Dear Dr Mitchell,
Do women only get pregnant after/during ovulation?
Is it possible for a woman to get pregnant if she has unprotected intercourse four to five days after her periods (and seven to eight days before ovulation)?
The normal menstrual cycle is usually on average every 28 days with a range of 21 to 35 days. Ovulation usually occurs at around the middle of the cycle, that is 14 days counting from the first day of the menstrual period. This is the usual case in a 28-day cycle. Now, if the menstrual cycle tends to occur at shorter or longer intervals, then the time at which ovulation occurs will also change.
In a 21-day cycle ovulation will occur at around day seven counting from the first day of the menstrual period. In a 35-day cycle ovulation occurs later, usually at around day 21. The time from ovulation to the onset of the menstrual period is usually fixed, while the time from the onset of the period to the time of ovulation is the variable part of the cycle.
The safe period in the cycle, assuming a 28-day cycle, is usually up to day 10 counting from the first day of the menstrual cycle and again from day 21 to day 28.
It is possible to conceive after unprotected intercourse four to five days after the period, even though this is usually the safe period in the normal 28-day cycle. If the cycle length is not 28 days and is of a shorter length, then this period is unsafe. Having sexual activity seven to eight days before ovulation is usually considered safe, assuming your cycle length does not change. You should not rely on this method of preventing pregnancy since your cycle can change without any advanced notice and conception can occur.
Several factors can change your pattern of ovulation. These include stress, weight gain, excessive weight loss, the use of certain drugs and drastic dietary change. Reliable methods of contraception include the oral contraceptive pill, the injection (Depo Provera, Mesigyna), the intrauterine contraceptive device (Mirena and Copper T), the patch and condom (female and male). In the event that sexual activity is unplanned and happens during the fertile period, then the emergency contraception (Postinor) will definitely help to reduce the chance of an unwanted pregnancy by as much as 75 per cent. This is usually taken within 72 hours of unprotected intercourse. This should, however, not be used more than two to three times within a month. A more long-term method should be used if you are serious about preventing an unplanned pregnancy.
Consult your doctor who will advise you further.
Dr Sharmaine Mitchell is an obstetrician and gynaecologist. Send questions via e-mail to allwoman@ jamaicaobserver.com; write to All Woman, 40-42 1/2 Beechwood Ave, Kingston 5; or fax to 968-2025. Dr Mitchell cannot provide personal responses.
The contents of this article are for informational purposes only and must not be relied upon as an alternative to medical advice or treatment from your own doctor.