Pregnant Sheep Research Articles

Circulating miRNAs in maternal plasma as potential biomarkers of early pregnancy in sheep.

MicroRNA (miRNA) plays an important role in the control of gene expression and is implied in many biological functions, including embryo implantation and development. The aim was to assess plasma miRNA profiles during the peri-implantation and ascertain potential candidate miRNA markers for early pregnancy diagnosis in ovine plasma. The plasma samples were obtained from a total of 24 ewes on days 12 (pre-implantation; P12, n = 4), 16 (implantation; P16, n = 4) and 22 (post-implantation; P22, n = 4) after mating, and on their corresponding days of 12 (Pre-C; C12, n = 4), 16 (Imp-C; C16, n = 4) and 22 (Post-C; C22, n = 4) of the estrous cycle. The miRNA profiles in plasma were assessed by microarray technology. We detected the presence of 60 ovine-specific miRNAs in plasma samples. Of these miRNAs, 22 demonstrated a differential expression pattern, especially between the estrous cycle and early pregnancy, and targeted 521 genes. Two miRNAs (oar-miR-218a and oar-miR-1185-3p) were confirmed using RT-qPCR in the ovine plasma samples. Protein-protein interaction (PPI) network of target genes established six functional modules, of which modules 1 and 3 were enriched in the common GO terms, such as inflammatory response, defense response, and regulation of immune response. In contrast, module 2 was enriched in the developmental process involved in reproduction, embryo development, embryonic morphogenesis, and regulation of the developmental process. The results indicate that miRNAs profiles of plasma seemed to be modulated during the peri-implantation stage of pregnancy in ewes. Circulating miRNAs could be promising candidates for diagnosis in early ovine pregnancy.

Involvement of neurosteroids in the control of prolactin secretion in sheep under basal, stressful and pregnancy conditions

Prolactin (PRL) secretion by the anterior pituitary (AP) is responsive to changes in physiological conditions and many external factors that also affect brain neurosteroid levels. This study tested the hypothesis that neurosteroids can affect PRL secretion in sheep under basal, stressful and advanced pregnancy conditions. In Experiment 1, luteal-phase sheep were subjected to a three-day series of intracerebroventricular (icv.) control (n = 12) or allopregnanolone (AL, 4 × 15 μg/60 μL/30 min at 30-min intervals, n = 12) infusions. Acute stressful stimuli, isolation and partial movement restriction were applied on the third day of infusion to half of the animals in each group. In Experiment 2, pregnant sheep were subjected to a three-day series of icv. control (n = 6) or finasteride (4 × 25 μg/60 μL/30 min at 30-min intervals, n = 6) infusions during the 16th week of pregnancy. As a result, the relative abundance of PRL transcript increased in the AP of luteal-phase sheep treated with stress, AL and AL in combination with stress (P < 0.05 - P < 0.01) compared to controls. The level of PRL mRNA in stressed-AL-treated sheep was higher (P < 0.01) than in sheep only subjected to stress. The PRL protein content in the AP decreased in stressed-only sheep compared to controls (P < 0.05) and increased in stressed-AL-treated sheep compared to controls and other groups (P < 0.05 - P < 0.01). Plasma PRL concentration increased (P < 0.05 - P < 0.01) in stressed-only sheep compared to controls; AL infusion counteracted the stress-induced increase in PRL levels (P < 0.05 - P < 0.01) and had no effect in non-stressed animals. Inhibition of neurosteroid synthesis in the brain of pregnant sheep by finasteride caused transient increases (P < 0.05 - P < 0.001) in plasma PRL concentration compared to controls. In conclusion, the presented results indicate a bimodal effect of AL on PRL secretion in sheep: first at the molecular level – stimulation of PRL mRNA expression; second – inhibition of hormone release from pituitary lactotrophs. Both AL activities may involve various mechanisms regulating PRL secretion. In general, cerebral neurosteroids can affect the supply of pituitary PRL in the body under certain conditions, such as stress and pregnancy.

