In traditional surrogacy (also known as the Straight method) the surrogate is pregnant with her own biological child, but this child was conceived with the intention of relinquishing the child to be raised by others such as the biological father and possibly his spouse or partner. The child may be conceived via sexual intercourse (NI), home artificial insemination using fresh or frozen sperm or impregnated via IUI (intrauterine insemination), or ICI (intracervical insemination) which is performed at a fertility clinic. Sperm from the male partner of the 'commissioning couple' may be used, or alternatively, sperm from a sperm donor can be used. Donor sperm will, for example, be used if the 'commissioning couple' are both female or where the child is commissioned by a single woman.
In gestational surrogacy (aka the Host method) the surrogate becomes pregnant via embryo transfer with a child of which she is not the biological mother. She may have made an arrangement to relinquish it to the biological mother or father to raise, or to a parent who is unrelated to the child (e. g. because the child was conceived using egg donation, sperm donation or is the result of a donated embryo). The surrogate mother may be called the gestational carrier.
Altruistic surrogacy is a situation where the surrogate receives no financial reward for her pregnancy or the relinquishment of the child (although usually all expenses related to the pregnancy and birth are paid by the intended parents such as medical expenses, maternity clothing, and other related expenses).
Commercial surrogacy is a form of surrogacy in which a gestational carrier is paid to carry a child to maturity in her womb and is usually resorted to by higher income infertile couples who can afford the cost involved or people who save and borrow in order to complete their dream of being parents. This procedure is legal in several countries including in India where due to high international demand and ready availability of poor surrogates it is reaching industry proportions. Commercial surrogacy is sometimes referred to by the emotionally charged and potentially offensive terms "wombs for rent", "outsourced pregnancies" or "baby farms".
In all cases a contract needs to be drawn up and agreed upon by all parties and an escrow agent hired to assist with the finances.
(Again we looked to Wikipedia)
Surrogacy Escrow Services