Intrapartum Synthetic Oxytocin and Its Effects on Maternal Well-Being at 2 Months Postpartum

Exogenous oxytocin administered to induce or augment labour is positively associated with quality of observed mother-infant bonding

Oxytocin is a key hormone in the transition to motherhood. The maternal endogenous oxytocin system facilitates many physiological and biological adaptations, including breastfeeding, maternal wellbeing, and brain plasticity. Additionally, maternal endogenous oxytocin works as a finetuned orchestrator prior to, during, and after the birth of a child to support birth progression and mother-infant bonding. Exogenous oxytocin may be administered to induce or augment labour when this is not progressing naturally and is a common obstetric intervention worldwide. However, the lasting impact of these widely varying levels of systemic exogenous oxytocin on mother-infant bonding is currently unknown. This study aimed to investigate the association between exogenous oxytocin administered to induce or augment labour and quality of observed mother-infant bonding. Thirty-eight mother and infant dyads participated (mothers aged 24-48 years; infants aged 2-5 months). Mother-infant bonding quality was assessed via the Recorded Interaction Task and hospital birth records were consulted to obtain exogenous oxytocin administration data. Demographic information and possible confounding factors were collected from dyads, and salivary oxytocin concentration was measured for both mother and infant. Mother's perception of infant sleep difficulty was identified as a confounding factor for quality of mother-infant bonding. After controlling for the confounding factor, receiving exogenous oxytocin to induce or augment labour, as opposed to not, was found to be significantly positively associated with higher quality of observed mother-infant bonding (p = 0.029). These novel findings highlight the need for further exploration, both of the impact of the treatment and of the mechanisms of action of intrapartum exogenous oxytocin on the endogenous oxytocin system. It is argued that particular focus be given to investigate action on the central oxytocin receptors, and if this may play a role in subsequent mother-infant bonding outcomes. It is vital to understand the full breadth and the clinical implications of this commonplace procedure.

Is Oxytocin Administration During Childbirth Associated With Increased Risk for Postpartum Posttraumatic Stress Symptoms?: A Preliminary Investigation

INTRODUCTION

Synthetic oxytocin is one of the most regularly administered medications to facilitate labor induction and augmentation. The present study examined the associations between oxytocin administration during childbirth and postpartum posttraumatic stress symptoms (PTSS).

MATERIALS AND METHODS

In a multicenter longitudinal study, women completed questionnaires during pregnancy and at 2 months postpartum ( N = 386). PTSS were assessed with the Impact of Event Scale. Logistic regression was used to examine the difference in PTSS at Time 2 between women who received oxytocin and women who did not.

RESULTS

In comparison with women who did not receive oxytocin, women who received oxytocin induction were 3.20 times as likely to report substantial PTSS ( P = .036, 95% confidence interval: 1.08-9.52), and women who received oxytocin augmentation were 3.29 times as likely to report substantial PTSS ( P = .036, 95% confidence interval: 1.08-10.03), after controlling for being primiparous, preeclampsia, prior mental health diagnosis, mode of birth, postpartum hemorrhage, and satisfaction with staff.

DISCUSSION

Oxytocin administration was associated with a 3-fold increased risk of PTSS. The findings may reflect biological and psychological mechanisms related to postpartum mental health and call for future research to establish the causation of this relationship.

Cumulative oxytocin dose in spontaneous labour - Adverse postpartum outcomes, childbirth experience, and breastfeeding

OBJECTIVES

This study aimed to determine the association between the total cumulative oxytocin dose during labour and adverse postpartum outcomes, childbirth experience and breastfeeding in term primiparous women with spontaneous onset of labour.

STUDY DESIGN

A prospective observational multicentre study, including 1395 women with spontaneous labour, in seven hospitals in Southeast Sweden. Multivariable logistic regression (Crude Odds Ratios (OR) and adjusted OR (aOR) for relevant confounders) was used to analyze the association between oxytocin dose and postpartum outcomes. The exposure was the cumulative oxytocin dose during labour, classified in percentiles (<25th, 25-75th, >75th). The outcomes were occurrence of obstetric anal sphincter injury, postpartum haemorrhage (blood loss > 1000 ml), Apgar score < 7 at five minutes, umbilical cord arterial pH, postpartum bladder overdistension, exclusive breastfeeding at one week and three months, and the woman's perceived birth experience.

RESULTS

Women receiving high amounts (>75th percentile, >4370 mU) of oxytocin infusion during labour had an increased risk of postpartum haemorrhage (OR 2.73 (1.78-4.19)), an overdistended bladder (OR 2.19 (1.11-4.31)), an infant with an Apgar score < 7 at five minutes (OR 2.89 (1.27-6.57)), a negative birth experience (OR 1.83 (1.25-2.69)), and a decreased chance of exclusive breastfeeding at one week (OR 0.63 (0.41-0.96)). After adjusting for confounders, all outcomes remained statistically significant except risk of low Apgar score and chance of exclusive breastfeeding.

CONCLUSION

In women with high cumulative oxytocin dose during labour prompt, and prophylactic administration of uterotonics after delivery of the placenta should be considered to reduce the risk of postpartum haemorrhage. The risk for bladder overdistension can be reduced by implementing routines for observation for signs of bladder filling in the early postpartum period, as well as routine use of bladder scans post micturition to assess for successful bladder emptying. As women's birth experience have a major impact on their future mental health, should be routinely assessed postpartum, and support should be offered to women with negative experiences.

Impact of intrapartum oxytocin administration on neonatal sucking behavior and breastfeeding

This study aimed to examine the effect of intrapartum oxytocin administration on neonatal sucking behavior and breastfeeding. 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. Sucking ability was evaluated by measuring Non-Nutritive Sucking (NNS) for 5 min. Data on the rate of exclusive breastfeeding at 1 month postpartum were collected. 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). 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). However, no NNS-mediated indirect effects were observed. 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.

A longitudinal study of the association of epidural anesthesia and low-dose synthetic oxytocin regimens with breast milk supply and breastfeeding rates

Breastfeeding is known to improve maternal and child health. However, epidural anesthesia (EDA) and synthetic oxytocin (synOT) are suggested to have negative effects on breastfeeding. In this study, we aimed to determine the effects of intrapartum synOT and EDA on breast milk supply, breastfeeding rates, and maternal salivary oxytocin levels. Women were recruited during pregnancy or after birth at a single hospital. Data were collected at 3 days postpartum (T1), 1 month postpartum (T2), and 4 months postpartum (T3) on 83 low-risk primiparous women who planned to breastfeed for at least 12 weeks postpartum to avoid dropouts from early discontinuance of breastfeeding. Women with cesarean section, twin pregnancy, premature neonates, and an Apgar score of < 7 at 5 min were excluded. Participants recorded their 24-h milk supply by test weights at 3 days and 1 month postpartum. Additionally, they filled out questionnaires assessing their breastfeeding level and lactogenesis stage II initiation. Salivary oxytocin levels were obtained at 3 days postpartum. Women who delivered using EDA had lower salivary oxytocin levels (P = .055, d = .442), breast milk supply in early postpartum (P = .025, d = .520) and at 1 month postpartum (P = .036, d = .483), and breastfeeding rates at 4 months postpartum (P = .037, V = .236) than women who did not deliver using EDA. There was no association between breastfeeding and the use of intrapartum synOT. In conclusion, this study showed that women who delivered using EDA had lower breast milk supply in the early postpartum period and breastfeeding rates at 4 months postpartum. It also revealed that using synOT at low doses during labor did not affect breastfeeding. Thus, women who deliver using EDA need support for increased breast milk supply in the early postpartum period.Trial registration: UMIN000037783 (Clinical Trials Registry of University Hospital Information Network).

