Obstetrics Flashcards
What happens at a booking visit and when is it?
8 - 12 weeks (ideally < 10 weeks)
Booking visit – with midwife. Give info on how baby develops during pregnancy
- general information e.g. diet, alcohol, smoking, folic acid 400mg, vitamin D, antenatal classes, pelvic floor exercises, discuss mental health classes
- Risk assessment
- BP, urine dipstick, check BMI
Booking bloods/urine
- FBC (anaemia/ low platelets), blood group, rhesus status, red cell alloantibodies, haemoglobinopathies (sick cell + thalassaemia)
- Infection: hepatitis B, syphilis, HIV
- Urine culture (mid-stream urine specimen) to detect asymptomatic bacteriuria. Urine: Glycosuria, proteinuria, haematuria
Risk assessment
- 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
No evidence that routine screening for GBS, toxoplasmosis, CMV, chlamydia, hep C or asymptomatic BV beneficial
What different DS testing occurs and when is it?
11 - 13+6 weeks
DS (+Edwards T18, Patau’s T21) screening including nuchal scan
- Nuchal translucency scan - Down syndrome
- Preferred: Combined – USS nuchal translucency measurement + blood test (↑HCG, ↓PAPP-A)
- NIPT: not offered by NHS routinely
If women book later in pregnancy
- Triple test: AFP, unconjugated oestriol, HCG
- Quadruple test: as above + inhibin-A
When is a fetal anomaly scan and what does it look at?
Fetal Anomaly scan: USS – limitations: depends on BMI + baby position
- Dating scan
- CRL used unless beyond >84mm. Then HC used
When is anti-D prophylaxis given? What else occurs then?
28 weeks then 34 weeks
- Routine care: BP, urine dipstick, FSH
- Second screen for anaemia and atypical red cell alloantibodies. If Hb < 10.5 g/dl consider iron
What conditions are screened for during pregnancy?
- Anaemia
- Bacteriuria
- Blood group, Rhesus status and anti-red cell antibodies
- Down’s syndrome
- Fetal anomalies
- Hepatitis B
- HIV
- Neural tube defects
- Risk factors for pre-eclampsia
- Syphilis
The following should be offered depending on the history:
- Placenta praevia
- Psychiatric illness
- Sickle cell disease
- Tay-Sachs disease
- Thalassaemia
Routine use of USS after 24 wks of gestation unsupported and only offered in specific circumstances such as?
- Low lying placenta at 20 wks - rescan at 32 weeks
- Suspected small for date on clinical examination/ customised growth charts
- Suspected malpresentation of clinical examination
- Women who decline IOL from 42weeks should be offered USS estimation of maximum amniotic pool depth
What are some of the Normal variant screening in pregnancy (previously soft markers?
- nuchal fold >6 mm
- Ventriculomegaly>10mm
- Echogenic bowel
- Renal pelvic dilatation
- Biometry <5th centile on national charts
What invasive procedures are offered for screening?
Amniocentesis - 15 weeks
Chorion villus sampling - 10 weeks
When is amniocentesis used and how?
after 15 weeks under USS guidance
- 15-20ml of aspirated using 22G needle
- Culture of amino types, harvesting and banding
- Risk of miscarriage is 1% preterm delivery, chronic liquor leak
- Assessment of fetal karyotype - maternal age, high risk for Down’s syndrome, USS findings, parental translocation, maternal request, measurement of AFP and ACHE assessment of congenital néphroses, virology screen
‣ PPROM to rule out chorioamnionitis
‣ OD 450 haemolytic disease
What are some RFs for breech presentation?
- uterine malformations, fibroids
- placenta praevia
- polyhydramnios or oligohydramnios
- fetal abnormality (e.g. CNS malformation, chromosomal disorders)
- prematurity (due to increased incidence earlier in gestation)
How is chorionic villus sampling carried out and for what?
10 weeks, USS guided, trans abdominal/ trans cervical. Risk of miscarriage. Results in 7 days
- Uses: to assess fetal karyotype and achieve a rapid result.
- Assessment of genetic abnormalities: CF, thalassaemia major, detection of viral DNA maternal sérosités conversion CMV
- Cordocentesis
- Fetoscopy
- Fetal skin biopsy
- Aspiration of fluid filled fetal cavities
What are some of the important terms in labour?
