Diagnosis and Management of Macrosomia and Shoulder Dystocia: A Comprehensive Review of Major Guidelines.

Importance: Macrosomia represents the most significant risk factor of shoulder dystocia (SD), which is a severe and emergent complication of vaginal delivery. They are both associated with adverse pregnancy outcomes. Objective: The aim of this study was to review and compare the most recently published influential guidelines on the diagnosis and management of fetal macrosomia and SD. Evidence Acquisition: A comparative review of guidelines from the American College of Obstetricians and Gynecologists (ACOG), the Royal College of Obstetricians and Gynaecologists, the National Institute for Health and Care Excellence, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), and the Department for Health and Wellbeing of the Government of South Australia on macrosomia and SD was conducted. Results: The ACOG and RANZCOG agree that macrosomia should be defined as birthweight above 4000-4500 g regardless of the gestational age, whereas the National Institute for Health and Care Excellence defines macrosomia as an estimated fetal weight above the 95th percentile. According to ACOG and RANZCOG, ultrasound scans and clinical estimates can be used to rule out fetal macrosomia, although lacking accuracy. Routine induction of labor before 39 weeks of gestation with the sole indication of suspected fetal macrosomia is unanimously not recommended, but an individualized counseling should be provided. Exercise, appropriate diet, and prepregnancy bariatric surgery are mentioned as preventive measures. There is also consensus among the reviewed guidelines regarding the definition and the diagnosis of SD, with the "turtle sign" being the most common sign for its recognition as well as the poor predictability of the reported risk factors. Moreover, there is an overall agreement on the algorithm of SD management with McRoberts technique suggested as first-line maneuver. In addition, appropriate staff training, thorough documentation, and time keeping are crucial aspects of SD management according to all medical societies. Elective delivery for the prevention of SD is discouraged by all the reviewed guidelines. Conclusions: Macrosomia is associated not only with SD but also with maternal and neonatal complications. Similarly, SD can lead to permanent neurologic sequalae, as well as perinatal death if managed in a suboptimal way. Therefore, it is crucial to develop consistent international practice protocols for their prompt diagnosis and effective management in order to safely guide clinical practice and improve pregnancy outcomes.

A rare case of adventitious placentation (diffuse semi-placenta) in a Jersey cow.

Placental abnormalities more frequently occur during pregnancy of somatic cell clones and may lead to pregnancy loss or dystocia. Adventitious placentation, or diffuse semi-placenta, is determined by the development of areas of accessory placentation between the cotyledons due to the abnormal growth of placentomes.After a full-term pregnancy, a 3-year-old Jersey heifer was referred for dystocia which resulted in the delivery of a dead calf. The cause of dystocia was found to be foetal malposition, while the placenta was physiologically expelled after dystocia resolution.Grossly, cotyledons appeared reduced in size and number in one placental horn, while the surface of the other horn was covered with microplacentomes. Numerous villous structures without trophoblastic coating were highlighted after histopathology. The dominant sign was an inflammatory reaction. The findings were consistent with inter-cotyledonal placentitis, which led to adventitial placentation.Diffuse semi-placenta compensates for the inadequate development of placentomes and may occur as a congenital or acquired defect. The outcome depends on its severity: in the worst scenario, pregnancy may not proceed beyond midterm and may be complicated by hydrallantois. In the case under examination, the dimensions of the cotyledons (from 2 to 10 cm) allowed for the natural course of pregnancy.

Perinatal mortality in German dairy cattle: Unveiling the importance of cow-level risk factors and their interactions using a multifaceted modelling approach.

