Perinatal dengue and Zika virus cross-sectional seroprevalence and maternal-fetal outcomes among El Salvadoran women presenting for labor-and-delivery.

BACKGROUND: Despite maternal flavivirus infections' linkage to severe maternal and fetal outcomes, surveillance during pregnancy remains limited globally. Further complicating maternal screening for these potentially teratogenic pathogens is the overwhelming subclinical nature of acute infection. This study aimed to understand perinatal and neonatal risk for poor health outcomes associated with flaviviral infection during pregnancy in El Salvador. METHODS: Banked serologic samples and clinical results obtained from women presenting for labor and delivery at a national referent hospital in western El Salvador March to September 2022 were used for this study. 198 samples were screened for dengue and Zika virus IgM, and statistical analyses analyzed demographic and clinical outcome associations with IgM positivity. RESULTS: This serosurvey revealed a high rate of maternal flavivirus infection-24.2% of women presenting for labor and delivery were dengue or Zika virus IgM positive, suggesting potential infection within pregnancy. Specifically, 20.2% were Zika virus IgM positive, 1.5% were dengue virus IgM positive, and 2.5% were both dengue and Zika virus IgM positive. Women whose home had received mosquito abatement assistance within the last year by the ministry of health were 70% less likely to test IgM positive (aOR = 0.30, 95%CI: 0.10, 0.83). Further, statistical geospatial clustering revealed transmission foci in six primary municipalities. Pregnancy complications and poor birth outcomes were noted among the dengue and/or Zika virus maternal infection group, although these outcomes were not statistically different than the seronegative group. None of the resulting neonates born during this study were diagnosed with congenital Zika syndrome. CONCLUSIONS: The high rate of Zika virus detected among pregnant women and the lack of Zika-specific neonatal outcomes monitoring during a non-outbreak year highlights the need for continued surveillance in Central America and among immigrant mothers presenting for childbirth from these countries. As changing climatic conditions continue to expand the range of the disease vector, asymptomatic screening programs could be vital to early identification of outbreaks and clinical management of cases.

Changes in salivary oxytocin in response to biologically-relevant events in farm animals: method optimization and usefulness as a biomarker.

Although best known for its established role in mediating parturition and lactation, the highly-conserved neuropeptide hormone oxytocin also mediates a range of social and stress-buffering processes across mammalian species. Measurements of peripheral oxytocin in plasma have long been considered the gold standard, but there is increasing interest in developing methods to detect oxytocin non-invasively in saliva. Here we present an analytical and biological validation of a novel method to measure salivary oxytocin (sOXT) in an under-studied research group: farm animals. Given their similarities with humans in physiology and brain, methods that can identify valued social contexts and social relationships for farm animals and investigate their function have implications for clinical research as well as for animal welfare science. However, current methods to measure sOXT vary greatly in terms of sample collection, pre-measurement processing and measurement and more rigorous standardization and validation of methods is critical to determine the utility of sOXT as a biomarker of salient social events and related emotions. We optimized a method for extracting sOXT in pigs and horses and measured sOXT in extracted samples using a commercially available enzyme-immunoassay. Extracted samples were within acceptable ranges for precision (CVs < 15.2%), parallelism and recovery (94%-99%) in both species. Salivary oxytocin increased in samples collected during birth in pigs (Friedmans, p = 0.02) and horses (Wilcoxon, p = 0.02). Salivary oxytocin tended to decrease in sows after a 90-min separation from their piglets (Wilcoxon, p = 0.08). We conclude that sOXT can be reliably linked to physiological events that are mediated by the oxytocinergic system in farm animals, but that more research is needed to determine whether sOXT is a reliable trait marker for more general oxytocin system activation in response to salient social events. Future research should characterize how individual attributes and salivary parameters influence sOXT measurement and should emphasize reporting of analytical and biological validations to increase acceptance of non-invasive methods.

Birth Experience Among Black Women in the United States: A Qualitative Meta-Synthesis.

