Intrapartum synthetic oxytocin reduce the expression of primitive reflexes associated with breastfeeding

The interplay of oxytocin and sex hormones

The neuropeptide oxytocin has historically been associated with reproduction and maternal behavior. However, more recent research has uncovered that oxytocin has a much wider range of roles in physiology and behavior. Despite the excitement surrounding potential therapeutical applications of intranasally administered oxytocin, the results of these intervention studies have been inconsistent. Various reasons for these mixed results have been proposed, which tend to focus on methodological issues, such as study design. While methodological issues are certainly important, emerging evidence suggests that the interaction between oxytocin and sex hormones may also account for these varied findings. To better understand the purpose and function of the interaction of oxytocin with sex hormones, with a focus on estrogens, progesterone, and testosterone, we conducted a comprehensive thematic review via four perspectives: evolutionary, developmental, mechanistic, and survival. Altogether, this synergistic approach highlights the critical function of sex hormone activity for accomplishing the diverse roles of oxytocin via the modulation of oxytocin release and oxytocin receptor activity, which is also likely to contribute to the heterogeneity of outcomes after oxytocin administration.

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).

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.

Effects of different doses of synthetic oxytocin on neonatal instinctive behaviors and breastfeeding

Synthetic oxytocin is the current domestic first-line agent of induced labor and labor augmentation, and its potential effects on neonatal neurobehavioral development is currently attracting increased attention. To explore the effect of different doses of synthetic oxytocin on neonatal instinctive breastfeeding behavior and breastfeeding by observing neonatal behaviors during skin-to-skin contact with mothers after delivery. Observations and comparisons of neonatal instinctive behaviors were conducted by using Widström's 9 Stages method. According to the total dosage of oxytocin administered during labor, participants were divided into a low dose group (≤ 2.5 U) of 39 pairs, a medium dose group (> 2.5 U) of 38 pairs, a high dose group (> 7.5 U) of 38 pairs and a control group (no synthetic oxytocin use) of 39 pairs. The occurrence time of newborns' instinctive movements and the duration of each behavior stage for the four groups were also analyzed. The number of exclusive breastfeeding sessions within 3 days after birth and the rate of exclusive breastfeeding at 3 months were collected and compared. There were significant differences among the four groups in the occurrence time of raising head or turning head (p = 0.004), eating hands (p = 0.011), moving body (p = 0.001), locating areola (p < 0.001), licking nipples (p = 0.002), containing nipple (p = 0.001), sucking (p < 0.001). There were significant differences among the four groups in the duration of activity (p = 0.004), clawing (p = 0.001), familiarization (p = 0.001), and sucking (p < 0.001). There was also a significant difference in the number of exclusive breastfeeding sessions of 24 h (p = 0.011), 48 h (p < 0.001), 72 h (p = 0.001) after birth among the four groups, but there was no statistical difference in the rate of exclusive breastfeeding at 3 months after birth. The intrapartum administration of synthetic oxytocin was associated with the expression of neonatal instinctive breastfeeding. With increases in drug dose, the effect of breast seeking activity and breast attachment was more significant, and the association of synthetic oxytocin on sucking and breastfeeding was dose-dependent.

Effects of Motherwort Injection Versus Intramuscular Oxytocin for Preventing Postpartum Hemorrhage Among Women Who Underwent Cesarean Section

Objectives: Subject to ethical constraints, real-world data are an important resource for evaluating treatment effects of medication use during pregnancy and the postpartum period. This study investigated whether motherwort injection, a traditional Chinese medicine preparation, was more effective than intramuscular (IM) oxytocin for preventing postpartum hemorrhage (PPH) in a real-world setting when intravenous (IV) oxytocin is administered.

Methods: We conducted an active-controlled, propensity-score matched cohort study using an established pregnancy registry database. Women who underwent cesarean section and received IV oxytocin at the third stage of labor were included. We used an active-comparator design to minimize indication bias, in which we compared IM motherwort injection in the uterus versus IM oxytocin, both on top of IV oxytocin use. We applied 1:1 propensity-score matching (PSM) to balance patient baseline characteristics and used a logistic regression model to estimate treatment effect (i.e., risk difference (RD) and odds ratio (OR)) by using the counterfactual framework. The outcomes of interest were blood loss over 500 ml within 2 h after delivery (PPH, primary) and blood loss over 1,000 ml (severe PPH, secondary). We conducted four sensitivity analyses to examine the robustness of the results.

