Antenatal care

1^st visit/ Booking visit

1. Symptoms of pregnancy
2. Menstrual history
3. Obstetric history
4. Gynae history
5. PMhx
6. Surgical hx
7. Fhx
8. Sociodemographic history
9. Lifestyle
10. Medication & Allergies
11. Examination –
    1. Wt
    2. Ht
    3. BP
    4. Teeth/gums
    5. Thyroid
    6. Breasts
    7. Chest/Heart
    8. Abdo
    9. Pelvic
12. Investigations
    1. beta hCG
    2. FBC
    3. ABO blood group & Ab
    4. Iron studies
    5. Rubella immunity
    6. Syphilis serology
       1. Consider repeat screening later in pregnancy in areas of high prevalence
    7. Hep B & C serology
    8. HIV serology
    9. Urine MCS
    10. Dating scan – Transvag USS/ Transabdo USS
    11. High risk:
        1. HbA1c – If Random glucose >5.5 perform 75gm GTT; HbA1c acceptable if GTT impractical
        2. First pass for U- PCR- Chlamydia/Gonorrhoea/ Trichomoniasis/ Mycoplasma genitalium
    12. optional
        1. Vitamin D (if indigenous or minimal sun exposure to skin, dark skin, obesity
        2. Vitamin B12 – vegetarian
        3. TFTs if symptoms/high risk
        4. Chlamydia < 25 or high prevalence area
        5. Gono if risk factors
        6. Early OGTT < 20 weeks – PCOS
        7. CMV immunity testing if frequent contact large numbers young children
        8. Lead Pb level
        9. Varicella zoster
        10. Strongyloides Serology
        11. MRSA screen if pt known to have been MRSA +ve prior to pregnancy – 2 sets of swabs at least 1 week apart.
13. Supplements
    1. Folic acid – 0.5mg
    2. Folic acid 5mg if
       1. BMI > 30
       2. risk of malabsorption
       3. pre-pregnancy DM
       4. risk factors for neural tube defects
       5. family history congenital heart disease
       6. MTFHR mutation
       7. multiple pregnancy
    3. Iodine 500mcg
    4. Multivitamin if previous bariatric surgery
    5. Calcium intake of 100mg daily
    6. Iron requirements
       1. During pregnancy, iron requirements increase by 50% from 18mg to 27mg per day.
       2. Routine supplementation during pregnancy is not recommended in Australia due to the fact that excessive iron intake can pose health risks to mother and child. 
       3. It is recommended women consume iron-rich foods during pregnancy and are aware of foods that facilitate iron absorption.
       4. Iron rich foods include red meat, poultry, tofu, and iron-fortified cereals, Eating foods high in vitamin C (e.g. oranges, kiwi fruit, capsicum, broccoli) can facilitate iron absorption.
14. Advise
    1. Toxoplasmosis – wash hands, fruit/vege, avoid raw meat and ready [prepared meals, gloves in soil/gardening, avoid cat faeces]
    2. Listeriosis – Wash raw fruit and vegetables thoroughly before eating.
       1. Avoid eating food if it has been made more than 24 hours ago. If you choose to eat food prepared the day before, it should always be reheated to steaming hot.
       2. Listeria is destroyed in normal cooking, so freshly cooked hot food is safe if eaten straight away.
       3. It is safe to eat foods that are listed as a higher risk provided it is heated above 74 °C for over two minutes.
    3. CMV – avoid contact children saliva/urine
    4. Healthy BMI
       1. Risks of excess weight gain during pregnancy
          1. Gestational diabetes during pregnancy, and type 2 diabetes after pregnancy
          2. Gestational hypertension
          3. Pre-eclampsia
          4. Depression
          5. Difficulties during birth
          6. Miscarriage or stillbirth
          7. Large for gestational age baby
          8. Later life obesity and metabolic syndrome for baby
          9. No, or shorter duration of breastfeeding

Target weight gains during pregnancy:

Pre-pregnancy BMI (kg/m2)	Rate of weight gain 2nd and 3rs trimester (kg/week)	Recommended total weight gain range (kg)
<18.5 underweight	0.51	12.5 to 18
18.5 to 24.9 normal weight	0.42	11.5 to 16
25.0 to 29.9 overweight	0.28	7 to 11.5
≥ 30.0 obese	0.22	5 to 9

Subsequent visits

• Q4 weeks until K28
• Q 2 weeks until K36
• Q 1 week until delivery

1. Events since last visit
   1. Pain
   2. Bleeding
   3. discharge
2. Fetal movements
3. Concerns
4. Examination
   1. BP
   2. Abdo
      1. fundal ht
      2. fetal lie
      3. fetal HS
      4. presentation
   3. LL oedema
   4. urinalysis (bacteruria, glucose, protein)

Investigations/Screening

• Are there any conditions in your family that have affected more than one family member?
• Has anyone in your family been born with a health or learning problem?
• Has anyone in your family had more than 3 miscarriages?
• Has anyone had a stillbirth or a baby who has died?
• Has anyone in your family attended special schools or been in a special class at school?
• Is there anything you are especially worried about? (While not specifically an assessment of family history, it may remind the patient about something not mentioned or uncover any other concerns).

