Högskolan i Skövde

Background: Oxytocin and prolactin stimulate milk ejection and milk production during breastfeeding. The aim of the present study was to make a detailed analysis of maternal release of oxytocin and prolactin in response to breastfeeding during the second day postpartum in mothers who had received oxytocin either intravenously for stimulation of labor or intramuscularly for prevention of postpartum hemorrhage and/or epidural analgesia or those who had received no such treatment in connection with birth.

Methods: In a descriptive comparative study plasma oxytocin and prolactin concentrations were measured in response to suckling during the second day postpartum in women who had received intravenous intrapartum oxytocin (n = 8), intramuscular postpartum oxytocin (n = 13), or epidural analgesia, either with (n = 14) or without (n = 6) intrapartum oxytocin infusion, and women who received none of these interventions (n = 20). Hormone levels were analyzed by enzyme immunoassay.

Results: All mothers showed a pulsatile oxytocin pattern during the first 10 minutes of breastfeeding. Women who had received epidural analgesia with oxytocin infusion had the lowest endogenous median oxytocin levels. The more oxytocin infusion the mothers had received during labor, the lower their endogenous oxytocin levels were during a breastfeeding during the second day postpartum. A significant rise of prolactin was observed after 20 minutes in all women, but after 10 minutes in mothers having received oxytocin infusion during labor. In all women, oxytocin variability and the rise of prolactin levels between 0 and 20 minutes correlated significantly with median oxytocin and prolactin levels.

Conclusion: Oxytocin, released in a pulsatile way, and prolactin were released by breastfeeding during the second day postpartum. Oxytocin infusion decreased endogenous oxytocin levels dose-dependently. Furthermore, oxytocin infusion facilitated the release of prolactin. Epidural analgesia in combination with oxytocin infusion influenced endogenous oxytocin levels negatively.

Background and Aims: In this study we made a detailed analysis of the mothers' release pattern of adreno-corticotropic hormone (ACTH) and cortisol during a breastfeeding session during the second day postpartum and related these patterns to maternal oxytocin levels as well to the duration of sucking and the duration of skin-to-skin contact before sucking the breast. Furthermore, we investigated if epidural analgesia and oxytocin administration during and after labor influenced the release pattern of ACTH and cortisol.

Methods: Sixty-three primiparae were included in the study. Fourteen received oxytocin intramuscularly postpartum, nine received oxytocin infusion, 14 received epidural analgesia combined with oxytocin infusion, and six received epidural analgesia alone. Twenty mothers did not receive any of these medical interventions. Blood samples were analyzed for ACTH and cortisol by enzyme-linked immunoassay.

Results: Both ACTH and cortisol levels fell significantly during the breastfeeding session. A significant negative relationship was found between oxytocin and ACTH levels, but not between oxytocin and cortisol levels. A contact before onset of sucking was significantly and negatively associated with lower cortisol levels, but not with ACTH levels. Cortisol levels differed significantly between mothers having received epidural analgesia with and without oxytocin.

Conclusions: Breastfeeding is associated with a decrease of ACTH and cortisol levels. Skin-to-skin contact contributes to this effect. ACTH correlated negatively with the duration of sucking and median oxytocin levels, whereas cortisol levels correlated inversely with the duration of skin-to-skin contact preceding sucking, suggesting a partial dissociation between the mechanisms regulating ACTH and cortisol release. In addition, medical interventions in connection with birth influence the activity of the hypothalamic-pituitary-adrenal axis 2 days after birth.

Objective: This study investigated possible influences of medical interventions during labor on maternal blood pressure during a breastfeed 2 days postpartum.

Subjects and Methods: Sixty-six primiparae with normal deliveries were consecutively recruited. Blood pressure was measured at –5, 10, 30, and 60 minutes during a morning breastfeed 2 days postpartum. Five treatment groups were formed based on the medical interventions received during labor: Non-medicated mothers (Control group, n=21); mothers receiving epidural analgesia (EDA) with oxytocin (OT) stimulation (EDA^OT group, n=14); mothers receiving EDA without OT stimulation (EDA^non-OT group, n=7); mothers receiving OT stimulation only (OT intravenously [iv] group, n=9); and mothers receiving 10 IU of OT intramuscularly (im) only (OT im group, n=15).