The evolved nest, oxytocin functioning, and prosocial development

Prosociality, orientation to attuned, empathic relationships, is built from the ground up, through supportive care in early life that fosters healthy neurobiological structures that shape behavior. Numerous social and environmental factors within early life have been identified as critical variables influencing child physiological and psychological outcomes indicating a growing need to synthesize which factors are the most influential. To address this gap, we examined the influence of early life experiences according to the evolved developmental niche or evolved nest and its influence on child neurobiological and sociomoral outcomes, specifically, the oxytocinergic system and prosociality, respectively. To-date, this is the first review to utilize the evolved nest framework as an investigatory lens to probe connections between early life experience and child neurobiological and sociomoral outcomes. The evolved nest is comprised of characteristics over 30 million years old and is organized to meet a child's basic needs as they mature. Converging evidence indicates that humanity's evolved nest meets the needs of a rapidly developing brain, optimizing normal development. The evolved nest for young children includes soothing perinatal experiences, breastfeeding, positive touch, responsive care, multiple allomothers, self-directed play, social embeddedness, and nature immersion. We examined what is known about the effects of each evolved nest component on oxytocinergic functioning, a critical neurobiological building block for pro-sociomorality. We also examined the effects of the evolved nest on prosociality generally. We reviewed empirical studies from human and animal research, meta-analyses and theoretical articles. The review suggests that evolved nest components influence oxytocinergic functioning in parents and children and help form the foundations for prosociality. Future research and policy should consider the importance of the first years of life in programming the neuroendocrine system that undergirds wellbeing and prosociality. Complex, interaction effects among evolved nest components as well as among physiological and sociomoral processes need to be studied. The most sensible framework for examining what builds and enhances prosociality may be the millions-year-old evolved nest.

Maternal and newborn plasma oxytocin levels in response to maternal synthetic oxytocin administration during labour, birth and postpartum - a systematic review with implications for the function of the oxytocinergic system

BACKGROUND

The reproductive hormone oxytocin facilitates labour, birth and postpartum adaptations for women and newborns. Synthetic oxytocin is commonly given to induce or augment labour and to decrease postpartum bleeding.

AIM

To systematically review studies measuring plasma oxytocin levels in women and newborns following maternal administration of synthetic oxytocin during labour, birth and/or postpartum and to consider possible impacts on endogenous oxytocin and related systems.

METHODS

Systematic searches of PubMed, CINAHL, PsycInfo and Scopus databases followed PRISMA guidelines, including all peer-reviewed studies in languages understood by the authors. Thirty-five publications met inclusion criteria, including 1373 women and 148 newborns. Studies varied substantially in design and methodology, so classical meta-analysis was not possible. Therefore, results were categorized, analysed and summarised in text and tables.

RESULTS

Infusions of synthetic oxytocin increased maternal plasma oxytocin levels dose-dependently; doubling the infusion rate approximately doubled oxytocin levels. Infusions below 10 milliunits per minute (mU/min) did not raise maternal oxytocin above the range observed in physiological labour. At high intrapartum infusion rates (up to 32 mU/min) maternal plasma oxytocin reached 2-3 times physiological levels. Postpartum synthetic oxytocin regimens used comparatively higher doses with shorter duration compared to labour, giving greater but transient maternal oxytocin elevations. Total postpartum dose was comparable to total intrapartum dose following vaginal birth, but post-caesarean dosages were higher. Newborn oxytocin levels were higher in the umbilical artery vs. umbilical vein, and both were higher than maternal plasma levels, implying substantial fetal oxytocin production in labour. Newborn oxytocin levels were not further elevated following maternal intrapartum synthetic oxytocin, suggesting that synthetic oxytocin at clinical doses does not cross from mother to fetus.

CONCLUSIONS

Synthetic oxytocin infusion during labour increased maternal plasma oxytocin levels 2-3-fold at the highest doses and was not associated with neonatal plasma oxytocin elevations. Therefore, direct effects from synthetic oxytocin transfer to maternal brain or fetus are unlikely. However, infusions of synthetic oxytocin in labour change uterine contraction patterns. This may influence uterine blood flow and maternal autonomic nervous system activity, potentially harming the fetus and increasing maternal pain and stress.

Peripartum effects of synthetic oxytocin: The good, the bad, and the unknown

The first clinical applications of oxytocin (OT) were in obstetrics as a hormone to start and speed up labor and to control postpartum hemorrhage. Discoveries in the 1960s and 1970s revealed that the effects of OT are not limited to its peripheral actions around birth and milk ejection. Indeed, OT also acts as a neuromodulator in the brain affecting fear memory, social attachment, and other forms of social behaviors. The peripheral and central effects of OT have been separately subject to extensive scrutiny. However, the effects of peripheral OT-particularly in the form of administration of synthetic OT (synOT) around birth-on the central nervous system are surprisingly understudied. Here, we provide a narrative review of the current evidence, suggest putative mechanisms of synOT action, and provide new directions and hypotheses for future studies to bridge the gaps between neuroscience, obstetrics, and psychiatry.

Neonatal breast-suckling skills in the context of lactation and peripartum hormonal changes and additional factors-a pilot study

BACKGROUND

Childbirth and lactation are intricate processes, involving several hormones, the most important of which are prolactin (a protein hormone) and cortisol (one of the glucocorticoids). The early postpartum period is crucial for both mother and newborn and has an impact on the lactation and breastfeeding process.

METHODS

The study included 78 patients who were admitted to the Gynecology-Obstetrics Clinical Hospital in Poznań for labor induction and/or in the active phase of the first labor stage. The levels of cortisol and prolactin in serum were assessed in these women during admission in labor, during the third labor stage, and on the second day postpartum. The levels of cortisol and prolactin in the umbilical cord serum were assessed immediately after cord clamping. The "Protocol for the assessment of breast-suckling skills" was used to assess the neonatal breast-suckling skills on the second day postpartum. Some additional parameters were evaluated in mothers via a telephone interview at three and six months postpartum. The study was conducted from January to August 2020, however the study was suspended during April-July 2020 due to the SARS-CoV-2 pandemic, which led to restrictions in the hospital limiting access to the hospital wards unless necessary.

RESULTS

Early breastfeeding with skin-to-skin contact was associated with low levels of hormones, cortisol levels were lower in serum (p = 0.0108) and umbilical vein (p = 0.0273) in mothers who breastfed immediately after childbirth. At three months postpartum, 88% of the mothers who did not offer a pacifier to the child during the first few days of life breastfed the child naturally (p = 0.037), and at six months, 96% of those who did not offer a pacifier continued to breastfeed (p = 0.0008). Multiple, statistically significant correlations were observed between the variables assessed according to the "Protocol for the assessment of breast-suckling skills" and breastfeeding after three months.

CONCLUSIONS

Breastfeeding immediately after childbirth, appropriate assessment of the breast-suckling skills of newborns, avoiding pacifiers and infant formula feeding, and offering support to new mothers in the early days after childbirth seem to be important factors for sustaining breastfeeding after three and six months of childbirth.

