Situations related to labor and delivery that may require
drug therapy are discussed, and treatment options are reviewed. The goal of
labor induction and augmentation at term is to facilitate vaginal delivery of a healthy infant. The primary
uterine stimulant used for this purpose is
oxytocin. Low-, intermediate-, and high-dose protocols have been reported; augmentation requires approximately half as much
oxytocin as induction does.
Mifepristone has also been used for
labor induction.
Prostaglandins are the primary agents used for cervical ripening, but
oxytocin,
relaxin, and
mifepristone have also been used. Mechanical dilators are available for cervical dilation, which may be necessary when
prostaglandins are contraindicated.
Oxytocin is the
drug of choice for preventing
postpartum hemorrhage; if it is not effective,
methylergonovine or
carboprost may be used to control the
hemorrhage.
Labor induction during the midtrimester may be necessary because of obstetrical or medical complications or
fetal death. These situations call for aggressive dosing of
uterine stimulants (e.g., high-dose
oxytocin, intravaginal
dinoprostone suppositories,
carboprost,
mifepristone).
Drug therapy may be required for
labor induction or augmentation, cervical ripening or dilation, and prevention or control of
postpartum hemorrhage.
Oxytocin is the most commonly used agent for
labor induction or augmentation and for prevention of
postpartum hemorrhage;
prostaglandins are frequently used for cervical ripening. Aggressive dosing of
uterine stimulants is required when labor must be induced during the midtrimester.