Results: Baseline diastolic, but not systolic, blood pressure differed between the groups as displayed by significantly lower diastolic blood pressure in the EDA^non-OT group compared with the Control group, the OT iv group, and the EDA^OT group (p=0.045, p=0.041, and p=0.024, respectively). Both systolic and diastolic blood pressure fell significantly during the breastfeeding session in the Control group (p=0.001 and p=0.004, respectively), the OT im group (p=0.006 and p=0.001, respectively), and the EDA^OT group (p=0.028 and p=0.002, respectively), and the fall in diastolic blood pressure tended to be significant in the OT iv group (p=0.050). The duration of skin-to-skin contact before breastfeeding correlated positively with the decrease in systolic blood pressure in the OT im group (R_s=0.540, p=0.046).

Conclusion: Administration of EDA during labor lowers baseline diastolic blood pressure and abolishes the fall in blood pressure in response to a breastfeed 2 days after birth.

The aim of this exploratory study was to determine heart rate and the levels of oxytocin, cortisol, and insulin in dogs and their owners in response to a short-term interaction. In addition, the dogs' behavior was studied. The owners' responses were compared with those obtained from a control group. Ten female volunteers and their own male Labrador dogs participated in an experiment during which the owner stroked, petted, and talked with her dog during the first 3 minutes. Blood samples were collected from both dog and owner before (0) and at 1, 3, 5, 15, 30, and 60 minutes after the start of the interaction. Blood samples were analyzed by EIA. Heart rate was monitored telemetrically. The data were analyzed using linear mixed models and paired t-tests. The dogs' oxytocin levels were significantly increased 3 minutes after the start of the interaction (p = 0.027). Cortisol levels were significantly increased after 15 and 30 minutes (p = 0.004 and p = 0.022, respectively), and heart rate was significantly decreased after 55 minutes (p = 0.008). The dogs displayed normal behaviors during the experiment. The owners' oxylocin levels peaked between 1 and 5 minutes after interaction (p = 0.026). No such effect was seen in the controls. Cortisol levels displayed a significant decrease at 15 or 30 minutes in both owners and controls, and insulin levels did so at 60 minutes (p = 0.030, p = 0.002 and p = 0.002, p < 0.0001, respectively). Heart rate decreased significantly in the owners at 55 and 60 minutes (p = 0.0008) but not in the controls. In conclusion, short-term sensory interaction between dogs and their owners influences hormonal levels and heart rate. However, further studies need to be performed in order to better understand the effects of interaction between dogs and their owners.

The aim of the present study was to explore possible correlations between dog owners' relationships with their dogs, as measured with the Monash Dog Owner Relationship Scale (MDORS), and oxytocin and cortisol levels in both the owners and their dogs. Ten female owners of male Labrador Retrievers completed the MDORS. The scores obtained from the single items, subscales, and total score of the MDORS were calculated. Ten blood samples were collected from each dog owner and her dog during a 60-minute interaction. Blood samples were analyzed for oxytocin and cortisol by Enzyme Immuno Assay (EIA) and mean values of oxytocin and cortisol were calculated in both owners and dogs. The MDORS scores obtained were correlated with basal and mean oxytocin and cortisol levels. The correlation analysis revealed some relationships between the scores of items in the MDORS that reflect the character of the dog-owner-relationship and the owners' hormone levels. For example, higher oxytocin levels in the owners were associated with greater frequency in kissing their dogs (r_s = 0.864, p = 0.001). Lower cortisol levels in the owners were associated with their perception that it will be more traumatic when their dog dies (r_s = -0.730, p = 0.025). The correlation analysis also revealed some relationships between the scores of items in the MDORS and the dogs' hormone levels. For example, greater frequency in owners kissing their dogs was associated with higher oxytocin levels in the dogs (r_s = 0.753, p = 0.029). Six items in the subscale Perceived Costs, as well as the subscale itself, correlated significantly with the dogs' oxytocin levels (r_s = 0.820, p = 0.007), that is, the lower the perceived cost, the higher the dogs' oxytocin levels. In addition, significant correlations between the oxytocin levels of the owners and the dogs were demonstrated. Possible mechanisms behind these correlations are discussed. In conclusion, the scores of some items and the subscales of the MDORS correlated with oxytocin, and to a lesser extent cortisol, levels in both the owners and dogs.