**2. Infertility**

Infertility can be defined as the inability to conceive after one full year of regular, normal sexual intercourse without the use of any contraception. Infertility is a major health problem that affects a sizeable population in the world and the cause may be the male or female, with more or less 30–40% being due to the male factor or around 50% due to the female factor [5–7].

Oligospermia, poor semen quality, low sperm motility, anatomical defects like block in vas deferens, infections leading to inflammation of seminal vesicles, epididymis or prostate, genetic abnormalities like Klinefelter syndrome could represent major causes of male infertility [5–7].

Irregular ovulation, poor oocyte quality, blocked fallopian tubes due to infection or endometriosis are some of the causes of female infertility. Polycystic ovaries, primary and secondary amenorrhea, pelvic inflammatory disease (PID) and hostile cervical mucus may be less common causes of female infertility apart from cancer chemotherapy [6, 7].

#### **2.1 Assisted methods of reproduction (ART)**

35 years of assisted reproductive technology (ART) use has become one of the standard procedure of infertility treatment. More than 5 million babies are born after ART (1–5% births). Therefore, it is necessary to monitor, evaluate and trace the modifications of procedures with growing technical development of medical practice in the field of reproductive medicine [8].

Assisted reproduction techniques (ARTs) are defined as "all treatments or procedures that include the in vitro handling of both human oocytes and sperm or embryos for the purpose of establishing a pregnancy" [8].

#### **2.2 Ovulation induction**

 Ovulation induction is useful in women with anovulatory or irregular ovulatory cycles. A hormone medication in tablet or injection form is administered to stimulate the production of follicle stimulating hormone (FSH). FSH then will help in the development of one or more follicles. Another hormone will then be administered to cause the release of ovum. The couples will be advised to have sexual intercourse during this period, creating a greater chance for conception [9].

#### **2.3 Artificial insemination (AIH)**

 Artificial insemination (AIH) is also known as intrauterine insemination (IUI). AIH is recommended in cases of unknown etiology in women with healthy fallopian tubes or in men with erectile dysfunction or mechanical trauma which may hamper normal intercourse with the women. In certain cases before cancer chemotherapy or due to other reasons, semen stored in the sperm bank may be used for AIH [10].

#### **2.4 In vitro fertilization (IVF)**

In vitro fertilization (IVF) is a process in which ovum and sperm are allowed to fertilize in vitro. The process involves retrieval of ovum from the women and semen from the male. If successful, the embryo is then implanted in the uterus of the woman using embryo transfer [11].