- Labour - progressive effacement and dilatation of the cervix in the presence of regular uterine contractions
- Delivery - expulsion of the fetus and placenta
- Show - cervical mucus plus
- SROM - spontaneous rupture of membranes, can precede labour
- ARM – artificial rupture of membranes
What are the three factors that affect labour?
Passage
- Pelvis: >11cm pelvis inlet. 12cm mid cavity. 10-11.5cm pelvic outlet
- Soft tissues: lower uterine segment, cervix, vagina, vulva, pelvic floor, perineum
Powers
- There is fundal dominance of contractions
- Contractions are rhythmic and occur ever 3-4 mins in early labour and every 2-3 minutes in advanced labour
Passenger
- Lie: oblique and transverse lies
- Presentation: part of the fetus lowermost in the uterus (céphalique, vertex, brow, face, breech, shoulder)
- Denominator: part of the fetus used as a reference point to describe position in the maternal pelvis (occiputs, mentum, sacrum, acromion)
Position: relation of the fetal denominator to the maternal pelvis
What is the normal mechanism of labour?
- Engagement
- Flexion
- Descent
- Internal rotation – contractions bringing the head down
- Extension
- External rotation
What monitoring goes on labour?
- FHR monitored every 15min (or continuously via CTG)
- Contractions assessed every 30min
- Maternal pulse rate assessed every 60min
- Every 4H: Maternal BP and temp, VE, maternal urine (for ketones and protein)
What are the different stages of labour?
-
Stage 1: from the onset of true labour to when the cervix is fully dilated (8-18h primip and 5-12 multip)
- Latent phase = 0-3 cm dilation, normally takes 6 hours – painful, irregular contractions and cervix effaces then dilates
- Active phase = 3-10 cm dilation, normally 1cm/hr (regular contractions)
-
stage 2: from full dilation to delivery of the fetus
- Passive: complete cervical dilatation but no pushing
-
Active: refers to the active process of maternal pushing (valsava) (usually 3h)
- less painful than 1st (pushing masks pain)
- lasts approximately 1 hours
- If longer than 1 hour (can be left longer if epidural) consider Ventouse extraction, forceps delivery or caesarean section
- episiotomy may be necessary following crowning
- Associated with transient fetal bradycardia
-
stage 3: from delivery of fetus to when the placenta and membranes have been completely delivered
- At uterus contract to a 24 week size post birth, the placenta separates from the uterus through the spongy layer of decidua basalis
- It then buckles and a small amount of retroplacental haemorrhage takes place
What are some of the common problems in labour?
- Failure to progress (delay in first or second stage)
- Malpresentation/ malposition
- Breach, transverse, oblique
- Suspected fetal compromise (fetal distress) – problems with fetal HR
- Vaginal birth after C section -
- Operative delivery – vaginal or abdominal
- Shoulder dystopia
What are some of the causes of failure to progress?
- Fetal malposition/malpresentation
- Cephalopelvic disproportion (relative, absolute)
- Obstructed Labour – e.g. haematuria, cervix becomes swollen and oedematous
- Maternal Exhaustion
- Mx: oxytocin
What problems arise from malrotation/ malpresentation?
- Malrotation: OP position – baby looking up. Changes how head presses on cervix
- Malpresentation:
- Face – when baby heais fully extended. Cannot come out vaginalis if chin is at the back.
- Brow – when head becomes more and more extended
What are of the complications of breech pregnancy?
- Intracranial haemorrhage, internal injuries, cord prolapse, trapped after coming head
- Higher incidence of fetal abnormality and neuro developmental problems regardless of mode of delivery
- Mx: ECV at 36 weeks, if still breech:
- Elective c section; Vaginal breech delivery
What indicates suspected fetal compromise?
-
Non-reassuring CTG: high sensitivity but low specificity
- Baseline tachycardia/ bradycardia
- Reduced baseline variability
- Absence of acceleration (non reactive)
- Presence of decelerations
- Passage of meconium
- Confirm by fetal acid base status
- Eliminate the need for the FBS
What are some of the causes of suspected fetal compromise?
