5. week of pregnancy


The fifth week of pregnancy is a very important time for the proper development of the child. The fifth week of pregnancy is still referred to as the embryonic development period, which lasts until the end of the eighth week of pregnancy. Pregnancy weeks are counted from the first day of the last menstrual period – known in medical terminology as post menstruation.

During this week, pregnancy tests are very likely to be positive, although there are tests that can be used earlier nowadays. The focus of the fifth week of pregnancy is on the organogenesis of the embryo – this is the time of organ development. For the first time, the embryo can now also be seen in the ultrasound examination.

Size and development of the embryo

The embryo is in the fifth week in a very important phase. The foundation stone for organ formation is laid. These develop continuously during the 5th – 8th week of pregnancy.

In the fifth week of pregnancy, the embryo is about 2 mm in size and has an elongated shape. Important structures and organs develop from the three cotyledons of the embryo (ento-, meso- and ectoderm). Organ development is a very complicated process, which is a sensitive phase for the integrity of the child.

Brain and facial structures of the embryo develop, as well as the urinary organs. Facilities for the legs and arms, called leg and arm buds, are created. The gastro-intestinal tract and important systems for the heart are also formed this week. Muscles, tendons and ligaments are applied and develop during the embryonic and later foetal period.

How’s the ultrasound look in 5th SSW?

In the fifth week of pregnancy the pregnancy is already detectable in the ultrasound examination. This is usually when the initial examination of the pregnant woman takes place. If there is no menstrual bleeding, a visit to the doctor is necessary, who can then determine the pregnancy during the examination.

The ultrasound image shows only the amniotic cavity, which looks like a black spot. Its diameter at the beginning of the fifth week is about 4 mm. By the end of the fifth week the diameter doubles to about 8 mm.

However, apart from the amniotic cavity, nothing is yet visible of the embryo. A heartbeat can be seen, although in most cases a heartbeat can only be seen with certainty from the 7th week of pregnancy. The embryo itself is not yet visible. But this is no reason for concern. Around the amniotic cavity you can see highly built up uterine mucosa.

What are typical signs of pregnancy in the 5th week of pregnancy?

There are sometimes very inconsistent statements about safe and unsafe signs of pregnancy. Ultimately, only a medical examination, including blood and urine tests and an ultrasound, can say with certainty whether a pregnancy exists or not. All signs that a pregnant woman herself perceives at the beginning of pregnancy are considered to be uncertain signs of pregnancy.

In the fifth week of pregnancy, pregnancy is still in a very early stage of the first trimester. No tummy is yet visible and no weight gain is noticeable. However, a very strong indication of pregnancy is the absence of periods from the fifth week of pregnancy.

Furthermore, due to hormonal changes, slight complaints such as breast tenderness or abdominal pulling can occur. However, these are very unspecific signs which are not exactly rare even outside of a pregnancy. Although the uterus is already enlarged, it cannot be palpated through the abdominal wall.

Abdominal pain as such is a very unspecific symptom that can indicate many different causes. Contrary to what is often assumed, it is not a typical sign of pregnancy. Especially in the fifth week of pregnancy, pregnancy does not cause abdominal pain.

In the course of the pregnancy, abdominal pain in the form of abdominal pulling is more frequent, as the baby starts to move and structures in the mother’s body are stretched. A slight pulling in the abdomen may occur in the fifth week, but this is usually due to hormonal changes and not a specific indication of pregnancy. Diarrhoea is not a typical symptom of early pregnancy, but usually an expression of food intolerance or infection.

In combination with spotting, the latter can be considered. Here too, however, there is not necessarily a connection between the symptoms. Spotting and diarrhoea are usually not an expression of the same problem.

A spotting can be a harmless contact bleeding after sexual intercourse. Diarrhoea occurring at the same time, on the other hand, can be an expression of a gastrointestinal infection. The two symptoms are therefore not linked. Nevertheless, if such symptoms occur during pregnancy, one should consult a doctor to rule out all eventualities.