Obstetrics Flashcards
Which class of diabetes medication is contraindicated in pregnancy AND breastfeeding?
Sulphonylureas (Gibenclamide, Gliplizide
Tolbutamide, Gliclazide)
Glinides (Repaglinides, nateglinide.)
What effect does pregnancy have on the thyroid?
Increase in size
Increase TBG levels
IncreasesfT4, decreasesTSH
What effect does HCG have on thyoxine levels?
Increases it
What effect does pregnancy have on Grave’s Disease?
Grave’s disease is often SUPRESSED during pregnancy (as there is immunosuppression in this time.) BUT rebound postpartum
Thyroid receptor antibodies TRAB should be measured in 3rd trimester to predict thyrotoxicosis risk for baby.
May require small doses of Carbimazole.
Managing Grave’s in pregnancy?
‘Wait & See’
1st trimester - avoid carbimazole & use Propythyouracil
2nd trimester - give carbimazole
What effect does hypothyroidism have on pregnancy?
Cretinism - dwarfism plus limited mental functioning.
risks infertility, pre-eclampsia, post-partum haemorrhage & preterm labour.
How should levels of levothyroxine be altered for pregnant women with hypothyroidim?
Increased by 50%
What crisis can be precipitated by labour? (related to the thyroid)
Thyroid crisis & transient neonatal thyrotoxicosis
What are the complications of thyroid crisis in labour?
increases risk of miscarriage, stillbirth
Which hormones are secreted from the posterior pituitary?
Oxytocin & ADH
Where is prolactin released from?
Anterior pituitary
How does pregnancy affect the respiratory system?
Tidal volume increases
Minute ventilation increases (Tidal volume x RR)
What is dilutional anaemia?
This is when plasma volume rises in pregnancy & RBCs are diluted. Hb conc falls
What is first line contraception for women who are breastfeeding?
Progesterone only
Can be used first day postpartum
Implant is most effective
IUS & IUD SHOULD BE AVOIDED DUE TO RISK OF PERFORATION.
Which contraceptives are contraindicated postpartum & why?
COC due to increases risk of VTE
IUS & IUD SHOULD BE AVOIDED DUE TO RISK OF PERFORATION.
Ibuprofen & Paracetamol can safely be used for analgesia during breastfeeding T/F?
True
Is aspiring contraindicated in breastfeeding?
Yes. (can lead to liver failure & thrombocytopenia in infant)
Opiates are contraindicated in breastfeeding T/F?
F - use with caution & seek help signs of toxicity
In CTG what does prolonged decceleration indicate?
Prolonged deccelaration >3min
Foetal bradycardia
On CTG what is a normal baseline variability?
> 5bpm
What is normal pH levels on foetal blood sampling?
> 7.25
What is a normal foetal heart rate?
100-160bpm
adult 60-100
What is Bishop’s score used for?
Check if its safe to induce labour
Induction of labour if bishop’s score is?
<5 labour unlikely to start without induction
>9 means its likely to occur spontaneously
How do you induce labour?
- Vaginal membrane sweeping
2. Vaginal PGE2 (but not misoprostol as this is for miscarriages)
What are the foetal cardinal movements in labour?
1…Engagement 2…Decent 3…Flexion 4…Internal Rotation 5…Crowning and extension 6…Restitution and external rotation (head adopts optimal position for shoulder) 7…Expulsion, anterior shoulder first
Describe foetal descent
Descent inocciput transverse position (widest pelvic diameter available for the widest part of the fetal head.)
Describe engagement
largest diameter of the fetal head is engaged when the widest diameter of the brim of the pelvis.
occiput transverse position
3/5ths or less of the foetal head should be palpable in the abdomen - station -2.
Foetus is at station 0 (ischial spine)
Why does flexion of the foetal head occur?
Fundal dominance of uterine contraction exerting pressure down the fetal spine forcing occiput to come into contact with the pelvic floor.
Flexion allows the circumference of the foetal head to reduce. This assists passage through the pelvis.
Describe internal rotation
Maternal contractions slowly push the foetal head to completing a 90 degree turn.
Will only occur in established labour. Commonly completed by the beginning of the second stage of labour (full dilation to delivery.)
Occiput transverse -> Occiput anterior position
Describe crowning
widest diameter of the fetal head successfully negotiates through the narrowest part of the maternal bony pelvis.
Head visible at the vulva and does not disappear between contractions.
Describute restitution & external rotation
Return of the fetal head returns to the correct anatomic position relative to the fetal torso.
This is shoulders that have only reached pelvic floor.
May need to return to occipito-transverse position to get these out.
What is the frequency of contractions during latent stage 1 labour?
varies from every 5-30 minute to every 3-5 minutes
or 2-3 every ten minutes
What is the frequency of contractions during ACTIVE stage 1 labour?
every 60-90 seconds, can even overlap.
What is the normal length (hrs) of the second stage of labour?
Prims 3hrs (with analgesia), 2 hrs (without analgesia) Multiparous 2hrs (with analgesia), 1hr (without analgesia)
What does foetal station measure?
The degree of descent Measured as presenting part relative to ischial spines. Pelvic inlet (station -5) Ischial spine (station 0) Vagina (station +5)
List the indications for continous CTG monitoring in labour:
suspected chorioamnionitis or sepsis, or a temperature of 38°C or above
severe hypertension 160/110 mmHg or above
oxytocin use
the presence of significant meconium
fresh vaginal bleeding that develops in labour - this could respresent placental rupture (the most common cause of antepartum haemorrhage) or placental praevia (second most common cause of antepartum haemorrhage) and therefore monitoring of the baby is required.
