- The 13-week mark is a monumental time for many moms. Thirteen weeks marks the end of the first trimester, where spontaneous miscarriage more frequently occurs. At this point, the mothers' body has adjusted to the increasing levels of hormones in her blood and she should begin to feel much better. Morning sickness may also begin to diminish.
- The baby weighs approximately 14 to 20 grams which is approximately 1 1/4 ounces. The length from the crown of the head to the buttocks is approximately 2.6 to 3.1 inches. The baby's head, which has been significantly larger than its body for the first 12 weeks, is now about 1/3 the size of the total body.
- The baby's body is covered with a soft, fine hair called lanugo. The toes and fingers are well formed and separate. Sockets for all 20 teeth are now in the gums. The ears have now moved into the correct position on the side of the head, and the eyelids meet and will fuse together. The kidneys and urinary track are functioning now, so the baby begins to process and urinate small portions of the amniotic fluid that has been swallowed.
- Depending on the obstetrician or midwife, the mother may have had an ultrasound by this point. The size and weight of the baby are approximations and are used to give a general overview of growth. In the event that the obstetrician or midwife has a concern about fetal growth, he may schedule the mother for additional testing. Keep in mind that babies grow at different rates and all the risks and benefits for any testing, if needed, are explained.
- Although the threat of spontaneous first trimester miscarriage may be over, you will need to contact your health care provider if you experience vaginal bleeding (filling more than one pad an hour is considered heavy bleeding) or your amniotic sac ruptures. Your health care provider may monitor you more closely if you have an incompetent cervix (a cervix that will not stay closed), or if you have a history of miscarriages, stillborns or genetic complications.
