Výsledek obrázku pro human mouse dog chicken fish embryogenesis I.Revision of embryonic and fetal development Petr Vaňhara, Dept. of Histology and Embryology LF MU Crash course H&E I 21-25.9.2020 Mouse embryo, approximately 10.5 days post-fertilisation (equivalent to day 28 in humans). Photo by Jim Swoger BNPS.co.uk (01202) 558833 Výsledek obrázku pro human mouse dog chicken fish embryogenesis Gametogenesis From fertilization to early embryo Embryogenesis to 8th week Fetal development Fetal position in uterus, hallmarks of newborn Introduction to teratology and prenatal diagnostics CONTENT Crash course H&E I 21-25.9.2020 GAMETOGENESIS Spermatozoon - Wikipedia Sperm (spermatozoon) Oocyte GAMETOGENESIS •meiosis •diploid primordial germ cells ® haploid gametes • •primordial germ cells •extraembryonic origin •spermatogonia ® spermatogenesis and spermiogenesis ® spermatozoon •oogonia ® oogenesis ® oocyte (® ovum) • •gonad •unique microenvironment for development of gametes •endocrine axis hypothalamus-pituitary gl. •important endocrine functions 2n 2c 2n 4c 1n 1c 1n 2c Hypothalamus Gonadotropins CNS SPERMATOGENESIS AND SPERMIOGENESIS Nucleus of Sertoli cell Cytoplasm of Sertoli cells Primary spermatocyte Secondary spermatocyte Spermatids Spermatogonia Spermatozoa Testis (HE) Pituitary Germinal epithelium Testes Ovarium OOGENESIS •Oogonia are present only during prenatal development in utero •After birth, only primary oocytes in primordial follicles are present •Cell cycle of primary oocyte is arrested in dictyotene stage of prophase M I until onset of puberty •In each ovarian cycle (starting in puberty), a cohort of follicles enters maturation, however, usually only a single follicle reaches ovulation. Atresia of the remaining follicles in cohort. •Primary oocyte ® Secondary oocyte ® Ovum (matures after fertilization) •Primordial follicle ® Primary follicle (unilaminar and multilaminar) ® Secondary follicle ® Graafian follicle (ovulation) •Luteogenesis (formation of corpus luteum) Hypothalamus Gonadotropins CNS Pituitary OVARIAN AND MENSTRUAL CYCLE •Synchronization of oogenesis (in ovarium) and readiness of endometrium (uterine lining) to putative implantation. Follicular cells: Estrogen Corpus luteum: Progesterone https://munispace.muni.cz/library/catalog/book/1440 Ovarian cycle Menstrual cycle Pituitary CNS (hypothalamus) FSH LH Gonadoliberins GAMETOGENESIS an illustration of spermatozoa approaching the egg FERTILIZATION Re-entry of oocyte to cell cycle Generation of 2nd polar body Replication of DNA of pronuclei Fusion of pronuclei Beginning of cleavage Fusion of oocyte and sperm Cortical (zonal) reaction (× polyspermy) Contact of sperm and oocyte Capacitation 300-500×106 sperms Oocyte in metaphase MII Ovulation Acrosomal reaction (acrozin) Contact with corona radiata Penetration of zona pellucida Ampulla of oviduct (most often) 3-Dart-LLC-MEDICAL 1 2 3 4 5 8 6 7 Fertilization START! 9 10 11 12 •Adhesion of blastocyst •Differentiation of trofoblast Implantation •End of implantation Embryogenesis •Differentiation of embryoblast •Bilaminar germ disc •Amniotic cavity •Primary yolk sac •Extraembryonic mesoderm 13 14 15 16 17 18 1st week 2nd week Cleavage Blastogenesis 3rd week File:Stage6 bf01.jpg Stage7.jpg •Trilaminar germ disc •Differentiation of epiblast •Primitive node and primitive streak •Differentiation of mesoderm •Differentiation of ectoderm and neuroectoderm •Somitogenesis 19 20 21 FIRST EVENTS IN HUMAN LIFE 1st week Conclusion: all blastomeres are equal. FIRST EVENTS IN HUMAN LIFE SOLO FOR BLASTOMERES WHAT IS DEVELOPMENTAL POTENTIAL OF BLASTOMERES? 