Ask An Expert: Contraceptive Use

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Ask An Expert: Contraceptive Use

Question:

I'm on the Nuvaring contraceptive. If I want to delay my period for another week, can I keep the ring in for four weeks instead of three and use another form of birth control?

Answer:

The Nuvaring is a hormone contraceptive that provides an alternative method to the traditional oral contraceptive pill. A soft plastic ring containing estrogen and progesterone is placed in the vagina for three weeks out of four. Hormones are gradually released from the ring and enter the blood stream. The hormones prevent pregnancy by inhibiting the release of an egg from the ovary.

The Nuvaring is a convenient and very effective method of birth control but it does not protect against sexually transmitted diseases.

Normally, the ring is removed from the vagina after three weeks. It remains out for seven days before inserting a new ring. A period occurs during this fourth week of the cycle. The period results from the withdrawal of hormone support to the lining of the uterus. As hormone levels drop, the uterine lining sheds, much as it does during a normal menstrual cycle.

If the Nuvaring is left in place for more than three weeks, the level of hormones and the contraceptive effectiveness begins to decrease. However, the ring is designed to allow some leeway so the decrease is very slight at first. The product literature states that if a ring is left in place for up to four weeks, the woman should continue to be protected. However, a backup form of birth control is probably wise if you use the product in any manner other than what is prescribed.

If a Nuvaring is left in place longer than three weeks, there is no guarantee that the hormone levels will remain high enough to prevent bleeding. When women delay a period by taking an extra week of the pill, they continue to get the same level of hormone every day. However, with the ring, the hormone level slowly begins to drop. If there is not enough to support the growth of the uterine lining, breakthrough bleeding may occur.

Joan Bengtson, M.D., is assistant professor of obstetrics, gynecology and reproductive biology at Harvard Medical School and a member of the Department of Obstetrics, Gynecology & Reproduction at Brigham and Women's Hospital.

Last updated:	July 23, 2007