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49 Cards in this Set
- Front
- Back
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Outline risk factors for high risk pregnancy
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Add 1 pt for each if > 4 pts = growth restricted
Previous LBW baby Previous stillborn or neonatal death in 1st week Maternal disease: e.g., BP > 140/90; Renal disease, Hx of UTI, present UTI Bleeding Wt gain > 0.5kg in 1 wk after 20 wks Decrease or no increase in girth Smoking (2 pts) Decrease or no increase in fundal height (3 pts) |
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What details on history are important when assessing a fetus which may be small for gestational age or have restricted uterine growth?
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Fetal movement
PV loss Previous history of GR baby Maternal illnesses incl. HT --> oligohydramnios and GR; IBD and renal failure --> GR Drugs, smoking, alcohol (cocaine and cigs --> decreased placental perfusion) Low SES |
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What are you going to examine in a woman with a suspected restricted uterine growth?
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Symphysis-fundus height measurements: most accurate from 20-33 wks - plot on reference chart
CTG If mother at high risk OR SFH lags > 2cm behind GA --> Anatomy US - assess biparietal diameter (gives an estimate of fetal weight), head and abdomen circumference, femur length, and fetal weight, amniotic fluid volume Doppler fetal blood flow velocity - if compromised (hypoxia), fetal blood flow is directed to the brain and decreased peripherally - look for reversed diastolic flow = poor outlook Cordocentesis (fetal blood sampling) - not justified > 1500g due to risk of fetal death |
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What are non-reassuring and abnormal fetal measurements on a CTG?
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HR
Non-reassuring 100-109 or 161-180; abnormal < 100 or > 180 Variability < 5 for 40-90 mins - non-reassuring < 5 for > 90 mins - abnormal Decels Non-reassuring - early, variable abnormal - late, atypical |
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Definition of macrosomia
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infant weight > 90th percentil for a particular GA or > 4000g
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Causes of IUGR
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Fetal causes:
Genetic; Chromosomal abnormalities; TORCH infections; multiple pregnancy Maternal causes: Smoking, ETOH, Drugs, stress, malnutrition Maternal medical hx: DM, SLE, pulmonary insuffieiency Maternal-fetal Any disease causing placental insufficiency (DM, gestational HTN, chronic HTN, chronic renal insufficeicny, placental morphological abnormalities (infarction, haemangiomas) |
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Describe the 2 types of IUGR
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Symmetric/ type I (20%)
early in pregnancy, inadequate growth of head and body head: abdomen ratio may be normal usually associated with congenital anomalies or TORCH infections Asymmetric/type II (80%) Occurs late in pregnancy brain is spared, therefore head: abdomen ratio increased usually associated with placental insuffieicny more favourable prognosis than type 1 |
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What investigations should be done to determine the cause of IUGR
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FBC
EUC, LFT, urate - pre-eclampsia TORCH screen - viral studies on swab/serology Karyotyping if early IUGR, severe < 3rd centile, structural anomaly identified, IUGR in the presence of polyhydramnios |
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How should IUGR be managed?
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Prevention
Induce labour if close to term < 34 weeks: US?AFI and CTG twice weekly, steroids if expect premature delivery Birth should NOT be > 40 wks |
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What complications are neonates with IUGR prone to?
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meconium aspiration, asphyxia, polycythemia, hypoclycaemia, mental retardation
Greater risk of perinatal morbidity and mortality |
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Causes of macrosomia
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maternal obesity
gestational DM past hx of macrosomic infant prolonged gestation multiparity |
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Birth risks of macrosomia
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birth trauma for baby and mother
birth asphyxia shoulder dystocia Erbs palsy - stretching of brachial plexus results in neuropathy: limb atony with shorter arm, internally rotated shoulder and flexed wrist |
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Investgiations to diagnose macrosomia
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serial SFH
US predictors polyhydramnios third trimester abdominal circumference > 1.5cm/week head circumference/AC ratio < 10th percentile femur length/AC ratio < 20th percentile |
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Macrosomia - NVB or CS?
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There is no evidence that prophylactic C/S improves outcomes BUT C/S reasonable option if estimated fetal weight > 5000g in nondiabetic women and > 4500 g in diabetic women
Early induction of labour is not recommended for non-diabetic moethers |
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Define polyhydramnios
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amniotic fluid volume > 2000 cc at any stage in pregnancy
US criteria: > 8 x 8cm (3.1 x 3.1 in) pocked of amniotic fluid |
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Causes of polyhydramnios
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Idiopathic (most common)
maternal - type 1 DM (causes abnormalities of transchorionic flow) maternal-fetal - chorioangiomas, multiple gestation, fetal hydrops fetal - chromosome anomaly, cystic adenomatoid malformed lung, anencephaly, hydrocephalus, meningocele, tracheoesophageal fistula, duodenal atresia, facial clefts (interfere with swallowing) |
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Clinical features of polyhydramnios in the mohter
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pressure sx from overdistended uterus (dyspnoea, oedema, hydronephrosis)
uterus large for dates, difficulty palpating fetal parts and hearing fetal heart tones |
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Complications of polyhydramnios
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cord prolapse, placental abruption, malpresentation, preterm labour, uterine dysfunction and PPH
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Management of polyhydraminos
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Determine underlying cause (maternal disease/infection; US)
mild-moderate - no Rx severe - hospitalise and consider therapeutic amniocentesis |
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Define oligohydramnios
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Amniotic fluid index of 5cm (2 in) or less
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Causes of oligohydramnios
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Early onset
Decreased production: renal agenesis or dysplasia, urinary obstruction, posterior urethral valves (male), chronic hypoxemia leading to IUGR resulting in shunting away from the kidneys to ensure profusion of the brain Increased loss: prolonged amniotic fluid leak (most often labour ensues) Late onset Amniotic fluid normally decreases after 35 weeks; common in post-term pregnancies; US doppler studies |
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Clinical features of oligohydramnios
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Cord compression
