Pregnancy Loss and ParturitionDistribution of Prenatal LossesDistribution of Prenatal Losses (cont.)Embryonic and Fetal Loss in CattleEmbryonic and Fetal Loss in PigsIncreased Prenatal LossEffect of Oocyte Age on Fertilization and Embryo ViabilityParturitionPowerPoint PresentationFetal Adrenal Changes with AgeHormonal Changes Associated with ParturitionSlide 12Slide 13Final Role of OxytocinOrientation of FetusFetal OrientationSlide 17Stages of LaborStages of Labor (cont.)Slide 20DystociaSlide 22Slide 23Slide 24Slide 25Perinatal Fetal ChangesSlide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Perinatal Fetal Changes (cont.)Slide 38Return to EstrusReturn to Estrus (cont.)Retained PlacentaRetained Placenta (cont.)Slide 43Induction of ParturitionSlide 45Slide 46Slide 47Slide 48Updated:01/13/19 Pregnancy Loss and ParturitionJohn ParrishUpdated:01/13/19 Distribution of Prenatal Losses•Fertilization 100%»Under optimal conditions•2/3 loss during embryonic development»Imprinting»Compaction»Blastocyst hatching and formation»Failure to prevent CL regression •Maternal recognition of pregnancyUpdated:01/13/19 Distribution of Prenatal Losses (cont.)•1/3 loss during fetal stage»Crowding»Placental insufficiencies»Not the fetus directlyUpdated:01/13/19 Embryonic and Fetal Loss in Cattle01020304050607080901000 1 2 3 5 CalvingPregnancy LossInterval From Breeding (months)PercentageUpdated:01/13/19 Embryonic and Fetal Loss in Pigs1012141618200 25 40020406080100Number Survival (%)Stage of Gestation (days)Number of CLs, Embryos or Fetuses Present% SurvivalUpdated:01/13/19 Increased Prenatal Loss•Nutritional Stress»Energy shortages»Mineral imbalances»Vitamin deficiencies•Disease of the reproductive tract•Endocrine imbalances•Aging of gametes prior to fertilizationUpdated:01/13/19 Effect of Oocyte Age on Fertilization and Embryo Viability0204060801000 4 8 12 16 204681012% Oocytes Fertilized Normally% Oocytes Fertilized NormallyViable Embryos at 25 Days of PregnancyViable Embryos at 25 Days of PregnancyAge of Oocyte at FertilizationUpdated:01/13/19 ParturitionUpdated:01/13/19 How Was Mechanism For Parturition Discovered?Skunk Cabbage - Sheep consuming this type of vegetation in western US had prolonged gestations. Fetus had congenital hypoplasia of Anterior PituitaryGene Defect - Autosomal recessive gene in Holstein breed Large calves grow in utero 1-2 months beyond delivery date. Congenital hypoplasia of Anterior PituitaryUpdated:01/13/19 Fetal Adrenal Changes with AgeFetal AgeAdrenal Gland WeightParturitionParturitionChange in Adrenal Size is a Response to Stress!!•Lack of space•Lack of gas exchange•Lack of nutrientsChange in Adrenal Size is a Response to Stress!!•Lack of space•Lack of gas exchange•Lack of nutrientsUpdated:01/13/19 Hormonal Changes Associated with ParturitionUpdated:01/13/19 ParturitionFetal NutritionalDemandsFetal NutritionalDemandsPlacentalInsufficiencyPlacentalInsufficiencyHypothalamusAnteriorPituitaryAdrenal CortexCRHCRHACTHACTHFetal Corticosteroids(Cortisol)Fetal Corticosteroids(Cortisol)Lung(surfactant)Lung(surfactant)Liver(glycogen)Liver(glycogen)Thyroid(metabolism)Thyroid(metabolism)ProgesteroneProgesteroneEstrogenEstrogenPGF2PGF2UterineContractionsUterineContractionsPGF2RelaxinOxytocinUterine