Postpartum adrenocortical function in dairy cows with dystocia submitted to cesarean section

The effects of the stress of dystocia on the adrenocortical function post partum in cows (n = 6) requiring a cesarean section were assessed by an adrenocorticotropic hormone (ACTH) stimulation test. Nine cows that calved normally were used as controls. The plasma glucocorticoid levels, before and 60 min after an intramuscular injection of 25 IU ACTH, were 4.4 +/- 0.5 (mean +/- SD) and 21.5 +/- 2.4 ng/ml 1 d post partum, 1.9 +/- 0.3 and 18.4 +/- 2.9 ng/ml 4 d post partum and 2.7 +/- 1.1 and 14.6 +/- 3.3 ng/ml 8 d post partum, respectively. Corresponding values of glucocorticoids in cows with normal calving were 4.5 +/- 3.6 and 18.1 +/- 5.2 ng/ml 1 d post partum, 1.7 +/- 1.3 and 13.2 +/- 5.5 ng/ml 4 d post partum and 1.9 +/- 1.7 and 14.6 +/- 3.3 ng/ml 8 d post partum. There were no statistically significant differences of the values between cows with dystocia requiring a cesarean section and cows with normal calving. The results indicate that dystocia requiring a cesarean section like normal calving does not lead to significant depression of the adrenocortical function post partum.     

胎膜早破与分娩方式的关系及产程观察

目的:探讨胎膜早破对分娩方式与结果的影响,提高对产程观察的重视。方法:统计分析249例孕足月胎膜早破者的分娩方式、产程及母儿并发症,并与249例随机抽取同期孕足月无胎膜早破的产妇进行对照。结果:胎膜早破组自然分娩率明显低于对照组(P<0.05),产褥感染、新生儿窒息发生率明显高于对照组(P<0.05)。结论:胎膜早破易感染,并导致胎儿宫内窘迫和新生儿窒息,与难产、剖宫产有相关性,应合理选择分娩方式,积极处理产程,以确保母婴安全。     

Effect of bacterial cell wall and lipopolysaccharide on arachidonic acid metabolism by caruncular and allantochorionic tissues from cows that calved normally and those that retained fetal membranes

Immunoactive eicosanoids may have a role in both placental separation and uterine involution in cattle. In the present study, we examined the effects of bacterial cell wall preparation and endotoxins on in vitro prostaglandin synthesis and arachidonic acid (AA) metabolism by caruncular and allantochorionic tissues. Placentomes were obtained about 6 h post partum from cows that delivered normally (n = 10) or those with retained fetal membranes (n = 4); the tissue explants were incubated for 6 h in the presence of labeled or nonlabeled AA. Prostaglandin F(2alpha) (PGF(2alpha)) and E(2) (PGE(2)) were measured by radioimmunoassay, and labeled AA metabolites were separated by reverse phase-high pressure-liquid chromatography. There was no effect of bacterial cell wall preparations or endotoxins on in vitro caruncular PGF(2alpha) secretion. However, bacterial products increased caruncular PGE(2) secretion in both cows that delivered normally and those with retained fetal membranes. For normal delivery cows caruncular tissue, bacterial product also increased leukotriene B(4) (LTB(4)) and decreased both thromboxane B(2) (TXB(2)) and hydroxy-eicosatetranoic acids (HETE) in vitro secretion. For the allantochorion, bacterial products increased in vitro PGF(2alpha) secretion only in cows that delivered normally and increased PGE(2) secretion essentially in cows with retained fetal membranes. In general, 6 keto PGF(1alpha) was the main metabolite secreted by both allantochorionic and carucular tissues. However, in cows with retained fetal membranes, PGE(2) became the most important metabolite secreted by allantochorion, especially in the presence of endotoxin. In conclusion, these results suggest that bacteria found in the early postpartum uterus or their endotoxin affect primarily caruncular and allantochorionic PGE(2) synthesis.     

Prostaglandin E(2) 9-keto reductase activity in bovine retained and not retained placenta

Prostaglandin E(2) 9-keto reductase (9-KPR) activity shifts reversibly PGE(2) into PGF(2 alpha) and may be responsible for the control of prostaglandins (PGs) levels in, among others, placental tissues. The retention of fetal membranes in cows is the postpartum disorder where the disturbances in PGs metabolism have been reported. It has been argued whether these disturbances are due to alterations in 9-KPR activity. In this study, the activity of the enzyme was determined in maternal and fetal bovine placental tissues which were divided into 6 groups as follows: (A) caesarian section before term without retained fetal membranes (n=10), (B) caesarian section before term with retained fetal membranes (n=10), (C) caesarian section at term without retained fetal membranes (n=12), (D) caesarian section at term with retained fetal membranes (n=12), (E) spontaneous delivery at term without retained fetal membranes (n=12), (F) spontaneous delivery at term with retained fetal membranes (n=12). The enzyme activity was measured spectrophotometrically and expressed in nanokatals (nkat) per protein content. The activity increased towards parturition and was significantly higher in maternal than in fetal part of placenta in all groups examined. The significantly higher values in retained than in not retained placental tissues were observed in the samples examined. The present results indicate that the disturbances in 9-KPR activity in bovine retained placenta exist but their reasons still require further experiments.     