INTRODUCTION: There are striking disparities in perinatal health outcomes for Black women in the United States. Although the causes are multifactorial, research findings have increasingly identified social and structural determinants of health as contributors to perinatal disparities. Maltreatment during perinatal care, which is disproportionately experienced by Black women, may be one such contributor. Qualitative researchers have explored Black women's perinatal care experiences, but childbirth experience data has yet to be analyzed in-depth across studies. The aim of this meta-synthesis was to explore the birthing experience of Black women in the United States. METHODS: PubMed, Embase, PsycINFO, and CINAHL databases were searched. Inclusion criteria were qualitative research studies that included birth experience data shared by self-identified Black or African American women who had given birth in the United States. Exclusion criteria were reports that did not include rich qualitative data or only included experience data that did not specify the race of the participant (eg, data pooled for women of color). The search began February 2022 and ended June 2022. The Joanna Briggs Institute Critical Appraisal Checklist for Qualitative Research was used to appraise the research. Results were synthesized using content analysis. RESULTS: Fifteen studies met inclusion criteria. Main themes included (1) trust: being known and seen; (2) how race influences care; (3) preserving autonomy; and (4) birth as trauma. DISCUSSION: Fragmented care resulted in reports of poor birth experiences in several studies. Open communication and feeling known by perinatal care providers was influential in improving childbirth experiences among Black women; these themes are consistent with existing research. Further prospective research exploring relationships among these themes and perinatal outcomes is needed. Limitations of this report include the use of content analysis and meta-synthesis which may lose the granularity of the original reports; however, the aggregation of voices may provide valuable, transferable, actionable insight that can inform future supportive care interventions.

Characterization of Typical Behaviors of Mares in the Opening Phase of Parturition-Influence of Parity and Dystocia.

The identification of typical behaviors in stage I of parturition, the opening phase, can be used to improve birth monitoring in the mare. Therefore, this study aimed to comprehensively analyze mare behavior during the opening phase. Real-time recordings of 66 births involving 56 warmblood mares were analyzed using camera footage. Behaviors such as increased locomotor activity, pawing with front hooves, lifting the tail, rolling, kicking with the hind legs toward the abdomen, and looking at the abdomen increased significantly (p < 0.001) in the four hours preceding parturition. Within the last hour of the observation period, a statistically significant change was observed for the duration of lying in the sternal and lateral position (p < 0.001). Significant correlations were observed between parity and the total number of repetitions of lying in the sternal position (p < 0.05). Furthermore, the birth process influenced the repetitions of lying in the lateral position (p < 0.05). These findings indicate distinct behavioral patterns during the opening phase of parturition, which were evident across the observed mares. Nonetheless, notable individual differences were also identified among the mares.

The Role of the NLRP3 Inflammasome in the Molecular and Biochemical Mechanisms of Cervical Ripening: A Comprehensive Review.

The uterine cervix is one of the key factors involved in ensuring a proper track of gestation and labor. At the end of the gestational period, the cervix undergoes extensive changes, which can be summarized as a transformation from a non-favorable cervix to one that is soft and prone to dilation. During a process called cervical ripening, fundamental remodeling of the cervical extracellular matrix (ECM) occurs. The cervical ripening process is a derivative of many interlocking and mutually driving biochemical and molecular pathways under the strict control of mediators such as inflammatory cytokines, nitric oxide, prostaglandins, and reactive oxygen species. A thorough understanding of all these pathways and learning about possible triggering factors will allow us to develop new, better treatment algorithms and therapeutic goals that could protect women from both dysfunctional childbirth and premature birth. This review aims to present the possible role of the NLRP3 inflammasome in the cervical ripening process, emphasizing possible mechanisms of action and regulatory factors.

Birth outcomes associated with a natural delivery approach in a perinatal center: A comparative retrospective study.

OBJECTIVES: At our center, natural home-like delivery settings have been established in or near conventional labor wards, for the care of pregnant women who prefer little or no medical intervention during labor and birth. We compared obstetrical and neonatal outcomes of women in active spontaneous labor, between those who chose to deliver in a natural-delivery setup and those who chose a conventional setting. METHODS: This retrospective study included low-risk women who delivered at term between March 1, 2020 and December 31, 2022, in a single tertiary university affiliated medical center. Birth outcomes were compared between 124 women who delivered by natural birth (the study group) and 244 who gave birth in a conventional setting (the control group). RESULTS: No cesarean deliveries were performed in the study group, compared to 18 (7.4%) of the control group, p = 0.004. Intrapartum fever, postpartum hemorrhage, and uterotonic administration were similar between the groups. For the study compared to the control group, breastfeeding was more common (71.3% vs. 12.3%, p < 0.001), analgesia administration within 48 h delivery was lower (4.1% vs. 10.7%, p = 0.033), and maternal and neonatal length of hospitalization were shorter. Of the women initially admitted to the natural-delivery room, 14 (11.5%) were transferred to a conventional-delivery room. CONCLUSIONS: Birth in a hospital natural-delivery setting was associated with increased likelihood of vaginal birth, increased immediate breastfeeding and breastfeeding at discharge, and lower postpartum pain.

