Breakthrough Bleeding


Bleeding may occur in between menstrual periods and this can be normal if the etiology behind this event is known. If the reason behind the bleeding is not known, it is advisable to consult a physician because this may be a sign of an underlying medical condition [1]


What is Breakthrough Bleeding?

Breakthrough bleeding is any bleeding or spotting that may occur in the middle of 2 menstrual periods. This may normally occur to those who are taking birth control pills whose estrogen level is not high enough. The bleeding is usually light but there are times when it can be heavy and similar to a menstrual period [1, 2, 3].

Read What is Decidual Bleeding

Read What is Spotting Between Periods


When the menstrual bleeding can’t be explained, it is referred to as metrorrhagia. This type of abnormal bleeding is heavier than the usual spotting and will not stop. This is not a normal finding and should be consulted to a physician [1, 2, 3].

How long does Breakthrough Bleeding Last?

Spotting usually lasts for 1-2 days and ceases by itself without any intervention. The occurrence bleeding will resolve once the body has adjusted to the hormone levels and this would take around 3-4 menstrual cycles [4].

Causes of Breakthrough Bleeding

Over-thickened endometrial lining

Although there are several possible causes of breakthrough bleeding, the most common cause is the over-thickening of the endometrial lining of the uterus. This event is usually harmless and may cause the period to stop for a few days but resume again [1].


When a follicle breaks free from the ovary, there is a small amount of blood that is released. Once an egg cell is fertilized, some spotting may occur once it implant in the lining of the uterus [1].

Birth control pills

These pills alter the natural hormone cycle and may cause breakthrough bleeding. This is due to the body’s attempt to adjust to the new hormone levels in the blood and will cease once the body has fully adjusted [1].

Read Depo Provera


Women who suffers from absent menstrual bleeding, or amenorrhea, may experience breakthrough bleeding due to the failure of the endometrial lining to build itself up during the cycle. They would miss their menstrual period and bleed in the middle of the next cycle [1].

Pathophysiology of Breakthrough Bleeding

Estrogen breakthrough bleeding

High levels of estrogen causes the endometrium proliferating in an undifferentiated manner. Without enough progesterone that should provide structural support, parts of the thickened endometrium will slough at regular intervals. The vasoconstriction and plugging of the platelets that occurs with progesterone will not happen and this will result to bleeding [5].


Progesterone breakthrough bleeding

Taking a contraceptive without any estrogen will elevate the progesterone-to-estrogen hormone ratio. Without enough estrogen, the endometrium will atrophy and may ulcerate. This may lead to bleeding in-between menstrual periods [5].

progesterone breakthrough bleeding

Differential Diagnosis of Breakthrough Bleeding

Health History and Physical Examination

A woman who experiences unexplained breakthrough bleeding should consult a physician. The physician will obtain a health history and it will cover the usual menstrual pattern, trauma and recent sexual activity. It will be followed by a physical examination to identify any possible signs of an underlying medical condition.

The vagina and the cervix will be checked for any lacerations or polyp growth and any vulvar or vaginal pathology will be identified. A bimanual uterine examination may be also performed to check for any uterine fibroids or endometrial cancer [5].

Laboratory Examinations

There are laboratory examinations that may be requested to support physical examination findings. A pregnancy test is done to all women who are in the reproductive age.

Complete blood counts will show the extent of blood loss and the adequacy of the platelets. A Papanicolaou smear test will be performed on a uterine tissue sample to verify the possible presence of a cervical dysplasia or any sexually transmitted infection [5].

Treatment of Breakthrough Bleeding

Breakthrough bleeding that does not stop by itself requires medical attention. There are several treatment options that may be advised to the patient [1, 6].


The bleeding will be attempted to manage first through the use medications. Birth control pills that contain both progesterone and estrogen are given to minimize the bleeding. Important reminders about taking birth control pills are to take it at the same time every day and all of the pills inside the pack should be taken.

If the hormone level drops even for a few hours, it will result to breakthrough bleeding. Patients should be advised that there will be bleeding while the body is adjusting to the birth control pills. The bleeding associated with the pill will cease itself once the body is used to the new hormone levels [1, 6].


If the medications are unsuccessful in controlling the bleeding, a surgical procedure may be advised. Examples of these procedures may include removal of uterus (hysterectomy) and cauterization of the endometrial lining. These procedures will make a female to be permanently infertile so this should be discussed with the patient prior to the procedure [1, 6].


  1. New Kids Center. (2015). What Causes Breakthrough Bleeding? Retrieved from New Kids Center:
  2. Mokate, T. (2013, September). Why do I have light bleeding in early pregnancy? Retrieved from Baby Centre:
  3. Ruby Cup. (2015). Breakthrough Bleeding. Retrieved from Ruby Cup:
  4. Miller, J. (2014). Break Through Bleeding: Just what you need to know. Retrieved from Menstruation Info:
  5. Oriel, K., & Schrager, S. (1999). Abnormal Uterine Bleeding. American Family Physician, 1371-1380.
  6. Streicher, L. (2015). Abnormal Bleeding. Retrieved from

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