Effectiveness rates using 2 methods of birth control

Effective contraceptive methods


I’m posting this because: Some of the students at St Lucy’s have begun to read this Blog and since summer vacation will be here soon I want to give them a familiar site they can bookmark if they have questions about the effectiveness of combining two different methods of contraception. Ideally a girl would insist on using condoms to protect against STIs during hookups or as added protection if she isn’t using her primary method perfectly, but we all know that the world of contraception is not ideal and neither men nor women like to use condoms so all we as their teachers and mentors can do is provide them with the information to make an informed decision.

The Buddy System: Effectiveness Rates for Backing Up Your Birth Control With a Second Method

Scarleteen
By Heather Corinna

You already know that no method of contraception is 100% effective (save permanent sterilization) to prevent pregnancy when you're engaging in sexual activity - read: genital intercourse -- which presents a risk of pregnancy. You probably also know, however, that there are reliable methods which are very effective when used properly, and that if you use contraception correctly and consistently, pregnancy becomes a whole lot less likely. But did you know that by doubling up and using two methods, with almost any combination you use, you can get mighty close to that 100% with many combos?

Hormonal methods of contraception are currently the most effective, reversible methods of birth control with perfect use. But with most of them, we can goof up -- maybe we skipped a couple pills or got a new prescription late, maybe we're not so timely about getting our injections or don't have consistent healthcare to get a new one on time, maybe we didn't realize our patch fell off. Oops. But if we're consistently backing up with a secondary method, even if our primary one fails, we're covered. As well, not everyone can use or wants to use a hormonal method: some of us prefer non-hormonal methods or those are our only safe or affordable options. While they aren't as effective in perfect use, if we add a backup method to the mix, we can be just as protected or even more protected from pregnancy as we could be with a more effective single method.

You'll see that some combinations can increase your level of protection substantially, while with other pairs -- especially where user error is a non-issue, like with an IUD or an implant -- the difference is so slight that backing up is just overkill. Regardless, there is no single combination of any two methods here which would leave you with less than 92% effectiveness, and most combinations will bump you up to over 95% protection. The highest combined methods' typical use effectiveness -- condoms paired with an implant - is 99.99% effective, while the lowest -- withdrawal buddied up with spermicide - is 92.17% effective. But no matter how you slice it, adding a second method always bumps up your protection against unwanted pregnancy.

The Caveats: This is a mathematical application. That doesn't mean it's not accurate -- it is, and I've got the migraine and a pile of paper covered with my chicken scratches to prove it -- but it does mean that these rates are arrived at through math, based on the combined effectiveness rates of single methods, not through specific study or clinical trials of the combined methods. The sources of our efficiency rates for single methods can be found on the Birth Control Bingo pages linked for each method.

In some cases, combining any two or more methods may possibly slightly reduce the effectiveness of one in actual use. For example, because oral contraceptive pills thicken cervical mucus, condoms, when not used with additional lubricant, can be more inclined to break due to increased friction. Using withdrawal with condoms may make it more likely to forget to hold the base of the condom and create a condom slip which may not have been as likely to happen without adding withdrawal to the mix. Without specific study on these things, we can't predict how much it may reduce the effectiveness of one method in those cases nor account for that possibility in the math. However, we have only listed combinations of methods which are safe and sound to use together and make for good mates. For instance, it would not be safe to combine Depo-Provera with another hormonal method. The vaginal effects of combining a ring and spermicides could cause a good deal of vaginal irritation . Using more than one condom is something we know makes condoms less effective, not more. Natural family planning can't be combined with oral contraceptives since a person using oral contraceptives no longer has a natural fertility cycle to chart in the first place.

We've also not done the math for using more than two methods. If you are properly and consistently using two reliable methods of contraception, the risk of pregnancy is incredibly small, and adding a third method is not likely to increase your protection by very much. The difference between a combined method that is 99.8% effective with typical use of both and three methods which are 99.78% effective together, for instance, is so small a statistical difference that adding a third method is likely to just be a needless expense and pain in your butt.