- Uterine hyperstimulation
- Maternal Hypotension – can cause fetal distress. Also epidural
- IUGR – poor fetal tolerance of labour
- Cord compression
- Infection
- Maternal disease
How is suspected fetal compromise mx’d?
- Rectify reversible causes e.g. maternal hypotension
- Left lateral position
- Stop oxytocin
- Confirm compromise by blood sampling where possible
- Deliver by speediest route if unable to correct or if significant acidosis
How is VBAC mxd?
- Do not use oxytocin/ prostaglandins to induce labours. Usual manual induction
- Risks: Emergency C section in labour
What are the CI, precautions and risks ax’d with VBAC?
- CI: previous uterine rupture or classical caesarean scar
- Precautions: IV access, G+S, continuous fetal monitoring. Avoid prolonged labour.
- Risks: Emergency C section in labour
What are some indications for operative delivery?
- Failure to progress to 2nd stage
- Fetal distress in 2nd stage
- Maternal reasons
What are some Pre-requisites for operative (instrumental) delivery?
- trained operator, full dilation, absent membrane, cephalic presentation, clearly defined position, presenting part engaged, no evidence of CPD, adequate analgesia, empty bladder
What are some complications of operative/ instrumental delivery?
- failure
- Fetal trauma
- maternal trauma
- PPH
- urinary retention
- cephalohaematoma: oedema following forceps delivery
What are some indications for C section?
- absolute cephalopelvic disproportion
- placenta praevia grades 3/4
- pre-eclampsia
- post-maturity
- IUGR
- fetal distress in labour/prolapsed cord
- failure of labour to progress
- malpresentations: brow
- placental abruption: only if fetal distress; if dead deliver vaginally
- vaginal infection e.g. active herpes
- cervical cancer (disseminates cancer cells)
What are some complications of C section?
- Infection
- haemorrhage
- bladder bowel injury
- thromboembolic disease
- requirement for blood transfusion
- TTN
- fetal trauma
What is shoulder dystocia?
- Complication of vaginal cephalic delivery.
- It entails inability to deliver the body of the fetus using gentle traction, the head having already been delivered
Who is at risk from shoulder dystocia?
- macrosomic baby
- diabetic mother
- using rotational instrument
- high maternal BMI
- prolonged labour
What are some of the complications of shoulder dystocia?
- Fetal death
- Asphyxia with resulting hypoxic damage
- Birth trauma (Erb’s palsy, fractured bones, brachial plexus injury)
- Maternal trauma: soft tissue, psychological
How is shoulder dystocia managed?
- McRoberts position: entails flexion and abduction of the maternal hips, bringing the mother’s thighs towards her abdomen. This rotation increases the relative anterior-posterior angle
- Supra public pressure – press on the side that the back is on
- Obstetric maneovres – wood screw – try and spin the baby around.
- Consider episiotomy. No oxytocin
How can a CTG be improved?
- Terbutaline
- Fetal scalp stimulation
What are some causes/ RFs for reduced fetal movements?
- Posture: positional changes in fetal movement awareness, generally being more prominent during lying down and less when sitting and standing
- Distraction: Awareness of fetal movements can be distractable
- Placental position: Patient with anterior placentas prior to 28 weeks gestation
- Medication: alcohol and sedative medications (opiates or benzos)
- Fetal position: Anterior fetal position means movements are less noticeable
- Obese patients
- Amniotic fluid volume: oligohydramnios and polyhydramnios
- Fetal size: SGA fetus
How are reduced FM Ixd?
Ix: handheld doppler.
-
28 weeks: handheld doppler.
- No HB? -> USS immediately
- If fetal HB - CTG
What are indications for Induction of Labour?
- prolonged pregnancy, e.g. 1-2 weeks after the estimated date of delivery
- prelabour premature rupture of the membranes, where labour does not start
- diabetic mother > 38 weeks
- pre-eclampsia
- rhesus incompatibility
- Bishops score
- Score of < 5 indicates that labour is unlikely to start without induction
- Score of ≥ 8 indicates that the cervix is ripe, or ‘favourable’ - there is a high chance of spontaneous labour, or response to interventions made to induce labour
What is bishop score?
- Score of < 5 indicates that labour is unlikely to start without induction
- Score of ≥ 8 indicates that the cervix is ripe, or ‘favourable’ - there is a high chance of spontaneous labour, or response to interventions made to induce labour
What methods are used for IOL?