Postpartum uterine flora following normal and abnormal puerperium in cows

Uterine swabs were taken from the uteri of three groups of cows (n = 5 each) on Days 1 and 2 and then at 3-d intervals up to 32 d post partum. Group I cows had a normal delivery, Group II cows had dexamethasone-induced parturition, and Group III cows were subjected to a Caesarian section. All cows in Group III and two cows in Group II retained their fetal membranes. A total of 230 bacterial isolates were made, and the most frequently isolated bacteria were Escherichia coli , streptococci, Proteus spp. , and clostridia. The highest number of bacterial isolates and the longest mean time to complete uterine involution were in the Group III cows.     

Spontaneous oxidative DNA damage in bovine retained and nonretained placental membranes

Retention of fetal membranes (RFM) is believed to be associated with conditions of oxidative stress. In this study, 8-hydroxy-2'-deoxyguanosine (8-OH-dG) was used for the determination of spontaneous oxidative DNA lesions in maternal and fetal parts of bovine retained and nonretained placentas. Placental specimens were collected directly after spontaneous delivery or during cesarean section from cows divided into 6 groups: (A) cesarean section before term without RFM, (B) with RFM, (C) cesarean section at term without RFM, (D) with RFM, (E) spontaneous delivery at term without RFM and (F) with RFM. Isolated DNA was hydrolyzed and analyzed by HPLC; native nucleosides were monitored at 254 nm and 8-OH-dG by electrochemical detection. No significant differences in 8-OH-dG levels between retained and nonretained placental tissues were found in all samples from preterm groups (mean concentrations between 13 and 42 micromol/mol deoxyguanosine (dG)). In the term cesarean section group with RFM a significant increase in 8-OH-dG concentration in DNA from maternal (8-fold) and fetal (18-fold) membranes were detected when compared to the respective nonretained tissues. Also, in the term spontaneous delivery groups maternal nonretained placental tissues showed increased levels of 8-OH-dG in comparison to the respective tissues of the retained placenta group. In placental tissues oxidative DNA lesions appear to be controlled by responsive mechanisms which, possibly following exhaustion, give rise to increased 8-OH-dG levels.     

The levels of lipid peroxidation products in bovine retained and not retained placenta

Unsaturated fatty acids undergo peroxidation processes. The presence of elevated levels of metabolites of lipid peroxidation processes may cause alterations in metabolic pathways which may lead to disturbances and clinical symptoms of illnesses. One such illness may be retention of fetal membranes (RFM) in cows. The aim of the study was the determination of thiobarbituric acid (TBA) reactive substances, conjugated dienes and hydroperoxides in bovine retained and not retained placenta in order to describe the oxidative status of cows affected with RFM. Placental samples were collected immediately after spontaneous delivery or caesarian section before term and at term and divided into 6 groups, with 16 animals in each group, as follows: A) caesarian section before term without RFM: B) caesarian section before term with RFM: C) caesarian section at term without RFM: D) caesarian section at term with RFM: E) spontaneous delivery at term without RFM; F) spontaneous delivery with RFM. The levels of TBA reactive substances, conjugated dienes and hydroperoxides were measured spectrophotometrically. The levels of all parameters were statistically significantly higher in the maternal than in the fetal part of placenta and the lowest in preterm groups. Statistically significantly higher concentrations in retained placenta samples than in control animals were observed. In conclusion, the metabolites of lipid peroxidation processes are elevated in cases of retained placenta and their presence might influence directly and/or indirectly the improper release of fetal membranes in cows.     

Cesarean section: trends and morbidity.

A review of 1683 cesarean sections performed at one hospital in a 3-year period (1977-79) showed that the cesarean section rate had trebled since 1967-79, the rates being 16.9% and 5.8%. The main indications for cesarean section responsible for this rise were dystocia, breech presentation and a previous cesarean section. AFter the operation 23.3% of received antibiotics. If the cesarean section rate is to fall, the biggest impact can be made by planning vaginal delivery in selected patients with a previous cesarean section and by improving the management of nonprogressive labour.     