Certainly, if you prefer more than two methods, so long as they don't interfere with one another, you can choose to do that, but we'd also encourage you to evaluate your feelings. If two methods with something like a less than 2% chance of pregnancy in typical use -- and that still allows for room when it comes to user error -- still doesn't leave you feeling safe enough, you might want to consider that you're not comfortable enough with the small amount of risk which will always be a part of sexual activities that can result in pregnancy. It would probably be a good idea in that case to revisit your readiness, and either stick with activities which don't carry those risks, or hold off on heterosex (genital intercourse with an opposite-sex partner) until you're feeling more prepared for some small level of risk. When you're so freaked about the possibility of pregnancy that no amount of birth control feels like enough, it's unlikely that even with four methods, that level of anxiety is not going to leave room for actually enjoying the sex you're having (which is the whole point). Your enjoyment is going to be seriously hindered if you're taking a pill, putting in a diaphragm, having your partner put on a condom, using withdrawal and then taking EC. It's ideal and laudable to be smart and to be safe, but if your contraceptive practices start to feel like you're building a bomb shelter in preparation for a nuclear war every time you have sex, you or your partners are probably better off when it comes to your pleasure and mental health to recognize that you're not up to any risk of pregnancy, even a very statistically unlikely one, and to choose to engage in activities where your risks are far lower or nonexistent.

Listings for each single method are alphabetical. The combinations are listed from most to least effective with typical use, since typical use tends to be the most accurate measure for real people in real -- and frequently imperfect -- life. For more information on any of the single methods listed, just click on the links in their titles.


Cervical Barriers (Diaphragm)
94% effective alone with perfect use - 86% effective alone with typical use
Cervical Barriers + The Contraceptive Implant = 99.99% effective with perfect use - 99.98% effective with typical use
Cervical Barriers + Intrauterine Devices = 99.99% effective with perfect use - 99.89% effective with typical use
Cervical Barriers + Depo-Provera = 99.98% effective perfect use - 99.58% typical use
Cervical Barriers + Combination OCP ("The Pill") = 99.98% effective with perfect use - 98.88% effective with typical use
Cervical Barriers + The Contraceptive Patch = 99.98% effective with perfect use - 98.88% effective with typical use
Cervical Barriers + Minipills = 99.98% effective with perfect use - 98.6% effective with typical use
Cervical Barriers + Male Condoms = 99.88% effective perfect use - 97.9% effective with typical use
Cervical Barriers + Fertility Awareness = 99.88% effective with perfect use - 97.2% effective with typical use
Cervical Barriers + Female Condoms = 99.7% effective with perfect use - 97% effective with typical use
Cervical Barriers + Emergency Contraception = 99.34% effective with perfect use - 96.5% effective with typical use
Cervical Barriers + Withdrawal = 99.76% effective with perfect use - 96.22% effective with typical use

Spermicides with cervical barriers are not listed because spermicide is supposed to be used with them, so effectiveness rates for barrier methods already include the addition of a spermicide. Since the sponge already contains a spermicide, spermicide was also excluded from combination with the sponge.

Combination Oral Contraceptives ("The Pill")
99.7% effective alone with perfect use - 92% effective alone with typical use
Combination OCP + Cervical Barriers = 99.98% effective with perfect use - 98.88% effective with typical use
Combination OCP + Male Condoms = 99.99% effective with perfect use - 98.8% effective with typical use
Combination OCP + The Sponge = 99.97%effective with perfect use - 98.72% effective with typical use
Combination OCP + Female Condoms = 99.98% effective with perfect use - 98.32% effective with typical use
Combination OCP + Emergency Contraception* = 99.97% effective with perfect use - 98% effective with typical use
Combination OCP + Withdrawal = 99.98% effective with perfect use - 97.84% effective
Combination OCP + Spermicide = 99.94% effective with perfect use - 97.68% effective with typical use