increased risk of adverse fetal outcomes early onset - fetal anomalies, amniotic fluid bands can lead to Potter's facies, limb deformities, abdominal wall defects Late onset: pulmonary hypoplasia |
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Management of oligohydramnios
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maternal hydration with oral or IV fluids to help increase amniotic fluid
vesicoamniotic shunt: if aetiology is related to fetal obstrcutvei uropathy injection of fluid via amniocentesis (improves condition for 1 week) consider delivery if at term |
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What is chorioamnionitis
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Infection of the chorion, amnion and amniotic fluid typically due to ascending infection by organisms of normal vaginal flora
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What are the common organisms in chorioamnionitis
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GBS
Bacteroides Prevotella E coli Strep |
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RF for chorioamnionitis
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Prolonged ROM
long labour Multiple vaginal exams during labour internal monitoring bacterial vaginosis and other vaginal infections |
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Clinical features of chorioamnionitis
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Maternal fever
Maternal or fetal tachycardia uterine tenderness foul and purulen cervical discharge Raised maternal WCC |
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Investigations in chorioamnionitis
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FBC
blood and amniotic fluid - leukocytes or bacteria in amniotic fluid |
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Management of chorioamnionitis
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IV antibiotics
expedient delivery regardless of gestational age |
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Complications of chorioamnionitis
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Bacteraemia of mother or fetus
wound infection if CS pelvic absecess infant meningitis |
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Which type of twin gives you a lambda sign on US
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Monozygotic
Dichorionic Diamniotic |
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Which type of twin gives you the C sign on US
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Monozygotic
monochoroionic Diamniotic |
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Fetal complications with twins
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prematurity (multiple gestation is more common cause of prematurity)
IUGR malpresentation congenital anomalies twin-twin transufion twin interlocking (twin A breech, twin B vertex) single fetal demise |
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Maternal complications with twins
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hyperemesis gravidarum
GDM - jump straight to GTT 75mg gestational HTN anaemia Cholestasis, acute fatty liver, PUPPS Thromboembolism increased physiological stress on all systems increased compressive symptoms C/S |
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Utero-placental complications of twins
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increased PROM
polyhydramnios placenta praevia placental abruption PPH (uterine atony) umbilical cord prolapse cord anomalies (velementous insertion, 2 vessel cord) |
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How do you diagnose multiple gestations?
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Usually via US
but also seen with rapid maternal weight gain, rapid uterine growth, increased beta-HCG, HPL(human placental lactogen), MSAFP (maternal serum alpha fetoprotein) for GA |
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What is twin twin transfusion syndrome?
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Unequal flow within vascular communications between twins in a shared placenta --> one anaemia, hypovolaemic, IUGR twin and one large, plethoric, polycythemic, hypervolaemic, CHF, oedema, polyhydramnios, kernicterus
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How do you diagnose twin twin transfusion syndrome
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US screening
Doppler flow analysis |
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How do you treat twin twin transfusion syndrome?
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therapeutic serial amniocentesis to decompress polydyramnios of recipient twin and decrease pressure in cavity and on placenta
intrauterine blood transfusion of donor twin if necessary Laser ablation of placental anastomoses |
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Delivery of twins
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If twin A presents as vertex + no maternal complications, and not MAMC - vaginal
Otherwise C/S - MAMC - done elective at 37 weeks Must have electronic monitoring and scalp monitoring, must have epidural or regional analesia |
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What is a complication of mo-mo twins
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They circulate in the same amnion (fluid sac) and so can get entangled
high rates of intrauterine foetal demise |
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What are the 2 different mechanisms for twinning?
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Monozygotic - both fetuses arise from a single fertilised ova
- both fetuses share placenta and chorion - 98% of MZ twins have their own amnion (fluid sac) 2% share amnion (risk of cord entanglement) Dizygotic - result of multiple ovulation with fertilisation by separate sperm Each fetus has own placenta, amnion, chorion |
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RF for dizygotic twins
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IVF
increased maternal age newly discontinued OCP Ethnicity (e.g., certain African regions) Family hx Previous DZ twins |
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What are the 4 types of monozygotic twins?
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Di-Di - split before day 3
Mo-Di (monochorionic (one placenta), diamniotic) - split on day 3-8 Mo-Mo - split day 8-13 Conjoined - split day 13-15 |
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What type of twin is at risk of twin twin transfusion?
What % develop it? |
10% of monochorionic twins
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What is the incidence of twins?
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1: 80 twins (2/3 are dizygotic) 69% DZ, 31% MZ
1: 7000 triplets Multiple gestation seen in 30-50% of IVF pregnancies |
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Describe the pathophysiology of rhesus iso-immunisation?
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If a mother is rhesus negative and a baby is rhesus positive, she can become sensitiesd to Rh antigen and develop antibodies against this. These are a problem with the second pregnancy.
IgG antibodies against Rh antigen can cross the placenta and cause foetal hydrops (foetal haemolysis and anaemia with extramedullary production of RBCs) NB: Risk in pregnancy is 1.5% but Rx reduces this to 0.2% |
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When is anti-D given?
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To Rhesus negative woman at:
28 weeks and 34 weeks and postpartum is neonate is Rh positive within 72 h of birth If fetal cells are present in maternal blood via Kleihauer test, then additional injection is needed OR fater CVS or amniocentesis ectopic preg, threatened miscarriage, APH or abdo trauma, abortion |
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What are mother's who've just given birth to twins particularly at risk of?
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PPH
Distended uterus - atonic + larger placental mass MUST give syntocinon with twins NB: also at big risk of PND |
