The Gynecologist

Oral Contraceptives: The little pill that could (and did!)

June 4, 2010 at 3:55 pm 7 comments

Continuing our journey through the world of contraception, I think The Pill deserves special mention.  It has been used in the US since 1960 as a way of preventing pregnancy.  It continues to be one of the most popular methods of birth control.

Running the risk of waxing overly poetic, I’ll tell you that The Pill has a long and storied history which has helped shape the roles of women in society.  It has freed a generation of women from fear of unwanted pregnancy and has helped countless others battle the miseries associated with their monthly gift.  But what is this miracle tablet?  What’s in it?  And  how is it used?  

‘The Pill’ is a common term for what the medical community calls a ‘combined oral contraceptive’ or ‘oral contraceptive pill’ (OCP).  This consists of a combination of estrogen and progesterone which is taken in order to prevent pregnancy. 

It does this in several ways.  The most important of these is that OCP’s prevent ovulation, the release of an egg from a woman’s ovary.  No egg, no baby.  Easy. 

It also causes a thickening of cervical mucus.  While this may sound kinda icky, it actually serves the important purpose of reducing the likelihood sperm will be able to pass through the cervix and up through the uterus and tubes on its way to fertilize an awaiting egg (which isn’t going to be there anyway… see above).  No egg-sperm rendezvous, no baby.

It also causes a thinning of the lining of the uterus, reducing the likelihood that, even if a runaway egg and super-ambitious sperm were to elope successfuly, a resulting embryo would not be able to implant.  No implantation, no pregnancy.  (This, by the way, is NOT an abortion.  An embryo needs to implant in order to establish a pregnancy.  Otherwise, you get a normal period.) 

In order for an OCP to effectively prevent pregnancy, it needs to be taken every day for 21-24 days a month.  In a best-case scenario, it should be taken at the same time every day.  This is what’s called “perfect use.”  Humans are not perfect.  Given an opportunity to screw up, we will most likely take it at some point in our lives.  This is called “typical” use.  Therefore, when we talk about the likelihood somebody will get pregant while taking OCP’s we talk about “perfect” and “typical” use patterns. 

The pregnancy rate among “typical” users of OCP’s varies depending on the population being studied and ranges from 2-8% per year. On the other hand, the rate of pregnancy among “perfect” users of OCP’s is about 0.3% per year.  I don’t know about you, but I think that’s pretty good motivation to stive for “perfection.” 

Some combined oral contraceptives aren’t pills at all, but are administered as a vaginal ring (Nuvaring) or a patch (Ortho-Evra).  These can be good options for some patients who can’t reliably take a pill every day.  (However, the Ortho-Evra patch has been scrutinized for the possibility that it delivers more estrogen than most other combined contraceptives, including the ring, and that it may lead to an increased risk of blood clots in some patients.  See below.)

A caveat:  You want to talk to your gynecologist before starting an OCP.  The pill doesn’t protect you against sexually transmitted diseases (STD’s).  If you are at risk for STD’s, you should be using a condom and getting tested at regular intervals.

The Pill also has some risks.  That’s because combined oral contraceptives (those containing estrogen) can increase a woman’s risk of blood clots, heart attack and stroke.  This risk is minimal if you are young (under 35– ouch!), otherwise healthy, and do not smoke.  You should ask your gynecologist (or other healthcare provider) about your risk factors to help determine whether The Pill is a safe option for you.

If you have certain medical problems (like heart disease, a prior blood clot, or a history of certain types of cancer), are a smoker over 35, or are taking certain other types of mediation, you should not take estrogen-containing combined oral contraceptives. Ever. There are other, potentially safer options out there for women who can’t take OCP’s.  More on that in a future post.

I’m also planning a post to explain WHY OH WHY there need to be SO MANY different pills out there!  Really, I promise there’s a good reason.  See you soon!

Entry filed under: Gynecology. Tags: birth control pill, combined oral contraceptive pill, contraception, contraceptive options, gynecologist, gynecology, nuvaring, OCP, oral contraceptive, ortho-evra, STD prevention, the pill.