SMALL BABIES Flashcards
outline how the rate of normal foetal growth changes throughout pregnancy?
growth is very slow in the embryonic period and in the foetal period this speeds up
what causes the weight gain in the early and late foetal stages?
in the early foetal stage the weight gain is due to protein deposition and in the late foetal stage it is due to adipose deposition
what is the Crown Rump length?
the length of the embryo/foetus from the top of its head to the bottom of its torso
outline how the body proportions change during the foetal period?
by week 9 the head is approximately half the crown-rump length and then body length and lower limb growth accelerates
what factors should you consider when calculating the optimal weight for a newborn?
gestational age, foetal gender, parity, maternal weight, maternal height, ethnic group and altitude
how does altitude affect the size of the newborn?
at higher altitudes there is lower pO2 so the baby will tend to be smaller
why do babies lose weight after birth?
when should they have regained weight by?
physiological weight loss due to fluid reduction
they should be back at their birth weight within 2 weeks
insulin-like growth factors 1 and 2 mainly
at what weight do we consider the baby to have growth restrictions?
<2500g
at what weight do we consider the baby macrosomia?
> 3500g
what is the crown-rump length for?
a primary measure of gestational age between 6-13 weeks. After 13 weeks it become more useful measurements for assessing fetal growth.
what is used to date pregnancies after 13 weeks?
head and abdominal circumferences
what is an umbilical arterial doppler ultrasound used for?
surveillance of fetal well-being in the third trimester of pregnancy
what does abnormal umbilical arterial doppler ultrasound findings mean?
placental insufficiency, marker of IUGR, suspected pre-eclampsia
what is intrauterine growth restriction?
a baby <10th percentile of birth weight for its gestational age
what is symmetrical IUGR?
where all fetal biometric parameters tend to be less than expected for the given gestational age.
what is asymmetrical IUGR?
where some fetal biometric parameters are disproportionately lower than others, as well as falling under the 10th percentile. The parameter classically affected is the abdominal circumference because growth is head sparing
what causes you to get either asymmetrical or symmetrical IUGR?
if a risk factor for IUGR occurs in the early pregnancy when growth is driven by hyperplasia then it will have symmetrical impacts whereas if this risk factor occurs later in development, when growth is driven by hypertrophy, then we see asymmetrical IUGR
at what weeks is hyperplasia the dominant growth type? and hypertrophy/
hyperplas- 0-20 weeks
hypertrophy 28 weeks - term
what are some maternal risk factors for IUGR?
smoking, alcohol, anaemia, medical disease like CVD, poor nutritional status, pollution exposure
what are some foetal risk factors for IUGR?
structural abnormalities, chromosomal abnormalities, multiple gestations, in utero infections
what are some in-utero infections which can cause IUGR?
TORCHS toxoplasmosis rubella cytomegalovirus herpes syphilis
what are some placenta risk factors for IUGR?
abruptio placenta, placenta preva, thrombosis or infarction, vasculitis, cord abnormalities
what are some uterine risk factors for IUGR?
decrease uterine blood flow, pre-eclampsia, structural anomalies, atherosclerosis of uterine spiral arteries