Perinatal mortality (PM) is a common issue on dairy farms, leading to calf losses and increased farming costs. The current knowledge about PM in dairy cattle is, however, limited and previous studies lack comparability. The topic has also primarily been studied in Holstein-Friesian cows and closely related breeds, while other dairy breeds have been largely ignored. Different data collection techniques, definitions of PM, studied variables and statistical approaches further limit the comparability and interpretation of previous studies. This article aims to investigate the factors contributing to PM in two underexplored breeds, Simmental (SIM) and Brown Swiss (BS), while comparing them to German Holstein on German farms, and to employ various modelling techniques to enhance comparability to other studies, and to determine if different statistical methods yield consistent results. A total of 133,942 calving records from 131,657 cows on 721 German farms were analyzed. Amongst these, the proportion of PM (defined as stillbirth or death up to 48 hours of age) was 6.1%. Univariable and multivariable mixed-effects logistic regressions, random forest and multimodel inference via brute-force model selection approaches were used to evaluate risk factors on the individual animal level. Although the balanced random forest did not incorporate the random effect, it yielded results similar to those of the mixed-effect model. The brute-force approach surpassed the widely adopted backwards variable selection method and represented a combination of strengths: it accounted for the random effect similar to mixed-effects regression and generated a variable importance plot similar to random forest. The difficulty of calving, breed and parity of the cow were found to be the most important factors, followed by farm size and season. Additionally, four significant interactions amongst predictors were identified: breed-calving ease, breed-season, parity-season and calving ease-farm size. The combination of factors, such as secondiparous SIM breed on small farms and experiencing easy calving in summer, showed the lowest probability of PM. Conversely, primiparous GH cows on large farms with difficult calving in winter exhibited the highest probability of PM. In order to reduce PM, appropriate management of dystocia, optimal heifer management and a wider use of SIM in dairy production are possible ways forward. It is also important that future studies are conducted to identify farm-specific contributors to higher PM on large farms.

Dystocia in cattle and horses: a compilation of historical artworks dedicated to Professor Gerhard Sand (1861-1921).

Professor Gerhard Sand (1861-1921) was the first professor of veterinary obstetrics at the Royal Veterinary and Agricultural University, Copenhagen, Denmark. He began teaching the theory and practice of obstetrics to veterinary students in 1887 and spent the following years until his death in 1921 developing the veterinary obstetrics teaching program. During this period, veterinary obstetrics was established as an independent discipline at the Royal Veterinary and Agricultural University. Professor Sand's teaching had a major impact on the field of veterinary obstetrics in Scandinavia. He was devoted to teaching veterinary obstetrics and produced a number of obstetrical illustrations, some of which showed different causes of dystocia, mainly fetal malpresentation in cattle and horses. Professor Sand created the illustrations with the intention of publishing a handbook of obstetrics, but due to illness and an early death, this work was never completed. This compilation of historical artworks of dystocia in cattle and horses includes some of these illustrations and is published to honour Professor Sand, with the intention of making his illustrations widely available for the teaching of veterinary obstetrics.

Patient characteristics, surgery outcomes, presumed aetiology and other characteristics of fistula surgeries and related procedures supported by Fistula Foundation from 2019 to 2021: a multicentre, retrospective observational study.

OBJECTIVES: Obstetric fistula is a devastating childbirth injury primarily caused by prolonged, obstructed labour. It leaves women incontinent, severely stigmatised and isolated. Fistula repair surgery can restore a woman's health and well-being. Fistula Foundation, a non-profit organisation, works in partnership with local hospitals and community organisations in Africa and Asia to address key barriers to treatment and to increase the number of women receiving surgical care. This paper presents data on fistula and fistula repair surgery across a large global network of hospitals supported by Fistula Foundation. The data were collected between 2019 and 2021. DESIGN: Multicentre, retrospective, observational, descriptive study. SETTING AND PARTICIPANTS: The study analysed deidentified data from 24 568 surgical repairs supported by Fistula Foundation to treat women with obstetric fistula at 110 hospitals in 27 countries. RESULTS: The data highlight patient characteristics and key trends and outcomes from obstetric fistula repair surgeries and related procedures. Of those surgeries, 87% resulted in a successful outcome (fistula dry and closed) at the time of discharge, highlighting the effectiveness of fistula repair in restoring continence and improving quality of life. Over the period studied, the number of supported surgeries increased by 14%, but there remains an urgent need to strengthen local surgical capacity and improve access to treatment. Women suffered an average of 5.7 years before they received surgery and only 4% of women sought care independently. This underscores the importance of enhancing community awareness and strengthening referral networks. CONCLUSIONS: This research provides essential insight from a vast, global network of hospitals providing highly effective fistula repair surgery. Further investment is needed to strengthen surgical capacity, increase awareness of fistula and remove financial barriers to treatment if stakeholders are to make significant progress towards the United Nations' ambitious vision of ending fistula by 2030.

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.

Prescriptive and proscriptive lessons for managing shoulder dystocia: a technical and videographical tutorial.