Results: A total of 22,519 pregnant women underwent cesarean sections, among which 4,081 (18.12%) PPH and 480 (2.13%) severe PPH occurred. Among included women, 586 (2.60%) were administrated with IM motherwort injection, and 21,933 (97.40%) used IM oxytocin. After PSM, patient baseline characteristics were well balanced. Compared with IM oxytocin, the use of IM motherwort injection was associated with significantly lower risk of PPH (RD −25.26%, 95% CI −30.04% to −20.47%, p < 0.001; OR 0.25, 95% CI 0.18 to 0.32, p < 0.001) and severe PPH (RD −3.58%, 95% CI −5.87% to −1.30%, p < 0.001; OR 0.39, 95% CI 0.20 to 0.71, p < 0.002). Sensitivity analyses showed that the results were similar.

Conclusion: With the use of data from a real-world setting, the findings consistently showed that among women undergoing cesarean section who had received IV oxytocin, the additional use of IM motherwort injection could achieve a lower risk of PPH as compared to the additional use of IM oxytocin. Our study suggested a paradigm for investigating the treatment effect of Chinese herbal medicine in the real-world practice setting.

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.

Birth signalling hormones and the developmental consequences of caesarean delivery

Rates of delivery by caesarean section (CS) are increasing around the globe and, although several epidemiological associations have already been observed between CS and health outcomes in later life, more are sure to be discovered as this practice continues to gain popularity. The components of vaginal delivery that protect offspring from the negative consequences of CS delivery in later life are currently unknown, although much attention to date has focused on differences in microbial colonisation. Here, we present the case that differing hormonal experiences at birth may also contribute to the neurodevelopmental consequences of CS delivery. Levels of each of the 'birth signalling hormones' (oxytocin, arginine vasopressin, epinephrine, norepinephrine and the glucocorticoids) are lower following CS compared to vaginal delivery, and there is substantial evidence for each that manipulations in early life results in long-term neurodevelopmental consequences. We draw from the research traditions of neuroendocrinology and developmental psychobiology to suggest that the perinatal period is a sensitive period, during which hormones achieve organisational effects. Furthermore, there is much to be learned from research on developmental programming by early-life stress that may inform research on CS, as a result of shared neuroendocrine mechanisms at work. We compare and contrast the effects of early-life stress with those of CS delivery and propose new avenues of research based on the links between the two bodies of literature. The research conducted to date suggests that the differences in hormone signalling seen in CS neonates may produce long-term neurodevelopmental consequences.

Relationships Among Factors Related to Childbirth and Breastfeeding Outcomes in Primiparous Women

OBJECTIVES

To explore the relationships among potentially modifiable factors related to childbirth and effective breastfeeding initiation at approximately 36 hours after birth and duration and exclusivity at hospital discharge, 2 weeks, 2 months, and 6 months after birth in primiparous women and to explore whether modifiable and nonmodifiable secondary factors and covariates influenced the relationships among factors related to childbirth and these breastfeeding outcomes.

DESIGN

A prospective, longitudinal, cohort study.

SETTING

The postpartum units of two general hospitals in eastern Canada.

PARTICIPANTS

Ninety-seven mother-infant dyads.

METHODS

We recorded demographic, childbirth, obstetric history, and breastfeeding data through chart review. A breastfeeding observation was completed at approximately 36 hours after birth by unit nurses. Participants maintained breastfeeding logs in hospital and for 6 months after birth and completed three self-report questionnaires before discharge. We analyzed outcomes using backward stepwise linear and logistic regression.

RESULTS

One childbirth factor, labor induced with oxytocin, was negatively associated with effective initiation of breastfeeding, and none was related to breastfeeding duration and exclusivity at any time point. Maternal weight; professional support; and newborn's gestational age at birth, 5-minute Apgar score, weight loss, LATCH score, and active feeds (newborn actively suckled at the breast) were significantly associated with breastfeeding outcomes.

CONCLUSION

Induction of labor with oxytocin should be used judiciously; when used, nurses must be hypervigilant to assess the mother-infant dyad for breastfeeding issues and to intervene to prevent or remediate them.