Effect of pre-conceptional nutrition and season on fetal growth during early pregnancy in sheep

Gestational age in sheep can be closely predicted through ultrasonographic measurement of fetal bones when correlated to standardized fetal growth curves. However, these standardized curves do not account for factors that are known modulators of fetal growth, such as maternal nutrition or health status. Despite being seasonal breeders, and studies reporting an effect of season on birth weight, the influence of season on fetal growth has not been well characterized. In this study, we hypothesized that season of conception will affect fetal growth curves during mid-gestation and that pre-conceptional nutrition would have no effect. We investigated this by provisioning treatments of low, control, and high planes of nutrition during the lactation and flushing pre-conceptional periods to multiparous Dorset x Polypay and Dorset ewes over two seasons (the optimal breeding season [n = 97] and the suboptimal breeding season [n = 104]). Females were mated naturally with mating dates recorded, fetal biparietal diameter measured via ultrasound between gestational days 35–71, and newborn weights recorded at lambing. Pre-conceptional nutritional treatments did not affect fetal biparietal diameter. However, low vs. high nutrition in the pre-conceptional lactation (but not flushing) period resulted in reduced lamb birth weights (P < 0.001). Early fetal growth tended to be faster in the suboptimal breeding season than in the optimal breeding season (P < 0.061) with lambs being heavier at birth in the optimal breeding season (P < 0.001). There was no effect of fetal sex or litter size on fetal biparietal diameter during the first half of pregnancy, however both sex and litter size influenced lamb birth weight (P < 0.001) with males being heavier than females and singletons being heavier than twins and triplets. Mating date within the flushing period had a significant effect on lamb birth weight regardless of season and independent of treatment, with ewes that conceived later in the flushing period having heavier lambs at birth (P = 0.007). These findings suggest that pre-conceptional under- or overnutrition resulting in substantial changes in body condition does not affect fetal growth during the first half of pregnancy. However, the reduction in lamb birth weight indicates that pre-conceptional maternal nutrition during the previous lactation period may affect fetal growth later in pregnancy.

MicroRNA‐210‐mediated mtROS confer hypoxia‐induced suppression of STOCs in ovine uterine arteries

Background and PurposeHypoxia during pregnancy is associated with increased uterine vascular resistance and elevated blood pressure both in women and female sheep. A previous study demonstrated a causal role of microRNA‐210 (miR‐210) in gestational hypoxia‐induced suppression of Ca2+ sparks/spontaneous transient outward currents (STOCs) in ovine uterine arteries, but the underlying mechanisms remain undetermined. We tested the hypothesis that miR‐210 perturbs mitochondrial metabolism and increases mitochondrial reactive oxygen species (mtROS) that confer hypoxia‐induced suppression of STOCs in uterine arteries.Experimental ApproachResistance‐sized uterine arteries were isolated from near‐term pregnant sheep and were treated ex vivo in normoxia and hypoxia (10.5% O2) for 48 h.Key ResultsHypoxia increased mtROS and suppressed mitochondrial respiration in uterine arteries, which were also produced by miR‐210 mimic to normoxic arteries and blocked by antagomir miR‐210‐LNA in hypoxic arteries. Hypoxia or miR‐210 mimic inhibited Ca2+ sparks/STOCs and increased uterine arterial myogenic tone, which were inhibited by the mitochondria‐targeted antioxidant MitoQ. Hypoxia and miR‐210 down‐regulated iron–sulfur cluster scaffold protein (ISCU) in uterine arteries and knockdown of ISCU via siRNAs suppressed mitochondrial respiration, increased mtROS, and inhibited STOCs. In addition, blockade of mitochondrial electron transport chain with antimycin and rotenone inhibited large‐conductance Ca2+‐activated K+ channels, decreased STOCs and increased uterine arterial myogenic tone.Conclusion and ImplicationsThis study demonstrates a novel mechanistic role for the miR‐210‐ISCU‐mtROS axis in inhibiting Ca2+ sparks/STOCs in the maladaptation of uterine arteries and provides new insights into the understanding of mitochondrial perturbations in the pathogenesis of pregnancy complications resulted from hypoxia.

