Your 13th Week of Pregnancy

Your 13th Week of Pregnancy

Last update: 24 April, 2018

A new trimester begins and so does another stage for the little one inside your womb. In your 13th week of pregnancy, your baby’s height is between 6.5–10 cm, and their weight ranges from 13–20 grams.

Their face begins to form its unique features, among other transformations that we’ll review below. It’s incredibly exciting!

In addition to the final location of their eyes and ears, there is a truly fascinating detail: the fingerprints are already there.

The brain is one of the most developed parts of the fetus, as are the structures that support and cover the organs.

At this point the head makes up half the total size of the fetus.

From now on, the body will begin to grow more quickly to catch up and thus achieve a proportional body.

In fact, at birth, the head represents only a quarter of the total size. In addition, there are also a couple of very important processes related to the fetus’ body and its function.

The first has to do with the production of red blood cells, which carry oxygen to all of the body’s tissues.

At this stage they form mostly in the liver. In children and adults, their production occurs in the bone marrow.

In the 13th week of pregnancy, the fetus has an immune system already. It’s beginning the process of being able to defend itself against foreign organisms.

Of course, it doesn’t have the capacity of a fully developed baby, because it’s still necessary for this system to mature and learn to recognize threats.

In this stage, there are a couple of very important processes related to the fetus’s body:

On the one hand, the mother’s antibodies will protect him from infections.

On the other hand, the liver secretes bile, the pancreas produces insulin and the kidneys form urine to eliminate waste in the amniotic fluid.

Your 13th Week of Pregnancy

13th week of pregnancy: what will happen to your body?

As in the 12th week, the mother will experience relief of certain symptoms.

Some women consider the second trimester the “honeymoon” of pregnancy, meaning this is the stage that can be enjoyed more.

Here are some of the changes your body will experience:

  • Nausea, tiredness and general lethargy, as well as frequent dizziness, are almost a thing of the past. They may still occur occasionally. Vitality increases and previous sleep loss goes away.
  • The uterus begins to enlarge considerably.
  • There may be discomfort caused by cramps in the abdominal area or intestinal discomfort. Specialists explain that pregnancy slows the muscles that we don’t have control over and that make our stomach, bladder and intestines move.
  • For the same reason as above, intestinal transit slows down. This produces slow digestion, which can cause heaviness, gas or constipation.
  • You may need to blow your nose more often, since the mucus membranes generate more secretions.  
Your 13th Week of Pregnancy

Check-ups at this stage

In the 13th week of pregnancy, the ultrasound for the end of the first trimester can still be performed if it hasn’t been done already.

This is the final step of the series of check-ups the mother must face since the pregnancy was first confirmed.

This is the point in which the evaluation of the first trimester is finalized.

It can be said that the most difficult and distressing part has already passed, especially for new mothers.

Medical check-ups will become less frequent, although only for a short period of time.

Monthly check-ups are needed to ensure the fetus is developing correctly and, of course, that the mother isn’t suffering any type of inconvenience either.

Tips for the 13th week of pregnancy

First of all, try to find comfortable clothes, since it’s very likely that as the pregnancy advances, your pants will become tight.

The most advisable thing is to avoid wearing tight clothes, uncomfortable shoes and heavy jewelry at all costs.

Remember that, although they may seem harmless, these elements can negatively affect your well-being and, of course, cause discomfort.

On the other hand, enjoy the renewed energy that you’ll feel after the disappearance of nausea and dizziness.

Take advantage of that vitality to rediscover intimacy with your partner and perform other pleasurable activities.

Enjoy yourself, because it’s the ideal time to start wearing that tummy with pride!

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • de la Calle Fernández-Miranda, María. “Estreñimiento y embarazo.” Solicitada acreditación a la Comisión de Formación Continuada de las Profesiones Sanitarias de la Comunidad de Madrid-SNS: 63.
  • Navero, Sofía Piñero, et al. “Características y modificaciones de la sexualidad durante el embarazo.” NURE investigación: Revista Científica de enfermería 50 (2011): 3.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.