Obstetrics Flashcards
When are health preggo women going to have routine scans?
10-14 weeks dating scan
18-21 week anomaly scan
What screening are women routinely offered?
- fetal anomalies (down syn opt in. and ALL women anomaly scan at 18-21 wks)
- Infectious diseases (HIV, Heb B, syphillis, rubella)
- Rh-ve
- Hb globinopathies
What prenatal diagnostic tests are offered? Indications for these tests?
- Chorionic villus sampling (+11wks) = inc risk of miscarriage
- Amniocentesis (15wks)
- Suspected chromosomal abnormality, NTD, abnormal maternal serum analyte
- Age > 35
- Previous child with congenital abnormality
- One of the parents has a chromosomal abnormality or other FHx
Maternal serum sampling at 11wks detects which hormones?
hCG (inc in downs and tri 18)
PAPP-A (preggo assoc plasma protein A) - Dec in down and Tri 18
Quadruple screening occurs when and includes which hormones?
15-20wks
- hCG = inc in downs
- Estriol (E3) = dec in downs and tri 18
- AFP (NTD)
- Inhibit A = inc in downs
What ultrasound scan is performed between 11-14 weeks and what does it look at?
CRL (accurate at measuring gestational age) - better than biparietal or femur length
Nuchal translucency (thickness of subcut tissue in nuchal region. > 3mm assoc with CV defects, and downs)
All women receive this scan at 20 weeks. what is it and what does it include?
Anomaly scan between 18 and 26 was.
- Looks for list of conditions (anencephaly, myelomeningocele, gastrochisis, cleft lip, heart defects)
- Head circus, abdo circum, femur length,
(macro or microsomia)
Rh-ve mum with rh-ve child = problem?
Rh-ve mum with 2nd rh+ve child = problem?
Rh-ve mum with 1st rh+ve child = problem?
Rx?
No to a rh-ve child and Not really problem if first pregnancy rh+ve but still offered treatment
If rh+ve child on second preggo, then sensitisation to the Rh+ve may have occurred in the mum to produce IgG Abs which can cross the placenta unlike in the first preggo where IgM Abs can not cross.
- If antigens from Rh+ve on 2nd preggo, enter maternal circulation, IgG response will occur.
The IgG Abs can cause haemolysis of the fetal RBC can haemolytic disease of the newborn.
Treatment is to give all Rh-ve women anti-D Ig IV at 28-30 days
= neutralises foetal Rh+ve antigens which would have entered the maternal blood leading to IgG production
IM injection of anti-D given after baby is delivered
What is hyperemesis gravidarum?
Excessive N&V of pregnancy such that women can not maintain adequate hydration and lose wt ( >2-5kg)
Peak onset and clinical features of hyperemesis gravidarum? Effect on foetus?
1% of preggos.
6-11wks
N&V Excess salivation Reduced urine output and epigastric pain Signs of dehydration inc ketones in urine and liver tenderness
If >10% wt loss then foetus could be restricted in growth.
In which trimester is heartburn more prevalent?
Adv to women?
What must you also be concerned about with epigastric tenderness?
Third trimester (70%). Reassure.
Adv low fat set, bland foot, small portions.
Adv against later night food. Adv raising head at night.
Avoid gastric irritants (caffeine)
Anatacids (magnesium trisilicate) = if lifestyle mods are ineffective.
Consider pre-eclampsia if unresponsive to simple antacids. Check BP and protein.
What are you likely to see on blood tests in hyperemesis?
Raised hCG. Raised TFTs without signs suggestive of hyperthyroidism. Inc urea if dehydrated. Electrolyte disturbances.
Check UandEs, LFTs, TFTs
Prevalence of Nausea in preggo?
Vomit in preggo?
Associated with?
N >80% from 4-6wks. should ease by 14-16wks.
V 50%
Any time of the day.
Odours and preparation/sight of food.
Mx of N&V, and hyperemesis gravidarum?
Reassure.
Exclude other causes of vomiting such as UTI, thyrotoxicosis.
