Perinatal veterinary medicine‐related evaluation in hematological and serum biochemical profiles of experimental beagles throughout pregnancy and parturition

Background: The aims of this study were(a) to ascertain age-related changes in the reference values in hematological and serum biochemical examinations of beagles,and(b) to clarify the changes in these findings, including acute phase proteins and oxidative stress, throughout pregnancy and after parturition.Methods: Clinicopathological parameters were measured in young beagles at 6, 9 and 12 months and in adult beagles aged from 24 to 60 months. Likewise, pregnant beagles were investigated throughout the pregnancy and after parturition.Results: Apparent age-related changes were found in erythrocytic parameters during the growth and development of beagles. Most of the parameters(total protein,albumin, blood urea nitrogen, creatinine, urate, alkaline phosphatase(ALP) and creatine kinase(CK) exhibited age-dependent transitions. White cell count significantly increased after 30 days of pregnancy. The values of erythrocytic parameters moderately decreased during the second half of the pregnancy. Triglycerides, total cholesterol, free cholesterol and phospholipid concentrations increased in the mid- and late stages of pregnancy. ALP, lactate dehydrogenase, CK and cholinesterase activities markedly increased during pregnancy and/or after parturition. C-reactive protein(CRP) concentrations gradually increased and reached a maximum after 30-40 days of pregnancy. Serum amyloid A(SAA) levels markedly increased at 30 days of pregnancy before subsiding, and then increased again 3 days after parturition. Reactive oxygen metabolites(d-ROMs) showed significant increases after 30 and 40 days of pregnancy.Conclusions: Reference values for hematological and serum biochemical examinations should be used for health evaluation of dogs, taking sex, age and the stage of pregnancy into consideration. Measurements of CRP, SAA and d-ROM levels are also useful for assessing maternal conditions in mid-pregnancy.

Separation Behavior for Parturition of Red Angus Beef Cows

Increased predation losses in beef cattle in the Northern Rocky Mountains raise the importance of research concerning maternal behavior around the time of parturition. Separation behavior of multiparous cows at parturition was studied by measuring the distance (m) between the birth place and the main herd with a GPS device. Age of cows and forehead hair whorl pattern (HW) were analyzed as possible factors affecting separation distance. A total of 333 cows (95% Red Angus and 5% Angus × Hereford commercial crossbreds;age range: 3 - 6 yrs) were studied. Separation distance was determined by approaching the cow-calf pair with a utility vehicle that gradually decreased the distance to the pair. The geographic coordinates per pair were recorded and the separation distance was calculated as a straight line between each pair and the main herd. The HW on the forehead of each animal was used as a measure of individual differences in temperament. Age and HW were collected when the animals were held in a squeeze chute. HW was classified into one of six groups: high, middle, low, abnormal, multiple HWs and no HW. The age of a cow influenced the separation distance for parturition (P < 0.001). Four-year-old cows were on average about 150 m further away than other aged cows when calving. Eighty-eight percent of cows separated more than 100 m from the herd. The hair whorl position had no influence on the separation distance (P = 0.405). Distinct separation behavior for parturition was observed in this herd which appears to be an innate behavior that is influenced by the individual temperament of the cow.

Comparison of Two Different Protocols for Induction of Parturition in Heifers with or without Estradiol Benzoate

Objectives of this study were to investigate the efficacy of dexamethasone in combination with estradiol benzoate in controlled induction of parturition in heifers, especially in the subjects of retained fetal membranes and dystocia caused by fetal oversize. A total number of 100 Holstein-Friesian heifers aged 24-25 months, mean weight 450 kg and body condition score of 3-4 from a dairy herd located in the suburb of Tabriz with similar nutrition and management systems were allocated at random into two groups. Group A （Control, n = 50） heifers, after passing the minimum 270 d of pregnancy were injected with 30 mg dexamethasone IM. Group B （Treatment, n = 50） heifers with the same period of pregnancy received 30 mg dexamethasone plus 20 mg estradiol benzoate IM on the same days of pregnancy. The overall durations of initial treatments to induction of parturition were （41.50 ~ 2.65） h in group A and （37.50 ：i： 1.27） h in group B. In group A, more dystocia cases were observed than in group B. After parturition, group A showed a higher percentage of retention of fetal membranes as well as the calf mortality and dystocia compared to group B. The differences between two groups were statistically significant （P 〈 0.05）. In conclusion, our results indicate that induction of parturition by estradiol benzoate and dexamethasone together will be more effective than dexamethasone alone because of the less retention of fetal membranes, easy calving and shorter time from induction to parturition.