Expression of nuclear factor kappa B in ovine maternal inguinal lymph nodes during early pregnancy

BackgroundPregnancy-induced immunological changes contribute to the maternal immune tolerance. Nuclear factor kappa B (NF-κB) pathway participates in regulating both innate and adaptive immunities, and lymph nodes play key roles in adaptive immune reaction. However, it is unclear whether early pregnancy changes the expression of NF-κB family in maternal lymph node in sheep.MethodsIn this study, the samples of inguinal lymph nodes were collected from ewes on day 16 of the estrous cycle, and on days 13, 16 and 25 of pregnancy, and expression of NF-κB family, including NF-κB p105 (NFKB1), NF-κB p100 (NFKB2), p65 (RELA), RelB (RELB) and c-Rel (REL), were analyzed through real-time quantitative PCR, Western blot and immunohistochemical analysis.ResultsThe expression levels of NF-κB p105 and c-Rel downregulated, but NF-κB p100 upregulated on day 25 of pregnancy. The expression levels of p65, RelB and c-Rel peaked at day 13 of pregnancy, and expression level of RelB was higher during early pregnancy comparing to day 16 of the estrous cycle. In addition, p65 protein was located in the subcapsular sinus and lymph sinuses.ConclusionThis paper reported for the first time that early pregnancy has effects on the expression of NF-κB family, which may contribute to the maternal immunoregulation through blood circulation and lymph circulation during early pregnancy in sheep.

Gebeliğin Sonunda Uygulanan Enerji Eksikliğinin Koyun ve Kuzu Doğum Ağırlıkları Üzerine Etkisi

Abstract: This study was carried out in Chios breed pregnant sheep which created experimentally energy deficiency. To determine the effect of low energy feeding on the birth weights of sheep and lambs in the last period of pregnancy. 38 Chios breed sheep, 4-6 years old, were used in the study. The live weight weights of the ewes before the pregnancy were done on the zero day and the other weight weights on the days 120, 127, 134, 141 and 148 of the pregnancy. On the 105th day of pregnancy, pregnant and non-pregnant sheep were divided into 3 groups as normal energy pregnant group (PNE), deficient energy pregnant group (PLE) and non-pregnant normal energy group (N-PNE). From the 106th day of pregnancy to delivery; The pregnant sheep in the PNE group were fed with the ration containing 13% HP and 10 MJ / kg ME, the pregnant sheep in the PLE group were fed with ration containing 13% HP and 8.0 MJ / kg ME. The sheep in the N-PNE group were fed with ration containing 11% HP and 8.8 MJ / kg ME. PLE and N-PNE groups were found to have lower body weight than the PNE group. However, there was no statistical difference between these groups. In all pregnant sheep, body weight was higher than 120 days of pregnancy, it was found to be higher than day 0 (p

Oxidative Stress and Fetal Growth Restriction Set Up Earlier in Undernourished Sheep Twin Pregnancies: Prevention with Antioxidant and Nutritional Supplementation.

Hypoxemia and oxidative stress, resulting in intrauterine growth restriction (IUGR) in undernourished twin sheep pregnancies, has been described in near-term studies. Our aim was to evaluate if the counteractive effects of maternal nutritional or antioxidant supplementation on the fetal redox status were evident before the accelerated fetal growth phase. Forty twin-bearing ewes grazing on natural Patagonian prairie were randomly assigned to four groups (n = 10 each; P: control ewes consuming mainly natural pasture; P+A: pasture plus antioxidants; P+C: pasture plus concentrate; P+A+C: pasture plus antioxidants and concentrate). Daily herbal antioxidants were supplemented in a feedstuff concentrate as a premix from day 35 until day 100 of gestation, when fetal venous cord blood samples and biometric measurements were obtained via cesarean section. The fetuses from group P were clearly hypoxemic. An analysis of variance showed that maternal antioxidant supplementation showed a trend of increased PO2, SatHb, and Ht, effects not observed in P+C fetuses. Antioxidants decreased the fetal MDA concentration (p < 0.05). Fetal TAC was increased by the antioxidants and concentrate (p < 0.05). Antioxidant supplementation showed a trend to increase fetal body weight but not biometry. The results suggest that negative effects of oxidative stress occur earlier than the overt growth arrest, and the maternal administration of antioxidants may constitute a good nutritional strategy for the early prevention of IUGR.