Female Condoms
95% effective with perfect use - 79% effective with typical use
Female Condoms + The Contraceptive Implant = 99.99% effective with perfect use - 99.97% effective with typical use
Female Condoms + Intrauterine Devices = 99.99% effective with perfect use - 99.37% effective with typical use
Female Condoms + Depo-Provera = 99.99% effective with perfect use - 99.37% effective with typical use
Female Condoms + Combination OCP = 99.98% effective with perfect use - 98.32% effective with typical use
Female Condoms + The Contraceptive Patch = 99.98% effective with perfect use - 98.32% effective with typical use
Female Condoms + the Vaginal Ring = 99.98% effective with perfect use - 98.32% effective with typical use
Female Condoms + Minipills = 99.98% effective with perfect use - 97.9% effective with typical use
Female Condoms + Cervical Barriers = 99.7% effective with perfect use - 97% effective with typical use
Female Condoms + the Sponge = 99.55% effective with perfect use - 96.64% effective with typical use
Female Condoms + Fertility Awareness = 99.9% effective with perfect use - 95.8% effective with typical use
Female Condoms + Emergency Contraception = 99.45% effective with perfect use - 94.75% effective with typical use
Female Condoms + Withdrawal = 99.8% effective with perfect use - 94.33% effective with typical use
Female Condoms + Spermicide = 99.1% effective with perfect use - 93.91% effective with typical use

Don't forget! The addition of condoms to any method always carries the joint benefit of both allowing men a part in birth control and greatly reducing the risks of sexually transmitted infections.

Male Condoms
98% effective alone with perfect use - 85% effective alone with typical use
Male Condoms + The Contraceptive Implant = 99.99% effective with perfect use - 99.99% effective with typical use
Male Condoms + Intrauterine Devices = 99.99% effective with perfect use - 99.88% effective with typical use
Male Condoms + Depo-Provera = 99.99% effective with perfect use - 99.55% effective with typical use
Male Condoms + Combination OCP = 99.99% effective with perfect use - 98.8% effective with typical use
Male Condoms + The Contraceptive Patch = 99.99% effective with perfect use - 98.8% effective with typical use
Male Condoms + the Vaginal Ring = 99.99% effective with perfect use - 98.8% effective with typical use
Male Condoms + Minipills = 99.99% effective with perfect use - 98.5% effective with typical use
Male Condoms + Cervical Barriers = 99.88% effective perfect use - 97.9% effective with typical use
Male Condoms + the Sponge = 97.7% effective with perfect use - 97.6% effective with typical use
Male Condoms + Fertility Awareness = 99.96% effective with perfect use - 97% effective with typical use
Male Condoms + Emergency Contraception = 99.78% effective with perfect use - 96.25% effective with typical use
Male Condoms + Withdrawal = 99.92% effective with perfect use - 95.95% effective with typical use
Male Condoms + Spermicide = 99.64% effective with perfect use - 95.65% effective with typical use

The Contraceptive Implant (Implanon)
99.9% effective with perfect use - 99.9% effective with typical use
The Contraceptive Implant + Male Condoms = 99.99% effective with perfect use - 99.99% effective with typical use
The Contraceptive Implant + Cervical Barriers = 99.99% effective with perfect use - 99.98% effective with typical use
The Contraceptive Implant + Emergency Contraception*= 99.99% effective with perfect use - 99.98% effective with typical use
The Contraceptive Implant + the Sponge = 99.99% effective with perfect use - 99.98% effective with typical use
The Contraceptive Implant + Female Condoms = 99.99% effective with perfect use - 99.97% effective with typical use
The Contraceptive Implant + Withdrawal = 99.99% effective with perfect use - 99.97% effective with typical use
The Contraceptive Implant + Spermicide = 99.98% effective with perfect use - 99.97% effective with typical use

The Contraceptive Patch ("The Patch")
99.7% effective with perfect use - 92% effective with typical use
The Contraceptive Patch + Cervical Barriers = 99.98% effective with perfect use - 98.88% effective with typical use
The Contraceptive Patch + Male Condoms = 99.99% effective with perfect use - 98.8% effective with typical use
The Contraceptive Patch + Female Condoms = 99.98% effective with perfect use - 98.32% effective with typical use
The Contraceptive Patch + Emergency Contraception*= 99.97% effective with perfect use - 98% effective with typical use
The Contraceptive Patch + the Sponge = 99.97%effective with perfect use - 98.72% effective with typical use
The Contraceptive Patch + Withdrawal = 99.98% effective with perfect use - 97.84% effective
The Contraceptive Patch + Spermicide = 99.94% effective with perfect use - 97.68% effective with typical use

