Glossary of Terms

Infertility is defined as failure for a couple to conceive after 12 months of unprotected sexual intercourse when the female partner is under the age of 35, or 6 months of unprotected intercourse if she is 35 years of age or older. Whether or not a couple describes themselves as “trying to conceive”,  time spent in a sexual relationship in the absence of the use of an effective method of contraception does count toward these time limits.

Infertility testing should begin with an evaluation of sperm quality for the male partner, and evaluation of the fallopian tubes (checking for blockage) and of ovulation and ovarian reserve for the female partner. Further testing is individualized, based upon the results of these tests or upon the couple’s particular medical history.

Ovulation induction is a medical infertility therapy in which the ovaries are stimulated with various fertility drugs in order to initiate ovulation (egg production and release), or to augment ovulation. Women diagnosed with polycystic ovarian syndrome may be candidates for treatment with insulin-sensitizing drugs such as metformin. Clomiphene citrate is an orally administered drug which stimulates ovulation and has a very low risk of multiple births. The aromatase inhibitors, letrozole and anastrozole, are drugs which have been shown to induce ovulation with similar outcomes as clomiphene citrate. Gonadotropins (human menopausal gonadotropins or recombinant follicle stimulating hormone) are available only in injectable form and are the most potent stimulators ovulation. Gonadotropins have a higher pregnancy rate but have a 20% frequency of twin pregnancy and a 5% frequency of triplet or even higher multifetal pregnancy.

IUI (intrauterine insemination) is an artificial insemination technique in which washed sperm is placed in the uterine cavity on the day of ovulation. Sperm washing separates the seminal plasma, which cannot be placed into uterus, from the sperm cells and concentrates the sperm into a 5 microliter ( 1/10 of a teaspoon) volume.  Thus, the number of motile sperm that reach the egg in the fallopian tubes is greatly increased.

In Vitro Fertilization-Embryo Transfer treatment involves ovulation induction with gonadotropins for the purpose of producing multiple mature oocytes(eggs) from the ovaries, followed by oocyte harvesting, introduction of sperm to the eggs in the IVF laboratory to allow fertilization to occur, and then after three to five days of incubation, transferring embryo(s) into the uterus. After the embryo transfer step, the embryo(s) must continue sufficient growth and development in order to implant into the uterine wall and produce a successful pregnancy. IVF pregnancy rates ( are dependent on a number of variables, the most important of which is the age of the female partner. Still, IVF treatment currently offers the highest success rate of all fertility therapies, regardless of age or past medical history.

Intracytoplasmic Sperm Injection (ICSI) is a microscopic procedure to assist the sperm in fertilizing the egg by directly injecting the sperm into the cytoplasm of the egg. This assisted fertilization is especially helpful in otherwise untreatable cases of severely low sperm counts, and produces the same pregnancy rates as we see with IVF done for female factor(s) when the husband's sperm count is normal.

Assisted Hatching is a microscopic procedure in which an opening is made in the outer shell of the embryo, the zona pellucida, in order to promote the embryo’s ability to attach itself to the uterine lining. This micromanipulation procedure is especially helpful for couples for whom there have been multiple failed IVF treatments, or for whom the wife is over 39 years old, or has diminished ovarian reserve.

Embryo Cryopreservation or embryo freezing offers a second chance to conceive from the one IVF treatment cycle. Not all couples going through IVF will have extra embryos that are suitable for freezing. Pregnancy rates from previously cryopreserved embryos have improved to the extent that they are approximately the same as with fresh embryos.

Polycystic Ovarian Syndrome is a clinical syndrome of irregular menstrual periods and symptoms of male hormone excess (acne, oily skin, facial hair growth), and a characteristic ultrasound appearance of the ovaries described below.  Two of these 3 features is sufficient to make the clinical diagnosis of PCOS.  The cause, while not completely understood, is considered to be insulin resistance at least to some degree. A characteristic pattern, easily visible by transvaginal ultrasound, of multiple small follicles arranged around the perimeter of the ovary gives this syndrome its misleading name. Ovulation disturbances are common in this syndrome, making ovulation induction treatment necessary to promote conception. Metformin treatment in combination with fertility drugs is often beneficial for patients with PCOS.

Ovarian Reserve may be tested by checking a single AMH (anti-Mullerian hormone) blood test on preovulation phase of the cycle or by a cycle day 2 or 3 blood test for FSH, LH, andEstradiol. Both tests are utilized to predict the woman's sensitivity to fertility drugs and to help counsel couples regarding the best treatment options for each couple

Donor Egg IVF may be accomplished using fresh or frozen eggs from an anonymous donor, or with fresh eggs from a known donor as long as that donor has no genetic relationship to the intended father. Success rates are predicted by the age of the donor, and not the age of the recipient. Donors undergo the oocyte stimulation and retrieval procedure. Then the donor’s eggs are fertilized by the intended father’s sperm and embryos are later transferred to the intended mother’s uterus. The screening procedures for qualifying potential oocyte donors, whether known or anonymous, are set forth by the FDA and the American Society of Reproductive Medicine.

Preimplantation Genetic Diagnosis (PGD) offers the opportunity to test an embryo for certain diseases caused by a mutation in a single gene (such as Cystic Fibrosis, Sickle Cell Anemia, and Huntington’s Chorea, to name a few ) prior to the embryo transfer procedure. This technology is beneficial when an inheritable disease is known to occur in one’s family or when DNA screening tests on the couple going through IVF are positive. 

Preimplantation Genetic Screening (PGS) offers the opportunity to test an embryo for all 23 pairs of chromosomes prior to the embryo transfer.  This technology is beneficial for some couples with recurrent miscarriages and for some older moms-to-be.

Blastocyst is the last stage of development an embryo must reach before it implants itself into the uterine wall. Only about 40% of human embryos will be capable of reaching this stage of development in the IVF laboratory after 5 to 6 days of incubation. Transferring blastocyst stage embryos on day 5 compare to transferring embryos at the 6-8 cell stage has been successful at reducing the multiple birth rates and maintaining the same high live birth rates in IVF treatments.


Contact Us (New Patients ONLY)

North Houston Center for Reproductive Medicine

11 Vision Park Blvd
Suite 110 
The Woodlands, TX 77384
(281) 444-4784

350 Kingwood Medical Drive
Suite 320
Kingwood, TX 77339
(281) 444-4784