Two pregnancies of an ornithine carbamoyltransferase defi ciency disease carrier and review of the literature / Dos embarazos de una portadora de la enfermedad por defi ciencia de ornitina transcarbamilasa (OTC) y revisión de la literatura

Background: the underlying cause of the deficiency of ornithine carbamoyltransferase (OTCD) is a gene mutation on the X chromosome. In females, the phenotype is highly variable, ranging from asymptomatic to neurologic compromise secondary to hyperammonemia and it can be prompted by numerous triggers, including pregnancy. Objective: the objective of this article is to report a case of two pregnancies of an OTCD-carrier, and to review the literature describing OTCD and pregnancy, parturition and postpartum. Methods: an extensive search in PubMed in December 2021 was conducted using different search terms. After screening all abstracts, 23 papers that corresponded to our inclusion criteria were identified. Results: the article focuses on the management of OTCD during pregnancy, parturition, and the postpartum period in terms of clinical presentation, ammonia levels and treatment. Conclusions: females with OTCD can certainly plan a pregnancy, but they need a careful management during delivery and particularly during the immediate postpartum period. If possible, a multidisciplinary team of physicians, dietitians, obstetrician-gynecologist, neonatologists, pharmacists, etc. with expertise in this field should participate in the care of women with OTCD and their children during this period and in their adult life.(AU)

Antecedentes: la causa subyacente de la deficiencia de ornitina transcarbamilasa (OTC) es una mutación genética en el cromosoma X. En las mujeres, el fenotipo es muy variable, desde asintomático hasta presentar un compromiso neurológico secundario a hiperamonemia, y puede ser provocado por numerosos factores desencadenantes, incluido el embarazo.Objetivo: el objetivo de este artículo es reportar un caso de dos embarazos de una portadora de OTC, y revisar la literatura que describe OTC y embarazo, parto y posparto. Métodos: se realizó una búsqueda exhaustiva en PubMed en diciembre de 2021 utilizando diferentes términos de búsqueda. Después de examinar todos los resúmenes, identificamos 23 artículos que correspondían a nuestros criterios de inclusión. Resultados: el artículo se centra en el manejo de la OTC durante el embarazo, el parto y el posparto en términos de presentación clínica, niveles de amonio y tratamiento. Conclusiones: las mujeres con OTC pueden planificar un embarazo, pero necesitan un manejo cuidadoso durante el parto, y particularmente, durante el posparto inmediato. Si es posible, un equipo multidisciplinar de médicos, dietistas, ginecólogos-obstetras, neonatólogos, farmacéuticos, etc., con experiencia en este campo, debe participar en el cuidado de las mujeres con OTC y sus hijos durante este periodo y en su vida adulta.(AU)

Assisted vaginal birth in 21st century: current practice and new innovations.

Assisted vaginal birth rates are falling globally with rising cesarean delivery rates. Cesarean delivery is not without consequence, particularly when carried out in the second stage of labor. Cesarean delivery in the second stage is not entirely protective against pelvic floor morbidity and can lead to serious complications in a subsequent pregnancy. It should be acknowledged that the likelihood of morbidity for mother and baby associated with cesarean delivery increases with advancing labor and is greater than spontaneous vaginal birth, irrespective of the method of operative birth in the second stage of labor. In this article, we argue that assisted vaginal birth is a skilled and safe option that should always be considered and be available as an option for women who need assistance in the second stage of labor. Selecting the most appropriate mode of birth at full dilatation requires accurate clinical assessment, supported decision-making, and personalized care with consideration for the woman's preferences. Achieving vaginal birth with the primary instrument is more likely with forceps than with vacuum extraction (risk ratio, 0.58; 95% confidence interval, 0.39-0.88). Midcavity forceps are associated with a greater incidence of obstetric anal sphincter injury (odds ratio, 1.83; 95% confidence interval, 1.32-2.55) but no difference in neonatal Apgar score or umbilical artery pH. The risk for adverse outcomes is minimized when the procedure is conducted by a skilled accoucheur who selects the most appropriate instrument likely to achieve vaginal birth with the primary instrument. Anticipation of potential complications and dynamic decision-making are just as important as the technique for safe instrument use. Good communication with the woman and the birthing partner is vital and there are various recommendations on how to achieve this. There have been recent developments (such as OdonAssist) in device innovation, training, and strategies for implementation at a scale that can provide opportunities for both improved outcomes and reinvigoration of an essential skill that can save mothers' and babies' lives across the world.