- Membrane sweep: passing through the cervix to rotate against the wall of the uterus, to separate the chorionic membrane from the decidua
- Vaginal prostaglandin E2(PGE2): insertion of gel, tablet (Prostin) or pessary (Propess) into the vagina. The pessary is similar to a tampon, and slowly releases local prostaglandins over 24 hours. This stimulates the cervix and uterus to cause the onset of labour
- Maternal oxytocin infusion: causes artificial ROM. Used when reason to not use vaginal prostins.
- Amniotomy (‘breaking of waters’)
- Cervical ripening balloon: passed through endocervical gland to gentle dilate cervix
- Oral mifepristone (anti-progesterone) plus misoprostol are used to induce labour where intrauterine fetal death has occurred.
What are the complications of IOL?
Uterine hyperstimulation – prolonged and frequent uterine contractions – ‘tachysystole’
- Consequences: intermittent interruption of blood flow to the intervillous space over time ->
- Fetal hypoxemia and acidemia
- Uterine rupture (rare)
- Mx: removal of vaginal prostaglandins, stop oxytocin infusion, tocolysis with terbutaline
What is the puerperium?
- Definition: time from delivery until the anatomical and physiological changes of pregnancy have resolved
- Roughly 6 weeks
- Period of manor physical, social and emotional change and adaptation
What physiological changes go through in pueruium?
- Lochia and uterine involution – bleeding in the discharge
- Lactation
- Menstruation and resumption of ovulation
What is lochia?
- Lochia: bleeding after delivery of baby in placenta.
- Endometrial slough of red and white cells: Mix of blood, tissue and mucus
- Blood for first few days
- Serosanguinous for up to 7-10 days
- Clear for 6 weeks
What happens in uterine involution?
- From 1kg to 100g
- Felt at the umbilicus after delivery
- Becomes a pelvic organ by 10 days – due to contractility of uterus
- Cervix firms at 3 days and closed Os by 3 weeks
What happens in lactation in the puerperium period?
- Oestrogen stimulates duct growth
- Progesterone stimulates alveolar growth
- Placental lactogen affects growth of epithelium in alveoli
- Colostrum – sero sanguinous – for first 3 days
- Followed by establishment of milk secretion
- Continued lactation depending on suckling
When does menstruation resume in lactating and non lactating women?
Non-lactating women:
- Resumption of menstruation after 8 weeks
- First ovulation approx 10 weeks
- About 40% of first cycles are ovulatory – so address contraception in timely manner
Lactating women:
- If for <1 month: menstruation resumes in approx 10 weeks
- If breast feeding after the first month: average interval to first ovulation is 16 weeks (6 months?)
- Breast feeding does not secure contraception beyond the 9th week post partum (up to 6months)
What information should be discussed at discharge?
- Inform GP and arrange for midwife and health visit: 6-8 weeks post natal examination
- Anti D – if indicated
- Discuss contraception + breast feeding
- Perineal care and post-natal exercise, pelvic floor exercise
- Vaginal loss, Hb check
- At post-natal visit in 6 weeks: discuss problems and assessment of fecal and urinary incontinence
What things should be ixd prior to discharge?
-
Observation of vital signs: temp, BP, HR, pulse, SATS, RR
-
Pyrexia in first 14 days: full assessment (sepsis), MSU, high vaginal swabs, blood sputum
- Unknown cause: cefalexin 500mg/8h and metronidazole 400mg/8h
- Breast infection: flucloxacillin (2nd clarithromycin); encourage breast feeding
-
Pyrexia in first 14 days: full assessment (sepsis), MSU, high vaginal swabs, blood sputum
- Uterine size and involution
- Lochia/ discharge – if still persistently red -> ?uterine involution/ 2o PPH
- Abdo would
- Perineum and para vaginal tissue
- Breast
- Lower limbs DVT
- Enquire about bladder function + bowel function
What methods of contraception are available in the puerperium period?