The Effects of Intrapartum Administration of Synthetic Oxytocin on Breastfeeding in the First 9 Months Postpartum: A Longitudinal Prospective Study

Background and Objective: Synthetic oxytocin (synOT) is a widely used drug to induce or accelerate labor and to prevent postpartum hemorrhage. Although some studies indicate there are associations between intrapartum synOT and impaired breastfeeding initiation or earlier cessation, the long-term effects of synOT on breastfeeding are largely understudied. The aim of this study was to examine the effects of synOT on breastfeeding status during the first 9 months postpartum. Materials and Methods: The women were recruited from five maternity hospitals during prenatal medical checkups or postpartum hospital stay. They reported their breastfeeding status on discharge from maternity hospital (mean 4.54 days postpartum) (N = 439), at 6 weeks (N = 439), and at 9 months postpartum (N = 274). The data related to synOT administration were extracted from the medical records. Results: In the analysis adjusted for maternal age, parity, educational level, marital status, child's sex, delivery mode, and labor analgesia/anesthesia, intrapartum administration of synOT predicted a lower probability of exclusive breastfeeding on discharge from maternity hospital (odds ratio = 0.37; p = 0.006), but we observed no effect on breastfeeding status at 6 weeks or 9 months postpartum. Conclusion: Our results suggest that adverse effects of synOT on breastfeeding do not persist beyond the first postpartum days.

Oxytocin: at birth and beyond. A systematic review of the long-term effects of peripartum oxytocin

Oxytocin is one of the most commonly used medications during labour and delivery. Recent insights from basic neuroscience research suggest that the uterotonic effects of oxytocin may arguably be trivial when compared with its profound effects on higher-order human behaviour. The purpose of this review is to highlight the potential consequences of manipulating oxytocinergic signalling during the peripartum period and its long-term impact on the maternal-infant dyad. We identified four domains where modulation of oxytocinergic signalling might be consequential: postpartum depression; breastfeeding; neurodevelopment; and chronic pain, and performed a literature search to address the impact of peripartum oxytocin administration. We have shown modest, but inconsistent, evidence linking peripartum oxytocin administration with postpartum depression. Breastfeeding success appeared to be negatively correlated with peripartum oxytocin exposure, perhaps secondary to impaired primitive neonatal reflexes and maternal-infant bonding. The association between perinatal oxytocin exposure and subsequent development of neurodevelopmental disorders such as autism in the offspring was weak, but these studies were limited by the lack of information on the cumulative dose. Finally, we identified substantial evidence for analgesic and anti-hypersensitivity effects of oxytocin which might partly explain the low incidence of chronic pain after caesarean birth. Although most data presented here are observational, our review points to a compelling need for robust clinical studies to better dissect the impact of peripartum oxytocin administration, and as stewards of its use, increase the precision with which we administer oxytocin to prevent overuse of the drug.

Spontaneous and induced labor: association with maternal well-being three months after childbirth

A woman's first childbirth represents a moment of elevated maternal emotional vulnerability. Indeed, there is a prevalence of anxiety and depression symptomatology in primiparas during the postpartum period that negatively influences the well-being of the woman, of her newborn, and of the quality of their attachment bond. Much attention has been paid to the possible risk factors involved in the onset of mood disturbance in the postpartum. However, knowledge is still limited regarding the role played by the specific clinical aspects linked to labor. Therefore, the aim of the present study was to explore whether spontaneous or elective induction labor is linked to the level of postnatal depression and anxiety three months after birth. One hundred and sixty-one women (M_age = 31.63; SD = 4.88) were recruited, using the following inclusion criteria: native Italian women; age > 18 years; physically and psychologically healthy nulliparous with singleton no-risk pregnancy; no previous abortion or interruption of pregnancy; no previous psychopathological diagnoses. Exclusion criteria: twin pregnancy, fetal pathologies, and planned elective cesarean. Data was collected at two different times: T1 (day of childbirth) clinical data of labor (spontaneous or induced) from hospital records; T2 (three months after birth) level of mother's depression and anxiety. In order to explore if the level of depression and anxiety three months after childbirth differ in women according to the type of labor, spontaneous or induced, two univariate analyses of variance (ANOVA) were conducted. Results showed that women who had a spontaneous labor reported lower levels of anxiety and depression than women who had an induced labor. Our results highlight the significant implications that the mode of labor has on the emotional well-being of mothers, underlining the need to support women throughout all their transition to motherhood, including the childbirth experience.

Preterm Labor Using Tocolysis as a Possible Risk Factor for Postpartum Depression: A 14-Year Population-Based Study in Taiwan

Postpartum depression (PPD) is associated with negative physical and mental health outcomes for the mother and infant. Women often experience elevated symptoms of PPD, and the incidence of PPD has increased in recent years. There were lack of studies to investigate the effects of medications during pregnancy. Herein, we focused on the most common obstetric medical therapies used in labor and determined whether the medical therapies cause mental stress in pregnant women. This 14-year retrospective population-based nationwide study was based on the National Health Insurance Research Database. Univariate and multivariate logistic regression analyses were used to evaluate unadjusted and adjusted odds ratios and 95% confidence intervals for each tocolytic and uterotonic treatments during pregnancy and common medical illnesses. In comparing the effects of tocolytic and uterotonic medications on maternal PPD, tocolysis with the injection form of ritodrine resulted in a significantly higher risk of PPD based on multivariate analysis. This study supports existing research demonstrating an association between tocolysis with ritodrine and PPD. Ritodrine treatment for preterm labor was a significant risk factor for PPD, especially the injection form. This information provides obstetricians and health policy providers to pay attention to maternal mental health outcomes among high-risk pregnant women.

Intrapartum synthetic oxytocin, behavioral and emotional problems in children, and the role of postnatal depressive symptoms, postnatal anxiety and mother-to-infant bonding: A Dutch prospective cohort study

OBJECTIVE

To examine the association between intrapartum synthetic oxytocin and child behavioral and emotional problems and to assess if maternal depressive or anxious symptoms or mother-to-infant bonding play a mediating role in this association.

DESIGN

Prospective cohort study.

SETTING

Population-based Pregnancy Anxiety and Depression Study.

PARTICIPANTS

Pregnant women in their first trimester of pregnancy visiting a total of 109 primary and nine secondary obstetric care centers in the Netherlands between 2010 and 2014 were invited to participate. Follow-up measures used for the present study were collected from May 2010 to January 2019. Women with multiple gestations and with a preterm birth were excluded.

MEASUREMENTS

Intrapartum synthetic oxytocin exposure status was based on medical birth records and was defined as its administration (Yes/No), either for labour induction or augmentation. Child behavioral and emotional problems were measured with the Child Behavior Checklist at up to 60 months postpartum. Maternal depressive symptoms, anxiety and mother-to infant bonding were measured with the Edinburgh Postnatal Depression Scale, State Trait Anxiety Inventory and the Mother-to-Infant Bonding Scale from 6 months postpartum. We used multivariable linear regression models to estimate standardized beta coefficients and unique variance explained.

FINDINGS

1,528 women responded. In total 607 women received intrapartum synthetic oxytocin. Intrapartum synthetic oxytocin administration was not associated with child behavioral and emotional problems, mother-to-infant bonding nor with postnatal anxiety. Intrapartum synthetic oxytocin was however significantly but weakly associated with more postnatal depressive symptoms (β=0.17, 95%CI of 0.03 to 0.30) explaining 0.6% of unique variance. Maternal postnatal depressive symptoms, postnatal anxiety symptoms and suboptimal mother-to-infant bonding were positively associated with child behavioral and emotional problems.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

We found no evidence that intrapartum synthetic oxytocin is associated with child behavioral and emotional problems, mother-to-infant bonding, or with postnatal anxiety symptoms. Because there was no association between intrapartum synthetic oxytocin and behavioral and emotional problems in children no mediation analysis was carried out. However, intrapartum synthetic oxytocin was positively but weakly associated with postnatal depressive symptoms. The clinical relevance of this finding is negligible in the general population, but unknown in a population with a high risk of depression.

