Obstetric complications Flashcards
What risk factors are there for pre-term labour?
NB 1/3 of cases are medically indicated, 2/3 are spontaneous
-Multiple pregnancy
-Pre-eclampsia
-IUGR
-OHx of preterm delivery
-OHx of miscarriage in 2nd trimester
-Cervical surgery
SCREENING = cervical length measurement (if <15mm –> intervention)
What can cause preterm labour to occur?
-Stretch of the myometrium and foetal membranes
-Cervical weakness
-Ascending infection
What key factors dictate the decision-making in the management of pre-term labour?
- Is the pregnancy viable? (>24 weeks)
- Have the membranes ruptured?
How is pre-term labour managed differently in pregnancies before vs after the point of viability?
<24 weeks
-Unlikely to be viable
>24 weeks
-Consider antenatal steroid for foetal lung maturation
-Consider tocolysis (magnesium sulphate, nifedipine, COX inhibitors)
-Consider transfer to tertiary NNU
How is pre-term labour managed differently in pregnancies where the membranes have vs haven’t ruptured?
Membranes ruptured
-May indicated infection –> erythromycin / ben-pen
-Not appropriate to use tocolysis
Membranes intact
-Tocolysis (if no sign of infection)
How is antepartum haemorrhage defined?
-Bleeding in pregnancy after 24 weeks
–If <24 weeks = threatened miscarriage)
-Minor = <50ml, major = >50ml
What can cause APH?
UTERINE CAUSES
-Placental abruption (separates from wall of uterus)
-Placenta praevia (sits in lower portion of uterus, in-between foetus and cervix)
-Vasa praevia (foetal blood vessels are within the foetal membranes and travel across the internal cervical os - when ROM occurs –> rupture of vessels)
-Marginal bleed
CERVICAL
-“Show” - loss of mucus plug from cervix
-Cervical cancer
-Cervical polyps / ectropion
VAGINAL
-Trauma
-Infection
When does placental abruption most commonly occur?
-25 weeks
-Outcome depends on degree of separation and amount of blood loss
What risk factors are there for placental abruption?
OBSTETRIC
-Pre-eclampsia
-PROM
-IUGR
-Polyhydramnios
-Multiple pregnancy
-PMHx of abruption
MATERNAL
-Smoking
-Increased maternal age
-Hypertensive disorders
-Thrombophilias
-Cocaine use
-Trauma
How does placental abruption present?
-Vaginal bleeding, usually dark red
-Abdominal pain
-Backache
-Uterine contractions
-Hyperreflexia
-Severe uterine tenderness and tension
-Foetal distress on CTG
What is the distinction between a low-lying placenta and placenta praevia?
-5% will have a low-lying placenta on USS at 16-20 weeks
-Most rise away from the cervix so incidence of placenta praevia at delivery is only 0.5%
What risk factors are there for placenta praevia?
-Multiparity
-Multiple pregnancy
-Fibroids
-Previous C-section (scarring in lower section)
-IVF pregnancies
How does placenta praevia present?
-Painless bright red vaginal bleeding
-Hypovolaemic shock in severe cases
-Foetus rarely affected unless massive haemorrhage
How is placenta praevia classified?
Stage I = placenta in lower segment but not internal os
Stage II = placenta reaches internal os but does not cover it
Stage III = placenta covers internal os before dilation but does not cover when dilated
Stage IV = placenta completely covers internal os
How is APH managed?
-Mother’s wellbeing is the priority
-CTG and establish foetal site
-Delivery if necessary to save mother’s life
-ABCDE
–IV access, left lateral position, bloods
-Anti-D if Rh-
Where do DVTs commonly occur in pregnancy?
-Left leg above the knee - increased embolic risk
-Oedema is common in pregnancy so may be asymptomatic until progresses to a PE
How are DVTs investigated in pregnancy?
-USS
-ECG/ABG
-Leg dopplers
-VQ scan (increased risk of leukaemia for baby)
-CTPA (increased risk of breast cancer for mum)
How are DVTs managed in pregnancy?
-Heparins (do not cross placenta)
PREVENTION
-If previous PE –> LMWH for 6 weeks postpartum
-If recurrent PE / FH of PE –> LMWH antenatally + 6 weeks postpartum
->3 persisting RFs –> LMWH for 28 weeks
->4 persisting RFs –> LMWH immediately
How are PEs managed in pregnancy?
-LMWH for remainder of pregnancy and postpartum
What anti-hypertensives should be stopped in pregnancy?
-ACEi’s eg ramipril
-ARBs eg losartan
-Thizaide diuretics eg indapamide
(Labetalol, nifedipine and doxazosin are all safe)
What groups of drugs should be avoided in pregnancy?
SWAB NOLS
-NSAIDs
–Block action of prostaglandins
–Cause closure of ductus arteriosus
–Delay in labour
-BETA-BLCOKERS
–IUGR
–Neonatal hypoglycaemia
–Bradycardia
-ACEis and ARBs
–Oligohydramnios
–Miscarriage or foetal death
–Hypocalvaria (incomplete formation of skull bones)
–Neonatal renal failure
–Neonatal hypotension
-OPIATES
–Neonatal abstinence syndrome ie withdrawal
-WARFARIN
–Foetal loss, congenital malformations
–APH, PPH, foetal intracranial bleeding
-SODIUM VALPROATE
–Neural tube defects and developmental delay
-LITHIUM
–Congenital heart abnormalities
-SSRIs
–1st trimester - congenital heart defects and malformations
–3rd trimester - persistent pulmonary HTN in neonate
How is essential hypertension differentiated from pre-eclampsia?
-In essential hypertension, diastolic BP tends to be normal
-In pre-eclampsia, diastolic BP tends to be high (and presence of other symptoms)
How are perineal tears classified?
1st degree = injury to the skin only
2nd degree = injury to perineum, involving perineal muscle (–> episiotomy)
3rd degree = injury to perineum, involving external anal sphincter
-3a = <50% of EAS torn
-3b = >50% of EAS torn
-3c = IAS torn
4th degree = injury to perineum involving EAS, IAS and anal epithelium
What are the principles of perineal repair?
-Suture ASAP to reduce bleeding and infection risk
-PR exam to assess injury to anal sphincter complex
-Severe cases should be repaired in theatre
-Lithotomy position and adequate analgesia
-PR exam post-procedure to ensure no sutures have passed into rectum or anal canal
What factors increase the risk of perineal tears?
-Forceps delivery
-Nulliparity
-Shoulder dystocia
-2nd stage >1hr
-Persistent OP position
-High birth weight
-Epidural anaesthesia
-IOL
What is placenta accreta?
When the placenta implants deeper into the uterus through and past the endometrium
-Makes 3rd stage of labour more difficult and causes increased risk of PPH
What is cord prolapse?
-When the umbilical cord descends below the presenting part of the foetus into the vagina
-Significant risk of the presenting part compressing the cord –> foetal hypoxia
How is a cord prolapse managed?
-Confirmed on VE or speculum
-Suspected if foetal distress seen on CTG
-Emergency C-section
-Tocolytics to prevent contractions and compression of the cord
