Biomedical

Quick Guide to Assisted Reproductive Technology (ART)

Infertility is the inability of a hetero-couple to achieve pregnancy (conception) after 12 months of unprotected, regular sexual intercourse.

Male Infertility can happen due to,

  1. Oligospermia or low sperm count,
  2. Poor sperm quality- Motility Shape Abnormality
  3. Autoimmune disorder – the body produces antibodies against its own sperm.

Female infertility can occur due to,

  1. Irregular ovulation caused by the hormone imbalance or absent ovaries or tubes,
  2. Physical blockage like Fibroids or Endometriosis/abnormal fallopian tubes,
  3. Vaginal secretions Hormones or certain disease

What is Assisted Reproductive Technology?

Assisted Reproductive Technology

Assisted Reproductive Technology (ART) makes use of medical techniques, such as drug therapy, artificial insemination, in-vitro fertilization to enhance fertility. ART procedures include fertility treatment in which both eggs and sperms are handled in the laboratory. It encompasses any procedure where the gamete is manipulated or removed from the body and returned, either as an oocyte or an embryo.

Why ART?

  • A large percentage of couples face difficulties in getting pregnant. Many have found success with ART.
  • ART involves a number of different procedures to help address fertility problems and increase the likelihood of pregnancy.

History of ART

  • 1959: Chinese scientists performed the first successful IVF births in rabbits
  • 1973: First human IVF pregnancy was achieved in Australia, but unfortunately, it ended in an early miscarriage.
  • 1978: First IVF baby named Louise Brown was born in Oldham, England.
  • 1984: Government of Victoria passed the first-ever legislation to regulate IVF and associated human research.
  • 1984: First surrogacy embryo-transfer (ET) baby was born in California, USA
  • 1992: First successful pregnancy using Intra-cytoplasmic Sperm Injection (ICSI)
  • 1996: Dolly, the sheep, was the first cloned mammal born using Somatic-Cell Nuclear Transplant (SCNT)
  • 1998: Baby Hannah was the first baby born via denoted embryos
  • 2000: First birth using cryopreserved oocytes and frozen sperm
  • 2009: Samrupa, the world’s first cloned Murrah buffalo calf in Karnal, India. But unfortunately, she died 5 days later due to due to a lung infection.
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Types of Assisted Reproductive Technologies (ART)

1. Timed Intercourse

As its name suggests, it is the process of timing intercourse to optimize the fertility period. Females are administered to promote ovulation, and monitored by regular ultrasounds to determine the precise timing of the egg release. Based on this information, the doctor can advise on the best timing of intercourse.

2. Artificial Insemination (AI)

It is a process of implanting sperms into the female reproductive tract with the purpose of impregnating, by using artificial means.

  • Intracervical insemination (ICI): ‘Unwashed’ or raw semen may be used. The semen is injected high into the cervix with a needleless syringe.
  • Intrauterine insemination (IUI): ‘Washed’ sperm injected directly into a woman’s uterus
  • Intratubal insemination (ITI): Semen is injected into the intrafallopian tube
  • Intraperitoneal insemination (IPI): Prepared semen is injected into Douglas pouch.
  • Problems with AI
    • Ovulation must be induced or synchronized by exogenous gonadotropins, which frequently do not work.
    • There are gross female anatomical differences, i.e., two uteri in marsupials, complex cervix in oryx, rhinoceros, and others.
    • The actual site of semen deposition frequently unknown, usually performed trans-abdominally by laparoscopy (invasive surgery).

3. In-vitro fertilization (IVF) & Embryo Transfer (ET).

IVF is a method in which egg cells are fertilized by sperm cells outside the mother’s womb. The IVF process begins with follicle suppression, followed by controlled ovarian hyperstimulation to stimulate egg production. Once that process is completed, the eggs are aspirated from the follicles and fertilized in a laboratory setting. After an incubation period, viable embryos are selected and transferred into the mother’s womb. To increase the chance of pregnancy, multiple embryos are implanted at a time.

  • Gamete Intra-fallopian Transfer (GIFT): The harvested eggs/oocytes are mixed with the prepared sperms suspension, and placed back into the woman’s Fallopian tubes during a single laparoscopy. Simple process, physiological & cheap than IVF, but the chances of success are lower than IVF.
  • Zygote Intra-fallopian Transfer (ZIFT): The eggs/oocytes are collected by transvaginal ultrasound-guided ovum retrieval. However, this requires two interventions, and IVF results are equal or better than this process.
  • Intra-cytoplasmic Sperm Injection (ICSI) is an in-vitro fertilization procedure in which a single sperm is injected directly into an oocyte/egg. This procedure is used to overcome male infertility and always used in conjunction with IVF. In ICSI, a specialist draws a single sperm into a needle and injects it directly into an egg. The fertilized eggs are then left to culture for a few days before being transferred back to the woman’s uterus.
  • Drawbacks of IVF
    • Multiple Pregnancies: About 20% of IVF pregnancies result in multiple babies when transferring 3 embryos or less. This number increases to 40% when transferring more than 3 embryos.
    • Ovarian Hyper-Stimulation Syndrome (OHSS) is caused by IVF medications. It can manifest as ovarian enlargement, abdominal distension and affects up to 7% of IVF patients.
    • Pelvic Infection, however, serious infection is rare in IVF.
    • Hemorrhaging can occur during egg collection.
    • Spontaneous Abortion
    • Intrauterine Growth Restriction
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4. Somatic cell nuclear transfer (SCNT)

SCNT is a technique in which the nucleus of a somatic (body) cell is transferred to the cytoplasm of an enucleated egg. It has been attempted in giant pandas (Chen et al. 2002), Argali sheep (White et al. 1999), gaur (Lanza et al. 2000), but these attempts did not result in viable offspring. But a healthy offspring resulted in trans-species cloning in mouflon sheep (Loi et al. 2001). The most practical application is in the reproductive cloning of farm animals that have exceptional qualities like abilities to produce large quantities of milk. Advancements in SCNT have provided us the ability to create life-saving therapies developed using each person’s DNA.

5. Parthenogenesis

It is a process in which an embryo is created solely from a female oocyte without any genetic contribution from a male. It occurs naturally in invertebrates like aphids, Daphnia, rotifers, nematodes, and others. But it can also be induced in mammalian oocytes by providing in-vitro stimuli. It is sometimes referred to as a “virgin birth.” The experimental induction of parthenogenesis in mammals began with the pioneering studies of Gregory Pincus and his collaborators. (Read More)

Conclusion

Despite all the advances in ART, there are still various ethical and moral issues that still to be addressed. As we move further into these artificial methods of reproduction, there might be other issues that we haven’t even thought of at this current point in time. Therefore, laws need to be put in place to protect the rights of everyone involved in the process. Furthermore, the costs of these treatments are really high and prohibitive to lower-income families.

However, despite all its drawbacks, these biomedical advances have provided a beacon of hope for couples who are unable to have biological children.

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