THE FETAL ADNEXA ASSOCIATE PROFESSOR IOLANDA BLIDARU MD

THE FETAL ADNEXA ASSOCIATE PROFESSOR IOLANDA BLIDARU, MD, Ph. D 2/28/11

THE FETAL MEMBRANES (chorion and amnion) 2/28/11

THE FETAL MEMBRANES (chorion and amnion) The surrounding limit for fetal development in utero life. Two structures, from outside to inside: • chorion • amnion • separated by a spongy stratum. Fetal origin 2/28/11

THE FETAL MEMBRANES (chorion and amnion) • • The chorion and amnion develops up to approximately 28 weeks; after that, enlargement → by stretching. The chorio-amnionic membranes → dynamic and metabolically active barriers. 2/28/11

THE FETAL MEMBRANES 2/28/11

THE CHORION - between decidua (adherent) and amnion (detachable → spongy layer) - at the level of placenta - becomes the chorionic plate - fibrous, transparent - thickness – 0. 2 mm - structure: two layers (a lax fibroblast layer + a reticular layer) - amniochorial pouches

THE AMNION • • • transparent, thin very resistant membrane lines the fetal face of the placenta + the umbilical cord Structure - 2 layers: - basal membrane - the epithelial layer (internal, amnion cells → secretory role, transfer role); - the connective tissue layer (external, lax, with elastic and nervous fibres, blood, lymphatic vessels). 2/28/11

THE ROLE OF THE FETAL MEMBRANES take part in the maternal-fetal transfers; take part in PG synthesis - (chorion, amnion and decidua → deposits of arachidonic acid (AA) esterified, precursor of PG); initiate the delivery (clinical arguments: premature rupture of membranes, chorioamniotitis, amnioinfusion with hypertone solutions or AA - induce the onset of uterine contractions); create the condition for uterine closure, protect the fetus against infections.

2/28/11

THE AMNIONIC FLUID 2/28/11

THE AMNIONIC FLUID The volume - 20 ml (7 weeks); - 300 ml (20 weeks); - 1000 ml (30 weeks) - 600 -1000 ml at term • liquid in excess → 1000 -2000 ml • hydramnios > 2000 ml • oligohydramnios < 500 ml Aspect : opalescent, small particles. ph: 6. 9 – 7. 2 (alcaline).

THE AMNIONIC FLUID • The production - resorption relationships of the amnionic fluid creates a balance which maintains the volume of this fluid relatively constant. • Amniotic fluid is totally renewed in 3 hours and water exchanges in this process involves 10 -12 l/day. 2/28/11

THE AMNIONIC FLUID Composition • at the beginning of pregnancy → resembles the maternal / fetal serum - water (98%); - mineral elements - 0, 7% (natrium chloride, potassium, calcium, phosphorus); - organic elements – 0, 25% (glucose, urea, creatinine, lipids, E 3, HPL, STH, bilirubin, Ig, alpha FP, PG). 2/28/11

THE AMNIONIC FLUID Cytology - desquamated fetal cells; - lanugo; - epithelial cells from fetal urinary system / vaginal epithelium; - fragments of sebum (granular and whitish aspect) 2/28/11

THE AMNIONIC FLUID Investigations • Lecithin / sphingomyelin ratio → lung maturation. • E 3 and HPL levels → fetal well-being • Bilirubin → liver maturation. • • AFP levels → increased in CNS malformations, in the intrauterine death The study of cells → evaluation of the fetal age, sex and karyotype. 2/28/11

THE AMNIONIC FLUID Origin - Fetal - at the beginning of gestation → embryo-fetal extracellular fluid effusion - later → fetal kidney excretion (600 m. L/day), the lung and umbilical cord secretions. - Amnionic – epithelium + placenta - Maternal - diffusion at the level of the membranes. 2/28/11

THE AMNIONIC FLUID Resorbtion Mechanisms: - fetal deglutition (≈ 500 ml/24 hrs); - resorption through amniotic epithelium (active for water + carbohydrates); The forming fetal skin (the first half of pregnancy) → important participation in the amniotic fluid circulation, lost after the 22 nd week, epidermal keratinization → impermeable skin. 2/28/11

THE AMNIONIC FLUID Roles 1) fetal hydration and mineral element supply ; 2) fetal protection (trauma, infections temperature variations); 3) fetal growth, movements, intrauterine accomodation; 4) antibacterial (Ig G, lizozim); 5) the umbilical cord protection; 6) protective role for the pregnant woman → diminishing the perception of the fetal movements; 7) during labor → forming the water pouch. 2/28/11

THE UMBILICAL CORD 2/28/11

THE UMBILICAL CORD It links the fetus with the placenta (connective-vascular adnexa), covered by amnion; Length = 55 cm, diameter = 1, 5 cm. Form: tubular, twisted; Glossy whitish colour; Irregular surface.

THE UMBILICAL CORD The fetal insertion → the umbilicus. The other extremity → on the chorionic plate (centrally); Structure: - 2 umbilical arteries; - 1 umbilical vein; - Wharton jelly (connective tissue). 2/28/11