This tutorial of the intrapartum management of shoulder dystocia uses drawings and videos of simulated and actual deliveries to illustrate the biomechanical principles of specialized delivery maneuvers and examine missteps associated with brachial plexus injury. It is intended to complement haptic, mannequin-based simulation training. Demonstrative explication of each maneuver is accompanied by specific examples of what not to do. Positive (prescriptive) instruction prioritizes early use of direct fetal manipulation and stresses the importance of determining the alignment of the fetal shoulders by direct palpation, and that the biacromial width should be manually adjusted to an oblique orientation within the pelvis-before application of traction to the fetal head, the biacromial width is manually adjusted to an oblique orientation within the pelvis. Negative (proscriptive) instructions includes the following: to avoid more than usual and/or laterally directed traction, to use episiotomy only as a means to gain access to the posterior shoulder and arm, and to use a 2-step procedure in which a 60-second hands-off period ("do not do anything") is inserted between the emergence of the head and any initial attempts at downward traction to allow for spontaneous rotation of the fetal shoulders. The tutorial presents a stepwise approach focused on the delivering clinician's tasks while including the role of assistive techniques, including McRoberts, Gaskin, and Sims positioning, suprapubic pressure, and episiotomy. Video footage of actual deliveries involving shoulder dystocia and permanent brachial plexus injury demonstrates ambiguities in making the diagnosis of shoulder dystocia, risks of improper traction and torsion of the head, and overreliance on repeating maneuvers that prove initially unsuccessful.

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.

The improvement and retention of skills in shoulder dystocia management with the use of high-fidelity simulation: The SAFE (SimulAtion high-FidElity) study.

BACKGROUND: Shoulder dystocia is a relatively uncommon but serious childbirth-related emergency. AIM: To explore the improvement and retention of skills in shoulder dystocia management through high-fidelity simulation training. METHODS: The SAFE (SimulAtion high-FidElity) study was a prospective cohort study that utilised a high-fidelity birth simulator. Registered midwives and final year midwifery students were invited to participate in a one-day workshop at 6-monthly intervals. There was a 30-minute initial assessment, a 30-minute theoretical and hands-on training, and a 30-minute post-training assessment on shoulder dystocia management. Pre-training and post-training values for the predetermined outcomes were compared. In each workshop we assessed the proportion of successful simulated births, the performance of manoeuvres to manage shoulder dystocia, the head-to-body birth time, the fetal head traction force, the quality of communication, the perception of time-to-birth, and the self-reported confidence levels. FINDINGS: The baseline workshop recruited 101 participants that demonstrated a significant increase in the proportion of successful simulated births (8.9% vs 93.1%), and a two-fold to three-fold increase in the score of manoeuvres, communication, and confidence after training. Those with low pre-training levels of competency and confidence improved the most post-training at baseline. There was a retention of manoeuvres, communication skills and confidence at 6 months. There was no reduction in fetal head traction force over time. Those being proficient before initial training retained and performed best at the 6-month follow-up. CONCLUSION: The SAFE study found a significant improvement in skills and confidence after the initial high-fidelity simulation training that were retained after 6 months.

Climatic and calf-related risk factors associated with failure of transfer of passive immunity in Holstein calves in a hot environment.

This retrospective observational study aimed to assess the effect of temperature-humidity index (THI) at calving and in the last trimester of pregnancy and calve-related factors affecting passive transfer of maternal immunoglobulin using Brix refractometry in Holstein calves. Blood samples from 4411 Holstein calves from a single large dairy farm in spring 2022 were used. A subset of data containing 6318 calvings was used to determine the effect of climatic conditions on the occurrence of agammaglobulinemia. Risk factors predictive of failure of passive transfer (FPT) were calculated using multiple logistic models. Females were 1.4 times more likely not to have FPT (56%; Brix% > 8 equivalent to ≥ 10 g/L IgG) than males (47.2%). Calves born as singles increased the likelihood of not presenting FPT (52.6%) than calves born as twins (42.9%). Calves from cows with no dystocic delivery had a lower risk for FPT (odds ratio = 2.3) than calves from cows with dystocia. Agammaglobulinemia was 1.5 and 1.8 times more likely to occur in calves with THI ≥ 80 and ≥ 82 in the last trimester of gestation and at calving, respectively, than in calves not experiencing heat stress. Agammaglobulinemia was twice as likely to occur in male than in female calves. Calves with birth weight ≥ 37 kg and gestation length ≥ 275 kg were less likely to present agammaglobulinemia than lighter calves and calves with shorter gestation periods. This study raises questions for management practices in Holstein calves undergoing in utero heat stress and around calving to avoid agammaglobulinemia.

Incisional Small-Bowel Strangulation after a Caesarean Section: A Case Report.

