The inability of a couple to achieve conception after a year of unprotected intercourse – six months if the woman is over 35 – or the inability to carry a pregnancy to live birth. Also see Subfertility.
Intracytoplasmic Sperm Injection (ICSI)
A single sperm is injected directly into an egg cell with microscopic guidance. If fusion takes place, the embryo is transferred into the uterus for implantation. This clinical procedure is often used in conjunction with In Vitro Fertilisation if the male partner has a very low sperm count, low sperm motility or poor-quality sperm.
Intrauterine device
(IUD): A contraceptive device consisting of a small piece of bent plastic, which prevents pregnancy by changing the environment of the uterus.
Intrauterine Insemination (IUI)
A procedure whereby sperm are deposited directly into the uterus via the cervix using a catheter.
Irregular ovulation
Menstrual cycles that vary more than a few days in length from month to month are considered irregular. Most menstrual cycles occur about every four weeks, with the normal range lasting between 24 and 35 days.
In Vivo
A process that occurs inside the body.
In Vitro Fertilization (IVF)
Eggs produced with the assistance of fertility drugs are retrieved from the woman’s body and fertilized by sperm in a laboratory environment. The resulting embryos are transferred via catheter to the uterus.
Immune system disorders
On rare occasions, an impaired immune system may regard the egg or sperm as a ‘foreign body,’ and attack it as an ‘intruder.’
Implantation
The process whereby the embryo embeds itself into the lining of the uterus. The cells from the embryo eventually connect with the mother’s blood vessels to form the placenta. See also ectopic pregnancy.