Q: Should I keep emergency contraception on hand, just in case?
A: Yes, I think that is an excellent idea.
As you know, your regular contraception can fail or, in the heat of the moment, remain unused. Women who take the birth-control pill are at risk of pregnancy if they miss a pill for several days.
There are approximately 3 million unintended pregnancies in the U.S. each year, more than half of which end in abortion. If more women were prepared with emergency contraception, many of these unintended pregnancies could be avoided.
The simplest form of emergency contraception is Plan B, approved in 1999 as a prescription medication. It consists of two tablets containing progestin, the ingredient used in birth-control pills.
The first tablet is taken as soon as possible after unprotected (or poorly-protected) intercourse. The second is taken 12 hours later.
Initially, women were told that the first dose had to be taken within 72 hours of intercourse to be effective, but now it seems that Plan B works even if taken a full five days (120 hours) later.
Moreover, both tablets can be taken together. You needn’t wait 12 hours for the second one.
Plan B reduces the chance of pregnancy by about 85 percent, with minimal side effects. Nausea, of varying degrees, occurs in 22 percent of women and vomiting in 8 percent. (Another emergency contraceptive pill, Preven, that combined estrogen and progestin, is no longer manufactured. It was slightly less effective than Plan B, and more likely to cause nausea.)
And here’s a too-little-known fact: Regular birth-control pills can also be used for emergency contraception.
If the pill is a low-dose one containing 0.03 mg of estrogen (ethinyl estradiol) you can take four of these pills at once, followed by another four pills 12 hours later. If the pill contains 0.05 mg of estrogen, you can take three pills, followed by another three 12 hours later.
In addition, there is a non-hormonal method of emergency contraception, but it requires a doctor’s intervention — the insertion of a copper-containing IUD (intra-uterine device) within 120 hours of unprotected intercourse. This reduces pregnancy rates by nearly 95 percent.
This is a good choice if you were planning to get an IUD anyway. It will prevent this pregnancy and future pregnancies for up to 10 years, or as long as you keep it in.
None of these are considered abortion-causing medications or techniques. They do not end a pregnancy. They prevent it by inhibiting ovulation, changing the uterine lining or interfering with the transport of an egg through the fallopian tubes.
And so back to the central point of your question: Because time is of the essence when you need emergency contraception, I suggest you not just get a prescription for Plan B, but you also have it filled. This way, you will have it on hand if and when you need it.
It’s not always possible to quickly get an appointment with a health-care provider who will write a prescription, especially on weekends, holidays or vacations (yours or the doctor’s). Many pharmacies do not regularly stock these pills.
In six states (Alaska, California, Hawaii, Maine, New Mexico and Washington) pharmacists can dispense emergency contraception without a prescription. But some pharmacists and stores (such as WalMart) choose not to do this, and those who do still need to have it in stock.
Dr. Reichman’s Bottom Line: Be prepared with emergency contraception, because it can prevent the life-changing consequences of contraceptive failure.
Dr. Judith Reichman, the “Today” show's medical contributor on women's health, has practiced obstetrics and gynecology for more than 20 years. You will find many answers to your questions in her latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," published by William Morrow, a division of .
PLEASE NOTE: The information in this column should not be construed as providing specific medical advice, but rather to offer readers information to better understand their lives and health. It is not intended to provide an alternative to professional treatment or to replace the services of a physician.