Why do I have break through bleeding on birth control?

Break through bleeding on birth control is spotting or bleeding on the days that hormone containing pills or vaginal ring are used. The two hormones contained in birth control, estrogen and progestin, work together to prevent ovulation and to stabilize the lining of the uterus. The progestin thins the lining. The estrogen balances this by preventing the lining from becoming too thin. If pills are taken regularly, this combination prevents the lining from breaking down and bleeding. When first starting birth control, break through bleeding comes from the lining of the uterus still adjusting to a different pattern and dose of hormones. When women have used hormonal contraception for an extended time, sometimes the progestin becomes a more dominant effect and the very thin lining bleeds or spots. In the first case, patience is almost always the answer. Break through bleeding stops after 2 to 3 cycles in about 80% of women. In the second scenario, or if break through bleeding doesn't stop after the first few cycles, choosing a method with a slightly higher dose of estrogen my help.

Since breakthrough bleeding is a result of too little estrogen, use a back-up birth control method until it subsides or you consult your health care provider. The level of estrogen in your pills may also be too low to suppress ovulation.

Breakthrough bleeding is normal for women just starting on the pill while their bodies adjust to new levels of hormone. The same thing can occur if the doctor prescribes a different pill with lower amounts of hormone and a readjustment happens.

Breakthrough bleeding is a result of too little estrogen in the pill prescribed. A higher dose may be required. If the bleeding lasts more than two cycles or is as heavy as a regular period, see your health care provider.