Depo-Provera ("The Shot")
99.7% effective with perfect use - 97% effective with typical use
Depo-Provera + Cervical Barriers = 99.98% effective perfect use - 99.58% typical use
Depo-Provera + Male Condoms = 99.99% effective with perfect use - 99.55% effective with typical use
Depo-Provera + the Sponge = 99.97%effective with perfect use - 99.52% effective with typical use
Depo-Provera + Female Condoms = 99.99% effective with perfect use - 99.37% effective with typical use
Depo-Provera + Emergency Contraception*= 99.97% effective with perfect use - 99.25% effective with typical use
Depo-Provera + Withdrawal = 99.98% effective with perfect use - 99.19% effective with typical use
Depo-Provera + Spermicide = 99.94% effective with perfect use - 99.13% effective with typical use

Fertility Awareness (FAM)
98% effective with perfect use - 80% effective with typical use
Fertility Awareness + Cervical Barriers = 99.88% effective with perfect use - 97.2% effective with typical use
Fertility Awareness + Male Condoms = 99.96% effective with perfect use - 97% effective with typical use
Fertility Awareness + the Sponge = 99.82% effective with perfect use - 96.8% effective with typical use
Fertility Awareness + Female Condoms = 99.9% effective with perfect use - 95.8% effective with typical use
Fertility Awareness + Emergency Contraception = 99.78% effective with perfect use - 95% effective with typical use
Fertility Awareness + Withdrawal = 99.92% effective with perfect use - 94.6% effective with typical use
Fertility Awareness + Spermicide = 99.64% effective with perfect use - 94.2% effective with typical use

Intrauterine Devices (IUD)
99.9% effective with perfect use - 99.2% effective with typical use
Intrauterine Devices + Cervical Barriers = 99.99% effective with perfect use - 99.89% effective with typical use
Intrauterine Devices + Male Condoms = 99.99% effective with perfect use - 99.88% effective with typical use
Intrauterine Devices + The Sponge = 99.99% effective with perfect use - 99.87% effective with typical use
Intrauterine Devices + Female Condoms = 99.99% effective with perfect use - 99.83% effective with typical use
Intrauterine Devices + Emergency Contraception* = 99.99% effective with perfect use - 99.8% effective with typical use
Intrauterine Devices + Withdrawal = 99.99% effective with perfect use - 99.78% effective with typical use
Intrauterine Devices + Spermicide = 99.98% effective with perfect use - 99.77% effective with typical use

Minipills
99.7% effective with perfect use - 90% effective with typical use
Minipills + Cervical Barriers = 99.98% effective with perfect use - 98.6% effective with typical use
Minipills + Male Condoms = 99.99% effective with perfect use - 98.5% effective with typical use
Minipills + The Sponge = 99.97% effective with perfect use - 98.4% effective with typical use
Minipills + Female Condoms = 99.98% effective with perfect use - 97.9% effective with typical use
Minipills + Emergency Contraception* = 99.97% effective with perfect use - 97.5% effective with typical use
Minipills + Withdrawal = 99.99% effective with perfect use - 97.3% effective with typical use
Minipills + Spermicide = 99.95% effective with perfect use - 97.1% effective with typical use

Spermicide
82% effective with perfect use - 71% effective with typical use
Spermicide + The Contraceptive Implant = 99.98% effective with perfect use - 99.97% effective with typical use
Spermicide + Intrauterine Devices = 99.98% effective with perfect use - 99.77% effective with typical use
Spermicide + Depo-Provera = 99.94% effective with perfect use - 99.13% effective with typical use
Spermicide + Combination OCP = 99.94% effective with perfect use - 97.68% effective with typical use
Spermicide + The Contraceptive Patch = 99.94% effective with perfect use - 97.68% effective with typical use
Spermicide + Minipills = 99.95% effective with perfect use - 97.1% effective with typical use
Spermicide + Male Condoms = 99.64% effective with perfect use - 95.65% effective with typical use
Spermicide + Fertility Awareness = 99.64% effective with perfect use - 94.2% effective with typical use
Spermicide + Female Condoms = 99.1% effective with perfect use - 93.91% effective with typical use
Spermicide + Emergency Contraception = 98% effective with perfect use - 92.75% effective with typical use
Spermicide + Withdrawal = 99.28% effective with perfect use - 92.17% effective with typical use

