Non Immune Fetal Hydrops TOG 2023

Question 1

What percentage of extra-cardiac anomalies associated with fetal hyrops present in third trimester?

Answer 1

10%
8% in 2nd trimester
5% in first trimester

Question 2

When does immune fetal hydrops commonly present ?

Answer 2

18 weeks gestation or beyond
Most first trimester hydrops are non immune

Question 3

What % of non immune fetal hydrops in first trimester are due to Chromosomal abnormalities?

Answer 3

> 2/3 (70%)
12.7% cardiac anomalies
8% Extracardiac structural anomalies and infections

Question 4

What % of NIFH identified before 14 weeks gestation ended in miscarriage or later in utero death?

Answer 4

66% (2/3rd), of the remaining 33% born alive, 40% die in neonatal period.

Question 5

What clause of the abortion act is applicable in termination for NIFH?

Answer 5

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 “

Question 6

With primary pleural effusions or chylothorax, what’s the % of regression or non-progression with insertion of thoracic-amniotic shunt?

Answer 6

25% ( 1/4)

Question 7

What is the theory underlying maternal mirror syndrome in NIFH?

Answer 7

Hydropic placenta
Endothelial dysfunction and
Trophoblastic injury
It is a rare complication of NIFH

Question 8

What’s the link between amnioreduction in severe polyhydramnios and the risk of preterm birth?

Answer 8

Paucity of evidence but association exist with PROM, preterm birth and placental abruption

Question 9

What % of NIFH in second trimester is caused by fetal infection?

Answer 9

20%
5% in first and third trimesters each

Question 10

What % of genetic causes account for NIFH in first trimester ?

Answer 10

75%
(70% chromosomal abnormalities, 5% monogenetic disorder)
40% in second trimester ( 20% each)
25% in third trimester ( 5% chromosomal, 20% monogenetic)

Question 11

What % of third trimester NIFH is caused by cardiovascular disorders

Answer 11

25%
Due to increased CVP

Question 12

What is the common clinical picture of maternal mirror syndrome ?

Answer 12

1. New onset symptoms of pre eclampsia
2. Anaemia
3. Haemodilution

Question 13

What’s the mortality rate of NIFH in second trimester?

Answer 13

50% mid-trimester / in-utero death
Neonatal death in 20% of those who survive

Question 14

What’s the morbidity/ mortality in NIFH identified after 25 weeks ?

Answer 14

1 in 6 die in utero
25% die in neonatal period

Question 15

What is the long term outcome of fetuses with NIFH?

Answer 15

90% survival at 1 year follow up
77% no considerable morbidity
23% with mild anatomical defect to severe neurodevelopmental delay

Question 16

What’s the most common identified cause of NIFH in second trimester ?

Answer 16

Chromosomal abnormalities in 20%
(With exome sequencing, 40% are due to monogenetic disorders )
Infection too is 20% !

Question 17

Common infectious causes of NIFH?

Answer 17

Parvovirus B-19
CMV
Toxoplasmosis
Syphillis

Question 18

What is the prevalence of NIFH and perinatal mortality rate?

Answer 18

1 in 2000 pregnancies
60% perinatal mortality rate

Question 19

What multi system anomalies increase the diagnostic yield of exome sequencing in NIFH?

Answer 19

Presence of joint or limp contractures known as arthrogryposis

Question 20

What is the commonest pathogenic single gene variant associated with NIFH?

Answer 20

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

Question 21

What is the primary investigation for genetic causes of NIFH?

Answer 21

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.

Question 22

When is delivery recommended in NIFH with worsening symptoms

Answer 22

After 34 weeks + antenatal steroids

Question 23

When should delivery occur in stable NIFH with no other indication for preterm delivery?

Answer 23

37-38 weeks in centres with level 3 neonatal unit and CTG monitoring