Oxytocin – everything you need to know, composition, application

Oxytocin is an organic chemical compound, a macrocyclic peptide hormone. It dissolves easily in water and is a neurotransmitter. Oxytocin is produced in the hypothalamus – in the paraventricular and supraventricular nucleus. It is transported via neurons to the pituitary gland, where it is stored. Oxytocin is a hormone responsible for causing muscle contractions. It is of particular importance at the time of childbirth, when the progesterone block ceases and oxytocin causes contractions in the muscles of the uterus. The action of oxytocin is enhanced by estrogens, and progesterones have an inhibitory effect.

Oxytocin is released as a result of irritation of the mechanoreceptors in the nipples, as well as of the cervical and vaginal receptors. Right after delivery, oxytocin is responsible for the return of the reproductive organs to their previous state. It constricts the uterus and the blood vessels that line its surface. As a result, the action of oxytocin inhibits the bleeding that occurs naturally after removal of the placenta. During the postpartum period, oxytocin is excreted as a result of the suckling of breast milk by the baby. As a result, breastfeeding stimulates the natural collapse of the uterus.

Oxytocin is also secreted during sexual intercourse. In such a situation, it is produced in both women and men. Its presence positively influences the possibility of achieving orgasm; in men, it is also responsible for causing an erection.

Oxytocin – pharmacological use

Oxytocin is given during labor when the body of the woman giving birth is unable to produce enough of it. Thanks to this, oxytocin accelerates the course of labor, induces uterine contractions and facilitates the birth of a newborn baby. In this situation, oxytocin is administered in the form of a drip. The dose of oxytocin administered is determined by the doctor; excessive amounts can cause unpleasant and painful labor contractions and, as a result, lead to the need for a caesarean section. If the administration of oxytocin in a drip did not lead to the commencement of labor, prostagladine is administered in the form of an injection.

In addition, doctors estimate that the use of oxytocin to induce labor also has a positive effect on the born child. Uterine contractions speed up labor and stimulate the baby to pass through the birth canals. Thus, they do some of the work for him, reducing the effort needed to be born into the world. Doctors also believe that the administration of oxytocin protects the newborn child against the possibility of hypoxia.

When is oxytocin used?

Oxytocin to induce or accelerate labor is used in the following cases:

1. an overdue pregnancy, also known as a transferred pregnancy (lasting more than 42 weeks),
2. preeclampsia,
3. inhibition of fetal growth inside the uterus,
4. the chance of a serological conflict (i.e. incompatibility of Rh factors in the mother’s and child’s blood),
5. hemolytic disease of the newborn,
6. premature leakage of amniotic fluid,
7. premature rupture of the fetal bladder,
8. uterine death of the fetus,
9. fetal development retardation,
10. uterine atony.

In the postpartum period, oxytocin is used to:

1. control of the level of bleeding from the genital tract,
2. supportive care in the event of a miscarriage
3. diagnostics of fetal-placental respiratory efficiency.

In addition, oxytocin is administered in some cases unrelated to pregnancy; the most common are:

1. type I diabetes,
2. hypertension,
3. chronic kidney disease
4. disturbance of the proper functioning of the thyroid gland.

Contraindications and undesirable side effects of oxytocin administration

The most common reasons for not using oxytocin to induce labor include:

1. premature birth,
2. disproportion between the size of the baby’s head and the size of the birth canal,
3. past injuries or surgery to the uterus,
4. cervical cancer or other damage / changes within it,
5. cardiovascular disorders,
6. overstretching of the uterus as a result of multiple births.

Moreover, it is not recommended to use oxytocin in the case of arterial hypertension and to administer general anesthetics.

The most common side effects include:

1. induction of postpartum hemorrhage,
2. vomiting, nausea,
3. hematoma in the pelvis,
4. lowering the pressure,
5. tachycardia,
6. zatokowa bradycardia,
7. water poisoning,
8. damage to the central nervous system of the fetus,
9. zamartwica,
10. neonatal jaundice,
11. retinal bleeding.