Antenatal Care Flashcards
In UK law when does pregnancy begin?
Implantation
6-12days post-fertilisation
How can pregnancy be diagnosed?
- Amenorrhoea
- Breast tenderness/swelling
- Sickness
- USS
- Positive pregnancy test
What is a pregnancy test based upon?
hCG levels
Rise rapidly up to 10weeks
Urine positive at: 25IU/ml
Can be detected in serum & urine 4weeks after LMP
What are the main landmarks before & after 12weeks?
BEFORE: Organ development, placenta assumes major role
AFTER: Growth & maturation
When is the highest chance of miscarriage?
before 12weeks
What happens at the initial booking visit?
- Calculate EDD
- Book first scan
- Obstetric Hx, risk assessment
- Obs: BP, BMI, urine (culture for asymptomatic bacteriuria)
- Dietary advice: Folic acid, iron, VitD, avoid certain diaries
- Lifestyle advice: smoking, OH-
- Bloods: FBC, Blood Group, Haemoglobinopathies (Rhesus -ve), resus status, red cell alloantibodies, Hep B, Syphilis, Rubella, HIV
- Consent for antenatal screening & Genetic disorders tests
- Flu vaccine
- Antenatal classes
When is the booking visit?
Ideally before 10weeks
What disorders are tested for in the antenatal screening tests?
- Combined test: Edward’s, Patau’s, Down’s syndrome
- Quadruple test for Down’s at 15-20weeks (women who present late)
How many antenatal appointments should be made for Multips & Primips?
P=10
M=7
What infections are screened for in antenatal clinic?
- HIV
- Syphilis
- Hep B
- Rubella
What are customised growth charts based on?
Age, ethnicity, parity, BMI, symphysis-fundal height (from 24weeks)
What will be seen at each of the following stages on USS? 4-5weeks 5-6weeks 6weeks 6-7weeks 8weeks
4-5: Gestational sac 6mm 5-6: Yolk sac 6: Fetal pole 5mm 6-7: Fetal heart activity 8: Limb buds, fetal movement
At what gestation will fetal movement occur?
Multips: 16weeks
Primips: 18weeks
Pattern to movement: 26weeks
What does a 1st &2nd trimester USS show?
1st: Optimal for dating (measure crown-rump length)
2nd: Placental location, relationship to internal cervical os
When is an anomaly scan done?
Screening test comes back with ‘high/increased probability’
18-22weeks
Checks for: Anencephaly, gastroschisis, heart defects, trisomy 13&18
How does the combined screening test work?
Opt-in 11-14weeks Measure crown-rump length Nuchal translucency scan Maternal blood test Cut off 1 in 150 High probability= CVS or amnio
What chemicals are measured in the combined screening test?
Nuchal translucency (measure size of nuchal pad at nape of the neck) Beta-human chorionic gonadotrophin Pregnancy associated plasma protein-A.
What is amniocentesis?
Sample of amniotic fluid by passing a needle through the abdomen into the amniotic sac
15weeks+
Gives info about karyotype of fetus
What are the risks of amniocentesis?
COMMON: Discomfort, failure to obtain sample, miscarriage (1%)
OCCASIONAL: fluid leakage
RARE: Fetal & bowel injury, failure of cell culture, chorioamnionitis
What is chorionic villus sampling?
Sample of placental tissue obtained transabdominal/transcervial
11-14weeks
LA often used
What are the risks of CVS?
COMMON: Discomfort, failure to obtain sample, miscarriage (2%)
OCCASIONAL: Same as amnio
RARE: Same as amnio
What does increased nuchal translucency reflect?
Fetal heart failure
Strongly associated with chromosomal abnormality
What happens if the mother is diagnosed with Hep B or Syphilis in pregnancy?
Hep B: Newborn on vaccination programme (5doses)
Syphilis: Receive full Tx 4weeks prior to delivery, newborn undergo IV therapy
What is the management of a rhesus negative mother?
Anti-D immune globulin 500IU at 28weeks
What is Rh incompatibility?
