Obstetrics: General Antenatal Care Flashcards
Define the following:
- Last menstrual period
- Gestational age (GA)
- Estimated delivery date (EDD)
- Gravida
- Primigravida
- Multigravida
- Para
- Nulliparous ‘nullip’
- Primiparorus
- Multiparous ‘multip’
- Last menstrual period: date of first day of last menstrual period
- Gestational age: duration of pregnancy starting from date of last menstrual period
- Estimated delivery date: estimated date of delivery (40 weeks)
- Gravida: total number of pregnancies a woman has had
- Primigravida: pt is pregnant for first time
- Multigravida: pt is pregnant for at least second time
- Para: number of times woman has given birth after 24 weeks gestation; regardless of whether fetus was alive or stillborn
- Nulliparous ‘nullip’: never given birth after 24 weeks gestation
- Primiparorus: technically refers to woman who has given birth after 24 weeks gestation once before BUT often used on labour ward to refer to woman who is due to give birth for first time
- Multiparous ‘multip’: given birth after 24 weeks 2 or more times
Initially, EDD is based on date of last menstrual period which determines gestational age and hence EDD; however, after the booking scan the gestational age is more accurately assess and EDD is updated accordingly. True or false?
True
State the Naegele rule and what it is used for
Describe how gestational age is expressed (same as neonates)
Described in weeks & days e.g.:
- 5 +0 = 5 weeks gestational age
- 13 + 6 = 13 weeks and 6 days
Outline when the:
- First
- Second
- Third
… trimester are from and to
- First: 0 - 12 weeks gestation
- Second: 13 - 26 weeks gestation
- Third: 27 weeks until birth
When do fetal movements usually start?
~20 weeks then continue until birth
*NOTE: in multigravida woman movement may start a little earlier
Outline the antenatal care timetable
From weeks 25-42 routine care (BP, urine dipstick, SFH) is offered alongside other things that are appropriate at that time. E.g. at 28 weeks and 34 weeks give anti-D prophylaxis
**Of course, dependent on pregnancy woman may have more interaction with healthcare services
How many antenatal visits does NICE recommend for the following women:
- First pregnancy uncomplicated
- Second or more pregnancy if uncomplicated
- First pregnancy “primip” uncomplicated: 10
- Second or more pregnancy uncomplicated: 7
If a woman fits certain criteria she may have additional appointments. Discuss when during pregnancy following appointments would be done if they were required:
- Oral glucose tolerance test for gestational diabetes
- Anti-D injections
- Additional ultrasound scan for women with placenta praevia
- Oral glucose tolerance test for gestational diabetes: 24-28 weeks
- Anti-D injections: 28 and 34 weeks
- Additional ultrasound scan for women with placenta praevia: 32 weeks
State what is covered at each routine antenatal appointment
*HINT: this can be discussions, measurements, investigations
- Discuss plans for the remainder of the pregnancy and delivery
- Symphysis–fundal height measurement from 24 weeks onwards
- Fetal presentation assessment from 36 weeks onwards
- Urine dipstick for protein for pre-eclampsia
- Blood pressure for pre-eclampsia
- Urine for microscopy and culture for asymptomatic bacteriuria
What vaccines are offered to all pregnant women and when?
- Whooping cough (pertussis): from 16 weeks gestation
- Influenza: when available in autumn or winter
*NOTE: live vaccines e.g. MMR are avoided in pregnancy
Outline what happens during the booking clininc
Woman meets with midwife and purpose is to discuss and arrange plans for pregnancy.
- Education
- Give green book
- Booking bloods (see separate FC)
- Basic measurements (BMI [weight, height], BP, urine dipstick for protein, urine culture for asymptomatic bacturia)
- Risk assessment
What would midwife discuss with woman as part of ‘education section’ in the booking clinic
- What to expect at different stages of pregnancy
- Lifestyle advice in pregnancy including supplements (see separate FC)
- Plans for birth
- Screening tests (e.g. Downs screening)
- Antenatal classes
- Breastfeeding classes
- Discuss mental health
What general lifestyle advice is given to pregnant women?