Predictive blood biomarkers of sheep pregnancy and litter size

Early detection of sheep pregnancy and the prediction of how many lambs a pregnant ewe delivers affects sheep farmers in a number of ways, most notably with regard to feed management, lambing rate, and sheep/lamb health. The standard practice for direct detection of sheep pregnancy and litter size (PLS) is ultrasonography. However, this approach has a number of limitations. Indirect measurement of PLS using blood biomarkers could offer a simpler, faster and earlier route to PLS detection. Therefore, we undertook a large-scale metabolomics study to identify and validate predictive serum biomarkers of sheep PLS. We conducted a longitudinal experiment that analyzed 131 serum samples over five timepoints (from seven days pre-conception to 70 days post-conception) from six commercial flocks in Alberta and Ontario, Canada. Using LC–MS/MS and NMR, we identified and quantified 107 metabolites in each sample. We also identified three panels of serum metabolite biomarkers that can predict ewe PLS as early as 50 days after breeding. These biomarkers were then validated in separate flocks consisting of 243 animals yielding areas-under-the-receiver-operating-characteristic-curve (AU-ROC) of 0.81–0.93. The identified biomarkers could lead to the development of a simple, low-cost blood test to measure PLS at an early stage of pregnancy, which could help optimize reproductive management on sheep farms.

Effect oral administration zinc oxide nanoparticles' or metal for Local Awassi Ewes in some productive trails

This experiment was conducted in a field of a breeder (private sector) in Wasit Governorate / Kut district for the period from 1/7/2021 to 1/4/2022. 50 pregnant local Awassi sheep, aged 3-4 years, with average 62.00±0.5kg Body weight were used in this experiment to study the effect of dosing on Nano zinc oxide. Or mineral for local Awassi ewes in some productive traits. The ewes were divided into 5 groups, a control group and four treatments, each group comprising 10 ewes. The first group represented the control group without addition, the first treatment was 40 mg/animal/day Zno, the second treatment was 20 mg/animal/day nZno, and the third treatment was 60 mg/animal/day Zno and the fourth treatment 30 mg/animal/day nZno. Ewes were dosed with zinc capsules at the beginning of the fourth month of pregnancy on 1/10/2021 and until30/11/2021. The results of this study showed that there were no significant differences in the weight of ewes for the control group and the first, second, third and fourth treatment when mating , and at the fourth month of pregnancy and the fifth month and at birth and the subsequent months, the first, second and third after birth.

Comparative study of pregnancy diagnosis in ewes (Ovis aries) using barium chloride and progesterone-kit

One hundred and twenty sheep were used to test a low-cost technique for early diagnosis of pregnancy in sheep from July 2017 to June 2018. Different age groups were randomly categorized under four groups (15 to 30 days, 31 to 45 days, 46 to 60 days &amp; 61 to 75 days). One mL barium chloride (1, 1.5 &amp; 2%) was mixed with one mL of urine and kept for 5 to 10 minutes at room temperature: precipitation indicated non-pregnant. Three to five drops of serum were added to Bovipreg kit (progesterone-based kit) and left at room temperature for 5 minutes. One red line was interpreted as negative and two red lines positive for pregnancy. Barium chloride solution gave 67 - 70.5% accuracy. The accuracy for progesterone-based early pregnancy diagnostic kit was 80 - 85%. Progesterone-based early pregnancy diagnostic kit is much more accurate. The Bangladesh Veterinarian (2020) 37(1 - 2): 36-41

A Pilot Study of Exposure to Nicotine in Human Pregnancy and Maternal and Fetal Testosterone Levels at Birth.