Adv small, frequent fluid and small amounts of carbs.
Self help = ginger and P6 acupressure
If dehydrated, and not tolerating oral intake = admit. Consider IV rehydration.
Antihistamine antiemetics such as cyclizine work best.
If prolonged, Vitamin B supplementation may be needed as Wernickes encephalopathy has been reported. High dose Corticosteroids may of benefit if severe.
Prevalence of constipation in preggo?
Rx?
40%
Inc fluid and fibre intake.
If necessary use a bulk forming laxative such as ispaghula husk (avoid stimulants as these inc uterine activity)
Prevalence of backache in preggo?
60%. worse in evenings. adv light exercise unless CI (pre-eclampsia)
What does HELLP stand for?
Haemolysis and elevated liver enzymes with low platelet count.
Variant of pre-eclampsia
How would you categorise high risk pregnancies?
Maternal conditions
- Obesity, DM, HTN
- chronic (renal, cardiac, endocrine, haem, AI), epilepsy
- Infections (HIV, HepB)
Social factors
- Maternal age > 40 or < 18
- Multiparous (inc risk of PPH) = Para > 6 or > 3 miscarriage
- Smoker, domestic violence, substance abuse
Obstetric issues in previous preggo
- Previous C-section
- Previous preterm delivery, still birth, death
- Pre-eclampsia, Eclampsia, HELLP
- Previous GDM
- Previous tears
- Previous psych illness
Problems in this preggo
- Multiple preggo
- Small or large for gestational age
- Placenta previa
- GDM
- pre-eclampsia
What are the four major mechanisms responsible for preterm labour?
Stress (maternal or foetal)
Infection (IU)
Stretch (excessive due to multiple preggo, polyhydramnios)
Haemorrhage (decidual = placental abruption)
Main causes of preterm labour?
PPROM
Intra-amniotic infection/inflammation
Idiopathic
Difference between PROM and PPROM?
PROM = premature rupture of membranes before onset of labour
PPROM = preterm premature rupture of membranes < 37wks
Absolute contradictions to the use of tocolytics?
Tocolytics = suppress uterine contractions
Indications = prolongation of preggo is beneficial for lung maturity etc.
CI
- APH
- Infection (evidence of chorioamniotitis = maternal pyrexia, uterine tenderness, raised WCC, CRP, foetal tachy)
- Foetal distress
- IU foetal demise
Caution in those with DM as betamimetics inc gluconeogenesis and therefore precipitate a DKA.
PPROM is a relative CI
Preggo lady at 31 wks presents and has suspected preterm labour. No CI. Mx?
Tocolytics
- Nifedipine (calcium channel blocker) 1st line
SE hypoTN, reflex tachycardia, nausea, headache, hepatotoxicity
- if nifedipine CI, then oxytocin receptor antagonists (atosiban)
SE N, headache, chest pain, arthalgia
Maternal corticosteroids
Magnesium sulphate for neuroprotection
Absolute indications for a C-section?
Maternal
- failed induction
- failure to progress
- cephalopelvic disproportion
Utero-placental
- Previous uterine surgery
- previous uterine rupture
- Outflow obstruction (fibroids)
- Placenta previa/large placental abruption
Foetal
- foetal distress
- cord prolapse
- foetal malpresentation (transverse lie)
Relative indications for C-section?
Maternal
- elective repeat C-section
- maternal disease (severe pre-eclampsia, cardiac disease, DM)
Utero-placental
- prior uterine surgery
- funic presentation
Foetal
- Foetal malpresentation (brow, breech, compound)
- Foetal anomaly (hydrocephalus)
- Macrosomia
Most common indication for first time C-section?
Failure to progress
What are the types of C-sections?
- Transverse (lower uterine segment) = most common. less blood loss
- high vertical (classic) = inc blood loss
- lower segment vertical
Complications of C-section?
- Haemorrhage
- Infection (inc chance if obese, DM, emergency section, fever, anaemia etc.)
- Injury to foetus
- Injury to adjacent organs (bladder, bowel, ureters)
Maternal mortality from C-section? and compared to vaginal delivery?
