It is really quite amazing to consider that the “non pregnant” uterus is about the size of a pear yet during pregnancy it expands to the size of a watermelon to eventually support a mature fetus. The uterus is composed of pliable cells that have the elasticity needed to support this growth.
The uterus must be free of large obstructions, such as endometrial polyps and fibroids (leiomyomas), for successful implantation and pregnancy to result, These conditions are often observed on the hysterosalpingogram (HSG), during hysteroscopy or at the time of 3D saline sonogram. (These tests are discussed in the “Fertility Tests” section of the Web site). Sometimes obstructions can be removed laparoscopically or by using the hysteroscope during outpatient surgery.
The uterus must also be normally shaped (triangular) and free of congenital defects such as the “double uterus (uterus didelphys) which has two “horns”, unicornuate uterus (only one half of the normal uterus), uterine septum (muscle growth from the top of the inside of the uterus that protrudes into the cavity) and a bicornuate uterus (heart shaped). Some of these defects such as a uterine septum can be corrected by a skilled reproductive surgeon.
The lining of uterus is known as the endometrium and consists of cells that can rapidly divide and develop under the influence of estrogen and progesterone. This development is necessary to provide an environment for optimal embryonic/fetal development. Unfortunately, some of these endometrial cells may enter the bloodstream during menses resulting in endometriosis. Sometimes the entire endometrium (lining) is not sloughed off during menses and the retained tissues forms an endometrial polyp. Large endometrial polyps can act almost like an IUD and should usually be surgically removed prior to further attempts at pregnancy.
When the uterus is severely damaged (from fibroids, prior surgery, or congenital abnormalities), the only available option may be to use a gestational surrogate mother. There are two types of surrogates known as gestational or traditional. A traditional surrogate becomes pregnant using her own eggs combined with the father's sperm using either intrauterine insemination (IUI) or in vitro fertilization (IVF). A baby born from traditional surrogacy has the genetic makeup of the surrogate and the father. Because of the custody battles that have occurred regarding the legal rights of the traditional surrogate, infertility programs no longer offer this type of therapy.
A gestational surrogate carries the embryo produced from an IVF cycle typically using both the parents’ gametes (sex cells, egg and sperm). A baby born using gestational surrogacy has the genetic makeup of the father and mother. Donor sperm or donor egg could also be used in a gestational surrogacy case if needed.