Other Complications of Later Pregnancy

Other Complications of Later Pregnancy

·        Key complications: preterm labour, pre-eclampsia and small babies

Antepartum haemorrhage (APH)

·        Any bleeding from the genital tract between 20^th week and delivery

·        Differential diagnosis:

o   Placenta praevia:

§  Implantation of the placenta in the lower uterine segment near or over the internal os.

§  Graded 1 to 4 (worst) 

§  Risk factors: prior c-section (uterine scar), grand multiparity (>5), multiple birth, maternal age >35, tobacco/cocaine use, fibroid uterus (ie anything that causes scarring or reduces places for embryo to attach) 

o   Placental abruption:

§  Premature separation of normally implanted placenta from the uterine wall 

§  Risk factors: ­maternal age, multiparity, maternal shock, poor nutrition, gestational diabetes, ­BP, smoking, anything that causes maternal vasoconstriction (trauma, cocaine, etc)

o   Onset of premature labour

o   Bleeding from other parts of the genital tract (eg cervical polyps, vaginitis, vulval varicosities) 

o   Fetal: Vasa praevia. Bleeding from an abnormal fetal vessel attached to the membranes over the internal os. Need ROM for this to occur. Mother will not be shocked

·        Clinical differences between praevia and abruption: 

o   History: previous bleeds, initiating factors, eg trauma, colitis 

o   ALWAYS ultrasound: exclude placenta praevia (detects 95 – 98% of cases) and major abruption with placental separation.

o   NO vaginal exam until praevia excluded

o   APT test to distinguish fetal from maternal blood

o   Bloods to monitor hypovolaemic shock, DIC

o   Fetal well-being, eg CTG 

o   If major blood loss, treat for shock ® transfuse, give O₂

o   Give steroids

o   If fetus alive, consider c-section before labour

o   If fetus dead, induce

·        Treatment:

o   If Rhesus negative and no antibodies yet, give Anti-D within 72 hours

·        Placenta praevia: If substantial, hospitalised till delivery, Caesar at 38 weeks 

·        Placental abruption: Hospitalise. Serious risk of PPH, also acute renal failure, pituitary necrosis, etc. Monitor retro-placental clot by serial ultrasound

Rhesus haemolytic disease*

·        Aetiology: if Rhesus –ive mother is „contaminated‟ by blood from a Rhesus +ive baby Þ anti-D IgG antibodies (isoimmunisation) 

·        Later in the pregnancy, or in a following pregnancy, IgG can cross the placenta causing Erythroblastosis Fetalis (® stiff oedematous lungs and hydrops – widespread oedema)

·        Test for anti-D antibodies in all Rhesus –ive mothers at booking and in 2^nd trimester. If elevated then monitor carefully

·        Anti-D immunoglobulin given prophylactically to Rh –ive mothers: 

o  Within 72 hours after incident (eg amnio, threatened miscarriage, spontaneous abortion, any risk of trans-placental haemorrhage – TPH, etc)

o  After birth if baby Rh +ive or group not known 

o  This prevents „iso-immunisation‟ – gobbles up antigen before mothers immune system generates antibodies

o  Don‟t give anti-D if mother already producing Anti-D

Premature labour

·        = Labour < 37 weeks

·        8% of babies, 85% of neonatal deaths

·        Over-diagnosed – over 80% diagnosed will deliver at term without treatment. Hard to diagnose – regular uterine contractions are normal, cervical changes in labour can be subtle

·        Braxton-Hicks contractions are usual from 30 weeks but are not painful

·        History: Is it true labour: check nature of contractions, urinary frequency (?UTI), backache, spotting or a change in vaginal discharge (normal in 3^rd trimester – lots, white, non-smelling).

·        Risks: 

o  Strongest association is previous preterm birth (­4 times risk)

o  Previous mid-trimester abortions (2 or more) – not 1^st trimester spontaneous abortions

·        Aetiology:

o  Spontaneous: 40% 

o  Multiple pregnancy: 10%, ­10 times risk

o  Maternal or fetal conditions (25%) 

o  Premature, preterm rupture of membranes (PPROM = rupture of membranes before labour commences and preterm) 

o  APH

o  > 28 weeks, 80 – 90% survival

o  > 32 weeks, similar survival as term babies but complications

·        Management: 

o  Investigations: temperature, BP, pulse, SFH, view cervix for clots etc (do NOT view cervix if risk of praevia – do US first), ?infection screen, US, MSU, fetal welfare

o  Consider tocolysis (inhibiting labour):

§  Inhibit uterine contractions – allows time for steroids to work and for transfer to neonatal unit 

§  b agonists – Ritodrine and Salbutamol (risk of pulmonary oedema) prolong labour for ~ 24 hours. Adverse effects: maternal and fetal tachycardia, vasodilation ® ¯BP. Contraindications: fetal distress, severe pre-eclampsia, APH, hypotension, tachycardia, asthma, etc 

§  Oral Nifedipine (Ca channel blocker) is replacing Salbutamol – equal efficacy and ¯side effects. 

§  If cervix is > 4cm then it should be allowed to progress – shouldn‟t use tocolytics

§  ?Not if PROM (premature rupture of membranes).  Can ® ­risk of infection

o  Steroids: dexamethasone and betamethasone (crosses placenta, prednisone doesn‟t) - 2 shots 12 hours apart. Always give first even if close to delivery ® maturation of lungs if between 24 and 34 weeks (­surfactant production ® ¯fetal distress syndrome) and neonatal better BP control post delivery 

o  Delivery. If < 26 weeks then vaginal delivery. C-section more likely if multiple pregnancy or breech. Epidural analgesia preferable to narcotics (® respiratory depression)

Premature Rupture of Membranes*

·        = Rupture of membranes before labour is established. Normally rupture of membranes follows establishment of labour

·        Check: have they really ruptured? Look for pooled liquor in posterior fornix. Do US for liquor volume and fetal well-being

·        Management:

o   Admit and monitor

o   Swabs for infection (a cause of PROM)

o   Check for signs of infection: fever, maternal or fetal tachycardia, ­WBC

o   After 24 hours (time varies) commence prophylactic antibiotics

o   Low threshold for induction