Assisted reproductive technologies

Many couples desperately want to have a baby. However God has not given the pleasure of becoming parents to all the couples. Infertility has now become a common problem affecting about 7% of the US population and is defined as an inability to conceive after one year of regular unprotected sexual intercourse (CDC, 2005). With advancement in the field of technology in last two decades, the ability of the physicians to help infertile couples achieve a pregnancy has significantly increased. This has been made possible due to introduction of assisted reproductive technology (ART).

According to the definition given by Center of disease Control (CDC 2005), ART includes all fertility treatments in which both eggs and sperm are handled. In general, ART procedures involve surgical removal of eggs from a woman’s ovaries, combination of egg with the sperm in the laboratory, and returning them to the woman’s body or donating them to another woman. They do not include treatments in which only sperm are handled (like intrauterine or artificial insemination) or procedures in which a woman takes medicine only to stimulate egg production without the intention of having eggs retrieved for the purpose of ART (CDC 2005).

Various types of techniques in ART are: in vitro fertilization (IVF), gamete intra fallopian transfer (GIFT) and zygote intra fallopian transfer (ZIFT). As shown in figure 1, IVF involves extraction of the woman’s egg, fertilization of egg with the sperm in the laboratory followed by the transfer of resulting embryos in the woman’s uterus through the cervix (CDC 2005). For some IVF procedures fertilization involves a special technique called intra cytoplasmic sperm injection (ICSI) which involves direct injection of sperm into the cytoplasm of the egg.

GIFT(a variant of IVF) involves using a fiber-optic instrument called laparoscope to guide the transfer of unfertilized eggs and sperms (gametes) into the woman’s fallopian tube through small incisions on the woman’s abdomen. ZIFT (another variant of IVF) involves fertilizing a woman’s egg in the laboratory and then using a laparoscope to guide the transfer of fertilized egg (zygote) into her fallopian tubes (CDC 2005). According to CDC (2005), in vitro fertilization can be classified depending on whether the procedure involved woman’s own eggs or eggs from a donor (another woman).

It can also be categorized according to whether the procedure used embryos which were newly fertilized (fresh) or had been previously fertilized, frozen and then thawed. Figure 1 Procedure of in vitro fertilization. The figure shows how fertilized oocyes (embryos) are introduced trancervically into the uterus. Embryos in 10 to 50 µL of media are placed through the catheter at 0. 5 cm from the upper fundus (uterus). Source: Chang, P. , & Sauer, M. (1999). Atlas of Clinical Gynecology: Reproductive Endocrinology. Morton Stenchever, M. A. , & Mishell, D. R. (EdS).

United States: McGraw-Hill. Possible Points in Favor of IVF IVF can be considered as a favorable technique for treatment of infertility (especially that due to tubal factors). Since past 2 decades popularity of IVF as an option for treating infertility has massively exploded. This is evident from the fact that as many as 1% of all births in US in 2003 were conceived in-vitro (CDC, 2005). IVF is now increasingly being used for infertility due to many causes as discussed below.

Success rate of IVF Wright, Schieve, Reynolds, and Jeng (2003) have reported a national live-birth delivery per transfer rate of 30. 8% for the year 2000 using assisted reproductive technologies. This success rate is high enough to encourage a desperate infertile couple to take a chance with the procedure. The success rate of ART depends on many factors like: the age of the woman undergoing ART, whether she had previously given birth, whether she had previously undergone ART, and the infertility diagnosis of both the female and male partners. The woman’s age has been found to be one of the most important factors to influence the success rate of ART.

Wright, Schieve, Reynolds and Jeng (2003) observed that the rates of life birth ranged from 38% among women aged <35 years to 6% among women aged >42 years. Nationally, the highest live-birth rates was found in women aged <35 years (38%). IVF is used in treating infertility due to many causes. IVF has been found to be successful in cases of infertility both due to female factor as well as some cases associated with male factor (Schieve, Reynolds, & Jeng, G. 2003).

The various types of infertilities as described by Schieve, Reynolds, & Jeng, G.(2003) which can be treated by IVF include the following: • Infertility due to tubal factors – IVF serves as a very useful option to achieve pregnancy in cases where the woman’s fallopian tubes are blocked or damaged which cause difficulty for the egg to be fertilized or for an embryo to travel to the uterus. The only other alternative in patients of complete tubal blockage is surgical reconstruction of tubes which is associated with increased health care costs and poor outcome (Van Voorhis, et al. 1997).

• Infertility due to ovulatory dysfunction – if the ovaries are not able to ovulate normally( polycystic ovarian syndrome etc) and do not respond to ovulation induction by use of medicines or hormones, IVF serves as a useful option • Infertility due to diminished ovarian reserve – the ability of the ovary to produce eggs may be reduced due to congenital, medical or surgical causes or advanced age (>40 years). In these cases IVF presents as the only option to produce pregnancy. • Infertility due to endometriosis – endometriosis is a disorder where uterine lining is present in abnormal locations (most common location being the ovaries).

Endometriosis produces infertility by both affecting the fertilization of the egg and embryo implantation. IVF serves as one of the most effective option for such patients. • Infertility due to uterine factors – IVF serves as an option for treating infertility resulting due to structural or functional disorders of the uterus. • Infertility due to male factor – Some cases of male infertility like a low sperm count or problems with sperm function that cause difficulty for a sperm to fertilize an egg under normal conditions can be treated with IVF.

• Infertility resulting from immunological problems, chromosomal abnormalities, cancer chemotherapy or serious illnesses can also be treated with IVF. IVF is a lucrative option for fertility preservation in young girls with cancer who lost their fertility due to radiotherapy which was administered for treating cancer. • Unexplained infertility –IVF proves useful in cases of unexplained infertility where no abnormality could be detected in either partner.

GIFT and ZIFT as an option for treating infertility in patients with patent tubes Since the procedures like GIFT and ZIFT require placement of gametes or zygote respectively in the fallopian tubes, these procedures can only be used in infertile patients with patent tubes (CDC, 2005). The results of the study done by Dooley, Urm-Howe, Savvas and Studd (1988) indicate that GIFT is a successful method of producing pregnancies in couples with long-term infertility in the presence of patent tubes.

According to them this technique is more physiological than IVF in cases where tubal patency has been confirmed, as it allows normal gamete transport and presents favorable milieu for early embryonic development.

GIFT may also be more acceptable to certain religious and cultural groups who oppose IVF as the ethical problems (like embryo modification, embryo research, etc) related to in vitro fertilization are avoided with GIFT. Dooley et al. reported a higher success rate of GIFT in comparison to that of IVF and concluded that GIFT in comparison to IVF is a superior method of treating infertile patients with patent tubes. However since their study involved a small number of subjects, larger studies are required in future to further prove this point.

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