Obstetrics Flashcards
What are the main functions of the placenta?
Nutrition Respiratoin Immunity Excretion Endocrine - oestrogen helps soften tissues and prepares mother's breasts // progesterone maintains pregnancy by keeping uterine muscles relaxed
what are the 3 stages of labour?
FIRST STAGE = Onset (true contractions) until 10cm dilation
a. Latent 0-3cm - 0.5cm/hr, irregular contractions
b. Active 3-7cm - 1cm/hr regular contractions
c. Transition 7-10cm - strong regular contractions
SECOND STAGE = 10cm dilation to delivery of baby. Success depends on Power, Passenger, Passage
THIRD STAGE = Delivery of baby to delivery of placenta
What are the 2 broad methods of managing the third stage of labour?
Physiological management - placenta delivered by maternal effort
Active management - IM oxytocin and careful traction to cord. This shortens 3rd stage and reduces risk of bleeding.
If haemorrhage or >1 hour delay, give active management.
What are the main movements of labour?
Engagement Descent Flexion Internal rotation Extension Restitution + external rotation Expulsion
What are Braxton-Hicks contractions?
Occasional irregular uterine contractions in the 2nd and 3rd trimester.
Advise reduce stress and keep hydrated.
What hormones from the Anterior pituitary have a physiological effect during pregnancy?
- Raised ACTH –> raised steroid hormones = improves automimmue conditions but more susceptible too infection and DM
- Raised prolactin - reduced FH and LSH
- Increased skin pigmentation
what happens to the following hormone levels during pregnancy?
TSH
HCG
Progesterone
Oestrogen
TSH - normal but T3/4 raised
HCG - doubles every 48 hours, plateaus at 8-12 weeks, then falls
Progesterone and oestrogen both rise throughout pregnancy
What type of anaemia is common in pregnancy?
Iron deficiency anaemia
Increased RBCs but blood volume increases even more
What might pruritis be a sign of in pregnancy?
May be normal but may be due to obstetric cholestasis
What normal blood changes would you see in pregnancy?
Raised WBC Low platelets (VTE risk) Raised ESR Raised D-dimer Raised ALP - up to 4x normal, due too excretion by placenta
What is premature rupture of membranes?
What is pre-term premature rupture of membranes?
occurs at least 1 hour prior to onset of labour, at ≥37 weeks - minimal risk of harm
Pre-term = <37 weeks, occurs in 2% of pregnancies and is associated with complications
What are the risk factors for PROM?
Smoking Previous PROM or preterm delivery Multiple pregnancy Cervical insufficiency Vaginal bleeding during pregnancy Invasive procedures eg. amniocentesis Polyhydramnios
What investigations would you do in a PROM/PPROM?
Speculum exam = pooling
IGFBP-1 or PAMG-1 in vaginal fluid
High vaginal swab to look for signs of infection (group B streptococcus –> give clinamycin/penicillin)
How would you manage a PROM?
Induction of labour from week 34
Before this aim to prolong gestation - give steroids
Give prophylactic abx to prevent chorioamnionitis (erythromycin for 10 days or until labour)
What is the definition of a miscarriage?
Loss of pregnancy <24 weeks gestation
What are the risk factors fir miscarriage?
Smoking / alcohol increased maternal age previous miscarriage chromosomal abnormalities Antiphospholipid syndrome uterine abnormalities or previous surgery
How is a miscarriage diagnosed on TVUSS?
- Fetal heartbeat
- Crown rump length - heartbeat should be seen at >7mm. If no heartbeat at <7mm scan again in at least 1 week before diagnosing a missed pregnancy.
- look for fetal pole. If no fetus seen measure mean sac diameter:
>25mm and no fetus = anembryonic miscarriage
<25mm and no fetus = re-scan in 10-14 days
What are the treatment options for a miscarriage?
- Conservative
- Medical
- Surgical
Regardless of tx type = if pt is Rh- and >12 weeks then give anti-d prophylaxis
What is medical management of miscarriage?
