Chapter 3: Assisted Reproduction Techniques
Even with all the causes outlined above, infertility can still be unexplained. Unexplained infertility accounts for approximately 5-10 % of all cases of infertility. Despite obtaining a detailed history, doing an appropriate physical exam, and performing all the necessary tests and procedures, fertility may still go unexplained.
Assisted Reproduction Techniques
Assisted reproductive techniques are a set of procedures that can be used to aid the fertility process. These techniques range from timed sexual intercourse, to highly specialised surgical procedures preformed by skilled fertility specialists.
Timed Intercourse: This involves timing intercourse with ovulation. Having sex 5 days before ovulation and on the day of ovulation seems to be the most successful. Ovulation predictor kits are a useful aid to help synchronize this process. Couples with low sperm counts should have sex every other day, while daily intercourse should be fine for those with normal and high counts.
Artificial Insemination (AI): The insertion of sperm into the female reproductive tract. Includes insemination at the cervix and intra-uterine insemination (IUI).
At-home Insemination (AHI): This can be done with donated sperm (though proper testing is suggested before doing this) or with the husband or partner's sperm. This is best done with an oral medicine syringe, rather than the often joked about "turkey baster". Semen is collected in a container or thawed from donor, collected into the syringe and slowly injected into the vagina as close to the cervix as possible.
Intra-uterine Insemination (IUI):Semen is collected and "washed" or "spun." The sperm is then injected through the cervix, into the uterus using a small catheter.
Intra-tubal Insemination (ITI): This is similar to IUI, but the catheter goes beyond the cervical opening and deposits sperm in the fallopian tube. This is a more uncomfortable procedure and may not greatly improve chances of success.
In Vitro Fertilization (IVF): IVF is one of the most popular reproductive options used by infertile couples. It involves the recruitment of mature embryos after a 6-8 week cycle of fertility drugs. After the follicles mature ova (eggs) are carefully removed from the ovaries for fertilisation. These eggs are combined with a sperm specimen under controlled conditions in a fertility laboratory. After a waiting period of about 8-12 hrs the samples are examined for signs of fertilisation. The fertilised eggs are then implanted into the uterus of the female. To optimise pregnancy, more then one fertilised egg is implanted, but to minimise multiple pregnancies only about 3-4 fertilised eggs are used.
Intra-cytoplasmic Sperm Injection (ICSI): Intra-cytoplasmic sperm injection is used to treat severe male infertility, as when little or no sperm are ejaculated in the semen. Immature sperm collected from the testicles are usually unable to move. In ICSI the immature sperm are physically injected into the cytoplasm offering more control on the fertility process. This process however is more delicate then IVF and requires more precision. ICSI is often tried when repeated attempts of IVF are unsuccessful.
Assisted Hatching or Assisted Zygote Hatching (AH, AZH): Assisted hatching involves putting a small opening in the embryo's outer layer called the zona pellucida. The embryo must break free of the zona pellucida to hatch out prior to implantation in the uterine lining. AH is often used for older women (38 or over), who often have a more rigid zona pellucida.
Non-surgical Embryonic Selective Thinning (NEST): Similar to assisted hatching, the main purpose is to weaken the outer shell to facilitate implantation of the fertilized egg and establish pregnancy. In this case however the embryo is slightly shaved prior to implantation to thin the zona pellucida rather than put a hole in it.
Gamete intra-Fallopian Transfer (GIFT): Combining eggs and sperm outside of the body and immediately placing them into the fallopian tubes to achieve fertilization (this is not generally practised in the UK).
Immature Oocyte Retrieval: Immature eggs are collected and grown in the lab using fertility drugs. When mature, they are fertilized and replaced in the same manner as IVF.
Zygote Intra-fallopian Transfer (ZIFT): This procedure involves IVF with the transfer of the zygote into the fallopian tube -- a combination of IVF and GIFT.
Stimulated Cycle Oocyte Retrieval in (office) Fertilization (SCORIF): This is a stimulated cycle using fertility drugs, like IVF. The eggs are then retrieved and placed in a capsule with sperm. The capsule is then inserted into the vagina so that fertilization takes place within the woman's body. After fertilization (2-3 days), the embryos are transferred into the woman's uterus.
Non-stimulated (cycle) Oocyte Retrieval in (office) Fertilization (NORIF): Natural cycle where eggs are retrieved, placed in a capsule with sperm and the capsule is inserted into the woman's vagina for fertilization. In 2-3 days the embryos are transferred in the uterus.