The Sponge
91% effective with perfect use - 84% effective with typical use
The Sponge + The Contraceptive Implant = 99.99% effective with perfect use - 99.98% effective with typical use
The Sponge + Intrauterine Devices = 99.99% effective with perfect use - 99.87% effective with typical use
The Sponge + Depo-Provera = 99.97%effective with perfect use - 99.52% effective with typical use
The Sponge + Combination OCP = 99.97%effective with perfect use - 98.72% effective with typical use
The Sponge + The Contraceptive Patch = 99.97%effective with perfect use - 98.72% effective with typical use
The Sponge + Minipills = 99.97% effective with perfect use - 98.4% effective with typical use
The Sponge + Male Condoms = 97.7% effective with perfect use - 97.6% effective with typical use
The Sponge + Fertility Awareness = 99.82% effective with perfect use - 96.8% effective with typical use
The Sponge + Female Condoms = 99.55% effective with perfect use - 96.64% effective with typical use
The Sponge + Emergency Contraception = 99.01% effective with perfect use - 96% effective with typical use
The Sponge + Withdrawal = 99.64% effective with perfect use - 95.68% effective with typical use

The Vaginal Ring
99.7% effective with perfect use - 92% effective with typical use
The Vaginal Ring + Male Condoms = 99.99% effective with perfect use - 98.8% effective with typical use
The Vaginal Ring + Female Condoms = 99.98% effective with perfect use - 98.32% effective with typical use
The Vaginal Ring + Emergency Contraception* = 99.97% effective with perfect use - 98% effective with typical use
The Vaginal Ring + Withdrawal = 99.98% effective with perfect use - 97.84% effective with typical use

Withdrawal
96% effective with perfect use - 73% effective with typical use
Withdrawal + The Contraceptive Implant = 99.99% effective with perfect use - 99.97% effective with typical use
Withdrawal + Intrauterine Devices = 99.99% effective with perfect use - 99.78% effective with typical use
Withdrawal + Depo-Provera = 99.98% effective with perfect use - 99.19% effective with typical use
Withdrawal + Cervical Barriers = 99.76% effective with perfect use - 96.22% effective with typical use
Withdrawal + Male Condoms = 99.92% effective with perfect use - 95.95% effective with typical use
Withdrawal + Combination OCP = 99.98% effective with perfect use - 97.84% effective
Withdrawal + The Contraceptive Patch = 99.98% effective with perfect use - 97.84% effective
Withdrawal + the Vaginal Ring = 99.8% effective with perfect use - 97.84% effective with typical use
Withdrawal + Minipills = 99.99% effective with perfect use - 97.3% effective with typical use
Withdrawal + the Sponge = 99.64% effective with perfect use - 95.68% effective with typical use
Withdrawal + Fertility Awareness = 99.92% effective with perfect use - 94.6% effective with typical use
Withdrawal + Emergency Contraception = 99.56% effective with perfect use - 93.25% effective with typical use
Withdrawal + Spermicide = 99.28% effective with perfect use - 92.17% effective with typical use

* EC is not advised for frequent use while using other hormonal contraceptives, or unless the primary hormonal method was known or strongly suspected to fail. Since the effectiveness rate for emergency contraception is variable, we have used Plan B, and used the most effective rate (89%) as perfect use and the least as typical (75%). We do not list EC as a sole method of contraception because due to the amount of hormones in oral EC, the expense and the perfect use effectiveness rate being lower than all other methods perfect use rates, it is not intended nor designed for use regularly, nor is sole use as a habit something we advise.

Special thanks to Scarleteen volunteer Courtenay for the math formula and her assistance! The link to the original article is: http://www.scarleteen.com/article/reproduction/the_buddy_system_effectiveness_rates_for_backing_up_your_birth_control_with_a_s

Contraceptive methods use in U.S. (2002)

Contraceptive methods use in U.S. (2002)

This poster - published with the article The Birth Control Riddle in the Wall Street Journal, [see my entry for 4-20-2010] - shows the percentage of users in the U.S. using a particular method of birth control based on 2002 data. Another similar study is due to be released soon but is expected to show little change in the popularity of particular methods.

Implants: Norplant has been replaced as the only hormonal implant by Implanon. Implanon is a single rod implant with 68mg of etonogestrel, the same progestin used in NuvaRing, isn’t shown because it was only approved by the FDA in 2006.