Basic Research Advances in China on Embryo Implantation,Placentation,and Parturition

This review aimed to summarize the major progress in maternal-fetal medicine achieved by Chinese scientists in recent years.PubMed was systematically searched from January 2020 to November 2023.Publications that reported the progress in embryo implantation,placentation,and parturition made by Chinese scientists in the last 3 years were selected.The milestone events during gestation,embryo implantation,endometrial decidualization,placentation,and parturition are pivotal to a successful pregnancy.Embryo implantation requires intricate interactions between implantation-competent blastocysts and receptive endometrium.To adapt to pregnancy,endometrial stromal cells transform into specialized decidual cells,which occur spontaneously under the influence of ovarian hormones in humans but require the presence of embryos in mice.With embryonic development,the placenta forms to support fetal growth until parturition.The maternal-fetal interface is composed of diverse cell types,including endometrial decidual cells,placental trophoblast cells,endothelial cells,and various immune cells,a sophisticated interplay among which contributes to the maintenance of pregnancy.Near term,the uterus transitions from quiescence to contractility,in preparation for delivery.Disruptions to these events lead to pregnancy-related disorders such as repeated implantation failure,recurrent pregnancy loss,preeclampsia,fetal growth restriction,preterm birth,and infertility.In recent years,Chinese scientists have made prominent achievements in basic research on the aforementioned pregnancy events.Chinese scientists have made remarkable contributions to reproductive biology and maternal-fetal medicine research in recent years,highlighting future research directions in this field.

Effect of Anrou-pressing and kneading Hegu(LI 4)and Sanyinjiao(SP 6)on uterine inertia during painless parturition

Objective:To observe the effect of Anrou-pressing and kneading Hegu(LI 4)and Sanyinjiao(SP 6)on uterine inertia during painless parturition.Methods:A total of 100 cases of patients with uterine inertia during painless parturition were randomized into an acupoint group and a medicine group by the SPSS programming,with 50 cases in each group.Patients in the acupoint group received the treatment of Anrou-pressing and kneading bilateral Hegu(LI 4)and Sanyinjiao(SP 6),while patients in the medicine group received intravenous oxytocin.The labor time and maternal-child safety were evaluated,and the labor stage was compared.Results:The latent and active phases in the 1st labor stage and the 2nd labor stage in the acupoint group were substantially shorter than those in the medicine group,and the between-group comparisons showed statistical significance(all P<0.05).The between-group comparison of the 3rd labor stage showed no statistical significance(P>0.05).The postpartum hemorrhage amount in both groups was within the safe range,and the between-group comparison showed no statistical significance(P>0.05).The newborn 1 min Apgar score was ranged 8-10 points,and the between-group comparison showed no statistical significance(P>0.05).The between-group comparison of the labor stage efficacy showed statistical significance(P<0.01),with a better progression in the acupoint group.Conclusion:Anrou-pressing and kneading Hegu(LI 4)and Sanyinjiao(SP 6)is both effective and safe for uterine inertia during painless parturition.

Reconstructing landscapes of ungulate parturition and predation using vegetation phenology