The association of oxytocin with major depressive disorder: role of confounding effects of antidepressants

Major depressive disorder is a genetic susceptible disease, and a psychiatric syndrome with a high rate of incidence and recurrence. Because of its complexity concerning etiology and pathogenesis, the cure rate of first-line antidepressants is low. In recent years, accumulative evidences revealed that oxytocin act as a physiological or pathological participant in a variety of complex neuropsychological activities, including major depressive disorder. Six electronic databases (Web of Science, PubMed, Scopus, Google Scholar, CNKI, and Wanfang) were employed for researching relevant publications. At last, 226 articles were extracted. The current review addresses the correlation of the oxytocin system and major depressive disorder. Besides, we summarize the mechanisms by which the oxytocin system exerts potential antidepressant effects, including regulating neuronal activity, influencing neuroplasticity and regeneration, altering neurotransmitter release, down regulating hypothalamic-pituitary-adrenal axis, anti-inflammatory, antioxidation, and genetic effects. Increasing evidence shows that oxytocin and its receptor gene may play a potential role in major depressive disorder. Future research should focus on the predictive ability of the oxytocin system as a biomarker, as well as its role in targeted prevention and early intervention of major depressive disorder.

Neurobiology of peripartum mental illness

At least one in seven pregnant or recently postpartum women will experience a mental illness such as an anxiety disorder, depressive disorder, or substance use disorder. These mental illnesses have detrimental effects on the health of the mother, child, and family, but little is known about the hypothalamic and other neural correlates of maternal mental health concerns. The transition to parenthood alone is a time of remarkable neural plasticity, so it is perhaps not surprising that current research is showing that maternal mental illness has unique neural profiles. Furthermore, the neural systems affected by peripartum mental illness overlap and interact with the systems involved in maternal caregiving behaviors, and mother-infant interactions are, therefore, highly susceptible to disruption. This review discusses what we know about the unique neural changes occurring during peripartum mental illness and the role of the hypothalamus in these illnesses. With an improved understanding of the neural correlates of maternal mental health and disease, we will be better equipped to predict risk, develop effective treatments, and ultimately prevent suffering for millions of parents during this critical time in life.

Sex differences of oxytocin and vasopressin in social behaviors

The neuropeptides oxytocin (OT) and vasopressin (VP) are known to mediate social cognition and behaviors in a sex-dependent manner. This chapter reviews the sex-dependent influence of OT and VP on social behaviors, focusing on (1) partner preference and sexual orientation, (2) memory modulation, (3) emotion regulation, and (4) trust-related behaviors. Most studies suggest that OT promotes familiar (opposite-sex) partner preference, strengthens memory, relieves anxiety, and increases trust. However, VP-regulated social cognition has been studied less than OT. VP facilitates familiar (opposite-sex) partner preference, enhances memory, induces anxiety, and influences happiness/anger perception. Detailed sex differences of these effects are reviewed. There is a male preponderance in the use of animal models and many study results are too complex to draw firm conclusions. Clarifying the complex interplay between the OT/VP system and sex hormones in the regulation of social behaviors is needed.

Oxytocin and postpartum depression: A systematic review

Postpartum depression (PPD) is a significant mental health concern, especially for women in vulnerable populations. Oxytocin (OT), a hormone essential for a variety of maternal tasks, including labor, lactation, and infant bonding, has also been hypothesized to have a role in postpartum depression. Women are routinely given synthetic oxytocin to induce or augment labor and to prevent postpartum hemorrhage. The aim of this study was to review the quality and reliability of literature that examines potential relationships between OT and PPD to determine if there is sufficient data to reliably assess the strength of these relationships. We conducted a literature search in December of 2018 using five databases (PubMed, Web of Science, Embase, PsycInfo, and CINAHL). Eligible studies were identified, selected, and appraised using the Newcastle-Ottawa quality assessment scale and Cochrane Collaboration's tool for assessing risk of bias, as appropriate. Sixteen studies were included in the analysis and broken into two categories: correlations of endogenous OT with PPD and administration of synthetic OT with PPD. Depressive symptoms were largely measured using the Edinburgh Postnatal Depression Scale. OT levels were predominately measured in plasma, though there were differences in laboratory methodology and control of confounders (primarily breast feeding). Of the twelve studies focused on endogenous oxytocin, eight studies suggested an inverse relationship between plasma OT levels and depressive symptoms. We are not able to draw any conclusions regarding the relationship between intravenous synthetic oxytocin and postpartum depression based on current evidence due to the heterogeneity and small number of studies (n = 4). Considering limitations of the current literature and the current clinical prevalence of synthetic OT administration, we strongly recommend that rigorous studies examining the effects of synthetic OT exposure on PPD should be performed as well as continued work in defining the relationship between endogenous OT and PPD.

bFGF promotes neurological recovery from neonatal hypoxic-ischemic encephalopathy by IL-1β signaling pathway-mediated axon regeneration

INTRODUCTION

Neonatal hypoxia-ischemic brain damage (HIBD) can lead to serious neuron damage and dysfunction, causing a significant worldwide health problem. bFGF as a protective reagent promotes neuron repair under hypoxia/ischemia (HI). However, how bFGF and downstream molecules were regulated in HI remains elusive.

METHODS

We established an in vitro HI model by culturing primary cortical neurons and treated with oxygen-glucose deprivation (OGD). We suppressed the expression of bFGF by using siRNA (small interfering RNA) interference to detect the neuronal morphological changes by immunofluorescence staining. To determine the potential mechanisms regulated by bFGF, the change of downstream molecular including IL-1β was examined in bFGF knockdown condition. IL-1β knockout (KO) rats were generated using CRISPR/Cas9-mediated technologies. We used an accepted rat model of HI, to assess the effect of IL-1β deletion on disease outcomes and carried out analysis on the behavior, histological, cellular, and molecular level.

RESULTS

We identified that OGD can induce endogenous expression of bFGF. Both OGD and knockdown of bFGF resulted in reduction of neuron numbers, enlarged cell body and shortened axon length. We found molecules closely related to bFGF, such as interleukin-1β (IL-1β). IL-1β was up-regulated after bFGF interference under OGD conditions, suggesting complex signaling between bFGF and OGD-mediated pathways. We found HI resulted in up-regulation of IL-1β mRNA in cortex and hippocampus. IL-1β KO rats markedly attenuated the impairment of long-term learning and memory induced by HI. Meanwhile, IL-1β^-/- (KO, homozygous) group showed better neurite growth and less apoptosis in OGD model. Furthermore, serine/threonine protein kinase (AKT1) mRNA and protein expression was significantly up-regulated in IL-1β KO rats.

CONCLUSIONS

We showed that IL-1β-mediated axon regeneration underlie the mechanism of bFGF for the treatment of HIBD in neonatal rats. Results from this study would provide insights and molecular basis for future therapeutics in treating HIBD.

How much synthetic oxytocin is infused during labour? A review and analysis of regimens used in 12 countries

Objective

To compare synthetic oxytocin infusion regimens used during labour, calculate the International Units (IU) escalation rate and total amount of IU infused over eight hours.