Perspectives of Pitocin administration on behavioral outcomes in the pediatric population: recent insights and future implications

Oxytocin plays an important role in the regulation of parturition as this peptide hormone promotes uterine smooth muscle contractility in gravid women undergoing labor. Here, we review the impact of Pitocin administration on behavioral outcomes in the pediatric population. Pitocin is a synthetic preparation of oxytocin widely used in the obstetric practice for the management of labor and postpartum hemorrhage. We begin by tracing the neuroanatomy of oxytocin-containing cells from an evolutionary perspective and then summarize key findings on behavioral and neural activity reported from offspring dosed with Pitocin during vaginal delivery. Finally, we discuss future directions that are experimentally tractable for understanding the developmental consequences of Pitocin administration on a small but growing subset of children worldwide. Given that fetal past experiences can shape the future behavior of the adult, further work on oxytocin signaling pathways will provide valuable references and insights for early-brain development and state-dependent regulation of behavioral outcome.

Inter-institutional variations in oxytocin augmentation during labour in German university hospitals: a national survey

BACKGROUND

There are several international guidelines on oxytocin regimens for induction and augmentation of labour, but no agreement on a standardised regimen in Germany. This study collated and reviewed the oxytocin regimens used for labour augmentation in university hospitals, with the long-term aim of contributing to the development of a national clinical guideline.

METHODS

Germany has 34 university hospital compounds, representing 39 maternity units. In this observational study we asked units to provide standard operational procedures on oxytocin augmentation during labour or provide the details in a structured survey. Data were collected on the dosage of oxytocin, type and volume of solutions used, indications and contraindications for use and discontinuation, case-specific administration, and on who developed the procedures. Findings were analysed descriptively.

RESULTS

A total of 35 (90%) units participated in this study. Standard operating procedures were available in 24 units (69%), seven units (20%) did not have procedures and information was missing from four units (11%). Midwives participated in the development of standard operating procedures in 15 units (43%). Infusions were most commonly prepared using six units of oxytocin in 500 ml 0.9% normal saline solution (12 mU/ml). The infusions were started at 120 mU/hour and increased by 120 mU/hour at 20-min intervals up to a maximum dosage of 1200 mU/hour. The most common indication for use was delayed progress in labour. Infusions were stopped when uterine contractions became hypertonic and/or the fetal heart rate showed signs of distress. Most of the practices described aligned with international guidance. All units used reduced oxytocin dosages for women with a history of previous caesareans section, as recommended in the international guidelines, and restrictive use was advised in multiparous women. The main difference between units related to combined use of amniotomy and oxytocin, recommended by three guidelines but used in only four maternity units (11%).

CONCLUSIONS

While there was considerable variation in the oxytocin augmentation procedures, most but not all practices used in these 35 German maternity units were comparable. Establishing a national guideline on the criteria for and administration of oxytocin for augmentation of labour would eliminate the observed differences and minimise risk of administration and medication error.

Drug use in delivery hospitalization: Pelotas births cohort, 2015

OBJECTIVE:

Trace the pattern of drug use during delivery hospitalization.

METHOD:

Cross-sectional study carried out from June to October 2015, included in the 2015 Pelotas births cohort. All women living in the urban area of the city who were hospitalized for delivery were part of the sample. We collected information regarding drug prescription and drug use by mothers during the whole period of hospitalization. Sociodemographic data were obtained in interview after delivery, and other data were obtained from medical charts. The drugs were classified according to the Anatomical Therapeutic Chemical system.

RESULTS:

All study participants (1,392 women) used at least one drug, with the mean amount being larger the higher the age of the mother, both prepartum/during delivery and postpartum. It was also higher in cases of spinal anesthesia or general anesthesia, cesarean deliveries, school hospitals, and longer hospitalizations. Analysis of the sample as a whole showed no significant difference in the number of drugs used according to hospitalization type, but when stratified by length of hospital stay the mean was higher in SUS hospitalizations than in private and health insurance hospitalizations. Drugs for the nervous system were the most used (30.5%), followed by drugs for the alimentary tract and metabolism (13.8%). The use of anti-infective agents and drugs that act on the cardiovascular and respiratory systems was higher in mothers who underwent cesarean delivery. This study showed high drug consumption in the delivery hospitalization period, and showed cesarean delivery and epidural anesthesia as the main factors related to high drug consumption in this period.

