normal foetal growth

Question 1

how is foetal growth information obtained

Answer 1

miscarriage samples

Question 2

when is foetal growth invariable

Answer 2

up to 16 weeks of gestation, with majority of growth and weight gain in second and third trimester

Question 3

define foetal growth

Answer 3

increase in mass that occurs
between the end of embryonic period
and birth

Question 4

2 components of foetal growth

Answer 4

genetic potential, substrate supply

Question 5

what is genetic potential derived from and mediated through

Answer 5

derived from both parents, mediated through growth factors e.g. insulin like growth factors

Question 6

where is substrate supply derived from

Answer 6

placenta (dependent on both uterine and placental vascularity)

Question 7

3 phases of normal foetal growth

Answer 7

cellular hyperplasia (weeks 4-20) -> hyperplasia and hypertrophy (20-28 weeks) -> hypertrophy alone (28-40 weeks)

Question 8

foetal organ growth between 24-40 weeks

Answer 8

brain and liver increase rapidly before slowing down after week 28, heart and kidney remain consistent

Question 9

weight gain during foetal growth

Answer 9

weight gain rate increases until over 34 weeks, where it slows

Question 10

techiques for measuring foetal growth

Answer 10

abdominal palpation, symphysis fundal height (tape measure from symphysis pubis to top of uterus), obstetric ultrasound

Question 11

4 reasons for smaller symphysis fundal height

Answer 11

wrong dates, small for gestational age, oligohydramnios, transverse lie

Question 12

7 reasons for larger symphysis fundal height

Answer 12

wrong dates, molar pregnancy

multiple gestation, large for gestational age, polyhydramnios, maternal obesity, fibroids

Question 13

2 advantages of symphysis fundal height

Answer 13

simple, inexpensive

Question 14

3 disadvantages of symphysis fundal height

Answer 14

low detection rate, great inter-operator variability, influenced by number of factors (e.g. BMI)

Question 15

why is dating by LMP inaccurate

Answer 15

irregular periods, abnormal bleeding, oral contraceptives, breastfeeding

Question 16

3 importance of correct dating

Answer 16

SGA or LGA confusion, iInappropriate inductions, steroids in preterm delivery

Question 17

how should all pregnancies (except IVF) be dated

Answer 17

CRL (crown-rump length)

Question 18

if first scan done after 14 weeks, how is pregnancy dated

Answer 18

HC (CRL >84mm)

Question 19

4 biometrical parameters by which foetal growth is assessed by ultrasound

Answer 19

BDP, HC, AC, FL and combination (EFW)

Question 20

what are normal growth curves constructed from

Answer 20

ultrasound measurements expressed in centiles

Question 21

what are normal growth factors used clinically to identify

Answer 21

normal intrauterine growth and detect risk of obstetric and neonatal complications

Question 22

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Question 29

maternal factors influencing foetal growth

Answer 29

poverty, age, drug use, weight, disease, smoking, alcohol, diet, prenatal depression, environmental toxins

Question 30

feto-placental factors affecting foetal growth

Answer 30

genotype (genetic potential), gender (male > female), hormones, previous pregnancy