1st week „inside-outside“ „cell polarity“ •16-cell embryo is still totipotent – later (32-cell), it loses the full developmental potential ® cell are determined. Výsledek obrázku pro 32 cell human morula FIRST EVENTS IN HUMAN LIFE DETERMINATION OF BLASTOMERES Mechanism of diferentiation 1st-2nd week Day 5 Day 6 Day 7 1/2 Day 8 Day 9 end of 2nd week hypoblast epiblast syncytiotrophoblast amnion primary yolk sac extraembryonic mesoderm extraembryonic coelom cytotrophoblast lacunae DEVELOPMENT OF GERM DISC FIRST EVENTS IN HUMAN LIFE BILAMINAR GERM DISC https://embryology.med.unsw.edu.au/embryology/images/c/ce/Stage5_bf11L.jpg File:Hertig1956 fig37.jpg 2nd week BILAMINAR GERM DISC ORGANIZER EXISTS IN MAMMALLS Primitive node 15 16 17 18 19 20 21 22 23 24 25 26 27 28 https://embryology.med.unsw.edu.au/embryology/images/b/b1/Hertig1956_fig49.jpg Výsledek obrázku pro trilaminar germ disc scheme 3. týden Day 16 File:Stage8 bf3.jpg File:Stage7.jpg Primitive node Primitive streak Neural plate Day 18 3rd week begins 2nd week ends 14 File:Stage7.jpg NEW STRUCTURES TRILAMINAR GERM DISC PRIMITIVE STREAK AND PRIMITIVE NODE Stage8 bf8.jpg Prechordal plate Neural plate 3rd week TRILAMINAR GERM DISC Notochordal process PRIMITIVE STREAK AND PRIMITIVE NODE File:Stage8 bf9.jpg Výsledek obrázku pro trilaminar germ disc scheme Day 17 Day 18 Day 19 3rd week TRILAMINAR GERM DISC PRIMITIVE STREAK AND PRIMITIVE NODE 3rd week TRILAMINAR GERM DISC PRIMITIVE STREAK AND PRIMITIVE NODE Výsledek obrázku pro endoderm hypoblast Výsledek obrázku pro primitive streak SEM http://biology.kenyon.edu/courses/biol114/Chap14/7stcelln.gif http://biology.kenyon.edu/courses/biol114/Chap14/8stcelln.gif http://biology.kenyon.edu/courses/biol114/Chap14/6stcelln.gif A new cell population appears - MESODERM 3rd week TRILAMINAR GERM DISC PRIMITIVE STREAK AND PRIMITIVE NODE NOTOCHORD DERIVATIVES OF MESODERM Výsledek obrázku pro notochordal process formation Výsledek obrázku pro paraxial mesoderm segmentation End of 2nd week End of 3rd week 3rd week Notochord induces differentiation of ectoderm – cellular basis of nerve system is established – NEUROECTODERM NEUROECTODERM NEURULATION 3rd week •Neural plate •Neural folds •Neural tube • •Neural crest • NEURULATION NEURAL TUBE 3rd week NEURAL TUBE NEURULATION Výsledek obrázku pro paraxial mesoderm segmentation http://biology.kenyon.edu/courses/biol114/Chap14/PEPhelps-neurulation.jpg Edtoderm and mesoderm produce BMP4, that induces development of epidermis Notochord produces inhibitors of BMP4 - noggin, chordin and follistatin (cranially) a wnt3a and FGF (caudally) - ectoderm differentiates into neuroectoderm. NEURAL TUBE AND NEURAL CREST NEURULATION 3rd – 4th week Výsledek obrázku pro neural tube sem NEURAL TUBE AND NEURAL CREST NEURULATION Výsledek obrázku pro neural crest Výsledek obrázku pro neural crest histology Výsledek obrázku pro neural crest SEM NEURAL TUBE AND NEURAL CREST NEURULATION NEURAL TUBE File:Stage10 sem6.jpg File:Stage10 neural sm.jpg File:Human brain growth 01.jpg Embryology.med.unsw.edu.auc Výsledek obrázku pro notochord nucleus pulposus https://www.researchgate.net/profile/Daisuke_Sakai/publication/272843641/figure/fig5/AS:27191198901 8641@1441840278987/Morphology-of-region-specific-IVD-cells-a-Histological-analysis-of-mouse-tail-IV Ds-and.png INTERVERTEBRAL DISC NOTOCHORD IN ADULT BODY 3rd week Chordomezodermový výběžek MESODERM GASTRULATION SOMITES DERIVATIVES OF MESODERM Výsledek obrázku pro paraxial mesoderm segmentation Výsledek obrázku pro paraxial mesoderm segmentation Výsledek obrázku pro paraxial mesoderm segmentation 3rd – 4th week Výsledek obrázku pro mesoderm differentiation Výsledek obrázku pro neural crest SEM Výsledek obrázku pro somites SOMITES DERIVATIVES OF MESODERM Výsledek obrázku pro sclerotome dermatome