Background and Objectives: Every surgical procedure has the possible risk of complications, and caesarean sections (CSs) are no exception. As CS rates are increasing worldwide, being familiar with rare but possible complications has become extremely important. Case report: We present a case of 25-year-old nulliparous patient who came to our hospital with twin pregnancy for a scheduled induction of labour. An urgent CS was performed due to labour dystocia. On the second postoperative day, the patient started to complain about pain in the epigastrium, but initially showed no signs of bowel obstruction, passing gas, and stools, and could tolerate oral intake. After a thorough examination, an early postoperative complication-small-bowel strangulation at the incision site-was diagnosed. Small bowels protruded in between sutured rectus abdominis muscle causing a strangulation which led to re-laparotomy. During the surgery, there was no necrosis of intestines, bowel resection was not needed, and abdominal wall repair was performed. After re-laparotomy, the patient recovered with no further complications. Conclusions: Although there are discussions about CS techniques, most guidelines recommend leaving rectus muscle unsutured. This case demonstrates a complication which most likely could have been avoided if the rectus muscle had not been re-approximated.

Pitfalls in the diagnostics of shoulder dystocia: an analysis based on the scrutiny of 2274 deliveries.

PURPOSE: Shoulder dystocia is an obstetric emergency with severe complications. Our objective was to evaluate the major pitfalls in the diagnostics of shoulder dystocia, diagnostic descriptions documented in medical records, use of obstetric maneuvers, and their correlations to Erb's and Klumpke's palsy and the use of ICD-10 code 066.0. METHODS: A retrospective, register-based case-control study included all deliveries (n = 181 352) in Hospital District of Helsinki and Uusimaa (HUS) area in 2006-2015. Potential shoulder dystocia cases (n = 1708) were identified from the Finnish Medical Birth Register and the Hospital Discharge Register using ICD-10 codes O66.0, P13.4, P14.0, and P14.1. After thorough assessment of all medical records, 537 shoulder dystocia cases were confirmed. Control group consisted of 566 women without any of these ICD-10 codes. RESULTS: The pitfalls in the diagnostic included suboptimal following of guidelines for making the diagnosis of shoulder dystocia, subjective interpretation of diagnostic criteria, and inexact or inadequate documentation in medical records. The diagnostic descriptions in medical record were highly inconsistent. The use of obstetric maneuvers was suboptimal among shoulder dystocia cases (57.5%). Overall, the use of obstetric maneuvers increased during the study period (from 25.7 to 97.0%, p < 0.001), which was associated with decreasing rate of Erb's palsy and increasing use of ICD-10 code O66.0. CONCLUSION: There are diagnostic pitfalls, which could be addressed by education regarding shoulder dystocia guidelines, by improved use obstetric maneuvers, and more precise documentation. The increased use of obstetric maneuvers was associated with lower rates of Erb's palsy and improved coding of shoulder dystocia.

Internal manual rotation in intrapartal arrest of fetal head engagement.

OBJECTIVE: The success of internal manual or digital rotation of the head in mechanical dystocia due to malpresentation, malposition or malrotation is presented in this paper on our own clinical material with reference of today's research and clinical recommendations. STUDY DESIGN: Through a retrospective bicentric clinical study, we investigated the success of internal head rotation in two University Clinics for gynecology and obstetrics from year 2017 to 2023. In 152 singleton term (37-42 weeks) in cases of persistens intrapartum arrest of the fetal head. After palpatory and ultrasonographically verified arrest of fetal head engagement, a therapeutic manual (Liepmann) or digital rotation was performed. RESULTS: In 152 cases, manual rotation was performed in 108 (71.05 %) and digital rotation in 44 (28.94 %) cases in 73 (48.02 %) primiparous and 79 (51.97 %) multiparous. Intrapartum identification by digital palpation was done in all cases, and the following are: persistent occipital posterior position in 68 (44.73%), persistent deep transverse head presentation in 12 (7.89%), persistent high (longitudinal) occipital presentation in 64 (42.10 %) and persistent anterior asynclitism in 8 (5.26 %) cases. Episiotomy was used in 36 (23.68%) cases. Vacuum extraction was completed in 14 (9.21 %) deliveries, and cesarean section due to unsuccessful internal rotation in 15 (9.8 %) cases (%) without other indication. We did not record any intrapartum complications or cardiotocographic abnormalities. Cervical lacerations were treated with sutures in 4 cases (2.63 %). Successful correction of internal rotation procedure with spontaneous vaginal delivery was found in 80.92 % of cases. If we exclude delivery assisted by vacuum extraction whose indications were fetal hypoxia or dystocia after successful internal head rotation procedure, then the success rate of this method was 90.13 %. CONCLUSION: Internal head rotation is a simple, safe and successful obstetric manual intervention that directly increases the rate of vaginal deliveries after correction of the birth mechanism anomaly and directly reduces the percentage of cesarean section. Manual or digital head rotation is an established midwifery/obstetric skill in several centers which, based on numerous clinical researches and experience, should become protocolized and included in the guidelines of professional associations.