Enhanced vegetation index(EVI)data can be used to identify and define the space in which ungulates practice parturition and encounter predation.This study explores the use of EVI data to identify landscapes linked to ungulate parturition and predation events across space,time,and environmental conditions.As a case study,we used the moose population(Alces alces)of northern Minnesota in the USA.Using remotely sensed EVI data rasters and global positioning system collar data,we quantified how vegetation phenology and moose movement shaped the births and predation of 52 moose calves from 2013 to 2020 on or adjacent to the Grand Portage Indian Reservation.The known sources of predation were American black bears(Ursus americanus,n=22)and gray wolves(Canis lupus,n=28).Satellite-derived data summarizing seasonal landscape features at the local level revealed that landscape heterogeneity use by moose can help to quantitatively identify landscapes of parturition and predation in space and time across large areas.Vegetation phenology proved to be differentiable between adult moose ranges,sites of cow parturition,and sites of calf predation.Landscape characteristics of each moose group were consistent and tractable based on environment,suggesting that sites of parturition and predation of moose are predictable in space and time.It is possible that moose selected specific landscapes for parturition despite risk of increased predation of their calves,which could be an example of an"ecological trap."This analytical framework can be employed to identify areas for future ungulate research on the impacts of landscape on parturition and predation dynamics.

A comparison of maternal fear of childbirth,labor pain intensity and intrapartum analgesic consumption between primiparas and multiparas:A cross-sectional study

Objectives:To describe and compare fear of childbirth and in-labor pain intensity between primiparas and multiparas and explore the association between the amount of actual pain relief and fear of childbirth.Methods:A convenience sampling method was used.A total of 260 women undergoing spontaneous or induced labor,including 97 primiparas and 163 multiparas,were recruited in a large academic specialized hospital in Guangzhou,China,from February 2018 to August 2019.The clinical data of maternal and neonatal were extracted from a structured electronic medical record system.Other demographic information,such as employment and family monthly income,was collected by a questionnaire.The Numeric Rating Scale(NRS)and the Chinese version of the Childbirth Attitude Questionnaire(C-CAQ)were applied to assess maternal in-labor pain intensity and fear of childbirth.The analgesic consumption and the frequency of manual boluses as rescue analgesia were stored and collected from the analgesia pump.Results:Eighty-two(84.5%)primiparas and ninety-nine(60.7%)multiparas received epidural analgesia(P<0.001).In the epidural subgroup,the primiparous average fear of childbirth(36.46±10.93)was higher than that of the multiparas(32.06±10.23)(P¼0.007).However,multiparas reported more intense in-labor pain[8.0(8.0,9.0)vs.8.0(7.0,8.0)],had more successful manual boluses per hour[2.68(1.65,3.85)vs.1.77(0.90,2.47)],more hourly analgesic consumption[23.00(16.00,28.25)vs.17.24(11.52,21.36)mL]and more average analgesic consumption[0.35(0.24,0.45)vs.0.26(0.19,0.35)mL/(h$kg)]than the primiparas(P<0.05).Spearman’s correlation analysis showed that the maximum in-labor pain was weakly positively correlated with fear of childbirth(r¼0.09)(P<0.05),hourly analgesic consumption(r¼0.16)(P<0.01)and average analgesic consumption(r¼0.17)(P<0.05).No statistically significant association was uncovered between analgesic consumption and maternal fear of childbirth.Conclusions:Fear of childbirth is a potential predictor of labor pain intensity.Further study is needed to explore its role and value in pain management during delivery.Parity is not a determinant of pain relief use and should not be a preconceived preference of obstetric care team members to determine the distribution of epidural analgesia,especially when analgesia resources are insufficient.

A review and comparison of common maternal positions during the second-stage of labor

The second-stage of labor is the most stressful part of childbirth process and the proper maternal position during this period is paramount for women's safe vaginal birth.Midwives play a pivotal role in managing maternal positions during the second-stage of labor.However,there is limited evidence to support an ideal maternal position during the second-stage of labor.Further,the difference between different maternal positions might not be apparent.This paper aims to review and compare the benefits and risks of common maternal positions during the second-stage of labor,thereby to provide midwives evidence-based practical guidelines.

