Fetal and Neonatal Physiology Flashcards
Gestational age
Day 1 is last day of normal menstrual period
Fertilization age (aka embryonic age or fetal age)
Day 1 is fertilization
How do you calculate gestational age using fertilization age?
Gestational age = fertilization age + 2 weeks
Prenatal hematopoeisis takes place primarily in the _____ from fetal months 1-3
Yolk sac
[considered primitive erythropoiesis]
Prenatal hematopoeisis takes place primarily in the _____ from fetal months 3-7
Liver
Prenatal hematopoeisis takes place primarily in the _____ from fetal months 7-birth
Bone marrow
After ____ weeks gestation, hematopoietic progenitors are no longer detected in the yolk sac
7
The _____ serves as the primary source of red cells from the 9th to the 24th week of gestation
Liver
Liver is primary site of _____ transcription throughout fetal life
The _______ production of this factor increases throughout fetal life
EPO; kidney
________ becomes the major site of hematopoiesis after the 24th week of gestation and remains so throughout the remainder of fetal life
Bone marrow
Major hemoglobin of fetal life
HbF (alpha2gamma2)
[contrast with adult HbA (alpha2beta2)]
Normal adult levels of ____ are achieved by ~12 weeks of life (full term)
HbA2
Hyperbilirubinemia during first 2 weeks of life (full term) = ______ jaundice
Physiological
The mean hemoglobin level in cord blood at term is 16.8 g/dL, with 95% of the values falling between 13.7 and 20.1 g/dL
What accounts for this variation?
This variation reflects perinatal events, particularly asphyxia and also the amount of blood transferred from the placenta to the infant after delivery
What iatrogenic cause appears to heighten the occurrence of anemia at 2 months and to impair cardiopulmonary adaptation
Early cord clamping
[delay of cord clamping may increase the blood volume and red cell mass of the infant by as much as 55%, resulting in fewer transfusions and fewer days requiring oxygen and ventilation in preterm infants]
The serum ____ level in cord blood of the normal infant is elevated compared to normal levels
Iron
[the mean serum ferritin levels in iron-sufficient infants are high at birth, 160 mcg/L, rise further during the first month, and then fall toa mean of 30 mcg/L by 1 year of age]
Describe the amount of iron in the marrow at birth and how this changes up to 6 months of age
The amount of iron in marrow at birth is small but increases in both term and premature infants during the first weeks after birth
Marrow iron begins to decrease after 2 months and is gone by 4-6 months in term infants and earlier in premature infants
Iron is preferentially allocated to ________ if the availability of iron is limited
Erythropoisis
When does nephrogenesis occur and when is it completed
Begins at 8 wks getation and completed ~36 weeks
When does fetal urine production begin?
Begins as early as 10 weeks through 20 weeks gestation
________ accounts for 70-80% of amniotic fluid
Fetal urine
During what trimester of pregnancy does renal function mature rapidly? When does functional development complete?
3rd trimester — resulting in body fluid balance, acid-base balance, and electrolyte balance
Functional development completes closer to 1 month of age
Describe the fetal liver handling of bilirubin, plasma proteins and coagulation factors, and gluconeogenesis
Poor conjugation of bilirubin
Deficiency in forming plasma proteins and coagulation factors
Deficient gluconeogenesis (blood glucose levels the 1st day could be as low as 30-40 mg/dL of plasma)
Since the fetal liver has lacking gluconeogenesis ability, what does the infant use for metabolism?
Stored fats and proteins until mother’s milk can be provided
Since the neonate is in a stage of rapid ossification of its bones at birth, a ready supply of _____ throughout infancy is necessary
Normally the adequate amount can be supplied by the usual diet of ________
Calcium
Milk
Absorption of calcium by the GI tract is poor in the absence of ______
_____ can develop in infants who have this deficiency
Vitamin D
Rickets
The fetus has distinct goals in terms of Ca, Phosphorus, and bone homeostasis regulation. What are they
Fetus must actively pump calcium, phosphorus, and magnesium from maternal circulation against concentration gradients, maintain serum mineral concentrations at higher levels than in maternal circulation, rapidly mineralize the skeleton during the final quarter of gestation, and achieve overall positive mineral balance
The infant’s _____ has stored enough iron to keep forming blood for ____ months after birth — provided that the mother has provided adequate iron in her diet during pregnancy
Liver; 6
Describe iron content of breast milk vs. infant formula
Iron content is low, but bioavailability is high
Studies show that infants exclusively breastfed for first 6 months of life have normal iron status at 6 months, provided mother has adequate iron status
Iron content of infant formula is high because bioavailability is lower than breastmilk
If the mother has iron insufficiency in her diet, _______ is likely to occur in infant after 3 months of life
Severe anemia
What vitamin, necessary for appropriate formation of intercellular substances, especially the bone matrix and fibers of CT, is not stored in significant quantities in fetal tissues but can be provided by breastmilk?
Vitamin C
T/F: the neonate does not form antibodies of its own to a significant extend, requiring dependence on mother
True
By the end of ____ month, there is a decrease in the baby’s gamma globulins (contain the antibodies)
1st
The baby’s own immune system begins to form Abs and gamma globulin concentration returns to normal by the age of _____
12-20 mos
Antibodies inherited from the mother protect the infant for about ____ months against most major diseases.
However, inherited antibodies against ________ are normally insufficient to protect the neonate - so they require immunization against this illness within the ~1st month of life
6
Whooping cough
T/F: other than whooping cough, immunization against most other diseases is usually not necessary before 6 months of age
True
Since most maternal-fetal iron transfer occurs in the 3rd trimester, low birth weight pre-term infants are at higher risk of what condition?
Iron-deficient anemia
Respiratory consequences of preterm birth
Respiration is usually underdeveloped; respiratory distress syndrome is common cause of death