Design

Observational study

Setting

Twelve countries, eleven European and South Africa.

Sample

National, regional or institutional-level regimens on oxytocin for induction and augmentation labour

Methods

Data on oxytocin IU dose, infusion fluid amount, start dose, escalation rate and maximum dose were collected. Values for each regimen were converted to IU in 1000ml diluent. One IU corresponded to 1.67μg for doses provided in grams/micrograms. IU hourly dose increase rates were based on escalation frequency. Cumulative doses and total IU amount infused were calculated by adding the dose administered for each previous hour. Main Outcome Measures Oxytocin IU dose infused

Results

Data were obtained on 21 regimens used in 12 countries. Details on the start dose, escalation interval, escalation rate and maximum dose infused were available from 16 regimens. Starting rates varied from 0.06 IU/hour to 0.90 IU/hour, and the maximum dose rate varied from 0.90 IU/hour to 3.60 IU/hour. The total amount of IU oxytocin infused, estimated over eight hours, ranged from 2.38 IU to 27.00 IU, a variation of 24.62 IU and an 11-fold difference.

Conclusion

Current variations in oxytocin regimens for induction and augmentation of labour are inexplicable. It is crucial that the appropriate minimum infusion regimen is administered because synthetic oxytocin is a potentially harmful medication with serious consequences for women and babies when inappropriately used. Estimating the total amount of oxytocin IU received by labouring women, alongside the institution’s mode of birth and neonatal outcomes, may deepen our understanding and be the way forward to identifying the optimal infusion regimen.

The oxytocinergic system in PTSD following traumatic childbirth: endogenous and exogenous oxytocin in the peripartum period

Birth experiences can be traumatic and may give rise to PTSD following childbirth (PTSD-FC). Peripartum neurobiological alterations in the oxytocinergic system are highly relevant for postpartum maternal behavioral and affective adaptions like bonding and lactation but are also implicated in the response to traumatic events. Animal models demonstrated that peripartum stress impairs beneficial maternal postpartum behavior. Early postpartum activation of the oxytocinergic system may, however, reverse these effects and thereby prevent adverse long-term consequences for both mother and infant. In this narrative review, we discuss the impact of trauma and PTSD-FC on normal endogenous oxytocinergic system fluctuations in the peripartum period. We also specifically focus on the potential of exogenous oxytocin (OT) to prevent and treat PTSD-FC. No trials of exogenous OT after traumatic childbirth and PTSD-FC were available. Evidence from non-obstetric PTSD samples and from postpartum healthy or depressed samples implies restorative functional neuroanatomic and psychological effects of exogenous OT such as improved PTSD symptoms and better mother-to-infant bonding, decreased limbic activation, and restored responsiveness in dopaminergic reward regions. Adverse effects of intranasal OT on mood and the increased fear processing and reduced top-down control over amygdala activation in women with acute trauma exposure or postpartum depression, however, warrant cautionary use of intranasal OT. Observational and experimental studies into the role of the endogenous and exogenous oxytocinergic system in PTSD-FC are needed and should explore individual and situational circumstances, including level of acute distress, intrapartum exogenous OT exposure, or history of childhood trauma.

First assessed cervical dilatation: is it associated with oxytocin augmentation during labour? A retrospective cohort study in a university hospital in Switzerland

OBJECTIVES

The primary objective of this study was to examine the association between the first assessed cervical dilatation in a labourward and the use of oxytocin augmentation during labour. Further analysis was performed by examining the actual stage of labour at the point oxytocin was first administered to those women.

DESIGN

Retrospective cohort study with the data collected from the medical records of the hospital.

SETTING

University Hospital Bern, Switzerland PARTICIPANTS: 1933 term nulliparous and multiparous women with a singleton pregnancy giving birth during the period June 2013 and May 2017, representing Robson groups 1 and 3.

MEASUREMENTS AND FINDINGS

Descriptive statistics and multivariable logistic regression models were performed. It was found that for the entire process of labour, nulliparous and multiparous women (n = 1933) with a first cervical dilatation of 5 or more cm were less likely to be augmented with oxytocin (OR 0.64, 95% CI 0.46; 0.88 and OR 0.56, 95% CI 0.38; 0.82, respectively) compared to women with a first cervical dilatation of less than 5 cm. Out of these augmented women (n = 746) having a first cervical dilatation of 5 or more cm, they had a lower likelihood of being augmented during the first stage of labour compared to women with a first cervical dilatation of less than 5 cm (OR 0.45, 95% CI 0.29; 0.7 for nulliparae and OR 0.32, 95% CI 0.16; 0.6 for multiparae). Additionally, it was observed that other factors contributed to the application of oxytocin. One such example was that epidural analgesia was associated with a high risk of oxytocin augmentation in nulliparae (OR 13.88, 95% CI 9.29; 20.74) and multiparae (OR 15.52, 95% CI 9.94; 24.22). The application of oxytocin was also found to affect the caesarean section rate in nulliparous and multiparous women as it was 20% and 13% respectively for those with oxytocin versus 13% and 4% respectively for those without oxytocin.

KEY CONCLUSIONS

Early admission to the labourward is associated with an increased use of oxytocin to augment labour, particularly, during the first stage of labour. Epidural analgesia is a main predictor for oxytocin augmentation in nulliparous and multiparous women.

IMPLICATIONS FOR PRACTICE

Pregnant women warrant more appropriate support during early labour, avoiding early maternal exhaustion and excessive obstetrical interventions.

Health in Preconception, Pregnancy and Postpartum Global Alliance: International Network Pregnancy Priorities for the Prevention of Maternal Obesity and Related Pregnancy and Long-Term Complications

In this article, we describe the process of establishing agreed international pregnancy research priorities to address the global issues of unhealthy lifestyles and rising maternal obesity. We focus specifically on the prevention of maternal obesity to improve related clinical pregnancy and long-term complications. A team of multidisciplinary, international experts in preconception and pregnancy health, including consumers, were invited to form the Health in Preconception, Pregnancy and Postpartum (HiPPP) Global Alliance. As an initial activity, a priority setting process was completed to generate pregnancy research priorities in this field. Research, practice and policy gaps were identified and enhanced through expert and consumer consultation, followed by a modified Delphi process and Nominal Group Technique, including an international workshop. Research priorities identified included optimising: (1) healthy diet and nutrition; (2) gestational weight management; (3) screening for and managing pregnancy complications and pre-existing conditions; (4) physical activity; (5) mental health; and (6) postpartum (including intrapartum) care. Given extensive past research in many of these areas, research priorities here recognised the need to advance pregnancy research towards pragmatic implementation research. This work has set the agenda for large-scale, collaborative, multidisciplinary, implementation research to address the major public health and clinical issue of maternal obesity prevention.