myotome Výsledek obrázku pro somitogenesis SOMITES DERIVATIVES OF MESODERM •Paraxial: sclerotomes, myotomes, dermatomes •Intermediate: nephrotomes •Lateral plate: somatopleura, splanchnopleura OTHER DERIVATIVES OF MESODERM 3rd – 4th week •heart, cardiovascular system •urogenital system •muscle and skeletal system •hematopoietic and lymphatic systems •connective tissue, dermis •mesothelium Výsledek obrázku pro derivatives of mesoderm DEVELOPMENTAL DISORDERS DURING GASTRULATION •Primitive streak is a temporary embryonic structure. Persistent primitive streak causes sacrococcgyeal teratoma. Výsledek obrázku pro sacrococcygeal teratoma Výsledek obrázku pro sacrococcygeal teratoma •Failure of primitive streak leads to absence of mesoderm in affected region - sirenomelia - -limbs -urogenital system -GIT Výsledek obrázku pro sirenomelia DEVELOPMENTAL DISORDERS DURING GASTRULATION •If two primitive streaks form, conjoined twins may develop FOLDING OF EMBRYO NEW BODY PLAN 4th week FOLDING OF EMBRYO NEW BODY PLAN extraembryonic coelom umbilical vein umbilical artery extraembryonic coelom FOLDING OF EMBRYO NEW BODY PLAN Cytotrophoblast Extraembryonic somatopleura Extraembryonic splanchnopleura Connective stalk and allantois Extraembryonic coelom Chorion and chorionic villi Skin umbilicus Neural tube http://www.embryology.ch/images/iimgperioembry/01carnegie/synoptique/i1_kyotostad07.jpg http://www.embryology.ch/images/iimgperioembry/01carnegie/synoptique/i1_kyotostad09sml.jpg 1 Primitive streak 2 Neural folds 3 Amnion Day 25 1.5-2.5 mm Carnegie stage 9 1 Yolk sac 2 Primitive streak 3 Primitive node 4 Germ disc Day 19 0.4 mm Carnegie stage 7 http://www.embryology.ch/images/iimgperioembry/01carnegie/synoptique/i1_kyotostad10asml.jpg Day 28 2-3.5 mm Carnegie stage 10 1 Amnion 2a Neural ridge 2b Neural tube 2c Caudal neuroporus 2d Rostral neuroporus http://www.embryology.ch/images/iimgperioembry/01carnegie/synoptique/i1_kyotostad10bsml.jpg 3 Neural folds 4 Somites 5 Yolk sac http://www.embryology.ch/anglais/iperiodembry/carnegie03.html#st710 Dorsal Ventral • bilaminar ® trilaminar germ disc • cephalocaudal and lateral flexion of embryo FOLDING OF EMBRYO NEW BODY PLAN Výsledek obrázku pro embryo 6th week 6W https://www.babycenter.com/ims/2015/01/pregnancy-week-7-tailbone_square.jpg,qwidth=384.pagespeed.ce .b1eADtun3C.jpg 6W 5W https://www.babycenter.com/ims/2015/01/pregnancy-week-5-amniotic-sac_square.jpg,qwidth=384.pagespee d.ce.2NhMZRfRIU.jpg 4W week 4-6 EMBRYONIC DEVELOPMENT •Mesoderm segmentation •Primitive gut •Esophagotracheal diverticulum •Heart (starts beating day 22-23) •Limb buds •Primary brain vesicles, closing of neuropores •Differentiation of neural crest •Origin of thyroid and anterior pituitary •Ectodermal placodes, optic vesicle •Liver diverticulum •Septum transversum •Segmentation of mesoderm continues •Posterior pituitary •Heart septation begins •Lung buds branch - pseudoglandular stage of lung development •Cochlea grows •Lens vesicle, nasal placodes •Fourth brain ventricle forms •Pharyngeal arches, ridges and pouches •Limb buds grow •Hematopoiesis in liver •Retinal pigment •Derivatives of endodermal pharyngeal pouches (parathyroid, thymus) •Adrenal gland •Heart and lungs descended to thorax •Innervation of limbs, differentiation of myoblasts •Face development – maxillary and mandibulary processes, palatine, choans •Telencephalon stratifies – archicortex, paleocortex and neocortex. Choroid plexus •Rotation of stomach •Pancreatic diverticula fuse • https://www.babycenter.com/ims/2015/01/pregnancy-week-10-fingernails_square.jpg,qwidth=384.pagespee d.ce.oBeJl2aXXT.jpg week 8 Výsledek obrázku pro embryo 8th week 7-8W 8-9W •Secretion from endocrine pancreas •Growth of liver, growth and luminization of bile ducts •Ossification of limbs begin •Development of brain nuclei •Joints of upper and later lower limbs allow rotation •Fingers grow •Stratification of cerebellar cortex •Perforation of anal membrane •Herniation of intestinal loops •Testes produce testosterone •Nose, meatus, eyelids, developer, external ears start to grow •Backbone - 33-34 cartilaginous vertebrae •Embryonic tail diminished EMBRYONIC DEVELOPMENT 280 days (= 40 weeks = 10 lunar months) from the first day of the last menstruation 266 days (= 38 weeks) from ovulation (gestation age) Calculation of term: First day of the last menstruation + 1 year– 3 months + 7 days LENGTH OF PREGNANCY Conception age Menstrual age Fertilization Beginning of the last menstruation 38 weeks 40 weeks DELIVERY 0 3 8 weeks preembryo embryo fetus https://www.babycenter.com/ims/2015/01/pregnancy-week-13-fingerprints_square.jpg,qwidth=384.pagespe ed.ce.Y6AMYvlbEI.jpg 3M month 4-5 •Fetus swallows amniotic fluid – necessary for GIT development •Rapid growth of head (non-proportional to rest of body) •Eyelids fuse •Ossification centers visible by ultrasound examination •Development of external genitalia •Kidneys produce urine, other organs start to work •Skeletal muscles innervated •Physiological umbilical hernia, in 12th weeks reposition of intestinal loops 60-70mm, 150 g FETAL DEVELOPMENT https://www.babycenter.com/ims/2015/01/pregnancy-week-16-heart-development_square.jpg,qwidth=384.pa gespeed.ce.lNn2G1p7gi.jpg 4M 130mm, 450 g •Rapid growth of fetus •Ossification of skeleton •Face growths, mandible visible •Apparent external genitalia month 5-9 https://www.babycenter.com/ims/2015/01/pregnancy-week-20-fetal-movement_square.jpg,qwidth=384.pages peed.ce.8mkE_5jDt_.jpg 5M •Limbs growth •Mother feels fetal movements •Vernix caseosa, lanugo •Short hairs and eyelashes •Fetus reacts to sound and later to light •Lungs start to produce surfactant •Limit of viability • • 160-200mm, 500-600 g https://www.babycenter.com/ims/2015/01/pregnancy-week-25-baby-fat_square.jpg,qwidth=384.pagespeed.c e.e7QTnsZ1zJ.jpg •Eyelids open •Wrinkled skin with visible capillaries •Subcutaneous fat •Hairs grow •Maturing of organ systems 300mm, 800-900 g 6-7M https://www.babycenter.com/ims/2015/01/pregnancy-week-38-eye-color_square.jpg,qwidth=384.pagespeed. ce.CWfjb4GQX6.jpg 8-9M •Subcutaneous fat accumulates in limbs •Smooth, red skin •Hallmarks of full term fetus • • • 400mm, 2000g FETAL DEVELOPMENT Výsledek obrázku pro fetus viability 24 week Major: •length (50 – 51 cm), •weight (around 3500 g, physiological range 2500 - 4000g), •head sizes •boys - testes in scrotum, girls - labia majora over labia minora Minor: •eutrophic fetus, subcutaneous fat •skin is not blue (no cyanosis), lanugo remains on shoulders and back, •eyelashes, hairs several cm long, nails over fingertips •cranial bones hard, anterior and posterior fontanelle are palpable, and separated •newborn cries and moves (Apgar score) HALLMARKS OF FETAL MATURITY Full term – related to length of pregnancy (menstrual age) •preterm (<37 weeks) •full term (38 – 40 weeks) •after term (>42 weeks) (meconium in amniotic fluid) Fetal maturity – development of fetus: mature X immature LENGTH OF PREGNANCY ´ FETAL MATURITY FULLTERM NEWBORN Diameter bitemporalis – 8,00 cm (join of the most distant points on sutura coronaria) Diameter biparietalis – 9,5 cm (join of midpoints of tubera parietalia) Diameter bitemporalis Diameter biparietalis HEAD SIZE FULLTERM NEWBORN Oblique sizes: •Diameter frontooccipitalis – 12.0 cm (join of forehead midpoint and most distant point of occiput) •Circumferentia frontooccipitalis – 34.0 cm •Diameter suboccipitobregmatica – 9.5 cm (join of protuberantia occipitalis externa and midpoint of large fontanelle) •Circumferentia suboccipitobregmatica – 32.0 cm •Diameter mentooccipitalis – 13.5 cm (join of chin midpoint and most distant point of occiput) •circumferentia mentoocipitalis – 35 - 36 cm •Diameter biacromialis – 12.0 cm, circumferentia biacromialis – 35 cm •(join of acromion – acromion) Diameter frontooccipitalis Diameter suboccipitobregmatica Diameter mentoooccipitalis HEAD SIZE FULLTERM NEWBORN RELATIONSHIP BETWEEN AGE AND LENGTH OF FETUS RULE OF HASSE RULE OF HASSE •forensic medicne 3. – 5. lunar month: length in cm = square of month 6. – 10. lunar month: length in cm = months multiplied by 5 Lunar month Length of fetus[cm] 3 9 4 16 5 25 6 30 7 35 8 40 9 45 10 50 1. LIE (SITUS) = relationship of the long axis of the fetus to that of the mother •longitudinal: (99 %) •transverse: (1 %) perpendicular axes • oblique: unstable ® longitudinal or transverse position 2. POSITION (POSITIO) = fetal backbone relative to uterus ridge • first= left (back to the left) • second= right (back to the right) • first/second common/less common 3. FETAL HABITUS (HABITUS) = relationship of one fetal part to another • regular = head and limbs in flexion • irregular = everything else • 4. PRESENTATION (PRAESENTATIO) = that part of the fetus lying over the pelvic inlet; the presenting body part of the fetus. • occiput (most common) • vertex, forehead, face (1%) • breech • trunk, shoulder FETUS IN UTERUS 1. LIE (SITUS) = relationship of the long axis of the fetus to that of the mother •longitudinal: (99 %) •transverse: (1 %) perpendicular axes • oblique: unstable ® longitudinal or transverse position FETUS IN UTERUS longitudinal - occiput longitudinal - breech transverse oblique 2. POSITION (POSITIO) = fetal backbone relative to uterus ridge • first= left (back to the left) • second= right (back to the right) • first/second common/less common • tranverse FETUS IN UTERUS Position of the uterus Note: Normally uterus is in anteversion and anteflexion (rarely retroversion, retroflexion) In late pregnancy, uterus is in dextroversion and dextrotorsion (rarely sinistroversion, sinistrotorsion) Výsledek obrázku pro position of fetus POSITION OF FETUS 1. LESS COMMON 2. COMMON 2. LESS COMMON 1. COMMON dextroversion dextrotorsion dextroversion dextrotorsion sinistroversion sinistrotorsion sinistroversion sinistrotorsion POSITION OF FETUS 3. FETAL HABITUS (HABITUS) = relationship of one fetal part to another • regular = head and limbs in flexion • irregular = everything else • FETUS IN UTERUS regular HABITUS irregular (any other) HABITUS AND PRESENTATION vertex forehead face occiput PRESENTATION 4. PRESENTATION (PRAESENTATIO) = that part of the fetus lying over the pelvic inlet; the presenting body part of the fetus. • occiput (most common) • vertex, forehead, face (1%) • breech • trunk, shoulder PHYSIOLOGICAL IMPOSITION OF FETUS IN UTERUS http://www.med.muni.cz/histology/MedAtlas_2/img_low/HP_obr6-1.jpg •LIE LONGITUDINAL - HEAD FIRST •POSITION FIRST COMMON •HABITUS REGULAR •PRESENTATION - OCCIPUT INTRODUCTION TO TERATOLOGY •Congenital disorders – due to abnormal developmental events •Genetic (inherited) or nongenetic (external) causes •Teratogens • •Life style (alcohol, smoking, drugs) •Infections (rubeola, HIV, toxoplasmosis) •Lack or abundance of key substances (folic acid ´ retinoids) •Chronic diseases (medical treatment) •Physical (temperature, radiation) A Teratogen Is….” Campaign from Yukon | Girls, Women, Alcohol, and Pregnancy INTRODUCTION TO TERATOLOGY Výsledek obrázku pro embryonic periods of sensitivity Critical developmental periods INTRODUCTION TO PRENATAL DIAGNOSTICS •Genetic