppression of ovarian function for it to be successful. Some pills are better at this than others. The better pills for this purpose contain stronger progestins, with longer half lives (such as levonorgestrel).

Success also hinges on the woman taking her pills regularly each day. Breakthrough bleeding is relatively common with this system anyway, and when pills are not taken regularly, the breakthrough bleeding can become substantial.

Even with the right pill and conscientous compliance, some women will occasionally experience a break-through ovulation, followed two weeks later by a menstrual flow. This ovulation usually poses no significant pregnancy risk because of the many other ways OCPs prevent pregnancy. But for women taking continuous BCPs, any ovulation will inevitably be followed 2 weeks later by a full menstrual flow (whether she’s taking BCPs or not), and such an event will certainly be noticed.