Foetal development Flashcards
When does fertilisation take place after the menstrual period?
2 weeks after the menstrual period
From when can the fetal heart beat be detected?
6 weeks gestation
At how many weeks of gestation is the developing organism a fetus?
10 weeks
Where does exchange of nutrients between the maternal blood and fetal blood take place in the placenta?
Intervillous space
What is a miscarriage?
Spontaneous loss of pregnancy before 24 weeks, which is when the baby reaches viability
What is an early pregnancy loss?
Pregnancy loss occurring within 6/7 weeks before fetal heart beat is identified.
Gestational sac is seen but no baby.
What causes an early pregnancy loss?
Chromosomal problem such as aneuploidy
What causes a late pregnancy loss?
Infection, antiphospholipid syndrome
What causes biochemical loss?
Implantation failure
What are the risk factors for miscarriage?
- gestational age - as the pregnancy progresses, the risk gets smaller
- chromosomal abnormality
- increasing maternal and paternal age
- previous miscarriage
- smoking, alcohol and excessive caffeine
- pre-pregnancy weight
What is a threatened miscarriage?
Miscarriage has not happened, patient is experiencing vaginal bleeding
What is an inevitable miscarriage?
Cervix has opened and the fetus does not remain in the uterus
What is an incomplete miscarriage?
Some parts of the fetus have miscarriaged
What is a complete miscarriage?
All parts of the fetus have miscarriaged.
What is an anembryonic miscarriage?
No fetal pole, just gestational sac
What is a missed miscarriage?
Fetus has developed but there is no fetal heart
When is the yolk sac seen within the gestational sac?
5 weeks
How can you distinguish a pseudo sac from a gestational sac?
A pseudo sac does not contain a yolk sac
Define recurrent miscarriage
Loss of three or more consecutive pregnancies
How does antiphospholipid antibody cause recurrent miscarriage?
Inhibits trophoblast function by causing thrombosis in the small vessels and complement activation
What is a hydatidiform mole?
Uncontrolled proliferation and invasion of trophoblast