Cervical barriers: Even as popular as diaphragms and cervical caps have become in the last eighteen months to two years out here the spike in usage as gas guards for protection during dive-sex has been too recent and I think wouldn’t be enough to change the figures.

IUDs: Rationally IUDs are by far the best choice as far as effectiveness and long term cost is concerned, but of course only GyneFix, or a stringless Mirena or ParaGard can be worn with a gas guard for dive-sex. And if a girl is having her brains fucked out uterine cramps can sometimes bend the frame of a Mirena or ParaGard so that it expels or perforates the uterus. That is why our clinic is so fortunate to be part of the clinical trial and fits only GyneFix IUDs for escorts or adventuresome women wanting to experience super intense sexual encounters under water. And, there are some of us, like me, who just can’t get comfortable with the idea of having a GyneFix implanted in our uteri. Almost all my circle have a GyneFix implanted and say they can’t feel them and the implant does not interfere with their cycle and I know all the rational arguments for GyneFix, but I just don’t like the idea of having one in my uterus. Every girl has her hang-ups and the thought of an IUD in my uterus gives me chills, while a tiny bit of transparent silicone rubber sucking on my cervix makes me confident and adventuresome. Go figure!

The birth control riddle

The birth control pill, Ca 1960

The Wall Street Journal
April, 21, 2010
By MELINDA BECK

The Birth-Control Riddle
Fifty Years After the Pill's Debut, Almost Half of Pregnancies in the U.S. Are Unplanned

“Next month marks the 50th anniversary of the birth-control pill in the U.S. The dawn of dependable contraception not only ended the post-war baby boom, it also ignited the sexual revolution and helped millions of women to enter the work force.

Nowadays, women can choose from a bevy of birth-control options, including pills, patches and rings that allow them to have as few periods as they like, even none. Implants and intrauterine devices (IUDs) can prevent pregnancy for years at a time and eliminate the need to refill and remember. Morning-after pills that can decrease the risk from unprotected sex are available without a prescription even to teenagers. Women who want to end their fertility permanently can do so in a doctor's office without undergoing surgery. Abstinence is still taught in many schools and homes as being 100% effective if followed diligently.

On the 50th anniversary of the pill, WSJ's Melinda Beck tells Simon Constable on the News Hub what's new in birth control. There are more options than ever, but despite all the choices, some three million U.S. women have an unplanned pregnancy ever year.

Yet despite all these options, the rates of unplanned pregnancies remain high: Almost half of all pregnancies in the U.S.—some 3.1 million a year—are unintended, according to the most recent government survey, from 2001. One out of every two American women aged 15 to 44 has at least one unplanned pregnancy in her lifetime. Among unmarried women in their 20s, seven out of 10 pregnancies are unplanned.

An updated version of those numbers from the 2006 National Survey of Family Growth is expected to be released next month. But population experts don't anticipate much change; the rate of unplanned pregnancy was the same in 1994, and smaller studies have found that even newer birth-control methods haven't made much of a dent.

Birth Control Methods

Why are the numbers so high?

The answer is a complex tangle of cultural, religious, behavioral, educational and economic factors. Many of those unplanned pregnancies become wanted babies. About a million are aborted each year and others are miscarried.

Almost half (48%) of unintended pregnancies involve contraceptive failures. In 52% of the cases, couples used no birth control at all. Cost is a factor for some of them. Even though most insurers now cover contraceptives, co-pays and deductibles can still present obstacles.

And many young people are in "the fog zone" in which their beliefs about pregnancy don't match their behaviors, according to a 2009 report by the National Campaign to End Teen and Unplanned Pregnancy. In a survey conducted by the Guttmacher Institute of 1,800 single men and women aged 18 to 29, more than 80% of both sexes said it was important to them to avoid pregnancy right now, yet 43% of those who are sexually active said they used no contraception or used it inconsistently.

Some population experts say the rates of unintended pregnancy would be far lower if more women used IUDs and implants that prevent pregnancy for years at a time. Only about 3% of American women currently do.

"There are terrible misperceptions about these methods— and about all forms of contraception," says James Trussell, director of

the Office of Population Research at Princeton University.

