Multiple gestation Flashcards
what proportion of IVF pregnancies are multiple pregnancies?
24% of successful IVF procedures
what is zygosity?
describes whether twins are identical or non-identical
if have come from 1 zygote (hence 1 fertilised ovum), then twins are monozygous (identical)
if they have come from more than 1 zygote (so there are 2 or more fertilised ova), they are dizygous (non-identical)
RFs for dizygotic (non-identical) twins?
previous multiple gestation FH (maternal side) increasing maternal age racial origin-more common if west african ancestry assisted conception
what is chorionicity?
this describes the number of placentae in a multiple pregnancy
so all non-identical (dizygous) twins each have their own placenta (dichorionic). however, identical (monozygous) twins may have their own placenta or they may share a placenta (monochorionic). In those pregnancies where the placenta is shared, each twin may have their own amnion (diamniotic) or may also share their amnion (monoamniotic).
what is twin-twin transfusion syndrome?
this is a complication of twin pregnancies where the twins are monozygotic (identical), monochorionic-so share a placenta. the placenta has abnormal blood vessels, and it ends up that 1 twin gets all of the blood and nutrients, and that is associated with them producing too much fluid to surround them, whereas the other twin is deprived of the blood and nutrients it needs to grow, so it ends up very small, and with inadequate fluid around it to protect it from trauma, and to allow normal lung and limb development.
can also occur in monochorionic and dichorionic triplet pregnancies, where r/f to as feto-fetal transfusion syndrome.
twin pregnancies are associated with a higher risk of stillbirth-so your baby dying before or during brith after 24 weeks of pregnancy, and twin-twin transfusion syndrome is associated with 20% of stillbirths.
possible complications for baby in a multiple pregnancy?
- higher risk of stillbirth
- miscarriage
- higher risk of mum going into labour early, so baby at risk of prematurity and assoc. complications
- IUGR
- twin to twin transfusion syndrome, polyhydramnios, oligohydramnios
- malpresentation
- congenital malformations
- cerebral palsy
possible complications for mum in a multiple pregnancy?
- pre-eclampsia
- prelabour ruputure of membranes, and premature labour
- anaemia
- need for operative delivery
- more severe pregnancy symptoms e.g. N+V, hyperemesis gravidarum
- PPH, APH
- gestational diabetes
- placenta praevia
recommendations during pregnancy for women with multiple pregnancies?
- more frequent monitoring-regular US scans of baby, in addition to dating scan and fetal anomaly scan that all other women have. you will have scans at least every 4 weeks from 24 weeks (so 24, 28, 32, 36) to check on baby’s growth and amount of fluid surrounding baby.
- how many clinic visits you have will depend on how many babies you’re having, the type of twin pregnancy, and any complications that arise.
- recommended you take iron supplements to prevent anaemia and give you more energy.
- you may need to leave work earlier in you pregnancy due to you getting tired more easily and becoming uncomfortable more quickly because you’re carrying more babies!
- you’ll be advised to have your baby in hospital where appropriate support and equipment is available to care for you and your baby to reduce any risks.
mode of delivery suitable for multiple pregnancies?
- you’re more likely to need some help with you delivery (interventional) e.g. using forceps, vacuum, or need for a C section, although it may be possible for you to have a vaginal delivery.
- if triplets or more C section advised.
- if twins, and 1st baby is head 1st, then we would usually recommend vaginal delivery-vs a C section you’re at a lower risk of infection, bleeding, clots, shorter stay in hospital, avoid complications of anaesthetic and damage to your bladder and bowels. presentation of leading baby should be established at 34wks.
- if 1st baby is breech (bottom 1st) at time of delivery, then a C section is the safest option.
- you may deliver your 1st baby vaginally, and then a C section is needed for your 2nd baby if they’re not in a suitable position or we think they are distressed with an abnormal heart tracing (1 in 100 risk).
advice for women with multiple pregnancy with regards to their labour?
- so will need to come into hospital for delivery.
- both midwives and doctors will care for you.
- an US scan may be needed to check the position of your babies in the delivery room.
- obs-temp, pulse, BP and urine for protein.
- continuous CTG will be used to monitor babies’ heartbeats, and if this becomes difficult or we want even closer monitoring of baby then we may use a fetal scalp electrode-small clip is attached to baby’s head (NOT if risk of baby having bleeding problem, or mum has a blood borne infection).
- may be advised an epidural for pain relief as may need to change position of 2nd twin before birth.
- lie of 2nd twin checked after delivery of 1st.
- IV cannula and G+S
- active 3rd stage to reduce risk of PPH-IM syntometrine, early cord clamping and controlled cord traction.
management of mum after giving birth to more than 1 baby?
- active 3rd stage of labour-with more than 1 placenta a larger area of your uterus will have been covered by them so you’re at a higher risk of bleeding, so we’ll give you an injection into your leg to reduce this risk, and your midwife/doctor will deliver your placenta by pulling gently on the UC and at the same time supporting your womb by gently pressing on your tummy. usually completed within 15mins.
- may need a longer hospital stay if you’ve had a C section, your babies are very small or premature-may need close observation of feeding, and extra support. also higher risk of jaundice-may need treatment with phototherapy.
recommended time for delivery in multiple pregnancy?
offer delivery at 37-38weeks=induction or elective C section.
