Two Contraceptives Are Better Than One

Dual-method contraceptive use seemed like a good topic in preparation for #ThxBirthControl Day. You don’t always have to pick just one! If you had a chance to read our article on contraceptive pregnancy rates, you can understand why adding another form of birth control would be helpful. Even when using a contraceptive, the risk of pregnancy can still be unsettlingly high.

Let’s start with the most popular contraceptive used by a quarter of women in the US: the Pill. The Pill has a perfect-use annual pregnancy rate of 0.3%, which is really low. But in the real world — where half of women indicate missing at least one pill in their last cycle — the annual pregnancy rate is 9%.

That means that for some women, their risk of pregnancy is higher and for other women their risk is lower than 9%. And because we live in the real world, we want to look at these typical-use pregnancy rates — not the best case scenario with perfect use.

Further, keep in mind that the 9% pregnancy rate for the Pill is only for the first year. When you look at the risk of pregnancy for a longer time period — say 10 years or more — the risk of at least one unintended pregnancy in that time is much higher. That risk over a longer period builds the argument to consider multiple methods, even with some highly effective contraceptives.

So unless you or your partner are sterilized, dual-method use should at least be on your radar. There at least, both methods have to fail for an unintended pregnancy to occur.

Keep in mind that we’re talking about simultaneous dual-method use at the moment. That approach uses both methods at once. That’s different than alternating dual-method use, which relies on a backup only when a primary method fails or is unavailable.

And some couples do use this dual-method approach. About 7% of women indicate using two methods at last intercourse, according to the most recent data from the National Survey On Family Growth. Among Pill users, 20% doubled up with a condom.

Just how effective is using multiple methods?

There are some assumptions involved in calculating dual-method use pregnancy rates, but we can estimate the annual typical-use pregnancy rate from simultaneous condom and Pill use at just over 1%. That’s still not as low as perfect-use with the Pill, but we’re at least much better off than where we started.

Doubling up with a condom makes a lot of sense. It drastically lowers the pregnancy risk when combined with another method. Plus, it addresses sexually transmitted infections for partners who are not yet mutually monogamous and tested. It’s also a way to involve men in the contraceptive responsibility.

Down the road as more contraceptive options open up for men, user error will certainly cause the typical-use pregnancy rate to be higher than the perfect-use rate. This is the case for any method that requires someone to remember an action such as to take a pill. In a male pill scenario, it may very well make sense for both partners to take a birth control pill.

Or, if there are hormonal side effects for the woman, the man could double up with a pill and condom. Doubling up with another less effective method such as fertility awareness may be beneficial as well. Combining a moderate to even poorly effective method with another method can bring more tolerable risk compared to relying on a single approach.

Given that only 7% of women indicated using more than one method at last intercourse, it’s clear this dual-method approach is underutilized. As more methods become available, the number of combinations for dual-method use will also increase. As long as we’re having sex, we’ll never get to zero risk of unintended pregnancy. But we can work to lower that risk as much as possible.

Let’s make sure that we consider this dual-method approach among our contraceptive options, particularly as new methods for men and women open up.

Originally published at on October 31, 2016.