Wis. Stat. § 48.19 : CHARITABLE, CURATIVE, REFORMATORY AND PENAL INSTITUTIONS AND AGENCIES — CHILDREN'S CODE — HOLDING A CHILD OR AN EXPECTANT MOTHER IN CUSTODY — Taking a child into custody

(1) A child may be taken into custody under any of the following:
(a) A warrant.
(b) A capias issued by a judge under s. 48.28.
(c) An order of the judge if made upon a showing satisfactory to the judge that the welfare of the child demands that the child be immediately removed from his or her present custody. The order shall specify that the child be held in custody under s. 48.207(1).
(cm) An order of the judge if made upon a showing satisfactory to the judge that the child is an expectant mother, that due to the child expectant mother's habitual lack of self-control in the use of alcohol beverages, controlled substances or controlled substance analogs, exhibited to a severe degree, there is a substantial risk that the physical health of the unborn child, and of the child when born, will be seriously affected or endangered unless the child expectant mother is taken into custody and that the child expectant mother is refusing or has refused to accept any alcohol or other drug abuse services offered to her or is not making or has not made a good faith effort to participate in any alcohol or other drug abuse services offered to her. The order shall specify that the child expectant mother be held in custody under s. 48.207(1).
(d) Circumstances in which a law enforcement officer believes on reasonable grounds that any of the following conditions exists:
1. A capias or a warrant for the child's apprehension has been issued in this state, or that the child is a fugitive from justice.
2. A capias or a warrant for the child's apprehension has been issued in another state.
4. The child has run away from his or her parents, guardian or legal or physical custodian.
5. The child is suffering from illness or injury or is in immediate danger from his or her surroundings and removal from those surroundings is necessary.
7. The child has violated the conditions of an order under s. 48.21(4) or the conditions of an order for temporary physical custody by an intake worker.
8. The child is an expectant mother and there is a substantial risk that the physical health of the unborn child, and of the child when born, will be seriously affected or endangered due to the child expectant mother's habitual lack of self-control in the use of alcohol beverages, controlled substances or controlled substance analogs, exhibited to a severe degree, unless the child expectant mother is taken into custody.
(2) When a child is taken into physical custody under this section, the person taking the child into custody shall immediately attempt to notify the parent, guardian, legal custodian, and Indian custodian of the child by the most practical means. The person taking the child into custody shall continue such attempt until the parent, guardian, legal custodian, and Indian custodian of the child are notified, or the child is delivered to an intake worker under s. 48.20(3), whichever occurs first. If the child is delivered to the intake worker before the parent, guardian, legal custodian, and Indian custodian are notified, the intake worker, or another person at his or her direction, shall continue the attempt to notify until the parent, guardian, legal custodian, and Indian custodian of the child are notified.
(3) Taking into custody is not an arrest except for the purpose of determining whether the taking into custody or the obtaining of any evidence is lawful.

Wis. Stat. § 48.19

1977 c. 354, 449; 1979 c. 300; 1985 a. 176; 1989 a. 31, 56, 107; 1993 a. 16, 56, 377, 490; 1995 a. 27, 77; 1997 a. 292; 2009 a. 94.

A viable fetus is not a "person" within the definition of a child under s. 48.02(2). A court may not order protective custody of a fetus by requiring custody of the mother. State ex rel. Angela M.W. v. Kruzicki, 209 Wis. 2d 112, 561 N.W.2d 729 (1997), 95-2480.