GBS Flashcards
What is the definition of Group B streptococcus?
Group B streptococcus is a gram-positive bacterium that normally colonises gastrointestinal tract, perineum, and vagina.
Approximately 30% of pregnant women are colonised with this bacterium and most have no symptoms. However, it can transmit to the neonate through colonisation of the respiratory tract and mucous membranes when passing through the birth canal. This can lead to an early onset of range of infection including sepsis, cellulitis, pneumonia, and meningitis.
What is the epidemiology/ statistics for Group B streptococcus?
Around 1 in 1750 neonates will develop Group B strep infection and while most will recover fully with a treatment, 1 in 19 will die and 1 in 14 will develop long term disability.
Women in Britain are not routinely tested for Group B strep.
What are the risk factors for Group B streptococcus?
Previous Strep B
Positive Strep B test in pregnancy
Prolonged rupture of membranes more than 24 hours before delivery
Prematurity
Maternal Pyrexia in labour
What is the physiology and pathophysiology of GBs and normal labour?
In normal low risk labour:
The onset is caused by a combination of hormonal and mechanical factors
In the last weeks of pregnancy, the maternal oestrogen rises and overcomes the inhibiting effects of progesterone. These high levels also cause uterine muscle fibres to prepare oxytocic receptors. Oestrogen also stimulates the placenta to release prostaglandins that produce enzymes which digest collagen in the cervix, helping with softening. This process is helped by well applied fetal presenting part and mechanical stimulation of the cervix and beginning of positive feedback mechanism. Which stimulates the posterior pituitary to release oxytocin, which causes smooth muscle of uterus to contract and retract. This causes more pressure of the presenting part on the cervix, mechanical stimulation, and further release of oxytocin.
STAGES:
Latent phase is beginning of irregular contractions that cause the cervix to efface and dilate from 0 to 4 cm. It can last for few days.
1st stage of labour is characterised by regular strong contractions 3-4 in 10, lasting up to 60 seconds and cervical dilatation from 4 to 10 cm
2nd stage of labour is when maternal effort and expulsive contractions pass the fetus through the birth canal
3rd stage of labour is separation of the placenta from decidua and expulsion of the placenta and membranes through the birth canal. Physiological or active management with administration of Oxytocin or Syntometrin IM and controlled cord traction. Signs of separation are blood trickle and lengthening of the cord.
Mechanism of labour:
The baby`s head Descent through the pelvis is aided by Braxton hicks, or through the contractions during labour
Engagement happens when the widest part of the fetal head enters the widest diameter of the pelvis.
Flexion and internal rotation is when the vertex meets the resistance of the pelvic floor which causes the head to flex and rotate the occiput. Then the occiput escapes under the pubic arch and the head is crowned, no longer recedes between contractions and the widest transverse diameter is born. The baby then extends head and bregma, face and chin sweep the perineum and the head is born. This is followed by Internal rotation of the shoulders as they meet the pelvic floor and rotate into anteroposterior diameter of the outlet. The neck then aligns with the shoulders and the head on the outside also rotates the same way. This is called Restitution. Anterior shoulder is released under the pubic arch and posterior shoulder over the perineum.
What is the intrapartum care plan for mother and baby?
Introduction to the woman and birth partner
Review notes to identify any risk factors
Birth plan discussed
Woman comfortable and informed of the care and plan
Informed consent obtained prior any care
Administer Benzylpenicillin prophylaxis, according to trust guideline of Loading dose 3g slow bolus over 10 min and then maintenance dose of 1.5g 4hourly until delivery bolus over 5 min. If allergic use Cefuroxime 1.5g bolus over 3.5 minutes, maintenance 750mg 8hourly until delivery. This will lower the chances of the baby developing an infection.
Check the resuscitaire and the room temperature in case of emergency and to maintain thermoregulation
Intermittent auscultation every 15 min for 1 min in 1st stage to monitor fetal wellbeing
Hourly pulse to ensure that fetal HR is not mistaken for maternal one and to monitor maternal wellbeing
4 hourly vital signs to rule out abnormalities. If any signs of infection, such increased respiration, pyrexia, low BP do Septic screen and escalate
Hourly fresh ears and documenting on partogram, contractions frequency every half an hour to assess progress. If any abnormality heard inform midwife in charge and transfer for CTG monitoring
Vaginal examination every 4 hours to assess the progress, expecting 2cm in 4 hours, if delayed encourage more mobilization, offer artificial rupture of membranes, and reassess in 2 hours.
Checking the colour of amniotic fluid to see if any signs of meconium or any excessive bleeding
Bladder care every 4 hours to help with descent, urinalysis to check for ketones, leucocytes, protein
Mobilising- encouraging active labour
coping strategies, emotional support, breathing, massage, involving partner, music, hypnobirthing, shower
Entonox, Pethidine 50mg IM, explain the risk of nausea and drowsiness and possible short term respiratory distress and slow feeding in baby - consider antiemetics 10mg of Metoclopramide,
Epidural: explain risks, need for CTG monitoring and need for transfer if in Birth centre.
Use of a birth pool if not drowsy and no opioids in last 2 hours, maintain temperature of 37 degrees by checking half hourly. Use of waterproof dressing for cannula is required.
Hydration/ light diet to make sure the woman is well energised and hydrated
2nd stage of labour: Fetal heart rate monitoring every 5 min or after each contraction, encourage upright position or the most comfortable position for the woman, support perineum
Following the birth stimulate the baby, and assess colour, tone, respiratory effort If baby well and vigorous and crying and no excessive maternal blood loss, delayed cord clamping to provide baby with maximum benefits of the cord blood and support safe skin to skin.
Then we would facilitate 3rd stage of labour either physiological up to 1 hour or active Syntometrine or Oxytocin administration IM and Controlled cord traction. Signs of separation are blood trickle and lengthening of the cord. Examine if complete to ascertain no retained products
What is the postnatal care for mother?
Initial postnatal assessment and bleeding
Vital signs to rule out deterioration
Assess and repair perineum
Offer analgesia
Emotional support and mental wellbeing
Monitor lochia/ uterus contracted
Help to mobilise/ signs of dvt/ preeclampsia
Monitor passing urine within 6 hours
Hydration/ diet
Feeding/ Expressing
Signs of unwell baby and where to seek help
Discharge talk and leaflets
Follow up in community.
What is the postnatal management for baby?
Initial neonatal check, weight, HC, Vit K with consent according to weight
4 Hourly observations for 24 hours to rule out early onset of infection. If any indication of early onset, escalate to neonatologist for review and IV antibiotics.
Observe for temperature, Heart rate and respiration but also for tone, signs of respiratory distress, grunting, unresponsiveness, not feeding well, not keeping feeds down
Support feeding
Discharge with information for parents how to recognise signs of unwell baby and how to seek help as GBS can occur up to 6 weeks of age.
