Obstetrics Flashcards
(228 cards)
What is gestational age? What do G and P refer to? What are the trimesters and when do foetal movements start
Gestational age is calculated from last menstrual period. EDD is 40 weeks gestation.
Gravida - number of pregnancies
Para/parity - number of deliveries after 24 weeks
First trimester - up to 12 weeks
Second trimester - 13-26 weeks
Third trimester - >27 weeks
Foetal movements start at 20 weeks
Hormonal changes in normal pregnancy
(Anterior pituitary hormones, TSH, HCG, Progesterone, Oestrogen)
Also give role of progesterone, and how does HCG rise
Anterior pituitary produces more prolactin, ACTH and melanocyte stimulating hormone.
Prolactin suppresses FSH and LH
ACTH increases cortisol and aldosterone (improvement in autoimmune conditions, increased susceptibility to diabetes)
MSH causes pigmentation of skin
TSH stays normal but T3/T4 rise
HCG rises, doubling every 48 hours until they plateau 8-12 weeks then gradually fall
Progesterone rises throughout pregnancy, maintaining pregnancy, preventing contractions and suppressing immunity to foetus. Corpus luteum produces for first 10 weeks, then placenta.
Oestrogen rises throughout, produced by placenta
What normally happens to blood pressure in pregnancy? What is defined as hypertension in pregnancy?
It falls during first trimester, and stays low until 20-24 weeks, then returns to normal.
HTN in pregnancy at >140 or >90 diastolic. OR increase of >30 or >15 diastolic
How is high risk of preeclampsia treated
75mg aspirin from 12 weeks gestation until birth
What should be done in a woman with HTN that becomes pregnant
If >140/90 before 20 weeks gestation, this is pre-existing HTN.
If taking ACEi or ARB, this should be stopped, and switched to alternative. Oral labetalol first line. (Nifedipine or hydralazine if asthmatic)
What is the difference between pre-eclampsia and pregnancy induced HTN
HTN (>140/90) in 2nd half (>20 weeks)
If symptomatic with proteinuria (>0.3g/24 hours) and/or oedema. this is pre-eclampsia.
if asymptomatic this is PIH (AKA Gestational hypertension). This resolves after birth, but increases risk of pre-eclampsia or HTN later in life.
Define pre-eclampsia
New >140/90 after 20 weeks gestation AND
- Proteinuria OR
- Other symptoms (oedema, renal insufficiency (Creatinine >90), etc)
Features of severe pre-eclampsia and how is it managed
- > 160/110
- Headaches and visual disturbance
- Papilloedema
- RUQ/Epigastric pain
- Hyperreflexia
- Reduced platelet count, abnormal liver enzymes or HELLP Syndrome
Magnesium sulfate for prevention of eclampsia
What can Pre-eclampsia cause, ti foetus, and to mother
- Eclampsia
- Foetal complications (intrauterine growth retardation, prematurity)
- Liver disease
- Haemorrhage (placental abruption, intra cerebral)
- Cardiac failure
- Neurological symptoms (stroke, altered mental status, blindness)
What are some high risk factors for pre-eclampsia
- HTN, in previous pregnancy or chronic
- CKD
- SLE or Antiphospholipid syndrome
- Diabetes
What are moderate risk factors for pre-eclampsia (>2 for prevention)
- First pregnancy
- > 40y
- > 10y since last pregnancy
- Obesity
- Family history
- Multiple pregnancy
If pre-eclampsia is found at 160/100 or higher, how should it be managed
Emergency secondary care assessment, admission and monitoring if >160/110
What is eclampsia
Development of seizures in association with pre-eclampsia
How is eclampsia managed
Magnesium sulphate.
- For prevention in severe pre-eclampsia and to treat seizures.
- IV bolus of 4g over 5-10 mins then 1g/hour infusion
- Monitor urine output, resp rate and O2 sats
- Until 24 hrs post last seizure or delivery
What should be monitored in patients with pre-eclampsia/Gestational HTN. What factor decreases in pre eclampsia
Urine dipstick, liver enzymes, FBC, renal profile weekly
Monitor foetal growth on scans
Platelet Growth Factor (PlGF) once between 20-35 weeks to rule out pre-eclampsia (PlGF is low in pre-eclampsia)
What is HELLP syndrome, how does it present, and how is it treated
Combination of features as a complication of pre-eclampsia
- Haemolysis
- Elevated Liver enzymes
- Low Platelets
Nausea/vomiting, RUQ pain and lethargy
Treated with delivery of child
What is gestational diabetes and what does it cause
Diabetes complicates 1/20 pregnancies, majority of which is gestational diabetes - insulin resistance during pregnancy which resolves after birth.
Most commonly it causes larges for dates fetus and macrosomia, implications for delivery including shoulder dystocia.
Also puts woman at further risk of T2DM.
Risk factors for Gestational Diabetes
BMI>30
Previous gestational diabetes
Previous macrosomic baby >4.5kg
First degree relative with diabetes
Family origin (South Asia, black Caribbean and Middle East)
How is gestational diabetes screened for, and when is this offered
OGTT (fasting glucose, followed by 75g glucose drink. Blood sugar measured again after 2 hrs. Normal, fasting: <5.6mmol/L, 2hrs: <7.8 mmol/L (!5678!))
In those with previous this is offered at first antenatal appt, and repeated 24-28 weeks if normal.
If risk factors, 24-28 week test.
If features (large for dates fetus, polyhydroamnios, glucose on urine dip, then do test)
How should gestational diabetes be managed
- Counselling, diet, exercise, and show how to take blood glucose.
- If fasting <7, trial non medical.
- If targets not met, add metformin
- If still not met add insulin
If >7 add insulin
How should pre existing diabetes be managed in pregnancy? What non diabetic drug needs to be given?
Weight loss if BMI>27
Stop oral drugs except metformin, and start insulin
Folic acid 5mg/day until 12 weeks
Glucose self monitoring targets in pregnancy
Fasting 5.3
1 hr after meals 7.8
2 hr after meals 6.4
Define miscarriage
The spontaneous loss of pregnancy before 24 weeks gestation.
Most common in first trimester and usually present with vaginal bleeding +- lower abdominal pain.
What is the most common cause of miscarriage, and how many known pregnancies are affected by miscarriage
Chromosomal abnormalities in fetus are most common.
Affects 1 in 8 known pregnancies