Antenatal Care And Screening Flashcards
Morning sickness
- afffects around 80-85% women
- worse in conditions where Human Chorionic gonadotrophin is higher eg twin, molar pregnancy
- can progress to hyperemesis gravidarum
Cardiac problems
- Cardiac output (CO) increases by 30-50% during pregnancy
- Palpitations are a common complaint
- At Term blood flow to the uterus must exceed 1L/min
Why does blood pressure drop in the second trimester?
- Expansion of the uteroplacental circulation
- A fall in systemic vascular resistance
- A reduction in blood viscosity
- A reduction in sensitivity to angiotensin
- BP usually returns to normal in the third trimester
Why does urine output increase during pregnancy?
- Renal plasma flow increases by 25-50%
- Glomerular Filtration Rate increases by 50%
- Serum urea and creatinine decrease
UTI in pregnancy
- There is an increase in urinary stasis
- Hydronephrosis is physiological in the third trimester and makes pyelonephritis more common
- Can be associated with preterm labour so important to treat
Haematological changes during pregnancy
- Plasma volume increases by about 50% and RBC mass by about 25% - This results in a drop in haemoglobin by dilution from 133-121g/L
- WBC increase slightly
- platelets fall by dilution
- 2-3 fold increase in requirement for iron
- 10-20 fold increase in folate requirements
- hypercoaguable
Respiratory problems during pregnancy
- Progesterone acts centrally to reduce CO2
- Tidal volume
- Respiratory rate
- Plasma pH -O2 consumption ↑ by 20%
- Plasma PO2 is unchanged
- Hyperaemia of respiratory mucous membranes
Gastrointestinal problems during pregnancy
- Oesophageal peristalsis is reduced
- Gastric emptying slows
- Cardiac sphincter relaxes
- GI motility is reduced due to ↑ progesterone and ↓ motilin
Pre-pregnancy counselling for all women
- General health measures
- Improve diet
- Optimise BMI
- Reduce alcohol consumption
- Smoking cessation advice
- Folic acid - 400 micro grams
Previous maternal pregnancy problems
- Caesarian section
- DVT
- pre-eclampsia
Actions to reduce risk of reoccurrence of previous maternal pregnancy problems
- Thromboprophylaxis
- low dose aspirin
Previous foetal pregnancy problems
- Pre-term delivery
- Intrauterine growth restriction
- Foetal abnormality
Actions to reduce risk of recurrence of previous foetal pregnancy problems
- Treatment of infection
- High dose folic acid
- Low dose aspirin
Antenatal Examination
- Routine enquiry
- Feeling well
- Feeling foetal movement (after 20 weeks)
- Blood Pressure - Detect evolving hypertension
- Urinalysis
- Abdominal Palpation
- Assess symphyseal fundal height (SFH)
- Estimate size of baby
- Estimate liquor volume
- Determine foetal presentation
- Listen to the foetal heart
Screening for infection
- Hepatitis B
- If infected can provide passive and active immunisation for baby
- Syphilis
- Easily treated with Penicillin
- HIV
- Maternal treatment and careful planning reduces vertical transmission
- MSSU
- Urinary tract infection
Other screening during pregnancy
- Iron deficiency anaemia
- Isoimmunisation
- Rhesus disease
- Anti C, anti Kell
First ultrasound scan (12 weeks)
- Ensure pregnancy viable
- Multiple pregnancy
- Identify abnormalities incompatible with life
- Offer and carry out Down’s syndrome screening
Detailed anomaly scan (20 weeks)
- Systematic structural review of baby
- Not possible to identify all problems
- Can identify problems that need intrauterine or postnatal treatment
First trimester screening for Down syndrome
- Carried out at 10-14 weeks gestation
- Uses maternal risk factors, serum β-human chorionic gonadotrophin (β-hCG) and pregnancy associated plasma protein A (PAPP-A) and foetal nuchal translucency (NT) measurement
Down syndrome further investigation options
- Further testing is offered if risk of Down’s syndrome is >1 in 150
- Options:
- CVS (chorionic villus sampling)
- Amniocentesis
- Non-invasive Prenatal testing
CVS (chorionic villus sampling)
- 10-14 weeks
- ~1-2% chance of miscarriage
Amniocentesis
- 15 weeks onward
- ~1% chance of miscarriage
Non-invasive prenatal testing
- Maternal blood taken
- Can detect foetal cell free DNA
- Can look for chromosomal trisomies
- Not offered on NHS
- If high risk, still recommended to have invasive testing to confirm
Second trimester biochemical screening for neural tube defect
- carried out if not able to get NT measurement
- maternal serum is tested for alpha fetoprotein
- >2MoM is high risk and warrants investigation
Give examples of structural abnormalities that can be detected at the second trimester ultrasound.
- hypoplastic left heart
- exomphalos
- cleft lip
General changes experienced surging pregnancy.
- Metabolism - ketones produced much earlier into fast (12 hours)
- Fatigue - particularly in early pregnancy
- Oedema - in 80% of women
- Thyroid - beta hCG resembles TSH so can result in hyperthyroidism
- General state of immunosupression
- Weight gain - average 14kg
Breast changes in pregnancy
- Increased size and vascularity - warm, tense and tender
- Increased pigmentation of the areola and nipple
- Secondary areola appears
- Montgomery tubercules appear on the areola
- Colostrum like fluid can be expressed form the end of the 3rd month
Intrapartum cardiovascular changes
- Autotransfusion of contractions
- Pain - increasing catecholamines
- CO increases by 10% in labour and by 80% in 1st post delivery hour
Postpartum cardiovascular changes. Comment on blood volume, BP, SVR, HR.
- return to normal by 3 months
- blood volume decreases by 10% 3 days post delivery
- BP initially falls then increases again days 3-7 (pre-pregnancy levels by 6 weeks)
- systemic vascular resistance increases over first 2 weeks to 30% above delivery levels
- HR returns to pre pregnancy levels over 2 weeks
Lab values for Hg, WCC, platelets, CRP, ESR during pregnancy.
Hg ↓
WCC ↑
Platelets ↓
CRP ↔
ESR ↑
Lab values for urea, creatinine, urate during pregnancy.
All ↓ but urate increases with gestation
Lab values for 24 hour protein, total protein, albumin during pregnancy.
24 hour protein ↑
Total protein ↓
Albumin ↓
Lab values for GGT/ALT/AST, alkaline phosphatase, bile acids, D dimer during pregnancy.
GGT/ALT/AST ↓
Alkaline phosphatase ↑↑
Bile acids ↔
D dimer ↑