Pelvic floor muscle training as a persistent nursing intervention: Effect on delivery outcome and pelvic floor myodynamia

Purpose:To evaluate the effect of pelvic floor muscle training as a nursing intervention on delivery outcomes and postpartum pelvic floor myodynamia.Methods:In total,106 nulliparas were randomised into an intervention group and control group.All nulliparas participated in a pelvic floor training programme led by a midwife.A pelvic floor physical therapist measured the women’s pelvic floor myodynamia and taught them how to correctly perform pelvic muscle contractions before the intervention.A registered nurse monitored the intervention group via twice-weekly telephone checkups.The control group did not receive individual direction.Results:There were no differences in the rate of Caesarean section or elective Caesarean section between the two groups(χ^(2)=3.446,p=0.076 and χ^(2)=2.343,p=0.185,respectively).There was a difference in the timing of the second stage of labour between the two groups(t=2.101,p=0.040);no difference was observed in the timing of the other two stages of labour(t=1.771,p=0.081 and t=1.142,p=0.263,respectively).In addition,no differences were observed in the gestational weight gain(t=0.196,p=0.845),neonatal weight(t=0.113,p=0.911),rate of episiotomy(χ^(2)=0.932,p=0.351)or rate of perineal laceration(χ^(2)=0.022,p=0.982)between the two groups.The pelvic floor myodynamia of the intervention group had improved to a greater degree than that in the control group at 6 weeks and 3 months after delivery(p<0.005).Conclusion:Persistent nursing intervention for pregnant/postpartum women helped to shorten the second stage of labour and contributed to the recovery of postpartum pelvic floor myodynamia.The influence of this intervention on the delivery mode,and rates of episiotomy and perineal laceration remains unknown.Medical staff should strengthen health education programmes that involve pelvic floor functional rehabilitation.

Energetic-protein supplementation in the last 60 days of gestation improves performance of beef cows grazing tropical pastures

Background： Nutrition is one of the most important factors that affect animal performance, and it therefore also impacts on financial results in beef systems. In this way, finding the best strategy for feeding supplements is of paramount importance. Aiming to evaluate the effect of supplement feeding strategies for beef cows in the last third of gestation, two experiments were conducted. In Experiment 1, 35 pregnant Nellore cows were assigned to a completely randomized design with four treatments： control, which received no supplement; supplementation for the last 30 d of gestation（30-d; 3.0 kg/d）; supplementation for the last 60 d of gestation（60-d; 1.5 kg/d）; or supplementation for the last 90 d of gestation（90-d; 1.0 kg/d）. All supplemented treatments received the same total amount of supplement throughout the experiment： 90 kg（20% of crude protein）. A second experiment（Experiment 2） was delineated to evaluate the effects of the amounts offered in Experiment 1 on intake and metabolism. Four multiparous pregnant Nellore cows were assigned to a 4 × 4 Latin square design, with periods of15 d each.Results： There was a linear effect of the number of days of supplementation on calving body weight（BW; P 〈 0.05）and a quadratic effect on BW change from parturition to d 31 post-calving（P 〈 0.05）, with cows on the 60-d strategy losing less BW post-calving. No difference was found in offspring birth BW（P 〉 0.10）. A significant linear effect on interval from parturition to conception（P 〈 0.05） was observed, with the highest calving to conception interval being observed in the 90-d strategy. The level of supplementation did not affect forage intake or neutral detergent fiber digestibility（P 〉 0.10）. Nitrogen excreted through urine tended to increase linearly with the level of supplementation（P 〈 0.10）.Conclusion： Providing 1.5 kg of supplement during the last 60 d of gestation improves cow performance after calving, reducing the magnitude of BW lost, and reduces the number of days from calving to re-conception in the following breeding season compared to the usually recommended period of supplementation of 90 d pre-partum.

Predicting Birth-Related Levator Ani Tear Severity in Primiparous Women: Evaluating Maternal Recovery from Labor and Delivery (EMRLD Study)