Many traditional forms of contraception have been updated in recent years. Here's a look at the latest developments:

The New IUDs

The IUD got a bad name in the 1970s due to the Dalkon Shield, whose design turned out to make it easy for bacteria and STDs from the vagina to ascend into the uterus and fallopian tubes, causing pelvic-inflammatory disease (PID) and infertility. After hundreds of lawsuits and several deaths, the shield was discontinued in 1974, and doctors were urged to remove them from women in 1980.

IUDs available in the U.S. now are much safer. The ParaGard is made with copper that is toxic to sperm, lasts up to 12 years and doesn't affect a woman's hormone levels. Mirena releases a small amount of progestin that blocks ovulation, and lasts up to five years. Both are more than 99% effective at preventing pregnancy.

Jeffrey Peipert, a top researcher at Washington University in St. Louis, notes that about 18% of female ob/gyns have opted for IUDs. "The most educated consumers are using the most effective methods at high rates," he says.

Cost: $175 to $700 for years of protection.

Downsides: IUDs do not protect against STDs. The ParaGard may increase cramping. In rare cases, IUDs can slip out or push through the uterine lining.

The Implant

Another long-acting contraceptive is Implanon, a rod a doctor inserts in a woman's arm. It prevents pregnancy for up to three years.

A previous implant called Norplant was beset by lawsuits over side effects and scarring and withdrawn from the U.S. market in 2002.

Doctors are required to undergo special training to insert and remove Implanon, which is also 99% effective at preventing pregnancy.

Cost: $400 to $800 for up to three years' protection.

Downsides: Irregular bleeding, possible headaches, sore breasts, nausea, pain at the insertion site. No STD protection.

Hormone Pills, Patches And Rings

The first birth-control pills had very high doses of hormones, and side effects including mood swings, weight gain and blood clots were common.

Dosages have since dropped to about one-tenth of their original strength. There are far fewer side effects and a host of benefits, including regularized periods and reduced acne, bloating, premenstrual syndrome and less bleeding due to uterine fibroids. What's more, the longer a woman uses the pill, the lower her risk of ovarian and endometrial cancer.

Still, some women remain wary. "For some reason, it has a really bad rap," says Rachel Bernstein, an ob/gyn in Fort Lauderdale, Fla., who says she has to explain that these days, the benefits outweigh the risks.

Today, there are about 40 different brands of birth-control pills, most of which contain a combination of estrogen and progestin.

Other versions work the same way, including the NuvaRing, a flexible ring that is inserted in the vagina every month and worn for three weeks, then removed for one week, and the Ortho-Evra patch, which is replaced every week for three weeks, followed by a patch-free week.

Newer pills, like Seasonique, allow women to have only four periods a year; Lybrel, approved in 2007, is designed to be taken for 365 days straight with no period. Experts say there is no health reason that women need to have a period if they are not ovulating or building up uterine lining each month. The traditional pills were designed to include a monthly period in part so that women would be reassured that they weren't pregnant.

Hormonal birth control is 99% effective at preventing pregnancy if used correctly, but in average use, with some forgetfulness, it's only 92% effective.

Cost: $15 to $50 per month

Downsides: Women who have breast cancer should not take estrogen, but the pill does not seem to increase the risk of getting it. It can cause blood clots in rare cases. But, says Vanessa Cullins, vice president for medical affairs of Planned Parenthood Federation: "We have to keep these things in perspective. A woman's risk for those problems is substantially higher during pregnancy."

A more long-lasting form, the Depo-Provera injection, releases progestin only and prevents pregnancy for 12 weeks. It can be used by women who can't take estrogen and by those who are breast-feeding.

Cost: Each injection costs $35 to $75

Downsides: Possible weight gain, depression, blood clots and bone thinning; usually recommended only for women who can't use other forms.

Condoms, Caps And Sponges

Using a receptacle to contain sperm during sex literally goes back to caveman days: It's depicted on the wall of a cave in France from 12,000 B.C. Over the millennia, condoms have been made of paper, animal intestines, leather and linen (a favorite of womanizer Giacomo Casanova in 18th century Italy). Charles Goodyear paved the way for mass production of "rubbers" when he patented the vulcanization of rubber in 1843, and they were a mainstay of birth-control efforts until the pill emerged as more dependable and convenient.