Soft-tissue dystocia due to paradoxical contraction of the levator ani as a cause of prolonged second stage: concept, diagnosis, and potential treatment.

Smaller pelvic floor dimensions seem to have been an evolutionary need to provide adequate support for the pelvic organs and the fetal head. Pelvic floor dimension and shape contributed to the complexity of human birth. Maternal pushing associated with pelvic floor muscle relaxation is key to vaginal birth. Using transperineal ultrasound, pelvic floor dimensions can be objectively measured in both static and dynamic conditions, such as pelvic floor muscle contraction and pushing. Several studies have evaluated the role of the pelvic floor in labor outcomes. Smaller levator hiatal dimensions seem to be associated with a longer duration of the second stage of labor and a higher risk of cesarean and operative deliveries. Furthermore, smaller levator hiatal dimensions are associated with a higher fetal head station at term of pregnancy, as assessed by transperineal ultrasound. With maternal pushing, most women can relax their pelvic floor, thus increasing their pelvic floor dimensions. Some women contract rather than relax their pelvic floor muscles under pushing, which is associated with a reduction in the anteroposterior diameter of the levator hiatus. This phenomenon is called levator ani muscle coactivation. Coactivation in nulliparous women at term of pregnancy before the onset of labor is associated with a higher fetal head station at term of pregnancy and a longer duration of the second stage of labor. In addition, levator ani muscle coactivation in nulliparous women undergoing induction of labor is associated with a longer duration of the active second stage of labor. Whether we can improve maternal pelvic floor relaxation with consequent improvement in labor outcomes remains a matter of debate. Maternal education, physiotherapy, and visual feedback are promising interventions. In particular, ultrasound visual feedback before the onset of labor can help women increase their levator hiatal dimensions and correct levator ani muscle coactivation in some cases. Ultrasound visual feedback in the second stage of labor was found to help women push more efficiently, thus obtaining a lower fetal head station at ultrasound and a shorter duration of the second stage of labor. The available evidence on the role of any intervention aimed to aid women to better relax their pelvic floor remains limited, and more studies are needed before considering its routine clinical application.

Dystocia frequency and causes in horses with pregnancy disorders or a history of dystocia: A prospective study.

Dystocia typically presents a life-threatening condition for both the mare and the foal. This prospective long-term study aimed to ascertain whether mares with prior pregnancy disorders or a history of dystocia were at a higher risk of experiencing subsequent dystocia in comparison to those without such medical antecedents. To achieve this goal, the authors analysed 207 parturitions and 164 mares over a 10-year period. Of these, 57 were associated with pregnancy disorders or prior dystocia (Group 1), while 150 parturitions followed uneventful pregnancies in mares that had not yet experienced dystocia (Group 2). Mares in Group 1 were significantly more likely to develop dystocia than those in Group 2 (p = .0180; odds ratio = 2.98). Foetal causes of dystocia were more prevalent than maternal causes (p < .0389). Maternal mortality stood at 0.5%, and neonatal mortality reached 1.9%. The results demonstrate that mares are at significantly higher risk of developing dystocia after experiencing pregnancy disorders or parturition complications during previous pregnancies, emphasizing the need for systematic birth monitoring.

Successful Childbirth During Satralizumab Treatment in Neuromyelitis Optica Spectrum Disorder.