counselling •Biochemical and ultrasound screening •Karyotyping and DNA diagnostics •Clinical diagnostics •Revealing high risk pregnancies, access to preventive and therapeutic care •Preventing delivery of fetuses with severe congenital malformations •Support of delivery of genetically high-risk babies •Planning and providing clinical care •Interdisciplinary care – biochemistry, genetics, gynecology and obstetrics, neonatology – parts of fetal medicine •Indication: -congenital disorders in family -positive screening in 1st or 2nd trimester -abnormal finding by ultrasound -maternal age (over 35 years) ČR 1994-2008 GENETIC COUNSELING •Anamnesis (case history) •Preconception counselling •Explaining of examination results, causes, clinical symptoms, therapeutic options •Minimization of risk of repeated disease •Providing diagnosis and information for free choice •Providing precise diagnosis and risk estimation •Providing care during pregnancy and later Výsledek obrázku pro genetický rodokmen •NONDIRECTIVE •ALL EXAMINATIONS AND PROCEDURES ARE VOLUNTARY Výsledek obrázku pro pedigree symbols BIOCHEMICAL SCREENING •Non invasive -Revealing high risk pregnancies – chromosomal aberrations and clefts -Screening is not a diagnostics ® further examinations (amniocentesis, karyotype, US) • •Tests between weeks 14-16 („TRIPLE test“) -low sensitivity and specificity (50-60%), high false positivity (70%) -AFP, E3, hCG -chromosomal aberrations, abnormal closing of neural tube, defects of body walls - •Combined screening in week 11-13 -chromosomal aberrations – Down: 47,XY,+21, Edwards: 47,XY,+18, Patau 47,XY,+18 -US –nuchal translucence, NT -PAPP-A, hCG (multiplies of median, MoM) -age included in algorithm -output: screening positive vs. negative (limit 1:100) Výsledek obrázku pro nuchal translucency down syndrome INVASIVE DIAGNOSTICS •Amniocentesis -16th-20th week -US controlled amniotic fluid aspiration -Cell culture, karyotype -Risk of miscarriage 0.5-1% •Chorion villus biopsy -10th-13th week -Karyotype, molecular genetic examination -Risk 0.5-1% - •Cordocentesis -22nd week -Sampling of venous umbilical blood -Now diagnostics and therapy of blood diseases (anemia, infections), or diagnostics in multiple pregnancies -Risk 1% - •Fetoscopy -Transabdominally (earlier transcervically) -Visualization and fetal biopsy -Risk 3-10%, done rarely Výsledek obrázku pro karyotyp down https://upload.wikimedia.org/wikipedia/commons/3/35/Sky_spectral_karyotype.png ULTRASOUND DIAGNOSTICS •6-8th week -confirmation of pregnancy, heart action -number of fetuses •13-14th week -nuchal translucence (risk > 3 mm) -nasal bone (present ´ absent), minor markers (omphalocele, tricuspidal regurgitation, abnormality in ductus venosus flow, enlargement of urinary bladder-megavesica) -fetal size - •20-22nd week -detailed screening -fetal biometry (biparietal diameter, head circumference, length of femur) -head and CNS (shape, cavity in septum pellucidum, ventricles, cerebellum, cisterna magna), face (lip, jaws, nose, orbits, profile), heart (action, size, axis, 4-chamber projection, outflow tracts, ...), thorax (pathological structures), abdominal cavity (stomach, intestine, kidneys, urinary bladder, umbilicus and umbilical vessels), backbone, limbs, palms, feet -placenta, volume of amniotic fluid - •30th week -fetal size -volume of amniotic fluid -placenta (exclusion of placenta praevia) ADVANCEMENTS IN MOLECULAR GENETICS •Analysis of cell-free fetal DNA in maternal blood •Since 12th week •Massive paralell sequencing (Next-Gen Sequencing) •Common aneuploidies (trisomy 21,13,18) •Monogeneous disorders • Questions and comments pvanhara@med.muni.cz http://www.med.muni.cz/histology Thank you for attention