The Link Between Antenatal & Newborn Screening

for Hbo’s

Brigid Keane

Specialist midwife

December 2016

Notation of Hbo’s

Over 1,000 known haemoglobin variants even have our very own - Hb Tyne

HbA+A = Normal haemoglobin

HbA+C/D/E etc = Normal plus carrier of an altered

gene HbSS = no normal haemoglobin present

Antenatal Screening

Booking bloods - 8 -10 weeks

Family Origin Questionnaire (FOQ)

High and low prevalence areas

High = all women

Low = F.O.Q.

Family Origin Questionnaire (FOQ)

Ethnic Group

% Carriers Carriers, 1in: (approximate)

Northern European 0.2 1in 500

Black Caribbean 16.8 1in 6

Black African 27.0 1 in 4 Black Other 16.8 1 in 6

Indian 7.3 1 in 14

Pakistani 7.1 1 in 14

Bangladeshi 7.3 1 in 14

Other Asian 3.5 1 in 30

Chinese & other SE Asian 8.5 1 in 12

Other ethnic group 6.0 1 in 17

Greek 7.4 1 in 14

Turkish 6.0 1 in 17

Italian 4.1 1 in 24

Cypriot 18.0 1 in 6

Mixed ethnicity N European & Black Caribbean 8.5 1 in 12

N European & Black African 13.3 1 in 8

N European & Asian 3.8 1 in 27

N European & Cypriot 9.0 1 in 12

N European & Chinese 4.3 1 in 24

Other Mixed Depends on ethnic origins of parents

Distribution of the Major Hbo’s

Malaria

Sickle Gene

AUTOSOMAL RECESSION INHERITANCE

Process during Antenatal Period

Mother = HbAA No partner testing indicated

Mother = HbA+? Partners screen ASAP

Partner = HbA+?

Offer Pre-natal diagnosis

CVS/B (from 11 +1 weeks)

Amnio (from 15 weeks)

Oxford labs (2 weeks)

Counseling

Pre-Natal diagnosis

Alpha Vs Beta Thalassaemia

Alpha Thal is a

major is a disorder

of intrauterine life

Beta Thal major is

a disorder of post uterine life

Local Figures (RVI - 2015 -2016)

Number of women screened with +ve result = 92

At risk couples = 5

Pre-natal diagnosis = 1 (CVS)

(4 declined)

Recent Developments in Pre-Natal diagnosis

Aspiration of Coelomic fluid from the Cavity (6 weeks)

Theoretically less traumatic to fetus

Maternal cell contamination a potential problem

First trimester gestational sac: • ECC ϭ exo-coelomic cavity • YS ϭ yolk sac • AC ϭ amniotic cavity

http://www.todayifoundout.com/wp-content/uploads/2013/05/stork.jpg

“The only reason for time is so that everything doesn't happen at once” (Albert Einstein)

Newborn Bloodspot Screening

Day 5-8 (day of birth = day 0)

Bloodspot card to ‘Screening Lab within 24hrs.

Result issued by lab within 4 days

Results to Parents by 6 week P/N check

Screened positive babies referred immediately to appropriate medical team.

What do we Screen for?

Congenital hypothyroidism (CHT)

Cystic fibrosis (CF)

Six Inherited metabolic diseases -

PKU; MCADD; MSUD; IVA; GA1; HCU.

Sickle cell disease (SCD)

Avoiding problems

“Once is enough ….. getting it right first time”

Role of specialist Midwife

Liaise with:

Screening labs

Haematology Consultant

Primary Care Teams

Ensure:

Results given to parents in timely fashion

All positive screened babies referred to Haematology

Support:

Training & education across the region

Case Study 1

White couple, early 20’s – low prev. area

Baby = HbAS

Distressed ++++

Both Parents tested by GP

Screening = Mother HbAS/father=HbAA

Outcome: Anger at Screening programme

Case Study 2

African Couple – 2nd child

A/N screen = Mother HbAA on – therefore no partner testing indicated

Baby = HbAS on Newborn screening

Father tested 3 weeks post delivery = HbAA

? Paternity issues

Outcome: Baby retested at 7 months at father’s request: baby = (HbAS) but lasting damage to family

Case Study 3

African couple 1st baby

Arrived UK at 15/40

A/N Screen = Mother = HbAS Father =HbAS

Parents reported that test in Nigeria = HbAA

Outcome: Parents distressed++ and full of guilt:

Feel unable to return to Nigeria.

Screening - a moral dilemma?

Reporting carrier results – what value?

More harm than good -“bad blood”

Can be emasculating

Awareness of cultural issues/beliefs

-arranged marriages

-a woman’s issue (baby in womb)