Nicotine exposure in pregnant rats and sheep has shown a more than 50% increase in female fetal testosterone (FFT) levels. Increased testosterone levels have also been linked to infertility, increased anogenital distance (AGD), and reduced second to fourth digit (2D:4D) finger length ratios (FLR). In humans, we hypothesized that maternal total testosterone (MTT) levels would increase in smoking mothers and would cause increased FFT levels, increased AGD, and decreased 2D:4D FLR. This prospective study separated women expecting a female fetus into nonsmoking and smoking cohorts. Maternal cotinine (MC) was tested at 3rd trimester and delivery to assess nicotine exposure. MTT levels were drawn at delivery, and FFT levels were collected from cord blood. The AGD and 2D:4D FLRs were measured at birth. Data were analyzed using parametric and nonparametric tests. The data of 36 smokers and 28 nonsmokers were analyzed. Smoking mothers had higher parity, drug abuse history and were more likely white race. No statistical differences were seen among the primary outcomes of MTT and FFT. MTT was higher among nonsmokers versus smokers (144 versus 107ng/dL). No correlations were noted between MC levels at delivery, MTT, and FFT levels. No statistical differences were noted among secondary outcomes of AGD and FLR. Although animal studies showed increased FFT levels after nicotine exposure, this was not seen in our human study. Placental differences in animals and humans may be at work. Our pilot study reveals a need for research on the effects of smoking in pregnancy on fetal hormones.

In vivo investigation of ruminant placenta function and physiology-a review.

The placenta facilitates the transport of nutrients to the fetus, removal of waste products from the fetus, immune protection of the fetus and functions as an endocrine organ, thereby determining the environment for fetal growth and development. Additionally, the placenta is a highly metabolic organ in itself, utilizing a majority of the oxygen and glucose derived from maternal circulation. Consequently, optimal placental function is required for the offspring to reach its genetic potential in utero. Among ruminants, pregnant sheep have been used extensively for investigating pregnancy physiology, in part due to the ability to place indwelling catheters within both maternal and fetal vessels, allowing for steady-state investigation of blood flow, nutrient uptakes and utilization, and hormone secretion, under non-stressed and non-anesthetized conditions. This methodology has been applied to both normal and compromised pregnancies. As such, our understanding of the in vivo physiology of pregnancy in sheep is unrivalled by any other species. However, until recently, a significant deficit existed in determining the specific function or significance of individual genes expressed by the placenta in ruminants. To that end, we developed and have been using in vivo RNA interference (RNAi) within the sheep placenta to examine the function and relative importance of genes involved in conceptus development (PRR15 and LIN28), placental nutrient transport (SLC2A1 and SLC2A3), and placenta-derived hormones (CSH). A lentiviral vector is used to generate virus that is stably integrated into the infected cell's genome, thereby expressing a short-hairpin RNA (shRNA), that when processed within the cell, combines with the RNA Induced Silencing Complex (RISC) resulting in specific mRNA degradation or translational blockage. To accomplish in vivo RNAi, day 9 hatched and fully expanded blastocysts are infected with the lentivirus for 4 to 5h, and then surgically transferred to synchronized recipient uteri. Only the trophectoderm cells are infected by the replication deficient virus, leaving the inner cell mass unaltered, and we often obtain ~70% pregnancy rates following transfer of a single blastocyst. In vivo RNAi coupled with steady-state study of blood flow and nutrient uptake, transfer and utilization can now provide new insight into the physiological consequences of modifying the translation of specific genes expressed within the ruminant placenta.

Pregnancy in Slaughtered Lambs and Sheep-A Cross-Sectional Study in Three Abattoirs in Switzerland.

Simple SummaryThe slaughtering of pregnant livestock and its relevance to animal welfare has become an ethically controversial topic. In this study, the prevalence of sheep and lambs being slaughtered while pregnant in Switzerland was assessed as well as the stage of pregnancy and the life signs of the fetuses. Data collection was carried out over one year in three Swiss abattoirs. Overall, 7.6% of the female animals were pregnant at slaughter, and 25.5% of them were in the third trimester of pregnancy, where 81.1% of the fetuses showed signs of life, such as a heartbeat or umbilical artery pulsation. To assess the relevance of animal welfare, it is discussed whether fetuses feel pain and stress. Even though science disagrees as to whether fetuses are capable of feeling conscious pain, it cannot certainly be ruled out, which is why the slaughter of pregnant sheep and lambs should be minimized as much as possible.The slaughter of pregnant sheep and goats is not restricted in Switzerland. The aim of this study was to assess the prevalence of pregnant sheep and lambs being slaughtered in Switzerland and to determine the state of gestation and vital signs of the fetuses in order to assess the need to take measures and raise awareness of this issue. The data collection was carried out from March 2021 to February 2022, comprising 115 days in three abattoirs. A total of 18,702 sheep and lambs were included in this cross-sectional study, and 8770 were female (46.9%), 663 of which were pregnant at slaughter (7.6%). The pregnancy rate varied by age category: 404 lambs (6.1%) and 259 sheep (11.9%) were pregnant. The highest pregnancy rate was found in winter (25.7%). Among the 663 pregnancies, more than a quarter were multiple pregnancies (28.2%). A total of 169 animals were in the third trimester of pregnancy (25.5%), where living fetuses were mainly found (81.1%). As it cannot be definitively ruled out that fetuses feel conscious pain, the data from this study underline that, from an ethical point of view, there is a need for action and that measures must be taken to reduce the number of pregnant slaughtered animals.