Clinical applicability of external and internal body dimensions in predicting dystocia in late-gestation Holstein-Friesian heifers.

The objective of this study was to determine the clinical applicability of maternal intrapelvic area (PA) and selected morphometric parameters that can be measured before parturition in predicting dystocia in dairy heifers. The measurements were performed in 374 late-gestation Holstein-Friesian heifers. Inner pelvic height and width were measured using a pelvimeter, and PA was calculated. The heifers were monitored continuously around the time of calving, and calving difficulty was categorized as: unassisted calving (UC), slight assistance (SA), considerable difficulty (CD) and veterinary assistance (VA). Calving performance was analysed with the χ2 test, and the effect of body dimensions on the course of parturition was evaluated by one-way analysis of variance. Dystocia (CD + VA) was predicted with the use of the classification tree method. Dystocia accounted for 29.14% of all deliveries. The percentages of stillbirths and retained placenta increased (p < .01) with increasing calving difficulty. Average PA immediately before parturition was smaller (p < .01) in group VA (223.2 cm2 ) than in group UC (253.3 cm2 ). According to the classification tree, dystocia may occur (74.07% odds) in heifers with PA < 254.2 cm2 and a rump angle <5.68° before parturition. Measurements of heifer's cannon circumference and sire's body size improve the accuracy of dystocia prediction.

Studying the Effects of Shoulder Dystocia and Neonate-Focused Delivery Maneuvers on Brachial Plexus Strain: A Computational Study.

The purpose of this computational study was to investigate the effects of neonate-focused clinical delivery maneuvers on brachial plexus (BP) during shoulder dystocia. During shoulder dystocia, the anterior shoulder of the neonate is obstructed behind the symphysis pubis of the maternal pelvis, postdelivery of the neonate's head. This is managed by a series of clinical delivery maneuvers. The goal of this study was to simulate these delivery maneuvers and study their effects on neonatal BP strain. Using madymo models of a maternal pelvis and a 90th-percentile neonate, various delivery maneuvers and positions were simulated including the lithotomy position alone of the maternal pelvis, delivery with the application of various suprapubic pressures (SPPs), neonate in an oblique position, and during posterior arm delivery maneuver. The resulting BP strain (%) along with the required maternal delivery force was reported in these independently simulated scenarios. The lithotomy position alone served as the baseline. Each of the successive maneuvers reported a decrease in the required delivery force and resulting neonatal BP strain. As the applied SPP force increased (three scenarios simulated), the required maternal delivery force and neonatal BP strain decreased. A further decrease in both delivery force and neonatal BP strain was observed in the oblique position, with the lowest delivery force and neonatal BP strain reported during the posterior arm delivery maneuver. Data obtained from the improved computational models in this study enhance our understanding of the effects of clinical maneuvers on neonatal BP strain during complicated birthing scenarios such as shoulder dystocia.

First and Second Stage Labor Management: ACOG Clinical Practice Guideline No. 8.

PURPOSE: The purpose of this document is to define labor and labor arrest and provide recommendations for the management of dystocia in the first and second stage of labor and labor arrest. TARGET POPULATION: Pregnant individuals in the first or second stage of labor. METHODS: This guideline was developed using an a priori protocol in conjunction with a writing team consisting of one maternal-fetal medicine subspecialist appointed by the ACOG Committee on Clinical Practice Guidelines-Obstetrics and two external subject matter experts. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements. RECOMMENDATIONS: This Clinical Practice Guideline includes definitions of labor and labor arrest, along with recommendations for the management of dystocia in the first and second stages of labor and labor arrest. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence.

Pelvic dimensions and occurrence of dystocia in Black-and-White and Holstein-Friesian heifers.