Objective: To determine which maternal characteristics or birth events independently predict severity of levator ani muscle (LA) tears at first vaginal birth in a longitudinal/observational investigation in a tertiary care hospital. Sample: Ninety primiparas with at least one at risk for LA tear inclusion factor at vaginal birth: maternal age ≥ 33 years, second stage ≥ 150 minutes, macrosomia, instrumented delivery, and/or anal sphincter laceration were studied. Methods: Magnetic Resonance Imaging (MRI) was obtained early postpartum (mean ± sd 48.9 ± 21.6 days) to identify LA tear. Severity of LA muscle fiber loss was graded on an ordinal scale of: “0” as no loss, “1” as <50% unilateral loss, “2” as ≥50% unilateral or <50% bilateral loss, and “3” as ≥50% bilateral loss. Data were analyzed using proportional odds modeling. Inclusion factors were explored as predictors of LA tear severity and at analysis episiotomy, time spent actively pushing, epidural, and oxytocin were also considered. The main outcome measures of interest included grading of severity of LA muscle fiber loss on an ordinal scale. Results: Respective counts/percentages of women within each 0 thru 3 ordered category of LA tear severity were: “0” = 58(64%), “1” = 9(10%), “2” = 15(17%), and “3” = 8(9%). Estimates and 95% CI for significant demographic or obstetric univariate predictors of LA tear severity level were age, OR 1.093 (CI 1.012 - 1.180), p = 0.023;and time spent in active pushing, OR 1.089 (CI 1.005 - 1.180), p = 0.038. The other factors considered were not significant. There were too few women with forceps deliveries to analyze. Conclusion: In our enriched sample of primiparous women, 26% showed a significant LA tear. Maternal age and time spent actively pushing independently predict LA tear severity.

5<i>β</i>-Dihydroprogesterone and Human Preterm Labor

We previously investigated the progesterone metabolite 5β-dihydroprogesterone (5βDHP) in relation to human parturition at term, demonstrating that peripheral venous concentrations decrease in association with the onset of spontaneous labour. In this study our aim was to determine if 5βDHP concentrations were lower in women presenting in spontaneous preterm labour than in controls matched for gestational age. Blood samples were obtained from women presenting in spontaneous preterm labour (n = 20). The diagnosis was made on the presence of regular contractions and cervical effacement and dilatation of at least 3 cms. All women in the preterm labour group delivered before 37 weeks gestation. Blood samples were then obtained from controls, closely matched for gestational age with uncomplicated pregnancies. The preterm labour group was further stratified by cause into three groups, chorioamnionitis (n = 5), abruption (n = 4) and idiopathic (n = 11). Following organic solvent extraction, steroids were separated by HPLC and 5βDHP quantified by radioimmunoassay. Women in the idiopathic preterm labour group were found to have significantly lower circulating concentrations of 5βDHP than controls

Bali Rituals and Therapeutic Communication in the Traditional Rural Society in Sri Lanka

Bali is a form of classical ritual that makes a sound performance of a variety of psychological and physical treatments for many psychiatric and cultural diseases. Bali is defined as a form of oblation for gods and deities. Bali is determined by the ephemeral cycle of one＇s life, so that the procedures and practices of specific Bali performances are planned to communicate with the planetary system, which is based on his/her astrology. Hence, Bali is made to perform with the use of traditional dance, music and local cultural substances. There are nearly eighty four thousand forms of Bali performances derived out from the constellation. History of Bali goes back to the early kingdom of Kotte which started in early fifteen century. However, it is considered that the origin of Bali resembles with the Indian Hindu religious cults, so that the Sri Lankan Bali tradition has been transformed by the local cultural and Buddhist religious milieu. This study explores the content and effects of Bali ritual. As the qualitative research, it assumes that Bali constitutes a broad spectrum of human needs and wants despite its communication to the supernatural elements of planetary system. Sederaman （1965） has explored Bali to the extent of its entire performance with respective lyrics and dancing procedures, as the pioneering study. However, present study looks at the diversity of the objectives and effects of a performance of Bali in the set-up of real Kandyan rural village in Sri Lanka. Finally, based on the research, it yields following conclusions. Bali in the rural Kandyan village, is designed to be conducted continuously up to fourteen days. It is traditionally performed by the classical exorcist gurus of Bali, who have been trained by the practice of word of mouth by their generation by generation. They are used to reciting, singing and dancing all the forms of communication from their memory and recalling at the very time of performance without any script or written text. Many Bali doctors are used to conducting entire performance with number of classical lyrics and poems with mellifluous musical melodies, attractive rhythms of dance and theatrical performances, which are not yet scientifically classified. Further, Bali is determined by the use of significant characteristics of one＇s astrology, so that the disease or pathetic situation is the fact that decides the specific Bali form. There are nearly eighty-four thousand Bali which are for numerous physical and psychological illnesses including variety of mental disorders and sexually transmitted diseases. Moreover, as this study found a very rare Ola leaf manuscript, that describes the entire eighty four thousand Bali, which is called Balipatuna in Sinhala （Contents of Bali） from a traditional Bali custodian in Laheba Bali Tradition at Kotabe in Mathale District in Sri Lanka. On the other, knowledge and practices of the traditional local medical sciences of parturition （Child birth） health in the pregnancy and the science of child birth （delivery） is also treated by the faculties of Bali schools. And Also, Bali figures are designed, based on the narration of the Bali lyrics, which explains a group of stars forming a recognizable pattern that is traditionally named after its apparent form and it is identified with a mythological figure. However, this has been the source for very colorful temple arts and craftsmanship at the Buddhist temples built up during the era of Kandyan kingdom （1469-1815 ）.

