[1] Labor induction in the third trimester of pregnancy may be required due to medical necessity, or may be desired for social reasons.
These reason include, but are not limited to, pregnancies that are prolonged, prelabor rupture of the fetal membranes, and concerns about the health and safety of the mother and/or child.
[2] Postpartum hemorrhage, also known as PPH, is defined as a loss of 500 mL or greater of blood within 24 hours after giving birth.
Occurring in 5% of all women giving birth, these situations are considered emergencies and require a quick, adequate response and the proper resources to prevent the death of the mother.
[5] Uterotonics can be utilized in these chemical pathways in order to medically stimulate contractions in labor induction or to treat postpartum hemorrhage.
These functions include, enhancing mood and social relationships, promotion of maternal behaviors and stimulations of uterine contractions, among others roles.
This occurs due to oxytocin's similar structure to vasopressin (antidiuretic hormone), which acts to retain water in the body.
Hypotension, or low blood pressure, is also a common side effect due to oxytocin's ability to relax smooth muscle of vessels.
[11] Carbetocin: A long-acting synthetic analog with a half-life 4 to 10 times longer than natural oxytocin, it is used to control postpartum hemorrhaging or bleeding after giving birth.
Heat-stable carbetocin does not require refrigeration unlike oxytocin; a notable advantage for use in low medical resource areas.
[11] In Canadian and German guidelines, carbetocin is recommended as a first-line therapy treatment for post-partum hemorrhaging with notable efficacy when used with cesarean section deliveries.
Primarily known for its role in mediating inflammation: pain, swelling, redness, and warmth, prostaglandin synthesis is a target for many drugs.
Vaginally administered misoprostol had improved outcomes of inducing labor within twenty four hours compared to oxytocin, but was associated with uterine hyperstimulation.
[8] Unlike oxytocinergic uterotonics, ergot alkaloids work primarily through agonistic activity of serotonin receptors along the smooth muscles of the uterine wall.
[8] Methylergonovine, a synthetic analog of ergometrine that is primarily used to treat postpartum hemorrhaging due to uterine atony.
[10] Similar to ergometrine, methylergonovine works through agonism of the serotonin receptors found on the smooth muscles of the uterine wall.
In 2012, ACOG published a warning regarding use of methylergonovine's usage in people with hypertension where it was suspected to have caused myocardial infarction and ischemia in those individuals.