Bleeding Between Periods

Arguably one of the most annoying things someone can experience is bleeding in between scheduled periods. At first you may wonder, has a whole month speed by already? Did I miscalculate my dates? Then it inevitably sinks in that you are indeed bleeding off-cycle. The question becomes “why?” How long will this bleeding last? Does this mean something is wrong with me? Do I need to call my doctor?

Intermenstrual bleeding or unscheduled periods may be a one time fluke or a signal that a disease process is occurring. In order to recognize this deviation from the norm one would have to know their normal cycle, therefore gynecologists encourage you to track your periods. Periods that are abnormal can prompt proper investigation. There are numerous apps on both the apple and android systems that facilitate seamless, hassle-free period tracking.

Normal periods occur every 21-35 days, last 3-7 days and require a change in feminine hygiene products >2 hours. If your periods fall outside these set points they are most likely abnormal and should be investigated by your healthcare provider as there could be many different intermenstrual bleeding causes.

Unscheduled periods are most likely due to reversible contraceptives. Contraceptives include birth control pills, patch, ring, injection, implant and intrauterine devices (IUD). The good news is most unscheduled bleeding with contraceptives are most prominent in the 1st 90 days after beginning the form of contraceptive. Subsequently a lighter scheduled period tends to be the case. An exception to this rule is the implant. Nexplanon is the only birth control implant FDA approved to be used in the US. The manufacturer states that 1 in 5 women will have heavier and unscheduled bleeding. 11% of women will discontinue this method due to heavy bleeding. (Nexplanon Prescribing Information). Of note 1 in 5 women will have no periods on Nexplanon. Unfortunately there is no way of knowing which woman will fit in each category prior to placement.

Another common cause of bleeding between periods is pregnancy. Most commonly pregnancy presents with no periods but 15-25% of pregnant women will have 1st trimester bleeding (Lykke). This may be confused as intermenstrual bleeding. If there is a possibility you may be pregnant, you should perform a home pregnancy test and/or contact your health provider.

A more worrisome cause of intermenstrual bleeding is skipped ovulation or anovulatory bleeding. Normal bleeding patterns are controlled by the following mechanism: The hypothalamus (a part of the brain) communicates with the anterior pituitary (another part of the brain) via small molecules known as hormones. The anterior pituitary then communicates with the ovary to create even more hormones and develop then release an egg. The release of the egg is known as ovulation. At the same time, the hormones created by the ovary communicate with the lining of the uterus (womb) to prepare a fluffy lining for a fertilized egg to implant and pregnancy to egin. If the egg is not fertilized by sperm then that fluffy lining is shed in the process we call menstrual bleeding.

You can imagine that if the process does not occur, aka if you do not ovulate, then this shedding will not occur in the expected fashion. This disorderly bleeding is known as anovulatory bleeding. This can occur due to stress, extremes in weight, excessive exercise, Polycystic Ovarian syndrome (PCOS), disorders of the thyroid, drugs (street and prescribed), birth control, menopause, disorders of the hypothalamus or pituitary glands and other rare disorders. The abnormal bleeding caused by these disorders usually persist past 3 cycles.

Other causes for intermenstrual bleeding include:
-infections (such as chlamydia)
-anatomical abnormalities: fibroids (abnormal growths in the muscle of the uterus), polyps (abnormal growths in the lining of the uterus)
-precancer or cancer of the cervix or endometrium (lining of the uterus)

Bottom Line:
-Track your periods and bleeding between cycles
-If you are on contraceptives and this is within the first 90 days, this is expected
-If you have unscheduled bleeding and are not on contraceptives, reach out to your health provider
-Expect a pregnancy test even if your tubes are tied as you could have an ectopic pregnancy (pregnancy in the fallopian tubes) and/or sexually transmitted infection panel
-If the irregular bleeding pattern is bothersome regardless of the use of contraceptives, reach out to your health provider
-If the pattern persists, request further workup for the rarer causes of intermenstrual bleeding

For all questions regarding your health and cycle, always make sure to advise a medical professional.

Citation:
Lykke, Jacob Alexander MD; Dideriksen, Katrine Lehrmann MD; Lidegaard, Øjvind MD, DMSc; Langhoff-Roos, Jens MD, DMSc First-Trimester Vaginal Bleeding and Complications Later in Pregnancy, Obstetrics & Gynecology: May 2010 - Volume 115 - Issue 5 - p 935-944

doi: 10.1097/AOG.0b013e3181da8d38

Nexplanon Prescribing information
https://www.organon.com/product/usa/pi_circulars/n/nexplanon/nexplanon_pi.pdf