Where does the baby’s urine and stool go when he or she is in the womb?

Although the embryo produces a dark mixture in the intestine, it is not enough to argue that it is excrement, after all the embryo does not eat and therefore does not produce feces. Meanwhile, urine is freely released into the amniotic sac (which surrounds the embryo). In fact, this fetal urine makes up most of the amniotic fluid and, consequently, is vital for the proper development of the embryo.

Pregnant woman meditating in bed

But it’s known as fetal urine for a reason, and that’s because it’s nothing like our urine. Almost 100% of fetal urine is water. The reason is very simple: the embryo does not have much waste to excrete, firstly because it does not feed and secondly because the metabolites (mainly urea, sodium and creatinine, which are also found in our urine) are sent directly to the mother via the umbilical cord, and excreted by her. The embryo can only urinate after the 16th week, when its kidneys are developed enough to filter the blood sent by the mother – separating oxygen, glucose, mineral salts and vitamins from the metabolites.

A short time later, around week 25, the cells of the intestine produce a dark secretion known as meconium, which coats the walls of the intestine to prevent them from collapsing. Sometimes, towards the end of pregnancy, the embryo can release this meconium into the amniotic fluid, something that can be dangerous at the time of the baby’s birth, when it takes its first breath (in its mother’s womb, all oxygen is supplied through the umbilical cord): if the newborn breathes the meconium, It can contaminate the lungs and develop pneumonia.

Therefore, before cutting the cord, doctors must aspirate the fluid that covers the newborn’s nose and mouth. In addition, releasing the meconium is an indication that the embryo’s intestine is more vascularized than normal and this could represent suffering.

If doctors find that the amniotic fluid is darkened during the weeks leading up to the due date, the birth could be brought forward. In that case, they tell the parents that “the baby pooped inside the mother’s belly” to facilitate the explanation, but just to be clear, that’s not excrement.

The cell that explodes.

Fifth week of pregnancy.

The embryo reaches a size of about 5 millimeters (like a bean kernel) and, at that size, already requires a basic survival package: a rudimentary heart, the buds of the arms and legs, and the brainstem (the structure of the brain that is responsible for controlling the heart rate).

Fifth week of pregnancy

Ninth week of gestation.

At approximately three centimeters in length and weighing 10 grams, the embryo begins to experience the first brain stimuli. According to some scientists, at this point he is already in pain. At this stage of development, he already has fingers and a differentiated genital organ.

Ninth week of pregnancy

Week 16.

The baby already has bone and muscle structures formed, although in size it still resembles a mobile phone. Their features are already well defined and doctors are able to identify sex by ultrasound.

Week Sixteen Pregnancy

Week 25.

Around the fifth month of pregnancy, the fetus meets the minimum requirements to live outside its mother’s womb. What determines this is the formation of the lung: even if it is born prematurely, it is already able to breathe on its own.

Twenty-fifth Week Pregnancy