Causes

• According to the National Institutes of Health (NIH), taking hormone contraceptives is the most common cause of breakthrough bleeding (BTB) or spotting. The relationship between birth control pills and BTB is not fully understood, but it associated with the hormones in the pills, not with your menstrual cycle.
  
  Breakthrough bleeding, while bothersome, is not typically a sign of a serious health problem.
  
  

Hormonal Contraceptives

• Use of traditional birth control pills that cause the reproductive system to mimic a regular 28-day cycle poses a risk of breakthrough bleeding. The NIH says that the combined estrogen/progestin oral contraceptives in particular have been linked to abnormal or breakthrough bleeding.
  
  Other hormone birth control methods, such as contraceptive implants (levonorgestrel, Norplant) may also cause breakthrough bleeding. The implants release a steady low dose of the progestin levonorgestrel over five years.
  
  Contraceptive injections such as Depo-Provera (medroxyprogesterone) remain effective for about 14 weeks. Breakthrough bleeding may occur during this time.
  
  

Seasonale & Lybrel

• Although breakthrough bleeding is possible with any hormonal contraceptive, it's more common with extended-cycle birth control pills such as the combination drug levonorgestrel-ethinyl estradiol (Seasonale). Women who take Seasonale will menstruate approximately every 12 weeks or four times a year instead of monthly.
  
  Lybrel contains low doses of both a progesterone and an estrogen. It is designed to be taken daily for one year. On and off bleeding is possible during the first few months of use. The Mayo Clinic says four out of 10 women will continue to have spotting or breakthrough bleeding that requires the use of sanitary pads or panty liners.
  
  

Triggers

• Breakthrough bleeding is more likely to occur if you miss a dose of your oral contraceptive or begin taking a new medication (antibiotics) that may obstruct the inner workings of the pill.
  
  Women who become ill with diarrhea or vomiting may experience breakthrough bleeding because these symptoms can prevent the proper absorption of the contraceptive.
  
  

Outlook

• Irregular bleeding caused by an oral contraceptive should diminish over time. In the case of Seasonale, it may take up to one year before breakthrough bleeding ceases. In rare cases, bleeding can continue until the next time you are scheduled to menstruate. It's not uncommon to get your next period following a stretch of breakthrough bleeding.
  
  

Solution

• If breakthrough bleeding becomes persistent or produces a heavy flow, your doctor may recommend another type of contraception.
  
  The NIH says Minera (a hormone contraceptive device that is placed in the uterus) can help in women with menorraghia (abnormally heavy or prolonged menstruation); however breakthrough bleeding and/or spotting remains a possibility.