Download - Physiology in Pregnancy lecture
Definition of fertilazation
Fertilization is defined as the course of combination of the oocyte and sperm
It onset 12h after ovulation usually in ampulla of the oviduct(fallopian tube)
Definition of pregnancy
Pregnancy is defined as the course of embryo and fetal growth and development in uterine
It begin at the fertilization and end the delivery of the fetal and it’s attachment
Normal Pregnancy
Pregnancy The course that the embryo and the
fetus grow in the maternal body Stages of pregnancy1. Early pregnancy: ≤12 weeks2. Mid pregnancy: ≥13 weeks,≤27 weeks 3. Late pregnancy:≥28 weeks4. Term pregnancy:≥37 weeks,<42
weeks
Formation of Embryo
Fertilization1. Place: oviduct (ampulla)2. Process capacitation → acrosome
reaction→ penetrate the zona pellucida→ second meiosis →zygote
Formation of Embryo
Implantation1. requirement1) Disappear of zona pellucida
2) Formation of syncytiotrophoblast3) Synchronized development of
blastocyst and endometrium4) Adequate progesterone
Formation of Embryo
2. Process1) morula (day 3) → enter uterine
cavity (day 4) → early blastocyst→ late blastocyst (day 6-7) → implantation
2) location→ adherence→ penetration
Development of embryo and fetus
Definition1. embryo: ≤ 8 weeks2. Fetus: ≥ 9 weeks, human shape
Development of embryo and fetus
Physiology of fetus1. Circulation1) fetus ←→placenta←→ mater2) 1 umbilical vein (full of oxygen), 2
umbilical artery (lack of oxygen)3) Mixed blood (vein and artery)
Development of embryo and fetus
Development of embryo and fetus
2. Hematology1) ErythropoiesisFrom yolk sac: 3 weeksFrom liver: 10 weeksFrom bone marrow and spleen: term
(90%)EPO production: 32nd week
Development of embryo and fetus
2) Fetal hemoglobinFetal hemoglobin: early pregnancyAdult hemoglobin: 32nd weekTerm: fetal type Hb 25%3) White cellsLeukocytes: 8 weekLymphocytes (antibody production): 12
week, thymus and spleen
Development of embryo and fetus
3. Gastrointestinal tract1) drink amniotic fluid: 4th month2) no proteolytic activity3) enzymatic deficiencies in liver: bilirubin is not easy to be clear.
Development of embryo and fetus
4. Kidney Its function begins at 11-14th week5) Endocrinology6) Fetal thyroid: the first endocrine gland
(6th week), synthesize thyroxine at 12th week
7) Fetal adrenal cortex: widen (20th week), a fetal zone. synthesize steroid hormones (E3, liver placenta mater)
Placenta
Structure1. Primary villus syncytiotrophoblast cytotrophoblast2. Secondary villus3. third class vilusfetal capillary enter the stroma
Structure of placenta
Round Weight:450-650g Diameter:16-20cm Thickness:1-3cm thick in center and thin in margin
Placenta
Function1. metabolism1) Exchange of O2 and CO2
2) Exchange of nutritive factors and waste
2. DefensiveLimited. IgG, virus, drug
Placenta
3. Endocrine1) HCG2) HPL3) E4) P5) Oxytocinase6) Cytokines and Growth Factors4. Immunity tolerance
Fetal membranes
Structure chorion and amnion Amnion A double-layered translucent
membrane Become distended with fluid
Umbilical Cord
Structure amnion, yolk sac, one vein, two
artery and Wharton jelly Length 30-70cm
Amniotic fluid
Source1. exudation of fetal membranes
(early pregnancy)2. Fetal urine3. Fetal lung4. Exudation of amnion and fetal skin
Volume of amniotic fluid 8 weeks:5-10ml
10 weeks:30ml
20 weeks:400ml
38 weeks:1000ml
Amniotic fluid
Absorb1. Fetal membrane2. Umbilical cord3. Fetal skin4. Fetal drinking Feature1000-1500ml at 36th-38th week (peak),
transparent → slightly turbid
Amniotic fluid
Function1. Protect fetal move freely, warm2. Protect mater prevent infection
Maternal changes during pregnancy
The maternal system may produce a series of changes in order to adapt to the needing of fetal growth and development influenceed by placenta hormone and neuro-endocrine
Physiologic changes in pregnant woman
Genital organs1. Uterus1) capacity: 5ml-5000ml.weight: 50g-
1000g2) Hypertrophy of muscle cells3) Endometrium→decidua: basal decidua,
capsular decidua, true decidua4) Contraction: Braxton Hicks5) Isthmus uteri: 1cm→ 7-10cm
Physiologic changes in pregnant woman
6) Cervix: colored7) Ovary: placenta replaces ovary (10th
week)8) Vagina: dilated and soft, pH↓(anti-
bacteri bacteria)9) Ligaments: relaxed
Physiologic changes in pregnant woman
Cardiovascular system1. Heart: move upward, hypertrophy of cardiac
muscle2. Cardiac Output increase by 30%, reach to peak at
32nd –34th week3. Blood pressure early or mid pregnancy Bp↓.late
pregnancy Bp↑ .Supine hypotensive syndrome
Physiologic changes in pregnant woman
Hematology1. Blood volume1) Increase by 30%-45% at 32nd –34th (peak)2) Relatively diluted2. Composition1) Red cells Hb:130→110g/L, HCT:38%→ 31%.2) White cells: slightly increase3) Coagulating power of blood: ↑ 4) Albumin: ↓,35 g/L
Physiologic changes in pregnant woman
The Respiratory system1. R rate: slightly ↑2. vital capacity: no change3. Tidal volume: ↑ 40%4. Functional residual capacity:↓ 5. O2 consumption: ↑ 20%
Physiologic changes in pregnant woman
The urinary system1. Kidney1) Renal plasma flow (RFP):↑35%2) Glomerular filtration rate (GFR):↑ 50%2. Ureter Dilated (P↑)3. Bladder Frequent micturation
Physiologic changes in pregnant woman
Gastrointestinal system1) Gastric emptying time is
prolonged→ nausea. 2) The motility of large bowel is
diminished → constipation3) Liver function: unchanged
Physiologic changes in pregnant woman
Endocrine1. Pituitary (hypertrophy)1) LH/FSH: ↓2) PRL:↑3) TSH and ACTH:↑2. Thyroid1) enlarged (TSH and HCG↑)2) thyroxine↑ and TBG↑ → free T3 T4
unchanged
Metabolism
Basal metabolism rate, BMR +15-20% Weight gain 12.5 Fetus 3400 g Placenta 650 g Amniotic 800 g Uterus 960 g Plasma, red cells 1450 g Mammary glands 405 g Extracellular, extravascular water 1480 g Deposition of fat and protein 3345 g Insulin resistance
Weight Gain in Pregnancy - Physiology 27.5 lbs (12.5 kg) is “normal”
physiologic gain (Hytten 1991) 9 kg (~20 lbs) is made up of fetus,
placenta, amniotic fluid, uterine/breast hypertrophy, increased blood volume and retained fluid
3.5 kg (7.5 lbs) is maternal storage fat