Early pregnancy regulates the expression of prolactin and its receptor in the thymus, the liver, the spleen and lymph nodes in sheep

As a pituitary hormone, prolactin (PRL) is also synthesized by immune system cells, and exerts its effects on the immune system by binding to its receptor (PRLR) via endocrine and paracrine/autocrine pathways. The immune organs adapt to the presence of fetal alloantigens during pregnancy, and the immune system is composed of primary organs and secondary organs. The objective of this study is to analyze the effects of early pregnancy on expression of PRL and PRLR in maternal immune organs in sheep. In this study, the thymus, lymph node, the spleen and the liver were sampled at day 16 of the estrous cycle, and at days 13, 16, and 25 of pregnancy in ewes. Expression of PRL and PRLR was analyzed through quantitative real-time PCR, Western blot and immunohistochemistry. Our data showed that there were an upregulation of PRL and PRLR in the thymus, lymph node and the spleen, and a downregulation in the liver during early pregnancy in ewes. In conclusion, it is reported for the first time that early pregnancy has tissue specific effects on expression of PRL isoform and PRLR isoform in the thymus, lymph node, the spleen and the liver, which may be owing to these organs exerting different functions during early pregnancy, and necessary for the successful pregnancy in sheep.

Comparison of the behavior of hybrids and domestic lambs in the early postnatal period

Using hybridization, breeds of merino sheep and archaromerinos were bred. At the same time, researchers note the possibility of transferring the characteristics of behavior and habits by inheritance from parents. The research aims to study the behavioral responses of first‐generation hybrid lambs in the early postnatal period in comparison with the behavior of ordinary domestic lambs. The object of the study was 4 hybrids of the first generation (ovchubuk) obtained from domestic sheep inseminated with the epididymal sperm of a bighorn sheep (chubuku), and 4 domestic lambs. Animals were kept in a pen of 625 m2 for close and constant contact with people. The observation was carried out from 9 a.m. to 5 p.m. In the early postnatal period ‐ from birth to 4.5 months and the post‐weaning period ‐ from 4.5 to 6 months. The manifestation of reflexes or instincts was recorded on a letter, photo, video. Attempts to stand up newborn hybrids showed in the first 8‐10 minutes, 12‐15 minutes after birth they rose to all limbs, the lambs were able to stand up for 25‐30 minutes. The hybrids received the first portions of colostrum for 18‐20 minutes domestic ones for 35‐38 minutes. A characteristic feature of the hybrids was the diversity and duration of the sucking reflex. It lasted only 15‐17sec with breaks every 10‐15 minutes. In the lambs of the control group, the sucking reflex was calm and prolonged ‐ 1.5‐2 minutes. All newborn hybrids jumped on the backs of their mothers. The hybrids were distinguished by increased activity while maintaining caution good orientation in space, which was not observed in the lambs of the control group. The instinct of self‐preservation in hybrids was “silence.” When weighing and collecting biomaterial, the hybrids did not make any extra sounds, which cannot be said about the control group. In the “man‐animal” system, hybrids were quickly tamed in a smaller containment area. In the mother‐offspring system, the lambs of both groups followed their mothers everywhere. The hybrids showed: curiosity, keeping alert, jumping from a place, jumped with a 180‐degree turn in flight. In general, the ethological features of hybrid lambs differ significantly from the behavior of domestic lambs. After the birth of hybrid offspring, they use the instinct of cubs to imitate the behavior of an adult animal from a very early age. In addition, it is necessary to organize work so that pregnant sheep are in constant contact with humans in compact pens.

