As a result, not only is there a possibility of reduced endogenous oxytocin secretion, but also of suppressed oxytocin receptors 10, 11. Specifically, it has been suggested that the administration of exogenous oxytocin disturbs the mechanism of physiological secretion, and the state of excess oxytocin in the mother causes negative feedback and suppresses endogenous oxytocin release 9. In contrast to the natural endogenous oxytocin secretion mechanism, the use of continuous intravenous administration of exogenous synthetic oxytocin preparations has been reported to have negative connotations. In cases that require labor induction and augmentation, synthetic oxytocin is the most commonly used uterotonic agent. This hormone promotes uterine restoration in postpartum mothers and is an essential hormone released during breastfeeding that causes the breast milk ejection reflex 8. Maternal oxytocin release increases via skin-to-skin contact with the infant 6, 7. Maximum levels of endogenous oxytocin are achieved within 1 h of delivery in both maternal and infant brains. During labor, endogenous oxytocin is released in pulses from the pituitary glands of women into the peripheral bloodstream to induce regular uterine contractions 5. Oxytocin is a peptide hormone released from the posterior pituitary gland. Additionally, in some areas of low- and middle-income countries, the use of oxytocin for labor induction or augmentation exceeded 50% of obstetric care facilities 4. Reports have shown that 25% of all full-term infants born in developed countries were born after induction or augmentation of labor 1, 2, 3. The induction and augmentation of labor during delivery have been increasing worldwide. This report demonstrates that infants born to mothers who receive intrapartum oxytocin may have impaired sucking ability for at least the first 48 h after birth, and breastfeeding support should be provided. However, no NNS-mediated indirect effects were observed.
Effects estimated using structural equation modeling revealed that intrapartum oxytocin exposure had a significant negative and direct effect on the practice of exclusive breastfeeding 1 month postpartum (β = −0.238, p = 0.047).
In the adjusted multiple regression models, intrapartum oxytocin exposure was significantly associated with fewer total NNS bursts (95% confidence interval (CI), −7.02 to −0.22), longer pause times (95% CI, 1.33 to 10.21), and greater pause-time variability (95% CI, 3.63 to 63.92). Data on the rate of exclusive breastfeeding at 1 month postpartum were collected.
Sucking ability was evaluated by measuring Non-Nutritive Sucking (NNS) for 5 min. A total of 64 pairs (29 in the group treated with intrapartum oxytocin and 35 in the control group) of normal infants within 24–48 h of birth and their mothers were recruited. This study aimed to examine the effect of intrapartum oxytocin administration on neonatal sucking behavior and breastfeeding.