Diagnosis of dystocia and management with cesarean section among primiparous women in Ottawa-Carleton.

We carried out a chart review study to determine the rate of diagnosis of dystocia (abnormal progress) and the use of cesarean section to treat dystocia among 3887 primiparous women who gave birth to a single baby in the vertex presentation at four hospitals in Ottawa-Carleton in 1984. Of the 3740 women who had some labour 1127 (30.1%) were given a diagnosis of dystocia. Cesarean section for dystocia was done during all phases of labour (41% of procedures in the latent phase, 38% in the active phase and 21% in the second stage). The cesarean section rate varied among the hospitals from 11.8% to 19.6%. A total of 75% of the cesarean sections were for dystocia, disproportion or failed induction. The findings suggest that cesarean section is being done for disproportion without a trial of labour beyond the latent phase and for dystocia in the absence of fetal distress. If these practices were modified the cesarean section rate could be reduced from 16% to about 8%, the rate found in some other centres and that observed in Canada in the early 1970s.     

Peripartum changes in the bovine placenta related to fetal membrane retention

To understand fetal membrane retention in dairy cattle, we examined these tissues in the immediate peripartum period before tissue separation. Placentomes were collected at 270-280 d of gestation from pre-partum Holstein cows (n = 5) and at 1, 3, 6, and 12 h postpartum from a) cows releasing fetal membranes in less than 12 h (n = 7), b) cows retaining fetal membranes for more than 12 h (n = 5), and c) cows induced to calve with dexamethasone (releasing membranes in more than 12 h; n = 5). Subjective evaluations of necrosis, distribution, and condition of binucleate giant and of principal cells were made. Necrotic foci and binucleate giant cells were counted for each interval for which tissue was available. Necrosis, existing prepartum, was identical to that observed at 1 h postpartum in all treatment groups (P > 0.05). Necrosis gradually increased in all treatment groups with time (P < 0.05); thus necrosis is unrelated to initiation of calving and is indirectly related to fetal membrane retention. Many binucleate giant cells were observed prepartum. In cows releasing fetal membranes normally, a significant (P < 0.05) decline in these cell numbers had occurred by 1 h postpartum. When fetal membrane retention occurred, no such decrease in binucleate giant cells was observed before 12 h postpartum. Loss of binucleate giant cells appears necessary for, or must occur with, separation of fetal membranes.     

Recent trends in cesarean section rates in Ontario.

After increasing steadily for 15 years the cesarean section rate in Ontario stabilized at 20.2 per 100 deliveries in the fiscal years 1986-87 and 1987-88. An important factor in the stabilization was a decrease in the rate of repeat section. The diagnosis and management of dystocia and fetal distress continue to put upward pressure on the cesarean section rate, which is higher than would be expected if recent practice guidelines had been fully implemented. There is a need for further research into the appropriate management of labour and delivery and into more targeted techniques for bringing practice into line with appropriate standards of care.     

Effects of dystocia, fetotomy and caesarian sections on the liver enzymes activities and concentrations of some serum biochemical parameters in dairy cattle

The aim of the present study was to determine the level of serum liver enzymes, triglyceride and some metabolites in cows with or without difficulties during parturition. The second goal was to compare between the possible effects of caesarian section and fetotomy on these parameters. A total number of 24 native breed cows at full term were included in this study. Out of them, 8 gave normal parturition, 16 cows were admitted with dystocia. The group of dystocia was subdivided into two groups; fetotomy (n=8) and caesarian (n=8) group. In the caesarian group, 4 cows were with uterine torsion. Five blood samples were collected from each cow: directly pre-partum, during and just after delivery and at, 24, 48 and 72 h post-partum. Serum samples were used for determination of aspartate amino transferase (AST), glutamate dehydrogenase (GLDH), gamma glutamyl transferase (gamma-GT), creatine phosphokinase (CK), glucose, total bilirubin, cholesterol and triglyceride. The results showed that AST, GGT, GLDH and CK activities were significantly increased in the group with caesarian sections due to uterine torsion than the control and fetotomy groups. There were insignificant changes in serum GGT and GLDH activities between control, fetotomy and dystocia group without uterine torsion at pre-partum and at 24 and 48 h post-partum. At 72 h post-partum, there was a significant increase in GLDH activity without significant increase in serum GGT activity. The concentrations of cholesterol and triglycerides did not differ in cows with dystocia compared to normal cows. In conclusion, cattle subjected to caesarian section and especially those with uterine torsion are associated with hepatic dysfunction. On the other hand, fetotomy has no effect on hepatocellular damage. The type of parturition has no effect on the bilirubin, cholesterol and triglyceride concentrations just before parturition to the 3rd day post-partum. It is recommended to supply cows with liver supportive therapy after caesarian section with uterine torsion.     