Continuous but not pulsed low-dose fetal betamethasone exposures extend the durability of antenatal steroid therapy.

Antenatal steroid (ANS) therapy is the standard care for women at imminent risk of preterm labor. Despite extensive and long-standing use, 40%-50% of babies exposed antenatally to steroids do not derive benefit; remaining undelivered 7 days or more after ANS treatment is associated with a lack of treatment benefit and increased risk of harm. We used a pregnant sheep model to evaluate the impact of continuous versus pulsed ANS treatments on fetal lung maturation at an extended, 8-day treatment to delivery interval. Continuous low-dose ANS treatments for more than 72 h in duration improved fetal lung maturation at 8 days after treatment initiation. If fetal ANS exposure was interrupted, the beneficial ANS effect was lost. Truncated treatments, including that simulating the current clinical treatment regimen, did not improve lung function. Variable fetal lung maturation was correlated to the amount of saturated phosphatidylcholine present in the lung fluid. These data demonstrate that 1) the durability of ANS therapy may be enhanced by employing an extended, low-dose treatment regimen by reducing total dose and 2) interrupting the continuity of fetal exposure by allowing it to fall below a minimal threshold was associated with comparably poor functional maturation of the preterm ovine lung.

Effects of maternal ritodrine hydrochloride administration on the heart rate of preterm fetal sheep with intraamniotic inflammation.

Ritodrine hydrochloride is used for pregnancy prolongation and intrauterine fetal resuscitation. However, its clinical significance in intraamniotic inflammation during preterm labor and intrauterine fetal distress is unclear. We investigated the effects of maternal ritodrine hydrochloride administration (MRA; 200 μg/min for 2 h, followed by 800 μg/min for 2 h after 24 h) on fetal physiological parameters. For this purpose, we used chronically instrumented pregnant sheep at 113–119 d (term = 145 d) of gestation without (Group 1, n = 5) and with (Group 2, n = 5) intraamniotic inflammation induced by lipopolysaccharide injection into the amniotic cavity. The changes in fetal heart rate (FHR) and short-term variability (STV) and long-term variability (LTV) in FHR, fetal blood pressure, and fetal arterial blood gas (FABG) values were measured before and at 1 and 2 h after initiating MRA. Before MRA, all parameters were similar between Groups 1 and 2; however, there was significantly higher STV in Group 2 than in Group 1 before MRA at 800 μg/min, significantly higher partial arterial pressure of carbon dioxide in FABG in Group 2 than in Group 1 before MRA at 200 μg/min, and significantly lower blood glucose (BG) in Group 2 than in Group 1 before MRA at 800 μg/min. One hour after MRA, the FHR, STV, and LTV were significantly higher at 800 μg/min than those at the baseline in Group 1, as determined by the Friedman test; however, no significant difference was observed in Group 2. Additionally, the FABG pH significantly decreased 1 h after MRA at 800 μg/min in Group 2, whereas FABG lactate and BG significantly increased 2 h after MRA at 800 μg/min in Groups 1 and 2. Thus, short-term MRA at 800 μg/min increased the FHR, STV, and LTV significantly; these values were further modified under intraamniotic inflammation.

Melatonin treatment during chronic hypoxic gestation improves neonatal cerebrovascular function

BackgroundFetal chronic hypoxia is associated with blood flow redistribution and oxidative damage in the brain, leading to increased perinatal morbimortality. Melatonin reduces oxidative stress, improves vascular function, and has neuroprotective effects. ObjectivesThis study aimed to determine the effects of an oral melatonin treatment to pregnant ewes at high-altitude, on the cerebrovascular function of their neonates. Study designTen high-altitude pregnant sheep received either vehicle or melatonin (10 mg/d) during the last third of gestation until delivery. Postnatal daily hemodynamic measurements were recorded from lambs until 12 days old. In addition, lambs were submitted to a graded oxygenation protocol to assess cerebrovascular responses. Subsequently, lambs were euthanized, and middle cerebral arteries (MCA) were collected for vascular function, protein levels, and morphostructural analyses. ResultsAntenatal treatment doubled plasma levels of melatonin in pregnant ewes. Melatonin increased carotid flow and decreased carotid vascular resistance in the lambs by the end of the first week. Furthermore, melatonin increased MCA's maximal vasoconstrictor and vasodilator responses, associated with nitric oxide-dependent and independent mechanisms. ConclusionsAn oral treatment with melatonin during pregnancy promotes postnatal cerebral perfusion in chronically hypoxic neonates. Melatonin is a potential treatment for cerebrovascular dysfunction due to perinatal chronic hypoxia.

