The ability to become pregnant and carry the pregnancy to term is known as fertility. Infertility, also called subfertility, is medically defined as having unprotected intercourse for one year and not becoming pregnant. Even if they became pregnant easily, women may experience many miscarriages, known as repeated pregnancy loss (RPL).
Causes of InfertilityEdit
Endometriosis, blocked tubes, annovulation, luteal phase defect, hostile cervical mucus, hormonal disorders such as abnormal thyroid function and PCOS.
Repeated Pregnancy LossEdit
Over 25% of pregnancies end in miscarriage, and it is very common for a woman to have one or two miscarriages before carrying a pregnancy to term. If a woman has four miscarriages in a row, however, she is considered to have repeated pregnancy loss, or RPL. Possible causes of RPL should be tested for by a doctor, possibly a reproductive endocrinologist (RE).
Low total sperm count, low percentage of motile sperm, low percentage of normally shaped sperm.
Drugs that induce ovulationEdit
In women who do not ovulate, or ovulate only rarely, the drug clomifene citrate (Clomid) may be prescribed. Clomid may also lengthen the luteal phase of women with luteal phase defect. However, clomid decreases the production of cervical mucus, possibly decreasing the number of sperm that are able to pass through the cervix into the uterus and fallopian tubes.
More powerful drugs - known as injectables - may be used if several unsuccessful cycles with Clomid or similar drugs do not result in pregnancy. While injectable cycles have higher pregnancy rates, they also have higher risks of conceiving multiple fetuses.
In intra-uterine insemination (IUI), a medical practitioner places the man's sperm directly inside the woman's uterus. This bypasses the cervix, overcoming any problems with cervical mucus and sperm transport.
In Vitro FertilizationEdit
In in vitro fertilization (IVF), the woman is given drugs to cause many ovarian follicles (eggs) to mature instead of the normal one or two per menstrual cycle. These eggs are harvested, and combined in a laboratory with the man's sperm. The resulting embryos are monitored for quality, and several days after fertilization one or more embryos are placed in the woman's uterus. Any embryos not transferred that cycle are frozen for future use.
Donor Eggs and SpermEdit
Some couples choose to use eggs, sperm, or both, from donors. This may be because the man or woman does not have any eggs or sperm of their own; their eggs or sperm are unable to create embryos; or one or both members of the couple have genetic health problems that they do not want to pass on. If the couple chooses to use donor eggs, they must use IVF. If they are only using donor sperm, they may use IVF, IUI, or artificial insemination (AI). (In AI, the semen is placed in the vagina, near the woman's cervix, with a diaphragm or diaphragm-style menstrual cup.)
If the woman is not capable of carrying a pregnancy, they may hire a surrogate. In traditional surrogacy, the man's sperm, or donor sperm, is used to impregnate the surrogate (through AI or IUI). Any resulting child is genetically the child of the surrogate. In gestational surrogacy, the intended mother's eggs, or donor eggs, are used to create embryos through IVF. Any resulting child is genetically unrelated to the surrogate.