The adoption process is not thorough simply because bureaucrats like to make people fill out dozens of forms. Adoption is a permanent decision, and each adoption needs to be made ironclad to avoid difficulties later on.
Probably the greatest fear adoptive parents have is that the birth parents will change their minds and petition to get their children back. Although the laws are thorough, sometimes a birth parent will challenge an adoption for any one of a number of reasons. Most states allow birth mothers to revoke or withdraw their consent to give up their children for adoption; in some states this can be done at any time before the adoption has been finalized. By law, birth mothers actually cannot give consent to an adoption until after their babies have been born; Alabama, Hawaii, Washington, and Wisconsin allow prebirth consent in certain circumstances. But there are strict rules regarding consent. A birth parent who has been proved to have deserted the child, for example, has no legal right to give or revoke consent.