Parasympathetic nervous activity is associated with oxytocin in multiparous, but not primiparous, women during the perinatal period

Oxytocin (OXT) is thought to have antidepressant/anxiolytic effects in postpartum women. Primiparous women tend toward an attenuated lactation compared with multiparous women. However, so far, little is known about the relationship between OXT and autonomic nervous activity (ANA) in perinatal women and whether it may be different in primiparous and multiparous women. Therefore, the objective of this study was to answer this question by determining both ANA and salivary OXT levels in primiparous and multiparous perinatal women. In 18 primiparous and 18 multiparous women, who underwent a physical and physiological examination, ANA measurement by heart rate variability and saliva sampling were performed during the perinatal period. Saliva OXT concentration was determined by a highly sensitive ELISA. OXT release into saliva was obtained from multiplying saliva OXT concentration by saliva flow rate. In the postpartum period, multiparous women had higher parasympathetic nervous activity (PNA) and lower physical stress index (PSI) compared with primiparous women. Furthermore, multiparous postpartal women had higher OXT compared with primiparous or multiparous prepartal women. In addition, in multiparous perinatal women, OXT correlated positively with PNA, but negatively with PSI. These results suggest that after parturition, multiparous mothers may switch over to the "feed and breed" system more quickly due to increased OXT compared with primiparous mothers. Our findings support antidepressant/anxiolytic and anti-stress effects of OXT. In postpartal women exposed to synthetic OXT, ANA measurement may provide a clue to clarify the effects of exogenous OXT on postpartum psychiatric disorders.

Relationship between postpartum depression and lactation status at a Japanese perinatal center: A cross-sectional study

Background:  Some studies have demonstrated that breastfeeding can protect mothers from postpartum depression; therefore, we examined the association between postpartum depression and lactation status at one month after delivery at a Japanese perinatal center.

Methods: We reviewed the obstetric records of all (total 809) nulliparous healthy women with vaginal singleton delivery at 37-41 weeks’ gestation at our institute between July 2018 and June 2019. A face-to-face interview with the women was conducted on admission for delivery to ask whether or not they hoped to perform exclusive breastfeeding for their babies, and an additional interview was conducted one month after delivery to ask about their feeding methods currently. Maternal mental status was examined based on the scores using the Edinburgh Postnatal Depression Scale (EPDS), and women with EPDS scores of ≥9 points were regarded as ‘positive screening’.

Results: 592 women (73.1%) hoped to perform exclusive breastfeeding for their babies on admission. Of these, at one month, 442 (74.7%) performed exclusive breastfeeding, while 150 (25.3%) performed mixed or artificial feeding. The average EPDS scores and the incidence of EPDS scores ≥9 points in the women performing exclusive breastfeeding were 4.3 ± 3.6 and 14.3% (63/442), respectively. They did not differ from those in the women performing mixed or artificial breast feeding [4.2 ± 3.7, p = 0.60 and 13.3% (20/150), p = 0.78].

Conclusion: Development of postpartum depression does not seem to be associated with incomplete breastfeeding at our hospital, and therefore there are other risk factors indicated in the development of postpartum depression.

Changes in salivary oxytocin levels and bonding disorder in women from late pregnancy to early postpartum: A pilot study

OBJECTIVES

This pilot study aimed to 1) follow the longitudinal changes in the salivary oxytocin level of pregnant women from late pregnancy to early postpartum, 2) examine the factors related to these changes, and 3) clarify the association of these changes with mother-infant bonding.

METHODS

This study used a longitudinal observational design and questionnaires to obtain objective and subjective data. For oxytocin evaluation, saliva samples were collected and their oxytocin levels were measured at 4-time points [i.e., 1) 36-37 gestation weeks, 2) 38-39 gestation weeks, 3) 1-2 days postpartum, 4) 4-5 days postpartum]. The oxytocin level was assayed in duplicates by enzyme-linked immunosorbent assay. Baseline data were evaluated using the Parental Bonding Instrument (25 items), State Trait Anxiety Inventory (20 items), and Center for Epidemiologic Studies Depression Scale. Postpartum data were evaluated using the Mother to Infant Bonding Scale Japanese Version (10 items), Maternity Blues Scale (13 items), and 'Fatigue after Childbirth' using the Visual Analogue Scale (VAS: 0-100 mm).

RESULTS

The participants were 13 primiparas with a mean age of 33 years. They had no depression or anxiety at the baseline. Their mean salivary oxytocin levels significantly increased from late pregnancy (36-39 gestation weeks) up to 1 day postpartum and then decreased until 5 days postpartum. There was a negligible correlation between the bonding disorder and the salivary oxytocin level on the 5th day after childbirth. A moderate correlation was observed between the maternity blues score and the salivary oxytocin level. There was a significant negative correlation between the postpartum fatigue and the salivary oxytocin level 1 day and 5 days after childbirth.

CONCLUSION

The mean salivary oxytocin levels significantly increased from the baseline up to 1 day postpartum and then decreased until 5 days postpartum. The salivary oxytocin level was moderately associated with maternity blues and significantly with postpartum fatigue.

Maternal plasma levels of oxytocin during physiological childbirth - a systematic review with implications for uterine contractions and central actions of oxytocin

BACKGROUND

Oxytocin is a key hormone in childbirth, and synthetic oxytocin is widely administered to induce or speed labour. Due to lack of synthetized knowledge, we conducted a systematic review of maternal plasma levels of oxytocin during physiological childbirth, and in response to infusions of synthetic oxytocin, if reported in the included studies.

METHODS

An a priori protocol was designed and a systematic search was conducted in PubMed, CINAHL, and PsycINFO in October 2015. Search hits were screened on title and abstract after duplicates were removed (n = 4039), 69 articles were examined in full-text and 20 papers met inclusion criteria. As the articles differed in design and methodology used for analysis of oxytocin levels, a narrative synthesis was created and the material was categorised according to effects.

RESULTS

Basal levels of oxytocin increased 3-4-fold during pregnancy. Pulses of oxytocin occurred with increasing frequency, duration, and amplitude, from late pregnancy through labour, reaching a maximum of 3 pulses/10 min towards the end of labour. There was a maximal 3- to 4-fold rise in oxytocin at birth. Oxytocin pulses also occurred in the third stage of labour associated with placental expulsion. Oxytocin peaks during labour did not correlate in time with individual uterine contractions, suggesting additional mechanisms in the control of contractions. Oxytocin levels were also raised in the cerebrospinal fluid during labour, indicating that oxytocin is released into the brain, as well as into the circulation. Oxytocin released into the brain induces beneficial adaptive effects during birth and postpartum. Oxytocin levels following infusion of synthetic oxytocin up to 10 mU/min were similar to oxytocin levels in physiological labour. Oxytocin levels doubled in response to doubling of the rate of infusion of synthetic oxytocin.

CONCLUSIONS

Plasma oxytocin levels increase gradually during pregnancy, and during the first and second stages of labour, with increasing size and frequency of pulses of oxytocin. A large pulse of oxytocin occurs with birth. Oxytocin in the circulation stimulates uterine contractions and oxytocin released within the brain influences maternal physiology and behaviour during birth. Oxytocin given as an infusion does not cross into the mother's brain because of the blood brain barrier and does not influence brain function in the same way as oxytocin during normal labour does.

Neural correlates of emotion processing comparing antidepressants and exogenous oxytocin in postpartum depressed women: An exploratory study

Despite common use of antidepressants to treat postpartum depression, little is known about the impact of antidepressant use on postpartum brain activity. Additionally, although oxytocin has been investigated as a potential treatment for postpartum depression, the interaction between antidepressants and exogenous oxytocin on brain activity is unknown. We explored postpartum depressed women's neural activation in areas identified as important to emotion and reward processing and potentially, antidepressant response: the amygdala, nucleus accumbens and ventral tegmental area. We conducted a secondary analysis of a functional imaging study of response to sexual, crying infant and smiling infant images in 23 postpartum depressed women with infants under six months (11 women taking antidepressants, 12 unmedicated). Participants were randomized to receive a single dose of oxytocin or placebo nasal spray. There was significantly higher amygdala activation to sexual stimuli than either neutral or infant-related stimuli among women taking antidepressants or receiving oxytocin nasal spray. Among unmedicated women receiving placebo, amygdala activation was similar across stimuli types. There were no significant effects of antidepressants nor oxytocin nasal spray on reward area processing (i.e., in the nucleus accumbens or ventral tegmental area). Among postpartum women who remain depressed, there may be significant interactions between the effects of antidepressant use and exogenous oxytocin on neural activity associated with processing emotional information. Observed effect sizes were moderate to large, strongly suggesting the need for further replication with a larger sample.