CONCLUSIONS:

We found high drug consumption in the delivery hospitalization period, and the main factors were cesarean delivery and epidural anesthesia. Drugs that act on the nervous system were the most used.

The effect of labor medications on normal newborn behavior in the first hour after birth: A prospective cohort study

BACKGROUND

Skin-to-skin contact after birth between mother and baby has immediate and long-term advantages. Widström's 9 Stages of Newborn Behavior offer an opportunity to evaluate a baby in the natural, expected and optimal habitat. Intrapartum drugs, including fentanyl administered via epidural and synthetic oxytocin (synOT), have been studied in relation to neonatal outcomes with conflicting results.

AIMS

Determine the effects of common intrapartum medications on the instinctive behavior of healthy newborns during the first hour after birth through a prospective cohort study.

STUDY DESIGN

Video record newly-born term infants during the first hour after birth while in skin-to-skin contact with mother. Code and analyze videos using Widström's 9 Stages; compare with the labor medications mothers received.

SUBJECTS

Convenience sample of sixty-three low-income mothers self-selected to labor with or without intrapartum analgesia.

OUTCOME MEASURES

Duration of time infants spend in each of Widström's 9 Stages for four cohorts: 1) exposed to no synOT or epidural fentanyl during labor, 2) exposed to fentanyl (but not synOT), 3) exposed synOT (but not fentanyl), 4) exposed to both fentanyl and synOT.

RESULTS

A strong inverse correlation was found between intrapartum exposure to fentanyl and synOT and the normal behavior of an infant, as measured by time in each Stage.

CONCLUSIONS

Intrapartum exposure to the drugs fentanyl and synOT is associated with altered newborn infant behavior, including suckling, while in skin-to-skin contact with mother during the first hour after birth. Widström's 9 Stages offer an opportunity to analyze newborn behavior whilst in the optimal habitat of the infant.

Cumulative Risk of the Oxytocin Receptor Gene Interacts with Prenatal Exposure to Oxytocin Receptor Antagonist to Predict Children's Social Communication Development

Compelling evidence for the far-reaching role of oxytocin (OT) in social cognition and affiliative behaviors set the basis for examining the association between genetic variation in the OT receptor (OXTR) gene and risk for autism spectrum disorder (ASD). In the current study, gene-environment interaction between OXTR and prenatal exposure to either OT or OXTR antagonist (OXTRA) in predicting early social communication development was examined. One hundred and fifty-three children (age: M = 4.32, SD = 1.07) were assigned to four groups based on prenatal history: children whose mothers prenatally received OXTRA and Nifedipine to delay preterm labor (n = 27); children whose mothers received Nifedipine only to delay preterm labor (n = 35); children whose mothers received OT for labor augmentation (n = 56), and a no intervention group (n = 35). Participants completed a developmental assessment of intelligence quotient (IQ), adaptive behavior, and social communication abilities. DNA was extracted via buccal swab. A genetic risk score was calculated based on four OXTR single nucleotide polymorphisms (rs53576, rs237887, rs1042778, and rs2254298) previously reported to be associated with ASD symptomatology. OXTRrisk-allele dosage was associated with more severe autism diagnostics observation schedule (ADOS) scores only in the OXTRA group. In contrast, in the Nifedipine, OT, and no intervention groups, OXTRrisk-allele dosage was not associated with children's ADOS scores. These findings highlight the importance of both genetic and environmental pathways of OT in signaling early social development and raise the need for further research in this field. Autism Res 2019, 12: 1087-1100. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: In the current study, we examined if the association between prenatal exposure to an oxytocin receptor antagonist (OXTRA) and autism spectrum disorder (ASD) related impairments are dependent on an individual's genetic background for the oxytocin receptor gene (OXTR). Children who carried a greater number of risk alleles for the OXTR gene and whose mothers received OXTRA to delay preterm labor showed more ASD-related impairments. The results highlight the importance of both genetic and environmental pathways of oxytocin in shaping early social development.

Parturition and the perinatal period: can mode of delivery impact on the future health of the neonate?