A 40-year-old woman with neuromyelitis optica spectrum disorder (NMOSD) and anti-aquaporin 4 antibodies suffered three NMOSD episodes between 35 and 37 years of age. Despite treatment with prednisolone and azathioprine, her condition repeatedly relapsed. We introduced satralizumab, targeting interleukin-6 receptors, which stabilized her condition. At the age of 38, she became pregnant and delivered a healthy baby at 38 weeks. Post delivery, both mother and child stayed healthy with no NMOSD relapses. This case illustrates the efficacy and safety of satralizumab in managing NMOSD, especially for women in their reproductive years who are planning pregnancy.

Multilayer perceptron and support vector regression models for feline parturition date prediction.

A crucial challenge in feline obstetric care is the accurate prediction of the parturition date during late pregnancy. The classic simple linear regression (SLR) model, which employed the fetal biparietal diameter (BPD) as the single input feature, was frequently applied for such prediction with limited accuracy. Since Multilayer Perceptron (MLP) and Support Vector Regression (SVR) are now two of the most potent scientific regression models, this study, for the first time, introduced such models as the new promising tools for feline parturition date prediction. The following features were candidate inputs for our models: biparietal diameter (BPD), litter size, and maternal weight. We observed and compared the performance results for each model. As the best-performed model, MLP delivered the highest coefficient score (0.972 ± 0.006), lowest mean absolute error score (1.110 ± 0.060), and lowest mean squared error score (1.540 ± 0.141), respectively. For the first time in this study, BPD, litter size, and maternal weight were considered the essential features for the innovative MLP and SVR modeling. With the optimized model parameters and the described analytical platform, further verification of these advanced models in feline obstetric practices is feasible.

The effect of a hiding space on the behaviour and heart rate variability of dairy calves during temporary separation from the dam.

In natural settings, newborn calves hide for several days before joining the herd. It is unclear whether dairy calves housed indoors would show similar hiding behaviour. This study aimed to describe the use of an artificial hide provided to calves during temporary separation from the dam and assess the effect it has on lying and sleep-like behaviour, as well as heart rate variability (HRV). Twenty-eight cow-calf pairs were randomly assigned to having a hide (n = 14), or no hide (n = 14). Hide use (n = 14), as well as lying and sleep-like behaviour (n = 28), were recorded continuously via video camera during the first hour after the dam was removed for morning milking on day three to seven. Heart rate and R-R intervals were recorded using Polar equine monitors for a subsample of 12 calves (n = 6 per treatment) on day six. Descriptive statistics were calculated for hide use. Wilcoxon Signed Rank tests were used to evaluate whether having a hide affected lying and sleep-like behaviours as well as HRV. Hide use decreased over days and was highly variable between calves. Lying behaviour did not differ between treatments. Duration of sleep-like behaviour was higher for calves without a hide compared to those with a hide. Calves with a hide tended to show signs of higher HRV and parasympathetic activity compared to calves without a hide. Results suggest that providing a hiding space to young calves may be beneficial during periods when the cow is removed from the pen for milking.

Deep Learning Model Using Continuous Skin Temperature Data Predicts Labor Onset.

Background: Changes in body temperature anticipate labor onset in numerous mammals, yet this concept has not been explored in humans. Methods: We evaluated patterns in continuous skin temperature data in 91 pregnant women using a wearable smart ring. Additionally, we collected daily steroid hormone samples leading up to labor in a subset of 28 pregnancies and analyzed relationships among hormones and body temperature trajectory. Finally, we developed a novel autoencoder long-short-term-memory (AE-LSTM) deep learning model to provide a daily estimation of days until labor onset. Results: Features of temperature change leading up to labor were associated with urinary hormones and labor type. Spontaneous labors exhibited greater estriol to α-pregnanediol ratio, as well as lower body temperature and more stable circadian rhythms compared to pregnancies that did not undergo spontaneous labor. Skin temperature data from 54 pregnancies that underwent spontaneous labor between 34 and 42 weeks of gestation were included in training the AE-LSTM model, and an additional 40 pregnancies that underwent artificial induction of labor or Cesarean without labor were used for further testing. The model was trained only on aggregate 5-minute skin temperature data starting at a gestational age of 240 until labor onset. During cross-validation AE-LSTM average error (true - predicted) dropped below 2 days at 8 days before labor, independent of gestational age. Labor onset windows were calculated from the AE-LSTM output using a probabilistic distribution of model error. For these windows AE-LSTM correctly predicted labor start for 79% of the spontaneous labors within a 4.6-day window at 7 days before true labor, and 7.4-day window at 10 days before true labor. Conclusion: Continuous skin temperature reflects progression toward labor and hormonal status during pregnancy. Deep learning using continuous temperature may provide clinically valuable tools for pregnancy care.