Sexual dimorphism of oxytocin and vasopressin in social cognition and behavior

The neuropeptides oxytocin (OT) and vasopressin (VP) are hormones that are known to mediate social behavior and cognition, but their influence may be sex-dependent. This paper aims to provide a comprehensive review of the sex-related influence of OT and VP on social cognition, focusing on partner preference and sexual orientation, trust and relevant behaviors, memory modulation, and emotion regulation. Most studies have suggested that OT facilitates familiar-partner preference in both sexes, with females being more significant, increased trust in others, especially for male, enhanced memory in either sex, and reduced anxious emotion in males. However, VP-regulated social cognition has been less studied. Other relevant studies have indicated that VP facilitated familiar-partner preference, improved memory, induced empathy formation, increased positive-emotion recognition, and induced anxiety without any sex difference. However, there was a male preponderance among studies, and results were often too complex to draw firm conclusions. Clarifying the interplay between OT/VP and sex hormones in the regulation of social cognition is necessary for further applications.

The effects of intrapartum synthetic oxytocin on maternal postpartum mood: findings from a prospective observational study

Postpartum depression (PPD) affects up to 19% of all mothers, with detrimental effects on both mother and child. The antidepressant and anxiolytic effects of plasma oxytocin are well-documented, but it is still disputable whether synthetic oxytocin (synOT) may protect women against postpartum mood alterations. The current study examined the association between synOT intrapartum and maternal mood postpartum using a prospective design. Two hundred sixty women were screened for depressive symptoms in the last trimester of pregnancy and then again 6 weeks and 9 months postpartum using the Edinburgh Postnatal Depression Scale. They also completed Maternity Blues Questionnaire in the first postpartum week. The data concerning the intrapartum interventions and health status of the newborn were extracted from the medical records. Cox proportional hazards regression adjusted for a history of depression, mode of delivery, and childbirth experience showed that synOT predicted a significantly lower risk of PPD (HR = 0.65, 95% CI 0.45-0.95, p = 0.025). The risk factors for PPD included a history of depression (HR = 3.20, 95% CI 2.33-4.40, p < 0.001) and negative childbirth experience (HR = 1.39, 95% CI 1.01-1.90, p = 0.040). Logistic regression adjusted for the same covariates found no significant effect of synOT on maternity blues (OR = 0.64, 95% CI 0.31-1.32, p = 0.23). While synOT administered intrapartum does not affect maternal mood immediately, it may come to effect some weeks after childbirth to protect mothers from developing PPD symptoms.

Cessation of breastfeeding in association with oxytocin administration and type of birth. A prospective cohort study

BACKGROUND

Some studies have suggested an association between synthetic oxytocin administration and type of birth with the initiation and consolidation of breastfeeding.

AIM

This study aimed to test whether oxytocin administration and type of birth are associated with cessation of exclusive breastfeeding at different periods. A second objective was to investigate whether the administered oxytocin dose is associated with cessation of exclusive breastfeeding.

METHODS

We conducted a prospective cohort study (n=529) in a tertiary hospital. Only full-term singleton pregnancies were included. Four groups were established based on the type of birth (vaginal or cesarean) and the intrapartum administration of oxytocin. Follow-up was performed to evaluate the consolidation of exclusive breastfeeding at 1, 3 and 6months.

FINDINGS

During follow-up, the proportion of exclusive breastfeeding decreased in all groups. After adjusting for confounding variables, the group with cesarean birth without oxytocin (planned cesarean birth) had the highest risk of cessation of exclusive breastfeeding (odds ratio [95% confidence interval], 2.51 [1.53-4.12]). No association was found between the oxytocin dose administered during birth and puerperium period and the cessation of exclusive breastfeeding.

CONCLUSION

Planned cesarean birth without oxytocin is associated with the cessation of exclusive breastfeeding at 1, 3 and 6months of life. It would be desirable to limit elective cesarean births to essentials as well as to give maximum support to encourage breastfeeding in this group of women. The dose of oxytocin given during birth and puerperium period is not associated with cessation of exclusive breastfeeding.

Breastfeeding Outcomes After Oxytocin Use During Childbirth: An Integrative Review

INTRODUCTION

Despite widespread use of exogenous synthetic oxytocin during the birth process, few studies have examined the effect of this drug on breastfeeding. Based on neuroscience research, endogenous oxytocin may be altered or manipulated by exogenous administration or by blocking normal function of the hormone or receptor. Women commonly cite insufficient milk production as their reason for early supplementation, jeopardizing breastfeeding goals. Researchers need to consider the role of birth-related medications and interventions on the production of milk. This article examines the literature on the role of exogenous oxytocin on breastfeeding in humans.

METHODS

Using the method described by Whittemore and Knafl, this integrative review of literature included broad search criteria within the PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, and Scopus databases. Studies published in English associating a breastfeeding outcome in relation to oxytocin use during the birth process were included. Twenty-six studies from 1978 to 2015 met the criteria.

RESULTS

Studies were analyzed according to the purpose of the research, measures and methods used, results, and confounding variables. The 26 studies reported 34 measures of breastfeeding. Outcomes included initiation and duration of breastfeeding, infant behavior, and physiologic markers of lactation. Timing of administration of oxytocin varied. Some studies reported on low-risk birth, while others included higher-risk experiences. Fifty percent of the results (17 of 34 measures) demonstrated an association between exogenous oxytocin and less optimal breastfeeding outcomes, while 8 of 34 measures (23%) reported no association. The remaining 9 measures (26%) had mixed findings. Breastfeeding intentions, parity, birth setting, obstetric risk, and indications for oxytocin use were inconsistently controlled among the studies.

DISCUSSION

Research on breastfeeding and lactation following exogenous oxytocin exposure is limited by few studies and heterogeneous methods. Despite the limitations, researchers and clinicians may benefit from awareness of this body of literature. Continued investigation is recommended given the prevalence of oxytocin use in clinical practice.

Sleep in the Postpartum: Characteristics of First-Time, Healthy Mothers

Goals for the present study were to (a) describe the sleep of healthy new mothers over a 6-month postpartum period, (b) examine how sleep quality relates to daytime levels of fatigue and sleepiness, and (c) evaluate the relationship between mothers' and infants' sleep parameters. The sample consisted of 37 healthy, partnered, first-time mothers who had experienced full-term vaginal birth and had a healthy infant. We investigated infants' sleep parameters and mothers' sleep, mood, and daytime functioning 2 and 6 months postpartum. We found that at 2 months postpartum, mothers reported sleeping 6 hours at night and just under one hour during the day. Despite relatively frequent nocturnal awakenings, mothers experienced minimal insomnia, nonrefreshing sleep, anxiety, depression, daytime sleepiness, or fatigue at either 2 or 6 months. The most robust relationship between mothers' and infants' sleep was in the number of nocturnal sleep-wake episodes. Of note is that none of the infant sleep parameters was related to mothers' anxiety, depression, fatigue, sleepiness, or nonrefreshing sleep at either time period. Our results indicate that (1) selected low risk new mothers are resilient in terms of sleep quality, daytime functioning, and mood and (2) these are independent of their infants' sleep parameters.

