[US Standard Certificate Of Birth Field 43]. This class represents obstetric procedures performed during this pregnancy. On the form, this is a multiple-choice question (i.e., "check all that apply"), although one of the choices is "None of the above", so if that one is chosen, there should not be any others chosen. Possible values include: Cervical cerclage; Tocolysis; External cephalic version, Successful; External cephalic version, Failed; None of the above.