Mycoflora of cervicovaginal fluids in dairy cows with or without reproductive disorders

Fungal infection of reproduction system of dairy cattle have not been received much more attention. The aim of this study was to determine the fungal infection of Holstein dairy cows with reproductive disorders or healthy. Fungal isolates of cervicovaginal fluids of 176 Holstein dairy cows were collected by using the double rod swabs for cervix and the sterilized cotton swabs for discharges of vagina. They were evaluated for fungal infections. The treatment group included 70 dairy cows with reproductive diseases, such as abortion, repeat breeder, endometritis, metritis, retention of fetal membrane, dystocia, cervicitis, and vaginitis. The control groups were included 42 healthy non-pregnant cows and 64 pregnant cows. Isolates of fungi were obtained from cervix and vagina of 27.1% and 28.6% of treatment group, 26.7% and 31.2% of pregnant cows, and 33.3% and 21.4% of healthy non-pregnant cows, respectively, indicating no significant differences. It is showed that the cervix and vagina of the treatment group have been infected by six different mycotic isolates. However, the cervix and vagina of pregnant and non-pregnant healthy cows in control group were infected with 5, 6 and 5, 4 different fungal agents, respectively. Penicillium and yeast were the most common isolated agents. Regarding to the result of this study, it is concluded that fungal infections can occur in cervicovaginal cavity of Holstein dairy cows with or without reproductive diseases.     

AN EVALUATION OF CESAREAN SECTION

The risks of cesarean section have been reduced in step with the increase in safety of all major surgical procedures.In a series of 13,153 deliveries, 1,265 (9.6 per cent) were by cesarean section. There were three obstetrical maternal deaths in 11,888 cases in which delivery was by the vaginal route—0.025 per cent. In the series of 1,265 deliveries by cesarean section there was one death attributable to the operation—0.08 per cent.The total uncorrected fetal loss following cesarean section was 3.8 per cent. This compares favorably with fetal loss of 3.2 per cent in the vaginal delivery group in this series, and with fetal loss rates reported from large obstetrical centers.Anesthesia by spinal injection is the method of choice in cesarean section. There were no maternal deaths or accidents attributable to spinal anesthetic, and in no case was it felt that fetal death was attributable to it.The incidence of maternal morbidity in the cesarean section group following spinal anesthesia was 15.8 per cent—less than half the incidence of morbidity following inhalation anesthesia.     

Equine retained placenta: technique for and tolerance to umbilical artery injections of collagenase

Under laboratory conditions and in clinical experiments, bacterial collagenase has proven to be effective in hydrolyzing placenta and detaching cotyledon from caruncle in the bovine species. Laboratory studies in which placental samples were incubated with collagenase have also demonstrated that collagenase is 3.7 times more effective in hydrolyzing equine placenta than bovine placenta. This led to the hypothesis that collagenase may be a potential treatment for mares with retained placenta. However, that collagenase may hydrolyze the uterine wall and perforate the uterus was a concern. It was the purpose of this study thus to determine any adverse effects of collagenase on the equine uterus and to develop a method for intraplacental injection of collagenase. Three normally expelled intact placentas from Arabian mares, 10 cyclic mixed-breed mares, and 4 mares of various breeds with retained placenta were used. Fluoroscein dye and latex were used to study the placental vasculature and to determine a suitable dose of collagenase; placentas were hydrolyzed by collagenase solution in vitro. Bacterial collagenase solution (40,000 units, 200 ml) was infused into the uterine lumen of each cyclic mare. Uterine biopsies were obtained from the mares before collagenase infusion and again at 16 h and 26 d after infusion. In the mares with retained placenta, each placenta was infused via its umbilical cord vessels with 200,000 units of bacterial collagenase in 1 L of saline. Results showed that none of the uteri from cyclic mares were damaged by collagenase treatment. During a 4-wk period of monitoring (including endoscopy) mares with retained placenta did not show any abnormalities. Retained placentas were expelled in less than 6 h after collagenase treatment. It was concluded that intraplacental injections of collagenase are a safe and potentially effective treatment for retained placenta in mares.     