Endometrium»Oxytocin receptorsUterine Myometrium»Gap junctionsOvary(CL)Cow,SowTriggersCLRegressionPlacentomePlacentomeCervicalRipeningCervicalRipeningUpdated:01/13/19 ParturitionFetal NutritionalDemandsFetal NutritionalDemandsPlacentalInsufficiencyPlacentalInsufficiencyHypothalamusAnteriorPituitaryAdrenal CortexCRHCRHACTHACTHFetal Corticosteroids(Cortisol)Fetal Corticosteroids(Cortisol)Lung(surfactant)Lung(surfactant)Liver(glycogen)Liver(glycogen)Thryoid(metabolism)Thryoid(metabolism)ProgesteroneProgesteroneEstrogenEstrogenPGF2PGF2UterineContractionsUterineContractionsPGF2RelaxinOxytocinUterine Endometrium»Oxytocin receptorsUterine Myometrium»Gap junctionsOvary(CL)Cow,SowTriggersCLRegressionPlacentomePlacentomeCervicalRipeningCervicalRipeningUpdated:01/13/19 Final Role of OxytocinSensory Neurons in CervixSensory Neurons in CervixOxytocin fromPosterior PituitaryOxytocin fromPosterior PituitaryMyometrialContractionsMyometrialContractionsUpdated:01/13/19 Orientation of Fetus•Fetus must reorient prior to parturition»Initially on back»Reorient so feet and head will exit first»Breech•Rear of fetus comes first•Orientation not important in pig•Abnormal orientation results in dystociaUpdated:01/13/19 Fetal OrientationUpdated:01/13/19 Fetal OrientationUpdated:01/13/19 Stages of Labor•Preparative (2 to 12 hours)»Myometrial contractions»Uterine pressure»Adominal discomfort»Cervical dilationUpdated:01/13/19 Stages of Labor (cont.)•Expulsion of fetus (30 to 180 min)»Strong uterine contractions»Rupture of the allantochorion»Appearance of the amnion»Maternal recumbence and straining»Not only uterine but abdominal contractions as well»Rupture of the amnion and deliveryUpdated:01/13/19 Stages of Labor (cont.)•Expulsion of the placenta (1 to 12 hours)»Uterine contractions»Chorionic villi loosen»Expulsion of the placenta»Delayed in ruminants due to presence of cotelydons separating independently»Suckling induces oxytocin release which triggers further uterine contractionsUpdated:01/13/19 Dystocia•Difficult birth•Abnormal presentations•Excessive fetal size•Multiple births (twins)»Twins presented at the same time»One is usually blocking the other»Uterus becomes fatiguedUpdated:01/13/19Updated:01/13/19Updated:01/13/19Updated:01/13/19 DystociaUpdated:01/13/19 Perinatal Fetal Changes•Cardiovascular»Ductus arteriosis»Foramen ovale»Ductus venosusUpdated:01/13/19 PlacentaLiverLeft Atrium Lungs Right AtriumForamenOvaleForamenOvaleDuctusVenosusDuctusVenosusDuctusArteriosusDuctusArteriosusAortaUmbilical ArteriesUmbilical VeinPortal VeinPortal VeinVena CavaVena CavaHeadand HeartTissuesFetal CirculatorySystemFetal CirculatorySystemUpdated:01/13/19 PlacentaLiverLeft Atrium Lungs Right AtriumForamenOvaleForamenOvaleDuctusVenosusDuctusVenosusDuctusArteriosusDuctusArteriosusAortaUmbilical ArteriesUmbilical VeinPortal VeinPortal VeinVena CavaVena CavaHeadand HeartTissuesTransitionalCirculatorySystemTransitionalCirculatorySystemUpdated:01/13/19 LiverLeft Atrium Lungs Right AtriumForamenOvaleForamenOvaleDuctusArteriosusDuctusArteriosusAortaPortal VeinPortal VeinVena CavaVena
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