• First and second trimester Evaluate
  • Down (1/500)
  • Edward / trisomy 18 (1/3000)
  • trisomy 13
  • open neural tube defects (1/750)

• Risk assessment – if high will be offered a diagnostic test
  • Diagnostic tests have small risk of miscarriage
  • Could go directly to diagnostic if significant risk factors
• Increased risk
  • Maternal age
  • Previous pregnancy with chromosomal abnormalities
  • Parent with a chromosome rearrangement
• Consider history of woman and partner
  • Inherited conditions – cystic fibrosis, fragile X, muscular dystrophy
  • Chromosomal condition
  • Birth defects – spina bifida, cleft lip/palate, cardiac defects
  • Intellectual disability
  • Recurrent miscarriage or unexplained perinatal deaths
• Consider ethnic background
  • Thalassemia, cystic fibrosis, fragile X
• Consider Pros of screening
  • Early screening – first trimester
  • High sensitivity
  • Non invasive
  • Some older women can avoid invasive tests
  • Early scan – accurate dating

• Cons of screening
  • Process may suggest diagnostic testing – risk miscarriage
  • Probability results difficult to understand
  • Costs
  • Unanticipated findings
  • Many positive results where baby does not have down syndrome
  • Anxiety from positive results and follow up testing
  • May lead to difficulty decisions

• Twins can be screened, multiples cannot

 TESTS

• 10-13 weeks: NIPT Screening
• 11-13 weeks: NT scan Screening – (11+1 to 13+6)
  • Fetal measurement need to be = crown rump length (CRL) = 45 -84mm to measre NT
  • Combined with Free beta-hCG + PAPP-A = high accuracy
  • collected preferably on the date of the US but will be valid within 3 days before or after the US
  • measures

• sagittal image through the fetal neck – <2 mm have a risk of <1%
• a value of less than 2.2-2.8 mm in thickness is not associated with increased risk, however, it is maternal age-dependent
• Nasal bone (NB) 

• Sensitivity
  • Downs syndrome 90%
  • Trisomy 18 80%
  • Anencephaly 100%
  • Spina Bifida 10% (NB 18 – 20 week morphology scan SB 98%) 
• Increased or decreased – cut off 1 in 300
• 5% false positive rate – 1 in 20 will receive positive result, most of these will be normal
• Screen positive rate of 2.5%
• Different risks may apply for different groups – e.g younger may want increased testing at 1 in 400
• If increased risk
  • for CVS sampling from 12-13 weeks
  • or amniocentesis from 15 weeks

• 14-20 weeks – Second Trimester Screening
  • 15-17 weeks – Quadruple Test weeks
    • Neural Tube defects 80%
    • Down Syndrome 66%
    • If positive amniocentesis from 15 weeks (less than 1% chance of miscarriage)
    • Tests:
      • Alpha fetoprotein (AFP)
      • Free βhCG (or total hCG)
      • Unconjugated estriol (uE3)
      • Some laboratories also include Inhibin A
  • 12-14 weeks: Chorionic villus sample, Miscarriage risk 1-2%
  • > 15 weeks : Amniocentesis, 0.5-1% miscarriage
• 18-20 weeks: morphology screen
• 24-28 weeks: GDM screen
• 28 weeks:
  • Flu and dTP vaccine
  • FBC, Rh Ab +/- USS for placental location
  • Rh –ve women will require prophylactic Anti- D 625IU at 28 and 34 weeks
• 34 weeks:
  • Rh Ab, USS fetal growth
• 35-37 weeks:
  • First pass for U-PCR- Chlamydia/Gonorrhoea/ Trichomoniasis (Esp. if high risk as above)
  • LVS for Group B Strep (GBS) 35 – 37 weeks; 
  • Ultrasound if indicated ( Hypertension, DM, IUGR, Mal presentation)

NIPT

• Non invasive prenatal testing
  • Cell free DNA – small amount of fragments released from the outer trophoblast layer into maternal blood
  • Fetal fraction of cfDNA approx 10% at 10 weeks
    • If not enough will not produced result
    • Can performs any any point from 10 weeks onward
  • Compares the different proportions of cfDNA from specific chromosomes
    • Aneuploidy can cause deviations from expected values
  • Specific form required
  • Risk only
    • Need invasive testing if high risk
    • Low risk NIPT does not guarantee absence, particularly if prior likelihood is high
  • Reasons it may be inaccurate
    • Low fetal fraction – more common high BMI
    • Twins – less accurate statistics and if demised twin DNA present
    • Maternal chromosomal abnormalities – bone marrow or tissue transplant, malignancy
    • Different genotype fetus and placenta – placental mosaicism, fetal mosaicism
  • Sex chromosome aneuploidies
    • Less accurate
    • Detection rate 90%, false positive rate 0.4%
  • Can consider individual microdeletions but much less data
  • Does not pickup other rare chromosome abnormalities
    • However these may be detected by USS or maternal markers in cFTS
    • Therefore follow up NIPT may still fail to detect some of these
  • Cannot detect single gene disorders (fragile X, cystic fibrosis) or non genetic defects e.g Neural tube defect, congential cardiac anomalies
  • Recommend doing USS as well

• Clinical use NIPT vs cFTS
  • Two pathways
  • FTS preferred for twins
  • If NIPT fails to get results consider
    • Detailed USS
    • cFTS< second trimester screening
    • Invasive testing
    • Repeat if low risk otherwise and early gestation