Impact of parental leave system on the childbirth plan among working married women: a three-year follow-up study of the Korean longitudinal survey of women and families.

BACKGROUND: The Korean government seeks to balance work and family and alleviate low fertility by implementing a parental leave system. This study aimed to identify the impact of the parental leave system on childbirth among married working women in South Korea. METHODS: This study used three-year follow-up data from the Korean Longitudinal Survey of Women and Families (2016, 2018, and 2020). The number of participants was 324 at baseline. Logistic regressions using a generalized estimating equation model were performed to examine the impact of parental leave on childbirth. Sub-analyses of covariates, childbirth support, and parental leave systems were conducted. RESULTS: Of workers covered by the parental leave system, 31.7% considered childbirth. Women covered by parental leave were 3.63 times more likely to plan childbirth (95% confidence interval [CI], 1.32-9.99). The tendency to plan childbirth was pronounced among those in their early 30s (adjusted odds ratio [AOR], 7.20) and those who thought that having children was necessary (AOR, 4.30). Child planning was more influenced by leave support (AOR, 6.61) than subsidies. CONCLUSIONS: Parental leave systems can have a positive impact on working married women's childbirth plans. Although this system was effective in a group interested in childbirth, it did not create a fundamental child plan. Time support is more important than money concerning childbirth plans. The parental leave system had an impact on childbirth plan. Appropriate parenting policies can effectively increase the fertility rate.

Disruption of the SP-A/SP-R210L (MYO18Aα) pathway prolongs gestation and reduces fetal survival during lipopolysaccharide-induced parturition in late gestation.

Prolonged labor can lead to infection, fetal distress, asphyxia, and life-threatening harm to both the mother and the baby. Surfactant protein A (SP-A) was shown to contribute to the maintenance of pregnancy and timing of term labor. SP-A modulates the stoichiometric expression of the SP-R210L and SP-R210S isoforms of the SP-R210 receptor on alveolar macrophages (AMs). Lack of SP-R210L dysregulates macrophage inflammatory responses. We asked whether SP-A alters normal and inflammation-induced parturition through SP-R210 using SP-A- and SP-R210L-deficient mice. Labor and delivery of time-pregnant mice were monitored in real time using a time-lapse infrared camera. Intrauterine injection with either vehicle or Escherichia coli lipopolysaccharide (LPS) on embryonic (E) day 18.5 post coitus was used to assess the effect of gene disruption in chorioamnionitis-induced labor. We report that either lack of SP-A or disruption of SP-R210L delays parturition by 0.40 and 0.55 days compared with controls, respectively. LPS induced labor at 0.60, 1.01, 0.40, 1.00, and 1.31 days earlier than PBS controls in wild type (WT), SP-A-deficient, littermate controls, heterozygous, and homozygous SP-R210L-deficient mice, respectively. Lack of SP-A reduced litter size in PBS-treated mice, whereas the total number of pups delivered was similar in all LPS-treated mice. The number of live pups, however, was significantly reduced by 50%-70% in SP-A and SP-R210L-deficient mice compared with controls. Differences in gestational length were not associated with intrauterine growth restriction. The present findings support the novel concept that the SP-A/SP-R210 pathway modulates timely labor and delivery and supports fetal lung barrier integrity during fetal-to-neonatal transition in term pregnancy.NEW & NOTEWORTHY To our knowledge, this study is the first to report that SP-A prevents delay of labor and inflammation-induced stillbirth through the receptor SP-R210L.

The hormonal control of parturition.