Reproductive Parameters and Characteristics of Labrador Breed

For a period of two years, a survey of 110 parturitions of Labrador breed bitches was carried out in Rosario City to determine the average number of puppies per litter, percentage of dystocia of all parturitions, percentage of males and females born and causes of dystocia, as well as the incidence of clinically detectable congenital pathologies. Over a total of 110 parturitions ninety three （84.5%） parturitions were normal and 17 （15.5%） were dystocic ones, it was established that atony 1 was the most numerous cause of dystocia （53%）, followed by atony 2 （23%）, dystocia by fetal disorders （6%）, hydramnios （6%）, uterine rupture （6%） and vagina fibrous band （6%）. The whole puppies born was 866, 7.9 puppies per litter, if comparison between normal parturitions and dystocic ones is made, numbers are 7.05 and 8.02 respectively. When sex evaluation percentage is made 51.5% are males and 48.5% are females. When viability of puppies born is calculated it is established that in ones born by normal parturition perinatal death was 9.3%, while in those born by dystocia it was 10.9%. Among clinically verifiable congenital disorders low weight at birth was the most frequent congenital alteration, followed by cleft palate, lethal congenital edema or walrus syndrome and hare lip.

Delivery of Bull Dog Calf from a Hydroallantoic Murrah Buffalo

An 8 years old Murrah buffalo in its 5^(th) party was presented with the history of 9 month of gestation and sudden bilateral abdominal distension since last 25 days.Animal was 7 anorectic with pale mucus membrane and had staggering gait.Per vaginum examination revealed closed cervix with intact cervical seal.By transrectal palpation only the fluid in the uterus could be palpable.Based on history and clinical examination findings,it was diagnosed as hydroallantois.Parturition was induced using cloprostenol and dexamethasone.Beside this an intracervical injection of closprostenol was also given on 6 o’clock and 12 o’clock position(250μg each)of external os to hasten the cervical dilation.A dead bulldog calf was removed with manual traction after 26 hours of initial treatment.It was concluded that the cloprostenol and dexamethasone are effective for the induction of parturition in animals suffering from hydroallantois provided fluid from the allantoic sac is removed slowly.

Spontaneous Preterm Birth:a Fetal-Maternal Metabolic Imbalance

Preterm delivery is a major global health problem associated with increased neonatal morbidity and mortality.To develop effective strategies to reduce preterm birth,it is important to address the causes of and risk factors for this condition.Maternal metabolism plays a crucial role in pregnancy outcomes,as it affects the availability of nutrients,energy,and other essential factors required for fetal development and growth.Several aspects of maternal metabolism can potentially contribute to the risk of preterm delivery.Severe energy deficiency as observed in women suffering from eating disorders can affect the hypothalamic-pituitary-gonadal axis resulting in amenorrhea and infertility,suggesting that maintaining a minimum maternal weight is essential to uphold a functional reproductive system,thus ensuring a successful pregnancy.Maternal undernutrition as observed in past famine and observations and animal studies may affect fetal growth and trigger an early activation of the parturition pathway leading to preterm delivery.A correlation exists between maternal size and gestation duration.Obesity is associated with a higher likelihood of medically indicated preterm birth.Low maternal body mass index and low gestational weight gain during pregnancy have been associated with preterm birth,potentially due to fetal-maternal metabolic imbalance;however,the exact mechanism remains to be determined,thus emphasizing the importance of appropriate weight management before and during pregnancy.Addressing metabolic-related risk factors for preterm delivery requires a comprehensive approach to reduce the burden of preterm delivery and improve neonatal outcomes.This review aims to explore various aspects of fetal-maternal metabolic imbalance that could potentially contribute to preterm birth.By doing so,we suggest a novel and comprehensive approach that sheds light on the intricate connection between fetal-maternal imbalance and the susceptibility to preterm birth.

