Bleeding with pregnancy loss in the first trimester of pregnancy

Bleeding with pregnancy loss in the first trimester of pregnancy

What is the first trimester bleeding?

The appearance of bleeding through the vagina at any moment of the pregnancy is called pregnancy metrorrhagia or obstetric metrorrhagia.

It is always a sign of alarm and always needs medical assessment.

It can appear at any week of the pregnancy. We will now speak about bleeding or metrorrhagia with pregnancy loss in the first trimester, which covers the first 12 weeks of pregnancy.

On the one hand, not all bleedings, which happen during the first trimester convey a pregnancy loss or an unviable pregnancy, since in many cases, it will be a “transitory alarm” that we call threat of miscarriage.

On the other hand, not all pregnancy losses or unviable pregnancies imply vaginal bleeding. 

Which are the causes of the first trimester bleedings that do end up in pregnancy loss?

There are three clinical situations that can cause bleeding and pregnancy loss in this period of the pregnancy:

  • EARLY MISCARRIAGE (happens before week 13). This is the most common pregnancy complication.
  • ECTOPIC PREGNANCY (or extrauterine pregnancy). Its most frequent location are the Fallopian Tubes. It happens in 1-2% of all pregnancies.
  • MOLAR PREGNANCY (or Gestational Trophoblastic Disease). It is a very rare complication (0.5-1 out of 1000 pregnancies), in which there is an abnormal growth of the trophoblastic tissue, which is the tissue that forms the placenta in normal pregnancies.

What are the symptoms of pregnancy loss?

The main symptoms are vaginal bleeding, with or without pain.

  • The amount of bleeding can be very variable from low to very heavy, even greater than that produced during a menstrual period. Heavy or very heavy bleeding, bright red, even accompanied by clots is more characteristic of miscarriage.
  • It can be painless or associated to various degrees of abdominal or lower back pain.
  • Little or very little bleeding, often painless in its initial stages would be more typical of ectopic pregnancy, although it can produce very intense abdominal pain in more advanced stages.
  • A molar pregnancy’s characteristics, bleeding and pain are indistinguishable from a miscarriage.

Establishing a final diagnosis from the characteristics of the bleeding is difficult and imprecise. Carrying out a vaginal ultrasound is essential and it is what will help us reach the specific diagnosis in each case.

How is it different from any other bleedings?

If we start from the fact that the woman knows that she is pregnant, there are no other diagnoses than those mentioned in relation to bleeding, whatever its presentation. The most frequent cause is the risk of miscarriage (if the pregnancy continues to evolve) or miscarriage if it stops. Sometimes, bleeding may appear after intercourse, but in this case, the coincidence in time between sexual intercourse and the appearance of blood loss from the vagina can be established. Bleeding is not usually abundant and it is painless and short-lived. This bleeding comes, in most cases, from the cervix and, therefore, sexual relations do not cause loss of pregnancy.

If a woman of childbearing age does not know if she is pregnant and has an unusual bleeding or bleeding different from her usual period, she should take a pregnancy test. If the test is negative, she should consult her gynecologist. The causes can be very diverse (fibroids, polyps, hormonal disorders, alterations in the mucous membrane of the uterine cervix, etc.). If the test is positive, she should contact her medical centre which will indicate the date of the first gestational control ultrasound.

Can it be prevented?

Unfortunately, it cannot be prevented.

The most important thing is to identify whether there are treatable risk factors for miscarriage or ectopic pregnancy prior to pregnancy in a pre-conception visit (please see the forums you can find on our website at this regard).

What should I do if bleeding occurs due to suspected pregnancy loss?

You should always contact your medical center of reference.

Depending on the intensity of the symptoms:

– You should go to your hospital, if the bleeding is very heavy and/or the pain is intense.

– Make a phone call and explain your symptoms, if they are less severe. It will be your doctor, who knows your medical history, who will give you the precise indications in each case.

Reference links:

  • Practical Guide to Emergency Medicine in Obstetrics and Gynecology (according to S.E.G.O. protocols). Dr. Ignacio Zapardiel Gutiérrez et al. 2008
  • Ectopic pregnancy. SEF (Spanish Fertility Society)
  • Miscarriage in the first trimester. This review describes the diagnosis and management of first trimester miscarriage Dr. Davor Jurkovic, Caroline Overton, Ruth Bender-Atik BMJ 2013;346:f3676


Dr. Lydia Luque, gynaecologist at Instituto Bernabeu

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