Iowa Code chapter 252F addresses establishment of paternity and chapter 600B discusses paternity and obligation for support of the child. There is also information available on the Iowa Judicial Branch website at: https://www.iowacourts.gov/for-the-public/representing-yourself/paternity/.
Establishing or disestablishing paternity is a very important matter and can be very complicated. You should talk to an attorney.
In a case to establish paternity, the court may require the child, mother, and alleged father to submit to blood or genetic tests. The party requesting testing must file a written motion with the clerk of court and provide copies to the opposing parties. The judge will then consider the request. See Iowa Code § 600B.41. There may be fees for blood or genetic tests.
If an expert concludes that the test results show that the probability of the alleged father’s paternity is 95% or higher, there is a presumption that the alleged father is the father. This presumption can be disproved only by clear and convincing evidence.
Disestablishing legal parentage is very complicated, and you should talk to an attorney.
If a child is born or conceived during a marriage and one of the parties wants the court to conclude that one of the parties is not a biological parent of the child and should be disestablished as (should no longer be) a legal parent of the child, the party can file a Motion to Disestablish Legal Parent. The form, with instructions, is available on the Iowa Judicial Branch website at: https://www.iowacourts.gov/for-the-public/representing-yourself/paternity/.