Antenatal care + Antenatal screening

Question 1

Outline the antenatal screening process

Answer 1

Before 10 weeks = Folic acid 400mcg + Vitamins + Food safety advice + Stop smoking/alcohol/drugs

At 10 weeks = Blood test > FBC, HIV/Syphilis/Hep B, G&S + DAT, Haemoglobinopathy screen (Thalassaemia + Sickle cell)

At 12 weeks = Dating USS scan + Nuchal translucency + Combined blood test

At 20 weeks = Anomaly scan

Question 2

What risks does alcohol pose to the fetus

Answer 2

Risk of:
- Low birth weight
- Pre-term birth
- Small for gestational age
- Fetal alcohol syndrome??

Question 3

Which prophylactic antibiotic should be given to Group B streptococci positive mothers?

Answer 3

Prophylactic Benzylpenicillin 3mg IV initially followed by 1.5mg every 4 hours during labour

(note, if expected to have Group B strep - swabs are performed at 35-37 weeks [3-5 weeks prior to expected delivery])

Question 4

Which risks are an indicator for Oral Glucose Tolerance Screening of gestational diabetes mellitus (name 3)

Answer 4

BMI >30
Previous macrosomic baby (>4.5kg)
Previous gestational diabetes
FHx of diabetes in first-degree relative
Ethnicity with high prevalence of diabetes (eg South asia, Caribbean, Middle eastern)

Question 5

How is gestational diabetes mellitus screened?

Answer 5

If risks of GDM is present then Screen with 2 hour 75g Oral glucose tolerance test (OGTT)

NOT > Fasting plasma glucose, HbA1C, Presence of glycosuria

Question 6

How is Gestational Diabetes Mellitus managed?

Answer 6

Stop any pre-existing oral hypoglycaemics (don’t stop Metformin)

1. Refer to joint diabetes-antenatal clinic + Dietician + 30 minutes exercise daily
2. If above unsuccessful after 1-2 weeks = Metformin (Gilbenclamide if cant tolerate)
3. If targets still not met with steps 1+2 = Add-on additional insulin
   – Ensure GlucoGel + Glucagon kit provided + partner knows how to use if on insulin

Question 7

What additional medications are provided for Gestational diabetes mellitus?

Answer 7

In addition to the Metformin/Insulin requirements:

Folic acid 5mg + Aspirin in 1st trimester&raquo_space; reduce risk of hypertension (esp Pre-eclampsia)

Question 8

What additional imaging requirements are used for Gestational diabetes mellitus?

Answer 8

Fetal growth scans (every 4 weeks) from 28-36 weeks

Question 9

What are the changes to the delivery process in Gestational diabetes mellitus?

Answer 9

DELIVERY:
o Pre-existing Diabetes = ELECTIVE DELIVERY from 37-38+6 weeks
o Uncomplicated GDM = by 40+6 weeks delivery
o If Macrosomia = discussion regarding risks + benefits of induction of labour, vaginal birth and caesarean section (2-4x higher risk of shoulder dystocia)

Pre-term labour = give Corticosteroids (use sliding scale for 24h after last dose of steroid)

Question 10

What monitoring is required during labour in Gestational diabetes mellitus?

Answer 10

Continuous fetal monitoring

Avoid hypERglycaemia (causes neonatal hypoglycaemia) – use sliding scale if DM on insulin or GDM >7mmol/L&raquo_space; Aim = 4-7mmol/L
» Halve insulin infusion on delivery of placenta in T1DM.
» Stop infusions at delivery in GDM and T2DM if not on insulin pre-pregnancy (return to pre-pregnancy regimen again).

Question 11

What pre-conception counseling is given to women with pre-existing diabetes?

Answer 11

Use contraception until good blood glucose control (HbA1C <=48mmol/L)
o AVOID PREGNANCY IF HbA1C >86mmol/L

Take Folic acid 5mg daily until 12 weeks gestation

Aim = BMI<27 (only lose weight prior to pregnancy; don’t attempt weight-loss during pregnancy)

Stop oral hypoglycaemics (except metformin), Statins, ACEi + ARBs

Treat retinopathy pre-pregnancy (retinopathy screen; <=20% develop proliferative retinopathy in pregnancy)
o Nephropathy may worsen antenatally; if severe; avoid pregnancy.

Question 12

Give 5 risk factors for pre-eclampsia

Answer 12

o Age >=40
o Nulliparity
o Pregnancy interval >10 years
o FHx of pre-eclampsia
o PMHx of pre-eclampsia
o BMI >=30kg/m2 (Obesity)
o Pre-existing vascular disease such as Hypertension
o Pre-existing renal disease
o Multiple pregnancy

Question 13

What are the criteria for admission with pre-eclampsia?

Answer 13

sBP >=160mmHg = Admit + treat
dBP >=110mmHg = Admit + treat
BP >140/90 + Significant proteinuria = Admit + treat
Significant symptoms = Admit + treat

Question 14

What are the symptoms of pre-eclampsia patients should look out for?

Answer 14

Severe headache
Visual problems (blurring or flashing before the eyes)
Severe epigastric or RUQ pain
Vomiting
Sudden swelling of the face, hands or feet.

Question 15

What are the components of the combined test?

Answer 15

Beta-HCG
Pregnancy associated plasma peptide A (PAPP-A)
Maternal age
Nuchal translucency

Assesses for Patau syndrome (13), Edwards syndrome (18), Down’s syndrome (21)

Question 16

What are the conditions assessed for on the 20 week anomaly scan?

Answer 16

Anencephaly
Serious cardiac abnormalities
Spina bifida (open)
Omphalocele + Gastroschisis
Bilateral renal agenesis
Lethal skeletal dysplasia
Cleft lip

Question 17

What are the components of the in-person antenatal appointments?

Answer 17

Blood pressure + Urine dip
From 24 weeks = Symphysis-Fundal height
From 36 weeks = SFH + Check fetal presentation (USS if uncertain)

NO routine auscultation (unless required)
NO routine “Formal” fetal movement counting
NO routine antenatal CTG in uncomplicated pregnancy (no benefit)

Question 18

How many antenatal appointments should a nulliparous and parous woman have

Answer 18

Uncomplicated + Nulliparous = 10 appointments
Uncomplicated + Parous = 7 appointments

Question 19

Give 2 indications for further scans in pregnancy

Answer 19

Low lying placenta at 20 weeks [= Rescan at 32 weeks]
Suspected Small for Dates on clinical examination / customised growth charts
Suspected Malpresentation on clinical examination

From 42 weeks, women who decline induction of labour should be offered ultrasound estimation of maximum amniotic pool depth

Question 20

What management is offered in pregnancy after 41 weeks?

Answer 20

Pregnancy after 41 weeks:
o Offer Membrane sweep
o Induction of labour beyond 41 weeks

If Induction of labour declined >=42 weeks&raquo_space; increase surveillance = CTG + USS

Question 21

When should External Cephalic Version be offered?

Answer 21

Breech presentation at term&raquo_space; Offer External Cephalic Version after 36 weeks in uncomplicated singleton
- Give anti-D to Rh-ve mothers

Question 22

Give 3 indications for Chorionic villus sampling // Amniocentesis

Answer 22

Maternal age,
High risk for aneuploidy screening,
Abnormal ultrasound findings,
Parental translocation,
Maternal request

Question 23

Give 3 risks of Amniocentesis

Answer 23

Miscarriage,
Infection,
Rhesus sensitisation,
Clubfoot