Obstetrics Flashcards
Risk factors for recurrent APH
HTN/PET Substances Antiphospholipid IUGR Short inter pregnancy interval Abdominal trauma Polyhydramnios
Risk factors placenta praevia
Maternal
- AMA
Ethnicity - Asian
Smoking
Obstetric IVF Previous praevia Previous cs Multiple Short inter pregnancy interval
Fetal fibronectin
Glycoprotein in amniotic fluid, placental tissue, and extracellular substance of decidua basalis.
Release through mechanical or inflammatory mediated damage to membranes or placenta before birth
PPV for birth <34 weeks approx 20%, quantitative may have mor value.
Cases preterm birth
IATROGENIC (40%)
PPROM (60%) Cervix - (ERPOC, multiple LLETZ, fully cs) Infection - MSU, chlamydia, BV SES - smoking Multiple Endocrine Haemorrhage
Consequence PTB
- Visual problems related to retinopathy of prematurity
- Sensorineural hearing loss
- Impaired gross and fine motor skills due to cerebral palsy
- Delayed speech and language acquisition
- Impaired concentration, increased rates of attention deficit disorder
Components safer baby bundle
Smoking cessation Side sleeping Fetal growth restriction Decreases fetal movements Timing of birth
Mirror syndrome and differences from PET
Generalised maternal oedema, often with pulmonary involvement, hydroponic placenta producing sFLT1
Anytime during antenatal or postpartum, rapid weight gain, increasing peripheral oedema, progressive SOB,
Contrast;
HCT usually LOW (haemodilut)
Amniotic fluid HIGH (rather than low)
Fetus always shows signs of hydrops
Brest milk production.
Alveoli - lacterious ducts, lacteriferous sinus, milk duct, ejection via nipple
AN: prolactin and placental lactogen producing milk, suppressed by estrogen and progesterone, once placenta delivered, sudden drop E+P allowing prolactin to stimulate milk production, oxytocin via nipple stimulation causes contraction of myoepithelial cells, milk expelled via lactiferous ducts—->sinus—> milk duct, nipple
Subgaleal haemorrhage
Subaponeurotic. Bleeding into space between epidural aponeurosis and periosteum, caused by rupture emissary veins (btwn dural sinuses and scalp veins).
LARGE space, tehrefore high mord and mort.
Can contain 250mL of blood with only 1cm increase scalp thickness. Mort 12-25%.
Apgar <7 without sign asphyxia, particularly if prolongd vacuum.
Later-haemodynamic instability, tachycardia/tachypnoea, poor activiy, pallor, anaemia, coagulopathy, hypotension, acidosis, death.
Localised - scalp swelling + laxity “older leather pouch” filled w fluid, pitting oedema over had/in front of ears, gravity dependent, displacement ear lobes, perieauricular oedema.
Caput succedaneum
Serosanguinous, extra-aponeurotic collection may extended over midline and suture lines.
Vacuum = prominnent articial caput at site of chignon, but chignon reduces within AN HOUR of birth, not assoc w NN haem.
Cephalohaematoma
Friction during birth gives bleeding between periosteum and underlying SKULL, can happy any time, more likely w instrumental. Soft, fluctuant, swelling, well defined. May increase over 12-24 hours, may take WEEKS to resolve.
Pathophys AFE
Fetal debris + amniotic fluid breaches maternal circulation, causes anaphylactoid reaction and peripheral vasodilation and reduced venous return/hypotension, triggers extrinsic coagulation cascade and get consumptive coagulopathy
Tocolytic agents
Terbutaline 250mcg sc or IV
Salbutamol 100mcg IV
GTN 400mcg sublingual
Factors that control FHR variability on CTG
Blood pressure/volume - baroreceptors
Oxygenation - chemoreceptors
Parasympathetic nervous - ACh from vagal nerve on SA node
SNS - adr/norad on myocardium
FIGO criteria for HIE/CP in term infants
Metabolic acidosis (pH <7.0, Base deficit >12, lactate >10)
Low apgars at 1 and 5 minutes
Early onset HIE
Early imaging studies showing acute and non-focal cerebral anomaly
Spastic quadriplegic or dyskinetic cerebral palsy
Exclusion of other etiologies such as birth trauma, COAg, infection, generic
Pathophysiology of RDS
Surfactant deficiency associated with prematurity
Surfactant reduces surface tension and allows aeration at end expiration. Without surfactant reduced aeration of lungs at end expiration, collapsed alveoli, reduced compliance, and mismatched ventilation and perfusion. Reduced surfactant also can cause irritation and inflammation, epithelial injury thus exacerbating the mismatch. This can result in hypoxia which manifests as tachypnoea, nasal flaring, indrawing, grunting, hypoxia
Strategies to prevent post CS endometritis
Pre-op antibiotic prophylaxis: 1st Gen cephalosporin within 30-60 mins knife to skin, RR0.5, CSOAP trial showed reduction with additional antibiotic of azithromycin
Appropriate skin prep - alcohol based
Pre op vagina cleansing: 30s with iodine containing solution RR 0.5 for endometritis, fever, wound infection
avoidance MROP
Closure of sc fat if >2cm
How to reduce cs rate (NIcE guideline)
Avoidance undiagnosed breech IOL from 41/40 for low risk women Use of partogram with 4 hour action line FBS for suspected fetal distress 1:1 support in labour Involve a consultant obstetrician in decision making for cs
Pregnancy risks and percentages bmi >40
HTN in preg 10%
GDM 7%
T1 or T2 4%
CS 52%
Perinatal death 2% Mechanical ventilation 10% Macrosomia 20% SGA 19% LGA 16%
Evidence for risking risk PET
LDA 100mg from 12/40, inhibits COX and TXA2 synthesis resulting in reduced platelet aggregation/vasodilation/reduced inflam response.
Reduced risk of PET 18%, stillbirth 14%, SGA16%. NNT 61 Cochrane 2019.
If at high risk, <20 weeks, NNT 19, somanz
Calcium 1g daily, reduced PTH and renin release, reduces intracellular calcium which leads to reduction in vasoconstriction. Reduces PET by 50% in high risk women and even greater if low dietary intake
Benefits of breastfeeding
Maternal: weight loss, strengthens bonding, helps uterus contract post delivery and reduce PPh risk, reduces risk breast, ovarian, endometrial cancer
Neonatal: decreases sudden infant death syndrome, protects against diabetes, reduces risk obesity, reduces atopy, reduces NEC, passive immunity, lower risk of infections (otitis media, upper respiratory tract infection, UTI) acts as a mild laxative
Priorities in PPH
Mechanical
Pharmacological
Surgical
Recognise Communicate Resuscitate Manage Monitoring
ANtiphospholipid criteria
Anticardiolopin IgG or IgM at high levels (IgG >40 or IgM >99th centile)
Lupus anticoagulant - positive
AntiB2glycoprotein IgM or IgG >99th
Two or more occasions, 12 weeks apart, only one positive test
