Fetal Problems Flashcards
Small for gestational age definition
Expected birth weight is less than the 10th percentile for that particular gestational age
Intrauterine growth restriction definition
The expected growth rate of fetus slows as pregnancy goes on indications of a pathological cause. Neonates have features of poor development.
Low birth weight definition
Birth weight less than 2500g irrespective of gestational age, sex, race, and clinical features
Fetal macrosomia definition
Macrosomia = birth weight over 4500g. Relates to
birthweight, therefore a fetus cannot technically be described as macrosomic until it is born
Large for dates definition
Expected birth weight is over the 90th percentile for that particular gestational age
Factors influencing intra-uterine growth restriction and small for gestational age
Maternal = smoking, alcohol consumption, malnutrition and poor diet, low BMI before pregnancy, under 17yrs or over 40yrs, cocaine use. Fetal = multiple pregnancy, antepartum haemorrhage, chromosomal abnormalities, Pathologies = anaemia, pre-eclampsia, renal disease, antiphospholipid syndrome, Diabetes, HTN.
Causes of decreased fetal movements and management
Fetal position. Maternal obesity. Fetal sleeping. Alcohol, corticosteroids or maternal substance misuse. Oligo/poly-hydramnios. Maternal or fetal anaemia. Placenta position. Fetal death. Mx = Doppler auscultation. CTG for at least 20mins. US scan.
Methods of fetal monitoring
Cardiotocography (CTG) Fetal ECG (direct via scalp (gold standard) or indirect via abdo)
Analysis of a CTG
Baseline HR (bpm)
Variability in HR
Presence of accelerations
Presence fo decelerations
Causes of a decrease in fetal HR variability
Sleeping baby, maternal dehydration, morphine and analgesia use.
Reassuring signs on CTG
110-160bpm HR
Up to 5bpm in variability
No decelerations
Presence of accelerations (due to uterine contractions)
Causes of decelerations
head compression, cord compression, utero-placenta insufficiency.
Classification of CTG
Measurements can be either reassuring, non-reassuring or abnormal and then collected info can be normal (all normal), suspicious (1 non-reassuring feature) or pathological (2 or more non-reassuring features or 1 or more abnormal features).
Types of lie for fetus
Normal = longitudinal Transverse = fetus is at 90 angle to maternal plane. Oblique = fetus is at 45 degree angle to maternal plane.
Types of presentation and fetal lie which predisposes them.
Normal = vertex/cephalic from longitudinal lie. Breech= from longitudinal lie. Frank, complete or footling. Brow = head partially extended, forehead first. Face = neck extended, face first. Shoulder = from transverse lie, need c-section.
Types of position of fetus
Normal = occiput-anterior.
Occiput posterior
Occiput transverse
Left or right positions possible.
Different types of breech presentations
Meconium stained!!
Complete - flexion of legs at hip and knee, legs bent underneath baby, bum first.
Frank - flexion of leg at hip but extend at knee, pike like position.
Footling - one or both legs extended at hip and knee, foot first.
Risk factors for an abnormal presentation
Multiple pregnancy, prematurity, macrosomia, fetal abnormality (hydrocephalus), placenta praaevia, Polyhydramnios, pelvic tumour.
Complications of malpresentation and management
Cord prolapse Placenta abruption Fetal hypoxia Fetal cervical cord injury Prolonged labour
Factors causing IUGR
MATERNAL = low socio-economic status, poor weight gain by mother during pregnancy. Maternal anaemia. Maternal smoking and drug use. Maternal co-morbidities e.g. HTN, DM, CVD. PLACENTAL = pre-eclampsia, multiple pregnancy, uterine malformations, placenta accreta, placenta praevia. FETAL = intrauterine infection, chromosomal abnormality.
Factors which influence growth of fetus
Maternal nutrition/obesity.
Multiple pregnancy
Infections (CMV)
Smoking and drug use
Pre-exisiting maternal pathology e.g. renal disease, DM.
Congenital/genetic abnormalities of fetus.
Investigating of IUGR
TVUS more regularly.
Uterine artery doppler - reduced blood flow due to poor trophoblast invasion.
Offer infection screening and karyotyping.
Management of IUGR
Close monitoring.
Consider corticosteroids if less than 36weeks gestation.
Describe the changes which occur to the fetal CVS system after birth
Umbilical vessels, ductus arteriosus, foramen ovale and ductus venosus constrict.
Origin of the ligamentum teres
umbilical vein
Origin of the ligamentum venosum
ducutus venosus
Intervention for breech presentation
External cephalic version at 37 weeks,
Contraindications for external cephalic version
Placenta praevia Pre-eclampsia Abnormal CTG Membranes have ruptured Uterine abnormality (bicornate)
Test for fetal-maternal haemorrhage and to measure the amount of fetal hemoglobin transferred from a fetus to a mother’s bloodstream.
Kleihauer test
