It is the most common type of Assisted Reproductive Technology (ART) treatments. In this treatment, the sperm fertilizes the ovum outside the human body and the physicians implant the fertilized egg into the uterus of a substitute mother to conceive. Normally, the IVF cycles takes at least four to six weeks to complete successfully. However, sometimes, women need to end multiple cycles to get pregnant.

According to the medical science, women under the age of 35 have 30% – 40% chances of getting pregnant through IVF and this percentage falls when the age increases. Therefore, most of the surrogate agencies prefer the women below 30 years to work as a surrogate as the age is less, the chances of getting pregnant through IVF will be more. The IVF treatment has four major steps.

Ovarian Simulation: In this step, the intended mother should take the fertility drugs prescribed by the doctor. These drugs is taken for 12 to 14 days as instructed by the doctors. These drugs help simulate the ovaries of a woman to produce multiple healthy ovum instead of producing only one ovum during the menstruation. Successful In-Vitro fertilization treatment needs multiple eggs as some eggs may or may not fertilize during the process. The doctors use ultrasound therapy and blood test to find when the ova are ready for returnal.

Egg retrieval: Once the ova are ready for retrieval, the doctors do transvaginal ultrasound aspiration to retrieve ova from the intended mother's body. Doctors remove oocytes from the ovary of a female body to enable fertilization outside the human body. A small amount of anesthesia is given to the patient to do this therapy. Once the matured ova are located through the ultrasound guidance, physician inserts needle to the follicles and retrieve the matured ova with suction.

Insemination: After retrieving the ova, the doctors check them and sort the best that holds the most potential for successful fertilization. The doctors place the most potential ovum in a cultured medium of IVF to expect insemination. Meanwhile, doctors separate sperm from the intended father's semen. The best swimmer is then added to the ovum stored in the incubator.

Fertilization: Normally, within a few hours, the best swimmers penetrate the ovum and fertilize it. The doctors confirm the fertilization only when they visually see formation of two pronuclei. These pronuclei are the foundation of embryo formation. The two pronuclei are united to form the nucleus of a zygote which then divides to become an embryo. One can see two to four cell embryo approximately two days after formation of an embryo. On the third day, a six to ten cell embryo will be formed. One the fifth day, the fertilized embryo appears as a blastocyst, a fluid cavity that results in formation of placenta and fetal tissues. At this stage, the fluid cavity is injected to the uterus of a surrogate mother to carry pregnancy for the rest nine months.

Gestational surrogate is the most accepted type of surrogacy where the baby born through this process is genetically related to the intended parents (if their sperm and eggs are used to form zygote) or related to the donor who is anonymous.