Fetal Development Flashcards
Babies with Fetal Growth Restriction are more likely to suffer
- Intrauterine Hypoxia/Asphyxia
- Stillborn
- Hypoxic Encephalopathy
- Neonatal multi-organ failure
- Hypothermia
- Hypoglycemia
- Infection
- Cerebral Palsy
- Enterocolitis
Low birthweight infants are more likely to develop
Hypertension
CVS diseases
Diabetes
Fetal Determinants of Fetal Birthweight
Genetic: chromosomal defects (c.13 Pateaus sign) (c.18 Edwards Syndrome) Trisomy 21 (Down Syndrome)
Example sentence: Trisomy 21 is also known as Down Syndrome.
Placental Determinants of fetal birthweight
Placental infarction (due to chronic hypertension)
Premature Separation
Maternal Determinants of Fetal Birthweight
Physiological: (age, weight, parity, ethnicity)
Behavioural (smoke, alcohol, drugs)
Pathological (Chronic hypertension, Cardiac diseases, Cystic fibrosis)
Carries oxygenated blood from placenta
Umbilical Vein
Connection between Umbilical Vein and Inferior Vena Cava
Ductus Venosus
Passage through which blood passes from right atrium to left atrium
Foramen Ovale
How blood flows through foramen ovale
Blood passes from IVC into RA , into RV then to pulmunary artery to lungs.
Alveoli in lungs are filled with fluid and put pressure on arterioles causing vasoconstriction.
Vasoconstriction= Increased Resistance in lungs which leads to increased pressure in pulmonary artery => increased pressure in RV => Increased Pressure in RA => forces blood through foramen ovale
Passage between Pulmonary artery and Aorta
Ductus Arteriosus
How blood flows from fetal heart to placenta
Blood from LA => LV => Aorta => Iliac Arteries => Umbilical Artery => Placenta
Lungs appear @
3-4 wks
Epitheleal tubes and vascular formation in lungs appear @
4-7 wks
Airway tree + vascularity well developed in lungs @
20wks
Surfactant production begins
30 wks
Alveolar formation, surfactant formation, dilation of areas related to gas exchange
30 wks - term
Closure of foramen ovale due to
Increase pressure in left atrium
Function of surfactant in lungs
Prevents collapse of lungs
Components of Lung Surfactant
80% Lecithin
20% Protein
Premature Delivery before proper maturation of surfactant
respiratory Distress syndrome
Symptoms of Resp Distress Syndrome
Tachypnea
Cyanosis
Complications of Resp Distress Syndrome
Hypoxia
Asphyxia
Enterocolitis
Intraventricular Haemorage
Causes of Resp. Failure @ Birth
Resp. Distress Syndrome
Oligohydraminos
Pulmonary Hypoplasia
Decreased Intrathoracic Space
Chest Wall Deformities
Primitive Gut is formed @
4 wks
Increase in Liver size, elongation of intestines, midgut herniates into umbilical cord @
5-6 wks
Midgut reenters abdominal cavity
12 wks
Failure of midgut to reenter abdominal cavity
omphalocele
Obstruction preventing fetus from swallowing amniotic fluid leads to
Polyhydraminos
Malrotation of gut leads to
Atresia or fistulas
Peristalsis begins @
2nd Trimester
Meconium released in utero may lead to
post term pregnancy
fetal hypoxia
Aspiration of Meconium may cause
Resp. Distress Syndrome
Meconium Aspiration Syndrome
Lymphocytes appear from
8wks
All phagocytic cells appear at
2nd Trimester
Why do some preterm infants get hyperbilirubinemia
Liver is deficient in conjucating enzymes. In utero, placenta deals with unconjucated bilirubin. Preterm baby= no placenta and liver deficient in conjucating enzymes => hyperbilirubinemia
Growth Restricted Fetus and Premature babies are prone to neonatal hypoglycemia because
Less glycogen stores
Amnion meets inner surface of chorion, adhere but dont fuse
12 wks
Function of Amniotic Fluid
Protects Fetus
Allows movement of fetus
Prevents adhesion of fetus to amnion
Permits fetal lung development
Oligohydraminos caused by
renal agenisis
cystic kidney
Growth restricted fetus
Polyhydraminos caused by
Anacephaly
Esophageal/Duedonal Atresia
Cause of neonatal hypoglycemia
Less glycogen stores
Example sentence: Infants born to mothers with poorly controlled diabetes may be at risk for neonatal hypoglycemia.
Amnion and chorion relationship at 12 weeks
Amnion meets inner surface of chorion, adhere but don’t fuse
Example sentence: The amnion and chorion form important protective layers around the developing fetus.
Function of Amniotic Fluid
Protects Fetus
Allows movement of fetus
Prevents adhesion of fetus to amnion
Permits fetal lung development
Additional information: Amniotic fluid also helps maintain a stable temperature for the fetus.
Causes of Oligohydramnios
Renal agenesis
cystic kidney
Growth restricted fetus
Additional information: Oligohydramnios is associated with an increased risk of fetal complications.
Causes of Polyhydramnios
Anacephaly
Esophageal/Duodenal Atresia
Example sentence: Polyhydramnios may indicate a structural abnormality in the fetus.