Factors of Fetal Origin in the Regulation of Labor Initiation and Preterm Birth

Preterm birth is the leading cause of mortality and morbidity in newborns and children under 5 years-of-age.In order to improve the survival rate and quality of preterm infants,there is critical need to identify the specific mechanisms underlying the initiation of labor.Pregnancy represents a period of constant interactive dialog between mother and fetus.A disturbance in the pattern of maternal-fetal communication can induce physiological or pathological labor.Although a number of studies have investigated the contributions of maternal factors to the initiation of labor,the concept that fetal organ development and maternal adaptation are coordinated has emerged over recent years,thus emphasizing that factors of fetal origin may serve as hormonal signals for the initiation of labor.In this review,we summarize and discuss several specific mechanisms by which factors of fetal origin may influence parturition during term or preterm labor,including the specific regulation of fetal organs,including the lungs and accessory organs during pregnancy.Future research may focus on the specific pathways by which signals from the fetal lungs and other fetal organs interact with the maternal system to initiate eventual labor.

Immune cells in term and preterm labor

Labor resembles an inflammatory response that includes secretion of cytokines/chemokines by resident and infiltrating immune cells into reproductive tissues and the maternal/fetal interface. Untimely activation of these inflammatory pathways leads to preterm labor, which can result in preterm birth. Preterm birth is a major determinant of neonatal mortality and morbidity; therefore, the elucidation of the process of labor at a cellular and molecular level is essential for understanding the pathophysiology of preterm labor. Here, we summarize the role of innate and adaptive immune cells in the physiological or pathological activation of labor. We review published literature regarding the role of innate and adaptive immune cells in the cervix, myometrium, fetal membranes, decidua and the fetus in late pregnancy and labor at term and preterm. Accumulating evidence suggests that innate immune cells （neutrophils, macrophages and mast cells） mediate the process of labor by releasing pro-inflammatory factors such as cytokines, chemokines and matrix metalloproteinases. Adaptive immune cells （T-cell subsets and B cells） participate in the maintenance of fetomaternal tolerance during pregnancy, and an alteration in their function or abundance may lead to labor at term or preterm. Also, immune cells that bridge the innate and adaptive immune systems （natural killer T （NKT） cells and dendritic cells （DCs）） seem to participate in the pathophysiology of preterm labor. In conclusion, a balance between innate and adaptive immune cells is required in order to sustain pregnancy; an alteration of this balance will lead to labor at term or preterm.

Maternal and fetal T cells in term pregnancy and preterm labor

Pregnancy is a state of immunological balance during which the mother and the developing fetus must tolerate each other while maintaining sufficient immunocompetence to ward off potential threats.The site of closest contact between the mother and fetus is the decidua,which represents the maternal–fetal interface.Many of the immune cell subsets present at the maternal–fetal interface have been well described;however,the importance of the maternal T cells in this compartment during late gestation and its complications,such as preterm labor and birth,has only recently been established.Moreover,pioneer and recent studies have indicated that fetal T cells are activated in different subsets of preterm labor and may elicit distinct inflammatory responses in the amniotic cavity,leading to preterm birth.In this review,we describe the established and proposed roles for maternal T cells at the maternal–fetal interface in normal term parturition,as well as the demonstrated contributions of such cells to the pathological process of preterm labor and birth.We also summarize the current knowledge of and proposed roles for fetal T cells in the pathophysiology of the preterm labor syndrome.It is our hope that this review provides a solid conceptual framework highlighting the importance of maternal and fetal T cells in late gestation and catalyzes new research questions that can further scientific understanding of these cells and their role in preterm labor and birth,the leading cause of neonatal mortality and morbidity worldwide.