Maternal morbidity assoc with C=section?
<0.1%.
Vaginal delivery is 2-10fold less
Morbidity = infection, thromboembolic events, wound dehiscence
Chance of success of VBAC? Features that inc chance of success?
65-80%
- prior vaginal delivery, total wt < 4kg, non-recurrent indication for previous section (breech, previa), not CPD
contraindications for attempted VBAC?
- absolute (prior classic section, foetal distress, placenta previa, transverse lie)
- relative (prior uterine rupture, breech presentation, previous full thickness myomectomy)
Benefits of VBAC?
shorter hospital stay and quicker recovery time
Reduce operative complications
Reduced risk of future complications
Risks of VBAC?
- risk of vaginal delivery = Pain and bruising from a tear incontinence Higher risk of - needing a blood transfusion - uterine rupture - uterine infection
Signs and symptoms of a uterine rupture?
Sinus bradycardia in 70%
Abdo pain in 10%
Vaginal bleeding in 5%
Haemodynamic instability
Hx: what are the presenting complaints you’re going to ask in an obs hx?
- Pain,
- Bleeding (fresh, clots, tissue)
- N&V
- Dysuria/freq
- Headaches, visual changes, swelling –> ?pre-eclampsia
- foetal movements,
- Leg pain/swelling –> ?DVT
SOCRATES each
Have they had it before?
Hx: Details to ask regarding history of current pregnancy?
- First pregnancy?
- Date of LMP
- EDD (scan or LMP + 7/7 + 9/12)
- How was the preggo confirmed?
- use of contraception
- Antenatal tests and investigations (dating or anomaly scan = placental location, growth on track)
- Foetal movements
- Labour pains
- Planned method of delivery
- Complications
+ 1st half = N+V
+ 2nd half = BP, anaemia, bleeding, UTI, DM,
What is gravida?
Number of times the mother has been pregnant irrespective of outcome
What is parity?
Para X + Y
X = number off deliveries after 24 wks (stillbirths or live)
Y = number of losses before 24 wks (spontaneous/induced)
What term would be given to a lady with Para 0 + 3?
Nulliparous = woman who has never given birth over 24 wks
What term would be given to a woman who has given birth one or more times over 24 wks?
Multiparous
Previous obs hx would include what questions?
Details of any previous pregnancies
- Live/stillborn
- Sex/wt/gestation
- mode of delivery (spont labour, induced, Section)
- current health of babies
Complications
- Antenatal (IUGR, hyperemesis gravidarum, pre-eclampsia)
- Labour (failure to progress, perineal tears, shoulder dystocia)
- Postnatal (PPH, retained products of conception)
As part of an obs hx, would would you ask in terms of a gynae hx?
- Menstrual cycle + sx
+ LMP (how long bleed for, flow)
+ IMB, PCB - Smear hx
+are you up to date?, has everything been normal? - Contraception
+ what?, how long? previous contraception? STDs
PMHx relevant to an obs hx?
- Past gynae and surgical hx
- Medical conditions
Thrombophillic
Epilepsy - antiepileptics some are teratogenic
DM - macrosomia + congenital defects
Hypothyroidism - risk of congenital hypoTH
Previous pre-eclampsia - higher risk of developing again
HTN
IHD
What drugs are teratogenic?
W TERATO Warfarin Tetracyclines Retinoids ACE-i Trimethoprim OCP
Methotrexate
Antiepileptics
What to include in the Fhx and Shx section of an obs hx?
Fhx = has everyone else’s pregnancies in the family been okay?
- twins,
- inherited disease
- obs/medical problems
Shx
- occupation (maternal leave)
- smoker (IUGR)
- alcohol (foetal alcohol syndrome)
- relationships
- Living circumstances and carers - independent. ADLs
How long is a regular menstrual period?
Menses last for how long?
Blood loss?
Anywhere between 23-35 days
2-8 days
Blood loss < 60-80mls
List three categories of hormonal contraception?
Combined
Progestogen only
Emergency