Implantation bleeding: How to recognize it?

One in three women have implantation bleeding. Between the first and second week of gestation they detect a slight loss of blood that happens when the embryo nests in the wall of the uterus. This may be one of the first obvious signs of pregnancy.

It can also be a time of real distress for those who wish to have a baby, as it can be mistaken for the start of the next period.

June is the month of infertility and from the blog of IVF-Spain we want to help clear up the doubts about this important topic for those who are looking for pregnancy, either with the help of medicine and an IVF or without it.

What is implantation bleeding?

During the first weeks of pregnancy the uterus is very irrigated. When the embryo adheres to the endometrium, which has thickened to receive the embryo, some blood vessels may break, causing slight vaginal bleeding.

Not all pregnant women have implantation bleeding and, if they have had it, it does not have to be repeated in all their pregnancies.

This can be a source of anxiety and stress for those who are anxious to have a baby, since it can be confused with the start of the next period.

When does implantation bleeding occur?

The egg meets the sperm in the fallopian tube and fertilization occurs, and together they begin their journey to the uterus. Then a process of cell division begins until they become a blastocyst (day 5-6 of fertilization). Once in the uterus, and for pregnancy to occur, the embryo must implant in the endometrium of the future mother.

This process takes approximately ten to fourteen days after conception, so that this small bleeding can be confused with the start of menstruation.

How do you differentiate between implantation bleeding and menstruation?

As we have already mentioned in this article, since implantation bleeding can occur during the first weeks of pregnancy, it is not strange that it can be confused with the beginning of the next period.

Although it is difficult to differentiate by date, there are other factors that can help us easily identify that it is bleeding due to the correct implantation of the embryo in the wall of the uterus.

One aspect to evaluate is the quantity. The bleeding that occurs when the embryo adheres to the uterine wall is lighter than that of menstruation. It can be from a drop to a light bleeding. It is true that the amount at the beginning of menstruation is usually light. However, it will increase as the days go by.

The colour can also help us identify one bleeding from another. Usually the blood from a implantation is darker, unlike the bright red that usually appears during the period.

Compared to menstruation, the duration of bleeding is shorter. While menstruation increases the amount of bleeding as the days go by, implantation may last a few hours or no more than three days. Another key factor is the texture, which tends to be more fluid and lighter.

The truth is that every woman is unique and so are her symptoms and the bleeding she experiences during each period. That is why it is important to look at other types of symptoms that may indicate the beginning of a pregnancy.

Pregnancy symptoms such as: breast sensitivity, nausea at certain times, tiredness or the constant need to go to the bathroom, may be giving us a clue that we have achieved the desired pregnancy.

How to get the confirmation that you are really pregnant?

The easiest way is to take a urine pregnancy test. The drawback is that it can be a little early to get a positive result. This type of test takes longer to detect the levels of the hormone hCG (human chorionic gonadotropin), so if it is not carried out at the right time, a false negative can be obtained even though the embryo has implanted.

To be able to do a urine pregnancy test properly, you must wait until you have had your period for a few days.

The hormone hCG, also known as Beta-hCG, is secreted by the embryo when it implants in the uterus. Measuring the levels of Beta-hCG is a reliable indicator of whether a pregnancy has been achieved.

In assisted reproduction centres such as IVF-Spain, ten days after the transfer of the embryo to the patient, the levels of the hCG hormone are measured with a blood test. In order for us to confirm that the pregnancy is progressing favourably, the levels of the hormone will grow exponentially during the first trimester.

That period, between the transfer of the embryo or the insemination until the result is obtained, is usually the most difficult time for patients within a fertility treatment. It is a life-changing blood test.

How should you act if you have a bleed?

If you have undergone fertility treatment, the first thing we recommend is to continue with the medication and contact our patient care team so that one of our fertility doctors can assess that everything is going normally and tell you the steps to follow.

On the other hand, if you have not undergone any treatment and if you have any doubts, the best thing to do is to consult your gynaecologist so that he can assess what type of bleeding it is.