Intraamniotic sealing of fetoscopic membrane defects in ex vivo and in vivo sheep models using an integrated semirigid bioadhesive patch

Preterm prelabor rupture of membranes is the most frequent complication of fetoscopic surgery. Strategies to seal the membrane defect created by fetoscopy have been attempted with little success. We previously developed an integrated semirigid bioadhesive patch composed of silicone and hydroxypropyl methylcellulose that achieved ex vivo sealing of membrane defects. To evaluate the feasibility of the insertion of our integrated semirigid bioadhesive patches using a fetoscopic technique and to test the adhesion in ex vivo human membranes and in an in vivo ovine model. An experimental study involving 2 experiments: (1) ex vivo-human fetal membranes were mounted in a custom-designed model with saline solution simulating intraamniotic pressure. The insertion of 2 different bioadhesive patches made of silicone-hydroxypropyl methylcellulose and silicone-polyurethane-hydroxypropyl methylcellulose was performed through a 12-Fr cannula mimicking fetoscopic surgery technique. The experiment was repeated 10 times with membranes from different donors. Measures included insertion time, successful insertion, and adhesion at 5 minutes; (2) in vivo-16 patches of silicone-hydroxypropyl methylcellulose were inserted by fetoscopy in the amniotic cavity of pregnant sheep (4 bioadhesives per animal, in 4 ewes). Measures included successful insertion, adhesion at 5 minutes, and adhesion at the end of surgery. In the ex vivo insertion study, there was no difference in the insertion time between silicone-hydroxypropyl methylcellulose and silicone-polyurethane-hydroxypropyl methylcellulose patches (P=.49). Insertion was successful in all cases, but complete adhesion at 5 minutes was superior for silicone-hydroxypropyl methylcellulose (P=.02). In the in vivo study, insertion of silicone-hydroxypropyl methylcellulose by fetoscopy was feasible and successful in all cases, and no complications were reported. Adhesion persisted at 5 minutes and at the end of the surgery in 68.8% and 56.3% of the patches, respectively. We describe the feasibility of deploying through a fetoscopic trocar a semirigid silicone-hydroxypropyl methylcellulose patch that seals fetal membranes after an invasive fetal procedure. The results warrant further research for improving long-term adhesion and developing a clinically applicable system.

Application of Environmentally Safe Bioelectrical Parameterization for the Assessment of Potential Multiple Pregnancy of Sheep and Offspring Growing Capacity

Functional state of the reproductive system of ewes, which determines their multiple pregnancy, is closely related to homeostatic processes, which can be assessed by the level of bioelectric potential of superficially localized biologically active centers (LBP of SLBACs). The purpose of the work is to develop a method for early diagnostics of multiple pregnancies in ewes, by studying the LBP of the SLBACs of ewes and their reproduction rate - multiple pregnancies, as well as studying the growing capacity of offsprings of young animals obtained from experienced ewes. The object of the study was ewes of the Romanov breed.As a result of the research and analysis of the data obtained, a straight-line relationship between the LBP of the SLBACs of ewes and their multiple pregnancies was established.The results of the control young sheep breeding of the Romanov breed obtained from the ewes with different LBP of SLBACs showed that the lambs obtained from the ewes with a low LBP of the SLBACs had the highest growing capacity. However, the ewes with a high biopotential level produce significantly more offspring, which allows increasing the level of mutton production and the profitability of the industry.On the basis of the data obtained, a method for early diagnosis of multiple pregnancies in sheep according to the LBP of the SLBACs of ewes before the mating campaign was developed.