Antenatal care and screening + physiology- pregnancy Flashcards
What general symptoms are experienced during pregnancy?
- metabolism change
- fatigue
- oedema
- heartburn/reflux
- breast enlargement
What percentage of women are affected by morning sickness?
When does morning sickness ususally stop?
What can cause morning sickness to be more severe?
What is hyperemesis gravidarum?
- 80-85%
- around 16 weeks
- conditions which increase Human Chorionic Gonadotrophin (eg twins)
- severe vomiting leading to weight loss + dehydration
What breast changes are experienced during pregnancy?
- inc. size and vascularity
- warm, tense, tender
- inc. pigmentation of nipple + areola
- secondary areola appears
- Montgomery tubercles on areola
- colostrum-like fluid can be expressed from end of 3rd month
What respiratory changes occur during pregnancy?
- dec. CO2- caused by progesterone
- inc. tidal volume
- inc. RR
- inc. plasma pH
- inc. O2 consumption by 20%
- plasma PO2 unchanged
- hyperaemia of respiratory mucous membranes
- dec. functional residual V
- dec. PCO2
What cardiovascular changes occur during pregnancy?
- cardiac output inc. by 30-50% (inc. stroke V)
- HR inc. to about 70-90 bpm
- palpitations common
- blood flow to uterus > 1L/min at term
- inc. blood V by 50-70%
- BP dec. in second trimester
- uteroplacental circulation expands
- dec. systemic vascular resistance
- dec. blood viscosity
- dec. sensitivity to angiotensin
* BP usually returns to normal in third trimester
What cardiovascular changes occur intrapartum?
- autotransfusion of contraction
- pain- inc. catecholamines
- cardiac output inc. by 10%
What cardiovascualar changes occur postpartum?
- cardiac output inc. by 80% in 1st hr
- falls over 24 weeks
- blood V dec. by 10% by 3 days
- BP dec. then inc. by days 3-7
- return to normal by 6 weeks
- systemic vascular resistance inc. by 30% by 2 weeks
- HR dec. to normal by 2 weeks
* everything usually returns to normal (pre-pregnancy) by 3 months
What haematological changes occur during pregnancy?
- inc. PV by around 50% + RBC mass by around 25%
- so dec. haemoglobin by dilution from 133 -> 121g/L
- Fe requirements inc. by 1g
- inc. WBC to 9000-12000/μL
- so dec. platelet count by dilution
* Fe supplements given if Hb < 110 at booking or < 100 at 28 weeks
What gastrointestinal changes occur during pregnancy?
- dec. oesophageal peristalsis
- slower gastric emptying
- cardiac sphincter relaxes
- dec. GI motility- caused by inc. progesterone + dec. motilin
What urinary changes can occur during pregnancy?
- inc. urine output
- inc. renal plasma flow by 25-50%
- inc. GFR by 50%
- dec. serum urea + creatinine
(by inc. GFR + inc. plasma V) - dec. bladder capacity from inc. uterus size
- increase risk of UTI
- inc. urinary stasis
- hydronephrosis in third trimester ∴ pyelonephritis more common
- associated with premature labour
What fraction of pregnancies are unplanned in Scotland?
1/3
What and why is the biggest cause of maternal deaths?
- cardiac disease
- women are older/more obese
For all women, what 3 topics are covered by pre-pregnancy counselling?
- general health measures
- improve diet
- optimise BMI
- dec. alcohol consumption
- smoking cessation advice
- folic acid (400mcg)
* can all be covered in primary care
For women with known medical problems, what topics may be covered by pre-pregnancy counselling?
- optimising maternal health
- psychiatric health
- stop/change unsuitable drugs
- advise regarding associated complication
- advise against pregnancy
- cardic/renal problems
For women with previous pregnancy problems, what topics may be covered by pre-pregnancy counselling?
Also what actions may be taken to reduce risk of reurrence?
- C-section*, DVT, pre-eclampsia (maternal)
- pre-term delivery, intruterine growth restriction, fetal abnormality (fetal)
- thromboprophylaxis, low dose aspirin (maternal)
- treatment of infection, high dose folic acid, low dose aspirin (fetal)
* if previous C-section was non-recurring cause (eg breech), ok to trial normal labour
* if 2 previous C-sections, customary to deliver by elective C-section
Antenatal examination idendifies what problems for; mother, fetus, social?
- pre-existing/developing illness
- ‘minor’ pregnancy problems (eg anaemia)
- small for gestational age
- fetal abnormalities
- support
- domestic violence
- psychiatric illness
What does an antenatal examination include?
- routine inquiry
- general health
- fetal movements (after 20 weeks)
- BP
- evolving hypertension
- urinalysis
- pre-eclampsia (hypertension + proteinuria)
- diabetes
- UTI
- abdominal palpation
- symphyseal fundal heigh (SFH)
- size of baby
- liquor volume
- fetal presentation
- listen to fetal heart
What conditions to screening tests cover?
- infections
- rubella
- Hep B
- syphilis
- HIV
- MSSU
- Fe deficiency anaemia
- isoimmunisation
- Rhesus disease
- Anti-C, Anti-Kell
What does a first visit US scan screen for?
- ensure pregnanacy viable
- multiple pregnancies
- identifiy abnormalities incompatiable with life
- offer Down’s syndrome screening
* performed at 10-14 weeks
What does a detailed anomaly US scan screen for?
- systematic structural review of baby
- identify problems needing intrauterine or postnatal treatment
*not possible to identify all problems
What is the risk of Down’s syndrome at 20 yrs and 45 yrs?
- 20 yrs- 1 in 1667 risk
- 45 yrs- 1 30 risk
What is measured during first semester trisomy screening?
- maternal risk factors
- serum β-human Chorionic Gonadotrophin (β-hCG)
- Pregnancy Asociated Plasma Protein A (PAPP-A)
- fetal Nuchal Translucency (NT) measurement
*detection rate ~90%, invasive testing rate 5%
What is Nuchal Translucency (NT) measurement?
- measurement between Crown Rump Length’s (45-84mm)
- NT increases with gestational age
- chromosomal and other abnormalities are related to size of NT
What tests follow a high risk chromosomal trisomy result?
- CVS (sample from placenta)
- 10-14 weeks
- 1-2% risk of miscarriage
- amniocentesis (sample from fluid)
- 15 weeks onwards
- ~1% risk of miscarriage
- non-invasive prenatal testing
- maternal blood test- test fetal cell free DNA
- if high risk, invasive tests recommended to confirm
* offered if risk > 1 in 150
What are the screening tests for Nural Tube Defects (NTD)?
- personal/family history
- take 5mg folic acid to dec. risk
- US (first trimester)
- anencephaly
- spina bifida
- US (second trimester)
- will detect >90% NTD
- biochemical screening (second trimester)
- if not able to get NT measurement
- maternal serum alpha fetoprotein test
(>2.0MoM is high risk)