The Black-and-White (BW) breed, which until recently had dominated in Europe, was replaced by the Holstein-Friesian (HF) breed. As a result, the incidence of dystocia has increased. Dystocia occurs most frequently in heifers, and it is associated with high calf weight and/or too narrow pelvic openings in heifers. The aim of this study was to evaluate retrospectively the effects of pelvic dimensions and rump angle on calving ease in two cattle breeds. The research was carried out in four barns where BW and HF cattle were used. The course of parturition was evaluated in 317 heifers (BW, n=169; HF, n=148) based on direct observations. Calves were weighed, external and internal pelvic measurements were performed (using the Rice pelvimeter), and rump angle was determined in heifers. Based on the course of parturition, heifers of both breeds were divided into easy calving (EC) and difficult calving (DC) groups. The frequency of DC was 24.3% in HF heifers and 13.1% in BW heifers. In comparison with DC heifers, EC heifers had a larger pelvic area, in particular the internal dimensions of the bony pelvis, and a higher rump angle. In comparison with BW heifers, HF heifers had a smaller rump angle, a narrower pelvis and a lower ratio of pelvic area to calf weight. High dystocia rates in HF heifers could result from a relatively large fetus size and a less preferable pelvic size and rump angle. High variation in the internal pelvic dimensions in HF heifers indicates that the incidence of dystocia can be reduced through selection for a larger pelvic size and the optimal rump angle.

Mmp2 Deficiency Leads to Defective Parturition and High Dystocia Rates in Mice.

Parturition is the final and essential step for mammalian reproduction. While the uterus is quiescent during pregnancy, fundamental changes arise in the myometrial contractility, inducing fetal expulsion. Extracellular matrix (ECM) remodeling is fundamental for these events. The gelatinases subgroup of matrix metalloproteinases (MMPs), MMP2 and MMP9, participate in uterine ECM remodeling throughout pregnancy and parturition. However, their loss-of-function effect is unknown. Here, we determined the result of eliminating Mmp2 and/or Mmp9 on parturition in vivo, using single- and double-knockout (dKO) mice. The dystocia rates were measured in each genotype, and uterine tissue was collected from nulliparous synchronized females at the ages of 2, 4, 9 and 12 months. Very high percentages of dystocia (40-55%) were found in the Mmp2-/- and dKO females, contrary to the Mmp9-/- and wild-type females. The histological analysis of the uterus and cervix revealed that Mmp2-/- tissues undergo marked structural alterations, including highly enlarged myometrial, endometrial and luminal cavity. Increased collagen deposition was also demonstrated, suggesting a mechanism of extensive fibrosis in the Mmp2-/- myometrium, which may result in dystocia. Overall, this study describes a new role for MMP2 in myometrium remodeling during mammalian parturition process, highlighting a novel cause for dystocia due to a loss in MMP2 activity in the uterine tissue.

[Morbidity and mortality of mare and foal following dystocia - a literature review]. / Morbidität und Mortalität von Stute und Fohlen nach Dystokie ­ eine Literaturübersicht.

Dystocia represents a life-threatening condition for mare and foal. Morbidity and mortality rates due to a difficult birth, as well as the influence on fertility of the mare were analyzed, based on a review of publications. This was aggravated by the fact that no standardized diagnostic code was used and that most publications do not clearly describe how extensively the examinations were performed beforehand. Retentio secundinarum is the most common complication caused by dystocia. Other complications are injuries to the soft birth canal and the colon. These occur more frequently after surgical obstetrics than following assisted vaginal deliveries. Performing a fetotomy increases the risk of injury to the birth canal. After a caesarean section, the risk for retained placenta increases significantly. In order to evaluate the possibility of medical progress over time, mortality rates of mare and foal were investigated and divided in surgical and conservative obstetrics within the period of 1970-1990 and 1991-2021. The average maternal mortality rate following caesarean section amounted to 18% in the time period between 1970 and 1990 and 14% between the years from 1991-2021. After fetotomy, the two determined mortality rates amounted to 29% and 10% for the time between 1970 and 1990. In the period 1991-2021, the rate varies between 4% and 44% with an average mortality rate of 14%. Following controlled vaginal delivery, the average mortality rate is 9%. Literary sources were however only available for the current time period and range between 6% and 29%. The morbidity and mortality rate of foals is very high. Following caesarean section on average 53% of foals are dead on delivery, with a range of 13-79% in case reports from the years 1991-2021. The number of dead foals in the context of conservative obstetrics is of a similar scale. Postnatal foal diseases are largely due to intrapartum hypoxia during dystocia and obstetric injury. In consequence of a difficult delivery, mares experience reduced fertility. In numerous cases this however may be compensated by pausing from further breeding in the same year. The number of cases evaluated in this context however remains too small to advocate any recommendations for breeding following incidents of dystocia.