Complications of pregnancy - demonstration Flashcards
Monozygotic v dizygotic
Monozygotic = develop from one zygote, which splits and forms two embryos
Dizygotic = develops from a separate egg and each egg is fertilised by its own sperm cell –> 2 separate zygotes
Types of twins (referring to amniosity and chorionicity) (5)
Dichorionic diamniotic
Dichorionic diamniotic with fused placenta (rare)
Twin to twin transfusion syndrome (TTTS) pregnancies
- monochorionic diamniotic
- monochorionic monoamniotic
Conjoined twins
Describe the zygosity and chorionicity of a singleton
Monochorionic monoamniotic
RF for multiple pregnancies, i.e. twins etc
Assisted reproduction techniques, e.g. IVF
Ovulation induction
RF of dizygotic twins
Increasing
- Parity
- Weight
- Height
- Age
FH
Ethnicity
Fertility treatment
Majority of twins are mono or diamniotic, mono or dichorionic
Dichorionic diamniotic
Multiple pregnancies suspected if
Small for gestational age
Multiple foetal HRs detected
Multiple foetal parts felt
hCG and maternal AFP elevated for gestational age
Pregnancy using assisted reproduction techniques
The timing of cleavage of the fertilised egg determines how many placentas there will be
How many days after fertilisation does cleavage happen for the following
-dichorionic diamniotic
DD - 3 days after
MC/DA - 4-8 days after
MC/MA - >8 days after
Conjoined - >12 days after
In order of increasing mortality
Complications of multiple pregnancy
High perinatal mortality + morbidity Abortion Preterm labour - most twins are 37 weeks IUGR PET Polyhydramnios PPH Placental abruption, praetor Discordant twin growth
Causes of perinatal mortality + morbidity
Premature (—> ARDS) Birth trauma Cerebral haemorrhage Birth asphyxia Congenital anomalies Stillbirth
TTTS pregnancies only occur when it’s mono…
Monochorionic - 1 placenta
Describe TTTS pregnancies
Disproportionate blood supply resulting in high morbidity and mortality (60-100%)
Connecting blood vessels in placenta allow blood to pass from one twin to the other but in monochorionic pregnancies, blood vessels ANASTAMOSE and disrupt the flow balance between the 2 foetuses so that one receives more and the other less
DONOR twin receives less blood —> slowing its growth (IUGR), oliguria and becoming oligohydramniotic
RECIPIENT twin receives too much blood —> strains its heart leading to heart failure and also becoming polyhydamniotic
Features of the
- donor twin
- recipient twin
Donor - IUGR, oligohydramnios, oliguria
Recipient - heart failure, polyhydramnios, hydrops
Treatment of TTTS pregnancies
Aminoreduction of the recipient twin
Intrauterine blood transfusion for the donor twin
Selective foetal reduction
Foetoscopic laser ablation of placental anastamosis
Antenatal management of multiple pregnancy
Good nutrition Prevent anaemia FREQUENT ANTENATAL VISITS US -chorionicity at 9-10wks -nuchal translucency at 12-13+ wks -foetal growth every 3-4 wks from 23 wks
How to determine chorionicity on US
- dichorionic diamniotic
- monochorionic monoamniotic
- dichorionic diamniotic
- monochorionic diamniotic
DD - 2 separate placenta, 2 sacs
MM - 1 placenta, 1 sac
2 sacs with fused placenta could either be
- DD with fused placenta
- MC/DA
Dichorionic twins have what symbolically shaped sign on US
Monochorionic twins have what symbolically shaped sign on US
Lambda sign - like Chinese character for people
T sign
Examination test for assessing foetal growth
Symphysiofundal height
Symphyisofundal height should correspond to the age in weeks in cm with a +/- of how many cm
3
Measurements on US to assess foetal growth
Abdo circumference
Femur length
Head circumference
Then plot these on a GAP/GROW chart to get liquor volume (measure of foetal weight)
Causes of small for gestational age
Low maternal BMI Age Ethnicity Social class Smoking/alcohol Maternal disease - PET, chronic hypertension, severe asthma, autoimmune Infections - toxiplasmosis, CMV Congenital, e.g. down’s, turner’s
Causes of large for gestational age
Multiparity Ethnicity Social class Genetic Maternal DM Polyhydramnios Foetal anatomical abnormality, e.g. duodenal atresia, tracheo-oesophageal fistula Multiple pregnancy
What tests to confirm foetal wellbeing
Foetal abdo movements
CTG
US Doppler of umbilical artery