Predictors of supplementation for breastfed babies in a Baby-Friendly hospital

PROBLEM

Supplementation of breastfed babies is common during the hospital stay.

BACKGROUND

The Baby Friendly Hospital Initiative (BFHI) optimises practices to support exclusive breastfeeding, yet supplementation is still prevalent.

OBJECTIVE

To determine predictors for supplementation in a cohort of breastfed babies in a Baby-Friendly hospital.

METHODS

Electronic hospital records of 1530 healthy term or near term singleton infants and their mothers were examined retrospectively and analysed to identify factors associated with in-hospital supplementation using Poisson regression (unadjusted and adjusted).

FINDINGS

Fifteen percent of breastfed infants were supplemented during their hospital stay. Analysis by multivariable Poisson regression found that supplementation was independently associated with overweight (reference normal weight) (aRR [adjusted relative risk]=1.46; 95% CI: 1.11-1.93); primiparity (aRR=1.40; 95% CI: 1.09-1.80); early term gestation (37-37⁶ weeks, aRR=2.79; 95% CI: 1.88-4.15; 38-38⁶ weeks, aRR=2.03, 95%CI: 1.46-2.82); birthweight less than 2500 grams (reference 3000-3499 grams) (aRR=3.60; 95% CI: 2.32-5.60) and use of postpartum uterotonic (aRR=2.47; 95% CI: 1.09-5.55). Greater than 65 minutes of skin-to-skin contact at birth reduced the risk of supplementation (aRR=0.66; 95% CI; 0.48-0.92).

CONCLUSION

These identified predictors for supplementation, can inform the development of interventions for mother-infant pairs antenatally or in the early postpartum period around increased breastfeeding education and support to reduce supplementation. It may also be possible to reduce supplementation through judicious use of postpartum uterotonics and facilitation of mother-infant skin-to-skin contact at birth for greater than one hour duration.

Birth setting, labour experience, and postpartum psychological distress

OBJECTIVE

although psychosocial risk factors have been identified for postpartum depression (PPD) and perinatal posttraumatic stress disorder (PTSD), the role of labour- and birth-related factors remains unclear. The present investigation explored the impact of birth setting, subjective childbirth experience, and their interplay, on PPD and postpartum PTSD.

METHOD

in this prospective longitudinal cohort study, three groups of women who had vaginal births at a tertiary care hospital, a birthing center, and those transferred from the birthing centre to the tertiary care hospital were compared. Participants were followed twice during pregnancy (12-14 and 32-34 weeks gestation) and twice after childbirth (1-3 and 7-9 weeks postpartum).

RESULTS

symptoms of PPD and PTSD did not significantly differ between birth groups; however, measures of subjective childbirth experience and obstetric factors did. Moderation analyses indicated a significant interaction between pain and birth group, such that higher ratings of pain among women who were transferred was associated with greater symptoms of postpartum PTSD.

CONCLUSION AND IMPLICATIONS FOR PRACTICE

women who are transferred appear to have a unique experience that may put them at greater risk for postpartum psychological distress. It may be beneficial for care providers to help prepare women for pain management and potential unexpected complications, particularly if it is their first childbirth.

Association of peripartum synthetic oxytocin administration and depressive and anxiety disorders within the first postpartum year

BACKGROUND

Due to its potent effects on social behavior, including maternal behavior, oxytocin has been identified as a potential mediator of postpartum depression and anxiety. The objective of this study was to examine the relationship between peripartum synthetic oxytocin administration and the development of depressive and anxiety disorders within the first year postpartum. We hypothesized that women exposed to peripartum synthetic oxytocin would have a reduced risk of postpartum depressive and anxiety disorders compared with those without any exposure.

METHODS

Population-based data available through the Massachusetts Integrated Clinical Academic Research Database (MiCARD) were used to retrospectively (2005-2014) examine this relationship and calculate the relative risk of peripartum synthetic oxytocin for the development of postpartum depressive and anxiety disorders in exposed (n = 9,684) compared to unexposed (n = 37,048) deliveries.

RESULTS

Among deliveries to women with a history of prepregnancy depressive or anxiety disorder, exposure to peripartum oxytocin increased the risk of postpartum depressive or anxiety disorder by 36% (relative risk (RR): 1.36; 95% confidence interval (95% CI): 1.20-1.55). In deliveries to women with no history of prepregnancy depressive or anxiety disorder, exposure to peripartum oxytocin increased the risk of postpartum depressive or anxiety disorder by 32% compared to those not exposed (RR: 1.32; 95% CI: 1.23-1.42).

CONCLUSIONS

Contrary to our hypothesis, results indicate that women with peripartum exposure to synthetic oxytocin had a higher relative risk of receiving a documented depressive or anxiety disorder diagnosis or antidepressant/anxiolytic prescription within the first year postpartum than women without synthetic oxytocin exposure.

Oxytocin and Human Evolution

A small, but powerful neuropeptide, oxytocin coordinates processes that are central to both human reproduction and human evolution. Also embedded in the evolution of the human nervous system are unique pathways necessary for modern human sociality and cognition. Oxytocin is necessary for facilitating the birth process, especially in light of anatomical restrictions imposed by upright human locomotion, which depends on a fixed pelvis. Oxytocin, by facilitating birth, allowed the development of a large cortex and a protective bony cranium. The complex human brain in turn permitted the continuing emergence of social sensitivity, complex thinking, and language. After birth is complete, oxytocin continues to support human development by providing direct nutrition, in the form of human milk, and emotional and intellectual support through high levels of maternal behavior and selective attachment. Oxytocin also encourages social sensitivity and reciprocal attunement, on the part of both the mother and child, which are necessary for human social behavior and for rearing an emotionally healthy human child. Oxytocin supports growth during development, resilience, and healing across the lifespan. Oxytocin dynamically moderates the autonomic nervous system, and effects of oxytocin on vagal pathways allowing high levels of oxygenation and digestion necessary to support adaptation in a complex environment. Finally, oxytocin has anti-oxidant and anti-inflammatory effects, helping to explain the pervasive adaptive consequences of social behavior for emotional and physical health.

Oxytocin pathways in the intergenerational transmission of maternal early life stress

Severe stress in early life, such as childhood abuse and neglect, constitutes a major risk factor in the etiology of psychiatric disorders and somatic diseases. Importantly, these long-term effects may impact the next generation. The intergenerational transmission of maternal early life stress (ELS) may occur via pre-and postnatal pathways, such as alterations in maternal-fetal-placental stress physiology, maternal depression during pregnancy and postpartum, as well as impaired mother-offspring interactions. The neuropeptide oxytocin (OT) has gained considerable attention for its role in modulating all of these assumed transmission pathways. Moreover, central and peripheral OT signaling pathways are highly sensitive to environmental exposures and may be compromised by ELS with implications for these putative transmission mechanisms. Together, these data suggest that OT pathways play an important role in the intergenerational transmission of maternal ELS in humans. By integrating recent studies on gene-environment interactions and epigenetic modifications in OT pathway genes, the present review aims to develop a conceptual framework of intergenerational transmission of maternal ELS that emphasizes the role of OT.