- Barrier
- IUCP
- Tubal ligation: mini lap, lap – consider at C section
-
Hormonal: mini/ pill/ depot injections
- POP/depot/ contraceptive implant: start any time post partum unless >x21 days for which you need 2 days other contraception
-
COCP: reduces breast milk, excreted in milk,
- If not breast feeding: start COP 3 weeks post-partum - increased risk of thrombosis if started earlier
- Need contraception for the first 7 days
What are the benefits of breastfeeding>
-
Newborn:
- Easily digested nutrients
- Antibodies: reduced risk of gastroenteritis, respiratory infection, otitis media, NEC (lysozyme, lactoferrin, IgA)
- Avoid milk allergies
- Good source of nutrition except Vit C, D and iron
- Cannot overfeed
- Reduced risk of hypocalcaemia
- To mother: Bonding, improved uterine involution, reduced risk of breast cancer, safe and cheap
What are some of the difficulties associated with breastfeding?
- Nipple inversion: correct by Waller shields in late pregnancy
- Maternal fatigue
- Emotional stress: due to sleep deprivation
What medications are CI in breastfeeding?
- antibiotics: ciprofloxacin, tetracycline, chloramphenicol, sulphonamides
- psychiatric drugs: lithium, benzodiazepines
- aspirin
- carbimazole
- methotrexate
- sulfonylureas
- cytotoxic drugs
- amiodarone
What mastitis and how does it present?
- Sx: fever, chills, malaise, pain, erythema, tenderness may induration, tender axillary lymphadenopathy, milk may be purulent
-
Two types:
- Acute intra mammary mastitis: secondary to engorgement, empty breast, cold compresses, abx prophylactically
-
Infective mastitis: secondary to staph aureus. Periareolar induration, axillary lymphadenopathy. Penicillin G resistent in 90% of cases
- Mx: Continue breast feeding; Drain existing breast abscesses. Flucloxacillin
What methods can be used to suppress lactation?
- Firm supporting bra, analgesia, +/- ice packs
- No milk expression or nipple stimulation
- Bromocriptine: not routinely used
What are the common complications of the puerperium?
- Puerperal pyrexia
- Secondary PPH
- Thromboembolic disease
- Mood changes, postnatal depression
- Urinary or faecal Incontinence
What is Puerperal pyrexia (sepsis) and how is its mxd?
- Definition: temp of 38 on any occasion in 6 wks after delivery
- Commonest organisms: Group A. B haemolytic strep, E.Coli, Staph. A
- Causes: UTI, endometritis, breast engagement (infective mastitis), chest infections or thrombosis (DVT)
- Ix: sepsis 6 pathway, MSU, HVS, blood cultures, sputum if indicated, USS, VQ etc
-
Mx: Unknown cause: cefalexin 500mg/8h and metronidazole 400mg/8h
- IV broad spectrum abx: piperacillin-tazobactam in 1h
What is 2ndary PPH?
- Definition: bleeding after 1st 24h (usually days 5-12)
- Causes: retained products, or blood clots, infection, incomplete uterine involution
- Management: conservative, abx, evacuating under GA – obstetric emergency, USS to look for retained products
what is urinary incontinence in the peurperium period and how is it mxd?
- Transient urinary retention relative common post partum
- Due to physiological effects of pregnancy, pain etc
- Mx: pelvic floor exercises, catheterisation and prophylactic abx
- Usually resolves spontaneous
what is faecal incontinence in the peurperium period and how is it mxd?
- Due to damage of perineum
- Strong association with child birth, particularly forceps delivery but not C section
What are the RFs for placental abruption?
ABRUPTION:
A for Abruption previously;
B for Blood pressure (i.e. hypertension or pre-eclampsia);
R for Ruptured membranes, either premature or prolonged;
U for Uterine injury (i.e. trauma to the abdomen);
P for Polyhydramnios;
T for Twins or multiple gestation;
I for Infection in the uterus, especially chorioamnionitis;
O for Older age (i.e. aged over 35 years old);
N for Narcotic use (i.e. cocaine and amphetamines, as well as smoking
What screening tools are used for dx post partum depression?
- GAD-2
- Edinburgh postnatal depression scale EPDS(14-15) – assesses how mother has felt this last week
What is neonatal abstinence syndrome?
caused by SSRI anti depressants taken during pregnancy
- Presentation: first few days after birth, sx: irritability and poor feeding.
- Mx: Neonates are monitored for this post delivery. Supportive mx
