• In about two-thirds, the leakage occurs when the penis enters the vagina (penetration).
• In about one-third, the leakage occurs only at orgasm.

What causes it?
The reason is not understood, but it is likely to be partly due to an irritable bladder or a weakness at the neck of the bladder. About 1 in 5 women have difficulty holding urine during the day also experience leakage during intercourse. Leakage of urine at orgasm (but not at penetration) is particularly linked with having an irritable bladder, whereas leakage at penetration may signal a weakness at the neck of the bladder (European Urology 2007).

Some women have leakage of urine during intercourse, but not at any other time. Could it be female ejaculation?

In 1950, a Dr Grafenberg described what he called “female ejaculation...the expulsion of large quantities of clear transparent fluid at the height of orgasm”. Some sex manuals still talk about this ‘female ejaculation’ as if it were some kind of discharge of sexual glands. They claim it comes from Skene’s glands, which are supposed to be similar to the prostate gland in men.

People who believe in ‘female ejaculation’ say that analysis of this fluid reveals high levels of an enzyme called acid phosphatase that is made by prostate-type gland tissue. In fact:

• a study in six women showed that their ‘female ejaculate’ fluid contained the same amount of acid phosphatase as their urine
• a study of just one woman did find high levels of acid phosphatase in the fluid she released at orgasm, but the method used to analyse it was unreliable.

The facts have been reviewed in an American medical journal (American Journal of Obstetrics and Gynecology 2001;185:359–62), and it now seems clear that this fluid is just urine.

What can be done

• Empty your bladder before sex.
• Cut down on caffeine-containing drinks and alcohol.
• Do not drink excessive amounts of fluid – not more than 1.5 litres (2.5 pints) over 24 hours.
• Discuss the problem with your doctor, especially if you have leakage at other times.
• Your doctor may prescribe oxybutynin or a similar drug for you. Medication may be particularly helpful if you experience leakage at orgasm, rather than during penetration (European Urology 2007). You should take this about 1 hour before sex (if you can plan that well ahead!).
• Alternatively, your doctor can prescribe imipramine, to be taken in the evening. This is normally given as an antidepressant, but it also has effects on the bladder (which is why a similar drug is used to treat bed-wetting in children). If your doctor suggests it, it is because of its bladder effects, not because he or she thinks you are depressed. The dose will be lower than given for depression.
• If none of these deals with the problem, or if you experience leakage mainly during penetration, you may have a weakness of the bladder neck. Therefore it would be worth asking for a referral to a gynaecologist, preferably one who specializes in urogynaecology. An operation to strengthen the bladder neck might be appropriate. Unfortunately this operation is successful in controlling leakage during intercourse in only two-thirds of people.
• In the end, you and your partner may simply have to come to terms with the problem, and enjoy your sex life in spite of it. If it is causing a real problem in your relationship, or affecting your feelings about yourself, a few sessions with a psychosexual counsellor can be very helpful.
• You can also contact a number of organizations for help and advice.