Non Immune Fetal Hydrops TOG 2023 Flashcards
What percentage of extra-cardiac anomalies associated with fetal hyrops present in third trimester?
10%
8% in 2nd trimester
5% in first trimester
When does immune fetal hydrops commonly present ?
18 weeks gestation or beyond
Most first trimester hydrops are non immune
What % of non immune fetal hydrops in first trimester are due to Chromosomal abnormalities?
> 2/3 (70%)
12.7% cardiac anomalies
8% Extracardiac structural anomalies and infections
What % of NIFH identified before 14 weeks gestation ended in miscarriage or later in utero death?
66% (2/3rd), of the remaining 33% born alive, 40% die in neonatal period.
What clause of the abortion act is applicable in termination for NIFH?
Clause E
“If there is substantial risk that if the child was born it would suffer from such physical or mental abnormalities as to be seriously handicapped “
With primary pleural effusions or chylothorax, what’s the % of regression or non-progression with insertion of thoracic-amniotic shunt?
25% ( 1/4)
What is the theory underlying maternal mirror syndrome in NIFH?
Hydropic placenta
Endothelial dysfunction and
Trophoblastic injury
It is a rare complication of NIFH
What’s the link between amnioreduction in severe polyhydramnios and the risk of preterm birth?
Paucity of evidence but association exist with PROM, preterm birth and placental abruption
What % of NIFH in second trimester is caused by fetal infection?
20%
5% in first and third trimesters each
What % of genetic causes account for NIFH in first trimester ?
75%
(70% chromosomal abnormalities, 5% monogenetic disorder)
40% in second trimester ( 20% each)
25% in third trimester ( 5% chromosomal, 20% monogenetic)
What % of third trimester NIFH is caused by cardiovascular disorders
25%
Due to increased CVP
What is the common clinical picture of maternal mirror syndrome ?
- New onset symptoms of pre eclampsia
- Anaemia
- Haemodilution
What’s the mortality rate of NIFH in second trimester?
50% mid-trimester / in-utero death
Neonatal death in 20% of those who survive
What’s the morbidity/ mortality in NIFH identified after 25 weeks ?
1 in 6 die in utero
25% die in neonatal period
What is the long term outcome of fetuses with NIFH?
90% survival at 1 year follow up
77% no considerable morbidity
23% with mild anatomical defect to severe neurodevelopmental delay
What’s the most common identified cause of NIFH in second trimester ?
Chromosomal abnormalities in 20%
(With exome sequencing, 40% are due to monogenetic disorders )
Infection too is 20% !
Common infectious causes of NIFH?
Parvovirus B-19
CMV
Toxoplasmosis
Syphillis
What is the prevalence of NIFH and perinatal mortality rate?
1 in 2000 pregnancies
60% perinatal mortality rate
What multi system anomalies increase the diagnostic yield of exome sequencing in NIFH?
Presence of joint or limp contractures known as arthrogryposis
What is the commonest pathogenic single gene variant associated with NIFH?
RASopathies commonest being Noonan syndrome in autosomal dominant de novo fashion: affected fetus with unaffected parents. That is not inherited.
Commonly mutated gene is PTPN11
What is the primary investigation for genetic causes of NIFH?
Dysmorphological evaluation of deep fetal phenotype with:
2D/3D ultrasound
MRI
Secondary investigation is whole exome or whole genome panel of proband(fetal) DNA plus parental DNA based on MDT decision.
When is delivery recommended in NIFH with worsening symptoms
After 34 weeks + antenatal steroids
When should delivery occur in stable NIFH with no other indication for preterm delivery?
37-38 weeks in centres with level 3 neonatal unit and CTG monitoring