Destruction of fetal erythrocytes from transplacental passage of maternal IgG antibodies produced by the immune system.
Anti-D antibodies produced to a Rh+ve foetus and can freely cross the placenta binding to and destroying RBCs.
Rh-: RBC’s do not carry inherited RhD antigen
What are the consequences of Rh incompatibility?
Sensitising event will cause maternal immune system to react to ‘foreign’ D antigens on RBCs & produce Abx
No problem in current pregnancy
Consequent pregnancies: Haemolytic disease of the newborn= Progressive fetal anaemia which may lead to hydrops fetalis and death
Which pregnant women should be given Rho D immune globulin?
Ectopic pregnancy
Miscarriage/TOP
Any invasive procedure (amnio, CVS)
Possibility of fetal-maternal haemorrhage
If they deliver a neonate who is Rh-positive
Which haemoglobinopathies should be tested for?
Thalassaemia (including carriers)
Sickle Cell
How can Sickle Cell be identified?
Newborn Blood Spot
5days post-delivery
What is IUGR an indicator of?
Placental insufficiency
What does it mean if a baby is constitutionally small?
Small baby due to e.g small mother, placenta working sufficiently
What fetal growth measurements should be taken?
BPD: Biparietal diameter
HC: Head circumference
AC: Abdominal circumference
FL: Femur length
How is EDD calculated?
LMP +7days +9months
Define gravidity & parity
G: Number of times a woman has been pregnant
P: Number of times that a woman has given birth with a gestational age of 24weeks
How is parity calculated?
Parity = (A) + (B)
A)Deliveries after 24weeks (live/stillborn)
B)Losses before 24weeks (TOP/miscarriage)
How do the following change in pregnancy:
- RR
- HR
- Hb Conc
- Albumin
- Renal blood flow
- RR: Stays the same
- HR: Increases
- Hb Conc: Decreases
- Albumin: Decreases
- Renal blood flow: Increases
What are the changes to the CV, Resp, GI system in pregnancy?
CV:
Inc= Plasma vol, HR, SV, CO, Uterine & renal BF
Same= MAP, CVP
Dec= Systemic & pulm vasc resistance, mid-trimester BP
Resp:
Inc= Tidal vol, Insp capacity, O2 consumption
Same= RR, Peak flow
Dec= Total lung capacity, resid vol, exp & insp reserve, functional resid capacity
GI:
Inc= Weight, Gallstones, reflux, Nutritional requirements
Same= Amylase
Dec= GI motility, Stomach pH
What are the changes to the liver, haematology, renal & immune system in pregnancy?
Liver:
Inc= Alkaline phosphatase
Same= Bilirubin
Dec= Albumin, Aspartate & Alanine transaminase
Haem:
Inc= MCV, RC mass, WCC, Total iron binding capacity
Same= MCHb, Ferritin
Dec= Hb Conc, Platelet count, haematocrit
Immune:
Inc= ESR
Same= CRP
Renal:
Inc= Blood flow, Creatinine clearance
Same= Daily voided vol, plasma Na+, K+, Cl-
Dec= Plasma urea, creatinine
What test can be used to detect if a fetomaternal haemorrhage has occured?
Kleinbauer test at 20weeks
Detects & quantifies level of haemorrhage
Can alter amount of anti-D required
What occurs at each antenatal appointment?
8-12: Booking
10-13+6: Dating scan
11-13+6: Triple test
16: Info on blood/rhesus results, routine BP & urine
18-20+6: Anomaly scan
25: PRIMIP ONLY- BP, urine, symphysis-fundal height
28: BP, urine, SFH, 2nd screen for anaemia & red cell alloantibodies. Hb < 10.5 g/dl consider iron, 1st dose anti-D to rhesus -ve women
31: PRIMIP ONLY- same as 25week
34: Routine monitoring as above, 2nd dose anti-D, info on labour & birth plan
36: Routine monitoring, check presentation (offer ECV), info on BF, Vit K, baby-blues
38: Routine monitoring
40: PRIMIP ONLY-Routine monitoring
41: Routine monitoring, discuss IOL
