Antenatal Care Flashcards
(155 cards)
You are seeing a 28 year old woman in the GP clinic. She is planning to get pregnant and would like to know how she can optimise her health for her baby. She has no significant PMH and is not taking any medicines. BMI normal, BP normal. Please counsel her.
- Diet advice: eat a healthy diet with fruits/veg, whole foods and high fibre. Do not ‘eat for two’.
- Exercise: good to maintain fitness, with aerobic exercise and strength. Pelvic floor exercises can be useful to decrease the risk of incontinence after delivery.
- Substances: stop smoking, no/little alcohol, no drugs
- Pregnancy multivitamins: from Boots/etc. Make sure folic acid at least.
- Refer to info: NHS website, Start4Life
A 29 year old woman attends antenatal clinic for her booking visit at 8 weeks. After a history and examination, what investigations would you like to do?
- Urine dip and MC&S (looking for asymptomatic bacteriuria, proteinuria, glycosuria)
- Bloods including FBC (anaemia, low platelets), serology for HIV, HBV, syphilis, G+S (ABO and RhD)
- USS between 10+0 and 13+6 weeks for dating
- Combined screening for Down’s syndrome
What are the two different screening methods for Down’s syndrome? What results are suggestive of Down’s syndrome?
1) Combined test: nuchal translucency, PAPP-A, BhCG
2) Quadruple test: BhCG, AFP, inhibin A, unconjugated oestriol
A high bhCG and inhibin A, as well as low PAPP-A, AFP, and oestriol indicate possible Down’s syndrome.
What are the risks to the mother and fetus of a high maternal BMI?
Mum: GDM, hypertension including pre-eclampsia, VTE, increased risk of operative delivery, increased complications after delivery.
Fetus: macrosomia and FGR, congenital malformations, stillbirth + miscarriage, childhood obesity.
You are seeing a woman after her booking visits to give her the results of her screening tests. She is HBV +. Please counsel her.
- Tell her diagnosis and check understanding
- Explain: viral infection affecting liver. Transmitted sexually and through blood products. Can be lifelong, or in some adults the body can clear the virus.
- Referral to GUM and hepatology for further tests and information
- For the pregnancy, this means there is an increased risk to the baby of getting the virus from the mum, though this doesn’t always happen
- Baby will need vaccination at birth and 2 more at 1 month and 6 months. Will also give baby antibodies, which will help the baby’s immune system to fight the virus.
- Check for understanding and questions. Give leaflets
What are the risk factors for pre-eclampsia? When and how would you prevent pre-eclampsia?
High risk: previous hypertensive disease in pregnancy, CKD, autoimmune disease like SLE, DM, existing hypertension
Moderate risk: primiparity, multiple gestation, age >40, BMI >35, FHx, 10 years between pregnancies
Prevention with 75-150mg aspirin in women with 1 high risk factor or 2+ moderate.
What are the risk factors for GDM? Who should be screened and how?
RFs: previous GDM or macrosomia, FHx of DM, ethnic origin, obesity.
In women with previous GDM, screen with 2 hour OGTT at 16-18 weeks and again at 24-28 weeks. In other women with RFs, only screen at 24-28 weeks.
What results in an OGTT diagnose GDM?
Fasting glucose >/=5.6mmol/L or 2 hour postprandial of >/= 7.8
What is the difference between exomphalos and gastroschisis? When are they abnormal?
Exomphalos: covered by membranes, umbilical cord inserts into apex of sac, associated polyhydramnios, high incidence of congenital abnormalities
Gastroschisis: free floating abdo contents (rough outline on USS), umbilical cord inserts laterally, associated oligohydramnios.
Herniation into the umbilicus eg. in exomphalos is normal from 5/6 weeks until 12 weeks. Diagnosis cannot be made before then.
What are the 2 main categories of prenatal testing? What do they include?
Non-invasive: USS, serology, cffDNA
Invasive: chorionic villus sampling, amniocentesis, cordocentesis
When can you do CVS and amniocentesis? What do they test? What are the complications?
CVS from 10 weeks, samples fetal trophoblast cells in placental villi. Amnio from 15 weeks, samples amniotic fluid to isolate fetal cells.
Risk of miscarriage- 2% in CVS, 1% in amnio. Pain, infection eg. chorioamnionitis, RhD alloimmunisation
What are the ways for monitoring fetal growth? Which is routinely used?
Symphisis-fundal height measurement and USS. SFH is measured at each antenatal visit, and USS used if there are any suspicions of abnormal growth eg. SFH large/small for dates, or to monitor high-risk pregnancies eg. GDM
What are the definitions of SGA and macrosomia?
SGA: below the 10th centile for age
Macrosomia: above the 90th centile
What are the complications of FGR?
Intrauterine: hypoxia, HIE, organ damage
Neonatal: NEC, hypothermia, hypoglycaemia, infection
Adulthood: chronic hypertension, DM, CVD
Describe the fetal circulation.
Oxygenated blood from the placenta is carried by the umbilical veins to the liver, then passes by the ductus venosus into the IVC and right atrium. From there, it goes through the foramen ovale into the left atrium, then LV, then out the aorta and to the head and neck.
Deoxygenated blood from the head and neck enters the RA, then to RV and into pulmonary artery. It is then shunted into the aorta by the ductus arteriosus, causing the blood travelling in the aorta to be less oxygenated. The umbilical arteries stem from the aorta and bring blood back to the placenta.
What is the purpose of amniotic fluid? How much is normal?
- Protects the fetus mechanically
- Allows movements
- Prevents adhesions
- Helps lung development
30 ml by 10 weeks, 300ml by 20 weeks, 1000ml by 38 weeks.
List 5-10 uses of USS in pregnancy.
Confirmation of viability Dating Growth monitoring Diagnosing multiple pregnancy Detecting fetal anomalies Assessing amniotic fluid volume Fetal wellbeing Estimating cervical length
What are the early signs of pregnancy on USS?
Gestational sac: 4-5weeks
Yolk sac: 5 weeks
Embryo: 5-6 weeks
Fetal heartbeat: 6 weeks
How can fetal size/growth be measured on USS?
Crown-rump length up to 14 weeks
Head circumference 14-20 weeks
Also biparietal diameter, femur length, abdo circumference used for monitoring
You are reviewing the combined screening of a mother at 12 weeks gestation. The fetus has a nuchal translucency of 5mm and the mother has low PAPP-A. Should you refer to a fetal medicine unit? Justify.
No. Referral should be made if the NT >6mm or there are 2+ soft markers.
How is amniotic fluid assessed? What is normal?
Split the uterus into 4 quadrants. Then determine the maximum vertical pool and amniotic fluid index (add deepest pool in each).
Maximum vertical pool should be 2-8cm.
AFI should be 5-25cm in the 3rd trimester.
What can cause oligohydramnios? Polyhydramnios?
Oligo: Fetal urinary tract abnormalities eg. renal agenesis. FGR/placental insufficiency, NSAIDs, post-dates
Poly: congenital abnormalities affecting swallowing eg. duodenal atresia, cleft palate. Fetal anaemia, DM, multiple pregnancy
A woman is referred to the obstetric unit for a large SFH at 30 weeks gestation. On USS, the baby appears normal but there is a maximum vertical pool of 9cm. What are the next steps?
OGTT, maternal antibodies, Doppler USS of fetal MCA, consider offering amniocentesis and karytype (especially in cases of mod/severe poly eg. 12cm+)
What gestation is the fetal anomy scan done at?
18+0 to 20+6