- Take folic acid 400mcg from before pregnancy to 12 weeks (reduces neural tube defects)
- Take vitamin D supplement (10 mcg or 400 IU daily)
- Avoid vitamin A supplements and eating liver or pate (vitamin A is teratogenic at high doses)
- Don’t drink alcohol when pregnant (risk of fetal alcohol syndrome)
- Don’t smoke (smoking has a long list of complications, see below)
- Avoid unpasteurised dairy (e.g. camembert, brie) or blue cheese (risk of listeriosis)
- Avoid undercooked or raw poultry (risk of salmonella)
- Continue moderate exercise but avoid contact sports
- Sex is safe
- Flying increases the risk of venous thromboembolism (VTE)
- RCOG say flying is generally ok in uncomplicated pregnancies up to 37 weeks in single pregnancy and up to 32 weeks in twin pregnancy. Advise on wearing compression stockings. Airlines often require a note after 28 weeks gestation from midwife, GP, obstetrician to state pregnancy is healthy and no additional risks
- Place car seatbelts above and below the bump (not across it)
Certain women, who are at increased risk of neural tube defects, should take an increased dose of 5mg of folic acid; state some examples of women who fall into this category
Certain women are at an increased risk of neural tube defects and thus should take an increased dose of 5mg folic acid. Women falling into this category include:
- Previous child with NTD
- Maternal or parental FH of NTD
- Diabetes mellitus
- Women on antiepileptic
- Obese (body mass index >30kg/m²)
- HIV +ve taking antiretrovirals co-trimoxazole
- Sickle cell
- Thalassaemia
- Coeliac disease
What bloods are included in the booking bloods?
- FBC: anaemia
- Blood group, red cell autoantibodies & rhesus D status: need to know if rhesus negative
-
Screening for haemoglobinopathies:
- Thalassaemia ALL WOMEN
- Sickle cell disease only women at HIGHER RISK
-
Infectious diseases:
- HIV
- Hepatitis B
- Syphilis
During booking clinic, midwife will asses woman for risk factors for certain conditions in pregnancy so that additional measures/plans can be put in place. State some of the conditions the midwife will assess the risk of
- Rhesus negative (book anti-D prophylaxis)
- Gestational diabetes (book oral glucose tolerance test)
- Fetal growth restriction (book additional growth scans)
- Venous thromboembolism (provide prophylactic LMWH if high risk)
- Pre-eclampsia (provide aspirin if high risk)
There is no safe level of alcohol in pregnancy. Greatest effects are in first trimester. State some potential complications of alcohol in early pregnancy
- Miscarriage
- Small for dates
- Preterm delivery
- Fetal alcohol syndrome
State some features (including visible characteristics and health problems) in fetal alcohol syndrome
- Microcephaly (small head)
- Thin upper lip
- Smooth flat philtrum (the groove between the nose and upper lip)
- Short palpebral fissure (short horizontal distance from one side of the eye to the other)
- Learning disability
- Behavioural difficulties
- Hearing and vision problems
- Cerebral palsy
State some potential complications/increased risks associated with smoking during pregnancy
- Fetal growth restriction (FGR)
- Miscarriage
- Stillbirth
- Preterm labour and delivery
- Placental abruption
- Pre-eclampsia
- Cleft lip or palate
- Sudden infant death syndrome (SIDS)
All women are offered screening for Down’s syndrome, Patau & Edward’s syndrome; true or false?
What is the purpose of screening?
- All women offered screening; woman’s choice if she wants to go ahead with screening.
- Purpose is to to decide whether women should receive more invasive tests to establish a definitive diagnosis
There are 3 screening tests for Down’s syndrome; state the name of each and when during pregnancy it can be done
- Combined test: 11 - 13 + 6 weeks gestation (FIRST LINE & MOST ACCURATE)
- Triple test: 15 - 20 weeks gestation
- Quadruple test: 15 - 20 weeks gestation
What is involved in the combined test (first line and most accurate) for Down’s syndrome?
- Ultrasound to measure nuchal translucency: nuchal translucency=nuchal thickness. Positive if >6mm
- Maternal blood tests:
- beta-hCG: higher = greater risk
- Pregnancy-associated plasma protein-A (PAPPA): lower = greater risk
*SUMMARY: Down’s syndrome is suggested by ↑ HCG, ↓ PAPP-A, thickened nuchal translucency
What is involved in the triple test for Down’s syndrome screening?
Only involves maternal blood tests:
- Beta-hCG: higher = greater risk
- Alpha-fetoprotein (AFP): lower = greater risk
- Serum oestriol: lower = greater risk
What is involved in the quadruple screening test for Down’s syndrome?
Only involves maternal blood tests:
- Beta-hCG: higher = greater risk
- Alpha-fetoprotein (AFP): lower = greater risk
- Serum oestriol: lower = greater risk
- Inhibin-A: higher = greater risk
Screening tests for Down’s syndrome give a risk score for fetus having Down’s syndrome; at what risk score is a woman offered further testing?
Risk is > 1 in 150, woman is offered:
- Invasive testing:
- Chorionic villus sampling
- Amniocentesis
- Non-invasive prenatal nesting (NIPT) **NOTE: relatively new. Gradually being rolled out in NHS as alternative to invasvie testing. Not definitive, unlike invasive, but gives very good indication.
