Lecture 13 - Fetal Growth And Development Flashcards
What is the time period of the fetal period?
From 9 weeks onwards
What is the function of/what occurs in the fetal period?
Growth and weight gain due to structures developed in the embryonic period maturing
What is the main function of the embryonic period?
When the organs develop and theres some growth
What is the main process taking place in Stage 1 of growth?
(First trimester)
Hyperplasia
Rapid mitosis increasing DNA content
What is the main process taking place in Stage 2 of growth?
(Second trimester)
Hyperplasia and Hypertrophy
Mitosis starts decreasing but size starts to increase
What is the main process taking place in Stage 3 of growth?
(Third trimester)
Hypertrophy
Rapid increase in size, weight and muscle growth
How can you date a pregnancy?
Date of Last Menstrual Period
Fetal movements (start at 20 weeks)
Symphysis-fundal height
Ultrasound
What is symphysis fundal height?
The distance between the fundus of the uterus and the pubic bone
What is the significance of the symphysis fundal height in dating a pregnancy?
Normally it’s size in cm is equal to the number of weeks in the pregnancy + or - 2cm
So a 28wk old pregnancy should be 28cm +or- 2cm
What weeks are ultrasounds normally done?
12wk
20wk
What is the purpose of the 12wk ultrasound scan?
Date pregancy (gestational age)
Multiple pregnancy
Chromosomal abnormalities (Down syndrome)
What is the purpose of the 20wk ultrasound scan?
The anomaly scan
Screening for Fetal abnormalities
Placental location
Size of baby
What is crown rump length?
What is its use?
The distanc from the top of the foetuses head along its back to the rump
Can date a pregnancy
Between what weeks can crown rump length be used to date a pregancy?
7-13 weeks
What other measurements can be taken to date a pregnancy in the 2nd or 3rd trimester (late stage pregancy)?
Biparietal diameter (distance between parietal bones)
Abdominal circumference
Femur length
What is the average birth weight?
3.5kg
What is macrosomia?
Large baby at birth
Weight > 4kg
What is considered low birth weight, very low birth weight and extremely low birth weight?
Low < 2.5kg
Very low 1 - 1.5kg
Extremely low <1kg
Why is important to accurately date pregnancy?
To determine whether a baby is premature or whether they’ve suffered and growth restrictions
To help determine the reason for them being low weight
What are the 2 different types of Intrauterine Growth Restriction?
Symmetrical
Asymmetrical
What is the difference between symmetrical and asymmetrical Intrauterine growth restriction?
The timing at which the thing causing the growth restriciton occurs
What is symmetrical Intrauterine Growth restriction?
When does it occur?
When all the measurements of the baby are all proportionally reduced (abdominal circumference, biparietal diameter and femur length)
Occurs early on
What can cause symmetrical intrauterine growth restriction?
Genetic Disorders
TORCH infections