Multiple Pregnancies Flashcards
What is a multiple pregnancy?
- when you are expecting two or more babies at the same time
- twins, triplets etc…
What is perinatal?
- perinatal is time from pregnancy and up to 1 year following birth
What is perinatal mortality?
- death of a foetus or baby
- during time from birth through to 1 year old
Perinatal mortality refers to the death of a foetus or baby. Is perinatal mortality higher in individual or multiple pregnancy (twins etc..)?
- multiple pregnancy
What are dizygotic twins?
- di = two
- zygotic = formation of a zygote from 2 gametes
- pregnancy but with 2 separate embryos , so NOT identical
What are monozygotic twins?
- mono = one
- zygotic = formation of a zygote from 2 gametes
- one zygote splits into 2 separate groups of cell = can be IDENTICAL TWINS but not always
What are a number of risk factors for increase perinatal mortality in dizygotic twins?
- genetics (African decent)
- BMI
- maternal age
Is the risk of developing morbidities such as cerebral palsy higher in single pregnancy or multiple pregnancy n dizygotic twins?
- multiple pregnancy
What is a stillbirth?
- baby dies in the womb after 20 weeks
A stillbirth is when a baby dies in the womb after 20 weeks. Does the risk of stillbirth increase with the number of multiple pregnancy?
- increases as number of multiple pregnancy increases
- singleton 6-8/1000 births
- twins 37/1000
- triplets 52/1000
- > 3 pregnancy 231/1000
In a women with multiple pregnancy the risk of morbidities such as neurological disorders such as cerebral palsy increases as the number of pregnancies increases. What are the 2 main reasons identified for this increase in morbidities with multiple pregnancy?
1 - high BMI and lower birth weight
2 - high BMI and premature births
3 - lower birth weight and premature birth
4 - lower birth weight and low BMI
3 - lower birth weight and premature birth
What does zygosity refer to?
- the genetic make up of a pregnancy
- in twins, this can be mono or dizygotic
What does mono and dizygotic mean?
- mono = 1 egg and 1 sperm form a zygote which then splits into 2 separate groups of cells
- di = 2 eggs and 2 sperm form seperate zygotes
What does chorionicity refer to?
- the chroion is the double layer membrane (trophoblasts) that form the placenta
- chorionicity refers to the number of placenta that are present
Chorionicity refers to the number of placenta present during pregnancy. What do mono and di-chorionic refer to?
- monochorionic = 1 placenta is shared
- dichorionic = there are 2 separate placenta
What does amnionicity refer to?
- the amniotic sacs that a foetus develops within
Amnionicity refers to the amniotic sacs that a foetus develops within. What does mono and diamniotic refer to?
- monoamniotic = foetus share the same amniotic sac
- dioamnioitc = foetus have their own individual amniotic sacs
Dizygotic twins are where there are 2 separate eggs and each gets fertilised by a separate sperm, forming 2 separate zygotes. Which of the following are dizygotic twins able to become:
1 - dichorionic monoamniotic
2 - dichorionic diamniotic
3 - monochorionic monoamniotic
4 - monochorionic diamniotic
2 - dichorionic diamniotic
- everything is separate so there will be 2 of everything
In monozygotic pregnancies we need to be aware of the different types of chorionicity and amnionicity, such as:
- chorionicity = mono or dichorionic
- amnionicity = mono or diamniotic
In a monozygotic pregnancy (identical twins) what types chorionicity and amnionicity can monozygotic twins have?
- dichorionic-diamniotic = separate placenta and amniotic sac
- monochorionic-diamniotic = same placenta BUT separate amniotic sac
- monochorionic-monoamniotic = same placenta and same amniotic sac
In monozygotic pregnancies we need to be aware of the different types of chorionicity and amnionicity. Monozygotic twins can be the following:
- dichorionic-diamniotic = separate placenta and amniotic sac
- monochorionic-diamniotic = same placenta BUT separate amniotic sac
- monochorionic-monoamniotic = same placenta and same amniotic sac
What determines which forms of chorionicity and amnionicity monozygotic twins develop into?
- the timing of when the embryonic cells divide
In monozygotic pregnancies we need to be aware of the different types of chorionicity and amnionicity. Monozygotic twins can be the following:
- dichorionic-diamniotic = separate placenta and amniotic sac
- monochorionic-diamniotic = same placenta BUT separate amniotic sac
- monochorionic-monoamniotic = same placenta and same amniotic sac
The timing of when the embryonic cells divide determines which forms of chorionicity and amnionicity a monozygotic twins develop into. What are the time points for each of the options above where the cells of the embryo divide?
- dichorionic-diamniotic = 2-3 days
- monochorionic-diamniotic = 3-8 days
- monochorionic-monoamniotic = 8-13 days
In monozygotic pregnancies we need to be aware of the different types of chorionicity and amnionicity. Monozygotic twins can be the following:
- dichorionic-diamniotic = separate placenta and amniotic sac
- monochorionic-diamniotic = same placenta BUT separate amniotic sac
- monochorionic-monoamniotic = same placenta and same amniotic sac
The timing of when the embryonic cells divide determines which forms of chorionicity and amnionicity a monozygotic twins develop into. Generally the splitting occurs before 13 days for all 3 variations. However, if there is no splitting, what can this lead to?
- conjoined twins
In a diochorionic diamniotic pregnancy how many babies, placentas and amnionic sacs would be present?
1 - 1 baby, 2 placenta, 2 sacs
2 - 2 baby, 1 placenta, 2 sacs
3 - 2 baby, 2 placenta, 2 sacs
4 - 2 baby, 2 placenta, 1 sac
3 - 2 baby, 2 placenta, 2 sacs
In a monochorionic diamniotic pregnancy how many babies, placentas and amnionic sacs would be present?
1 - 1 baby, 2 placenta, 2 sacs
2 - 2 baby, 1 placenta, 2 sacs
3 - 2 baby, 2 placenta, 2 sacs
4 - 2 baby, 2 placenta, 1 sac
2 - 2 baby, 1 placenta, 2 sacs