Five weeks after conception, Your baby is now already the size of a grain of rice, about of 0.2 to 0.52 inches (5 to 13 millimeters) in length and about 0.03 ounces (0.8 grams) in weight. Arms and legs continue to grow, although the fingers and toes haven’t quite started to develop, but what is developing are the lenses of the eyes, nostrils, intestines, pancreas and bronchi. As your baby’s face begins to take shape, the mouth perforation, miniature nostrils, ear indentations, and the pigmentation in the irises of the eyes are some of the changes taking place.
This week the umbilical cord, which provides nourishment and disposes of the baby’s wastes, develops from the implantation site of the blastocyst. In addition, the baby’s digestive tract and lungs continue to form. At this point, should you be pregnant with twins, some of the early signs that you are, would be:
- Faster rate of weight gain
- Greater tendency to retain water
- Increased fatigue.
The good news is that you will more than likely be in the final stages of your pregnancy symptoms. Morning sickness and fatigue should be starting to let up now. You may have even lost a few pounds, or even gained a few, either are normal at this stage of your pregnancy.
Now at a length: from crown to rump and a weight of 0.03 ounces (0.8 grams), your baby is constantly adapting to life inside the uterus. Around this time you’ll develop a mucous plug, which forms in the opening of the cervical canal and seals off the uterus to protect your growing child. Eventually you’ll lose this plug as your cervix dilates in preparation for labor.
Revision date: June 14, 2011
Last revised: by Sebastian Scheller, MD, ScD