Parturition is a complex physiological process that must occur in a reliable manner and at an appropriate gestation stage to ensure a healthy newborn and mother. To this end, hormones that affect the function of the gravid uterus, especially progesterone (P4) and 17ß-estradiol (E2), oxytocin (OT) and prostaglandins (PGs) play pivotal roles. P4 via the nuclear P4 receptor (PR) promotes uterine quiescence and for most of pregnancy exerts a dominant block to labor. Loss of the P4 block to parturition in association with a gain in pro-labor actions E2 are key transitions in the hormonal cascade leading to parturition. P4 withdrawal can occur through various mechanisms depending on species and physiologic context. Parturition in most species involves inflammation within the uterine tissues and especially at the maternal-fetal interface. Local PGs and other inflammatory mediators may initiate parturition by inducing P4 withdrawal. Withdrawal of the P4 block is coordinated with increased E2 actions to enhance uterotonic signals mediated by OT and PGs to promote uterine contractions, cervix softening and membrane rupture i.e., labor. This review examines recent advances in research to understand the hormonal control of parturition, with focus on the roles of P4, E2, PGs, OT, inflammatory cytokines and placental peptide hormones together with evolutionary biology of and implications for clinical management of human parturition.

Proteomics Analysis of Pregnancy in Ewes under Heat Stress Conditions and Melatonin Administration.

Melatonin is an indoleamine with broad spectrum properties that acts as a regulator of antioxidant and immune response in organisms. In our previous studies, melatonin improved redox status and inflammatory response in pregnant ewes under heat stress conditions. In the present study, using proteomics, the proteins regulated by melatonin during different stages of pregnancy and lambing were assessed. Twenty-two ewes equally divided into two groups, the melatonin (M) (n = 11) and control (C) group (n = 11), participated in the study and were exposed to heat stress during the first months of pregnancy. In the M group, melatonin implants were administered throughout pregnancy, every 40 days, until parturition (a total of four implants per ewe). Blood samples were collected at the beginning of the study simultaneously with the administration of the first melatonin implant (blood samples M1, C1), mating (M2, C2), second implant (M3, C3), fourth implant (M4, C4) and parturition (M5, C5), and MALDI-TOF analysis was performed. The results revealed the existence of 42 extra proteins in samples M2, M3 and M4 and 53 in M5 (sample at parturition) that are linked to melatonin. The biological processes of these proteins refer to boosted immune response, the alleviation of oxidative and endoplasmic reticulum stress, energy metabolism, the protection of the maternal organism and embryo development. This proteomics analysis indicates that melatonin regulates protective mechanisms and controls cell proliferation under exogenous or endogenous stressful stimuli during pregnancy and parturition.

Conductivity of mammary gland secretions is a sensitive and specific predictor of parturition in mares.

BACKGROUND: Accurate prediction of parturition is paramount to ensuring monitoring of delivery and preventing complications. Assessing the pH and electrolytes of the mammary gland secretions (MGS) helps detect impending parturition. As conductivity is related to electrolyte concentrations and pH, it could be a useful alternative for predicting impending parturition; however, this hypothesis warrants a critical assessment. OBJECTIVES: To assess the ability of conductivity, pH, and Brix in the MGS to predict parturition and to investigate their associations. STUDY DESIGN: Field study. METHODS: The MGS of periparturient mares (n = 241) was assessed daily for conductivity, pH, and Brix index from 320d until parturition. Receiving operating curve cut-off values for conductivity (≤4.8 mS/cm), pH (≤6.4), and Brix index (>23.6%) were used to calculate sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for predicting parturition in ≤24 h. RESULTS: Impending parturition was associated with a reduction in conductivity and pH (p < 0.05), and conductivity was strongly correlated with pH (r = 0.88) and Brix (r = -0.80) (p < 0.05). Sensitivity, specificity, PPV, and NPV for parturition in ≤24 h for conductivity (82%, 91%, 77%, and 92%, respectively), pH (79%, 84%, 81%, and 71%, respectively), and Brix (72%, 79%, 66%, and 83%, respectively) were determined separated and pairwise. Of interest, the sensitivity, specificity, PPV, and NPV, of combining conductivity and pH, were 80%, 95%, 90%, and 88%, respectively. Conductivity (≤4.8 mS/cm) presented the greatest odds ratio for predicting parturition in ≤24 h, and coupling it with pH (≤6.4 pH units) doubled its odds ratio (i.e., 25.4-62.3). MAIN LIMITATIONS: Field study. CONCLUSION: The conductivity of MGS is a sensitive and specific method to predict parturition. This is the first large-scale study showing that a combination of conductivity and pH is useful for predicting parturition in mares. The methods employed can likely apply to other settings with similar results.