What is involved in each of the following and when during pregnancy can they be done:
- Chorionic villus sampling
- Amniocentesis
- Non-invasive prenatal testing
- Chorionic villus sampling: ultrasound guided biopsy of placental tissue. Done <15 weeks
- Amniocentesis: ultrasound guided aspiration of amniotic fluid using needle & syringe. Used later in pregnancy once there is enough amniotic fluid to make it safer to take sample
- Non-invasive prenatal testing: take blood test from mother. Works on basis that blood will contain fragments of DNA- some of which will come from placental tissue and hence represent fetal DNA
What is involved in each of the following and when during pregnancy can they be done:
- Chorionic villus sampling
- Amniocentesis
- Non-invasive prenatal testing
- Chorionic villus sampling: ultrasound guided biopsy of placental tissue. Done <15 weeks
- Amniocentesis: ultrasound guided aspiration of amniotic fluid using needle & syringe. Used later in pregnancy once there is enough amniotic fluid to make it safer to take sample
- Non-invasive prenatal testing: take blood test from mother. Works on basis that blood will contain fragments of DNA- some of which will come from placental tissue and hence represent fetal DNA
Explain why rhesus negative women need anti-D prophylaxis
When a woman that is rhesus-D negative becomes pregnant, we have to consider the possibility that her child will be rhesus positive. It is likely at some point in the pregnancy (i.e. childbirth) that the blood from the baby will find a way into the mother’s bloodstream. When this happens, the baby’s red blood cells display the rhesus-D antigen. The mother’s immune system will recognise this rhesus-D antigen as foreign, and produce antibodies to the rhesus-D antigen. The mother has then become sensitised to rhesus-D antigens.
Usually, this sensitisation process does not cause problems during the first pregnancy. During subsequent pregnancies, the mother’s anti-rhesus-D antibodies can cross the placenta into the fetus. If that fetus is rhesus-D positive, these antibodies attach themselves to the red blood cells of the fetus and causes the immune system of the fetus to attack them, causing the destruction of the red blood cells (haemolysis). The red blood cell destruction caused by antibodies from the mother is called haemolytic disease of the newborn.
Copied straight from ZtoF
Discuss the management of rhesus incompatibility during pregnancy (include both prophylactic & sensitisation management)
Prophylactic management
Prophylactic intramuscular injections of anti-D. NICE recommend giving at:
- 28 weeks
- 34 weeks
Evidence suggest there is little difference in efficacy between single dose at 28 weeks and double dose regimes at 28 and 34 weeks; hence, RCOG advise either regime can be used.
Sensitisation event management
Intramuscular injections of anti-D should be given ASAP (at most within 72hrs) following possible sensitisation event. If sensitisation occurs in 2nd or 3rd trimester larger doses given.
- Termination of pregnancy
- Miscarriage if gestation >12 weeks
- Intrauterine death
- Ectopic pregnancy if managed surgically
- External cephalic version
- Antepartum haemorrhage
- Amniocentesis, CVS, fetal blood sampling
- Abdominal trauma
- Birth (if baby is rhesus +ve, do Kleihauer test to see how much anti-D to give)
How, on ultrasound scan, can you determine the type of twins?
- Dichorionic diamniotic: membrane between twins with a lambda or twin peak sign
- Monochorionic diamniotic: membrane between twins with a T sign
- Monochorionic monoamniotic: no membrane separating twins
- *Lambda or twin peak sign refers to triangular appearance where membrane between twins beets the chorion as the chorion blends partially into the membrane- separate placentas*
- *T sign refers to where the membrane between twins abruptly meets chorion giving T appearance- single placenta*
State a potential complication of lithium use- particularly in 1st trimester
Can lithium be used in pregnancy?
Can women taking lithium breastfeed?
- Congenital cardiac abnormalities in particular Ebstein’s anomaly (**tricuspid valve is set lower on the right side of the heart (towards the apex), causing a bigger right atrium and a smaller right ventricle)
- If it must be used as other options failed, then needs close monitoring (4 weekly, then 1 weekly from 36 weeks)
- No, it enters breast milk and is toxic to infant
Routine GBS screening is not done in the UK; discuss who should be screened and/or treated for GBS
- GBS detected in previous pregnancy- inform them that risk of GBS carriage in this pregnancy is 50% and offer either:
- Intrapartum abx prophylaxis
- Testing between 35-37 weeks or 5 weeks prior to delivery
- IAP should be given to women with previous baby with early- or late- onset GBS
- Women in preterm labour (regardless of GBS status)
- Women with pyrexia during labour
- Women with ROM >18hrs