The popularity of condoms soared in the 1980s, when the AIDS epidemic alerted public-health officials to the need for protection against STDs as well as pregnancy. Nowadays, condoms come in a variety of sizes, colors, materials and even flavors. Most are made of latex, but polyurethane and lamb-skin condoms are also available.

Cost: generally $1 each, but sometimes free; available without a prescription.

Effectiveness is still an issue. Roughly two of every 100 women whose partners use condoms correctly become pregnant each year, as do 15 of 100 women whose partners don't use them correctly.

Female condoms, plastic pouches inserted in the vagina before intercourse, are less effective. About five in 100 women who always use them correctly become pregnant each year, as do 21 out of 100 women who don't always use them correctly. They cost about $4 each and are sold without a prescription.

Other "barrier" birth-control methods include the Today Sponge, an updated version of the brand made famous on "Seinfield," that involves a spermicide-containing foam disc that covers the cervix and blocks sperm from entering; the FemCap, a reusable silicon cup filled with spermicide that covers the cervix, and the diaphragm, a much older rubber bowl filled with spermicide. Although all three are inexpensive, don't involve hormones and have few side effects, they are inconvenient, don't protect against STDs and are not very effective. Even with careful use, as many as 20 out of 100 women using them each become pregnant.

Even combined, they make up a very small percentage of birth-control users today. "There's a whole generation of women who didn't pick them up," says Mr. Trussell.

Emergency Contraception

Versions of "the morning-after pill"—a combination of hormones that abruptly halts ovulation—have been around quietly since the 1970s. In 1999, the FDA approved Plan B, a progestin-only pill that does the same, preventing pregnancy up to five days after unprotected sex or in case of a condom break or forgotten pill. It's currently available in three brands, Plan B, Plan B One-Step and Next Choice. Plan B and Next Choice are 89% effective if used within 72 hours after intercourse.

But emergency contraception is only effective if it is used every time after unprotected sex. "If you don't use it every time, then you are eventually going to get pregnant," says Mr. Trussell, who runs a Web site called Not-2-late.com with information on emergency contraceptives.

Cost: From $10 to $70, without a prescription for teens 17 and older

Downsides: They may cause temporary nausea, headaches and irregular bleeding; no STD protection.

Permanent Birth Control

Every year, about 700,000 U.S. women who no longer want children have a tubal ligation, a surgical procedure in which the fallopian tubes are cut and tied off. It's an outpatient procedure, but still requires a hospital stay and a cost of $5,000 or more.

A less-invasive version called Essure can be performed in a doctor's office. Using a hysteroscope, the doctor inserts a tiny titanium coil into each tube via the uterus. The woman's own tissue then grows around the coils, forming a natural but permanent barrier.

It's caught on slowly in the U.S., in part because doctors require additional training. Women must also have a follow-up test in three months to make sure a seal has formed, and to use other birth control in the meantime. But it's over 99% effective, without surgery or hormones.

A competing version, called Adiana that uses a smaller implant and radio-frequency energy, was approved by the FDA last year.

Cost: about $2,000

Downsides: The procedure may cause mild cramping, does not protect against STDs and is not reversible.

Vasectomy Variations

On the male side, there are new variations as well. Traditionally, a doctor makes an incision in the scrotum and cuts the two vas deferens, the tubes that carry sperm out of the testicles, and ties, stitches or seals them closed. The procedure takes about 30 minutes and is done in a doctor's office or clinic.

In one newer version, the doctor pokes a clamp through the skin instead of using a scalpel; there's less bleeding and fewer complications. In another, the vas deferens are locked closed with a clip, though some studies have shown that may not be as effective as other methods.

In general, vasectomies are nearly 100% effective—but since some sperm may remain in the blocked tubes, couples must use another form of birth control for three months. In very rare cases, the tubes may grow back together and permit the passage of sperm again.

Cost: $350 to $1000, covered by insurers and Medicaid.

Downsides: There's some minor pain, swelling and numbness for several days after the procedure, but most men can resume sexual activities within a week. Vasectomies theoretically can be reversed, but they are often not effective. Men should consider them permanent.”

Personal comment: This is a good overview of what is available to the general public but does not cover the barrier needs for professional escorts and women fetishists who routinely need gas guards for upper reproductive tract protection. However, those needs are covered in this blog.