单胎头位初产妇产程图分析

目的:探讨存在难产因素初产妇产程图的临床意义。方法:对2009年6月至2010年6月在济南军区总医院住院分娩的326例单胎头位初产妇的产程图进行回顾性分析。结果:产程图异常组中难产因素的构成比和剖宫产率均高于产程图正常组;存在难产因素的组别(胎方位异常组、宫缩乏力组、巨大儿组)产程中各阶段时限均较正常产妇组长,宫颈扩张速度均较正常组慢,胎头位置均高于正常组,以上差异均有统计学意义(P<0.05)。结论:在产程中对产程图中各阶段时限、宫颈扩张速度及胎头位置等指标进行监测,来预测和及时发现头位难产因素的存在,及时给予处理,改善母儿预后。     

In-vitro steroid synthesis by the placenta of cows in late gestation and at parturition

Placental tissues were collected during late gestation (Group I, N = 11), pre partum (Group II, N = 9) and post partum (N = 29): 15 of the post-partum cows released the fetal membranes normally (Group III) and 14 retained the fetal membranes (Group IV). Preparations of dispersed fetal placental cells, preparations enriched in binucleate cells (BNC) or in small principal cells as well as tissue minces were utilized. Maternal placental tissue (caruncle) and fetal placental principal cells made minimal conversion of prenenolone and androstenedione to other steroids (less than 15% conversion). Fetal placental tissue and enriched preparations of BNC were more active and were similar in their conversion of pregnenolone and androstenedione to other steroids. BNC converted pregnenolone primarily to progesterone during late gestation, but this was altered in the direction of oestrogens pre partum and post partum. BNC were capable of converting androstenedione to oestrogens, but this ability diminished greatly post partum if the fetal membranes were released normally. In-vitro treatment of fetal placental tissue minces with dexamethasone increased the conversion of pregnenolone to androstenedione and the oestrogens but did not alter the conversion the primary cell type involved in fetal placental steroidogenesis peripartum and that dexamethasone may alter this steroidogenesis by activating the C17,20-lyase enzyme complex.     

Hormonal concentrations in bitches with primary uterine inertia

Normal labor is accompanied by sequential changes in blood concentrations of prostaglandin F2α (measured as 15-ketodihydro-PGF2α = PGFM), progesterone, estradiol, oxytocin, vasopressin, and of elevated cortisol levels. The aim of this study was to investigate hormone concentrations in dogs diagnosed with primary uterine inertia before and during treatment by cesarian section. The hypothesis was the dogs would have abnormally low plasma concentrations in one or several of the hormones involved in parturition. The study comprised seven bitches with total primary uterine inertia (dystocia group) treated with cesarian section and six healthy bitches (control group) subjected to planned cesarean section. Blood samples were taken before anesthesia, before surgery started, on delivery of the first puppy and on delivery of the last puppy. The progesterone:PGFM ratio in plasma was higher in the dystocia group than in the control group, but the serum estradiol concentration did not differ between groups. The plasma concentrations of oxytocin and vasopressin increased in both groups when the first puppies were delivered, but both hormones were more elevated in the control group than in the dystocia group on delivery of the last puppies. The plasma cortisol concentration increased to the same level in both groups. In conclusion, the ratio between progesterone and PGFM was higher and the oxytocin and vasopressin concentrations lower in the dystocia dogs than in the control dogs. The findings indicate that these hormones are involved in the pathophysiology of total primary uterine inertia in bitches.     

Risk factors for dystocia in pigtailed macaques (Macaca nemestrina)

Dystocia (difficult labor) is an important component of the management of nonhuman primates and results in significant fetal and maternal morbidity and increased use of veterinary resources. Dystocias can arise from abnormalities of the maternal pelvis or fetus or uncoordinated uterine activity. Although risk factors for stillbirths have been established in nonhuman primates, risk factors for dystocias have not. The objective of this study was to determine maternal and fetal risk factors for dystocia in macaques. Retrospective data were collected from 83 pigtailed macaques (Macaca nemestrina) diagnosed with dystocia. The diagnosis of dystocia was made based on clinical or pathologic evidence. Maternal records of age, reproductive history, experimental history, clinical records, and fetal birth weight and any applicable fetal necropsy reports were reviewed. The gestational age of the fetus, the infant's birth weight, total previous births by the dam, and the proportions of both viable delivery (inverse effect) and surgical pregnancy interventions (direct effect) in the dam's history generated a model that maximized the experimental variance for predicting dystocia in the current pregnancy and explained 24% of the dystocia deliveries. The number of total previous births and proportion of previous cesarean sections accounted for the greatest effect. This model can identify individual dams within a colony that are at risk for dystocias and allow for changes in breeding colony management, more intense monitoring of dams at risk, or allocation of additional resources.