Caesarean section and instrumental delivery rates are increasing in many parts of the world for a range of cultural and medical reasons, with limited consideration as to how 'mode of delivery' may impact on childhood and long-term health. However, babies born particularly by pre-labour caesarean section appear to have a subtly different physiology from those born by normal vaginal delivery, with both acute and chronic complications such as respiratory and cardio-metabolic morbidities being apparent. It has been hypothesized that inherent mechanisms within the process of labour and vaginal delivery, far from being a passive mechanical process by which the fetus and placenta are expelled from the birth canal, may trigger certain protective developmental processes permissive for normal immunological and physiological development of the fetus postnatally. Traditionally the primary candidate mechanism has been the hormonal surges or stress response associated with labour and vaginal delivery, but there is increasing awareness that transfer of the maternal microbiome to the infant during parturition. Transgenerational transmission of disease traits through epigenetics are also likely to be important. Interventions such as probiotics, neonatal gut seeding and different approaches to clinical care have potential to influence parturition physiology and improve outcomes for infants.

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.

Oxytocin Receptor Antagonist (Atosiban) in the Threat of Preterm Birth: Does It Have Any Effect on Breastfeeding in the Term Newborn?

AIM

Oxytocin is a hormone involved in the mechanism of breastfeeding, uterine contractions, and social relationships. Atosiban (competitive oxytocin antagonist) is one of the most commonly used tocolytics for the threat of preterm labor in Europe. The aim of this study is to determinate if the administration of atosiban has any influence in the type of feeding in the term newborn at discharge. The secondary objective is to verify its effectiveness for the prevention of preterm delivery and in the possibility of applying treatment to complete lung maturation.

MATERIALS AND METHODS

Retrospective cohort study carried out in a tertiary University Hospital distinguished by WHO-UNICEF as a Baby-Friendly Hospital Initiative. The analysis included 264 women exposed to atosiban during a period of 4 years. One hundred met inclusion criteria. Unexposed infants born right after and before the exposed ones were selected as the not exposed subgroup (n = 200).

RESULTS

Among women treated with atosiban, 82% maintained exclusively breastfed (EBF), 8% had mixed breastfeeding, and 10% had formula feeding at discharge. In the nonexposed group, 82% maintained EBF, 9.5% had mixed breastfeeding, and 8.5% had formula feeding at discharge (p = 0.84). 97.5% of pregnant women treated with atosiban received corticosteroid for lung maturation, and 49.5% completed gestation with term newborns.

CONCLUSION

There were no significant differences in the type of feeding at discharge between the atosiban group and the nonexposed group. In most cases, the administration of tocolytic therapy allowed to complete lung maturation.

The Relationship of the Administration of Intrapartum Synthetic Oxytocin and Breastfeeding Initiation and Duration Rates

AIM

The consequences that intrapartum administration of hormones can have on breastfeeding are unclear. The aim of the study is to determine if synthetic intrapartum oxytocin, used routinely for induction/stimulation, has a relationship to initiation/duration of breastfeeding.

PATIENTS AND METHODS

We conducted a cohort study that was carried out in a tertiary university hospital distinguished by WHO-UNICEF as a BFHI (Baby-Friendly Hospital Initiative). A group of 53 mother and newborn dyads who had been exposed to intrapartum synthetic oxytocin were compared with 45 nonexposed dyads. A breastfeeding questionnaire was administered by a midwife blind to patient group through phone calls 3 and 6 months after delivery.

RESULTS

No statistically significant differences were observed between the two groups in the rates of mothers exclusively breastfeeding (EBF) or nonexclusively breastfeeding. The percentage of those who were EBF when discharged was 97.3% in the oxytocin-nonexposed group and 87.1% in the oxytocin-exposed group (p = 0.14). At 3 months, the group rates of exclusive breastfeeding were 72.5% in the nonoxytocin-exposed group versus 65.9% in the oxytocin-exposed group (p = 0.71). At 6 months, rates of breastfeeding were 31.4% versus 27.9% (p = 0.53) in the oxytocin-nonexposed and oxytocin-exposed groups, respectively.

CONCLUSIONS

In this study, no statistically significant effect of intrapartum synthetic oxytocin administration was observed pertaining to the initiation or duration of breastfeeding.