Vaginal misoprostol (prostaglandin analogue) - stimulates cervical ripening and contractions
Pregnancy test 3 weeks later
What is surgical management of miscarriage?
Manual vacuum aspiration under local anaesthetic if <12 weeks
Electrical evacuation of RPOC under GA if >12 weeks
What are the indications for surgical management of miscarriage?
haemodynamically unstable
infected tissue
gestational trophoblastic disease
What are the different types / stages of miscarriage?
Threatened = bleeding but cervix closed and fetus alive
Inevitable = bleeding and cervix open
Missed - no fetal pulse, ongoing discharge, may be asymptomatic
Incomplete - RPOC
Complete - symptoms settled
Septic
What are the risk factors for gestational diabetes?
BMI >30 previous GD Asian 1st degree relative with DM PCOS previous macrosomic baby
What are the fetal complications of gestational diabetes?
Macrosomia
Organomegaly
Erythropoiesis
polyhydramnios
Increased rates of pre-term delivery
Increased risk of hypoglycaemia after birth
Increased risk of transient tachypnoea of the newborn
How is gestational diabetes diagnosed?
FG >5.6 or 2 hour postprandial glucose >7.8
What is the management for gestational diabetes?
Lifestyle advice
Metformin
Glibenclamide if metformin not tolerated
insulin
What is pre-eclampsia?
What is the triad?
New HTN in pregnancy with end-organ dysfunction. It occurs due to abnormal formation of the spiral arteries after 20 weeks.
- Hypertension
- Proteinuria
- Oedema
If no proteinuria = pregnancy induced HTN
If seizures = eclampsia
What are the high risk and moderate risk RFs for pre-eclampsia?
Moderate >40yrs BMI >35 Multiple pregnancy First pregnancy FHx of pre-eclampsia
High pre-existing HTN previous HTN in pregnancy Autoimmune conditions DM / CKD
What are the SYMPTOMS of pre-eclampsia (other than the triad)
Headache Visual symptoms Epigastric pain (liver swelling) Oedema Brisk reflexes Nausea and vomiting
How is pre-eclampsia diagnosed?
BP >140/90 plus any of:
- Proteinuria
- Organ dysfunction
- Placental dysfunction (growth restriction or abnormal doppler)
Also - placental growth factor will be LOW
What is the management for pre-eclampsia?
Routine monitoring - BP, symptoms and dipstick. serial growth scans
Medical:
Aspirin from 12 weeks if 1 high risk RF or >2 moderate
- Labetolol
- Nifedipine
During labour: IV MgSO4 to prevent seizures, fluid restriction
What is HELLP syndrome?
A complication of pre-eclampsia
Haemolysis
Elevated Liver enzymes
Low platelets
What is placenta praevia?
Placenta is attached in the lower portion of the uterus (lower than presenting part of fetus)
What is the difference between a low lying placenta and placenta praevia?
Low-lying = placenta is within 20mm of internal cervical os
Praevia = placenta over internal cervical os
What are the possible complications of placenta praevia?
Antepartum haemorrhage
Emergency C section
Maternal anaemia / transfusion
Pre-term birth/ low birth weight
What are the grades of placenta praevia?
Minor/ I = placenta not reaching os
Marginal / II = reaching but not covering
Partial / III = partially covering
Complete
What are the risk factors for placenta praevia and accreta?
Previous C section or placenta praevia/accreta Older maternal age IVF smoking structural - fibroids
How does placenta praevia or placenta accreta present?
Asymptomatic or painless bleeding (antepartum haemorrhage)
Seen at 20 week scan
Placenta accreta may present at birth with PPH
How is gestational HTN managed?
Aim <135/85
Admit if >160/110
Dipstick weekly and monitor bloods
Serial growth scans
What is the management of placenta praevia
TVUSS at 32 + 36 weeks
Corticosteroids at 34-36weeks to mature lungs
Planned C section at 36-37 weeks