obstetrics Flashcards
when is gestational diabetes screened for
after 24 weeks
Unless you have previously had gestational diabetes in which case you screen as soon as possible after the booking clinic, if level than normal screen again at 24 to 28 weeks.
test and diagnostic values for gestational diabetes
- OGTT
- Fasting >5.6 = GDM
- 2hrs postprandial > 7.8 = GDM
treatment options for GDM
- diet and exercise if <7mmol/l fasting
- initiate insulin ± metformin immediately if fasting glucose >7mmol/l
1st line Mx for baby with breech presentation + when
external cephalic version offered as early as week 36
MC site of ectopic pregnancy
MC site of ectopic rupture
- fallopian tube:
ampulla> isthmus> fimbria - isthmus is MC SITE OF RUPTURE
which factor is most likely contributing to the polyhydramnios?
Other causes
maternal diabetes»>
other causes are chromosomal abnormalities foetal renal issues, foetal anaemia
how might oligohydramnios present
abnormally prominent foetal parts on abdominal palpation
complication of oligohydramnios
foetal pulmonary hypoplasia
main RF for oligohydramnios
smoking
GBS microscopic morphology
gram +ve cocci
define a complete molar pregnancy and what is seen on USS
- sperm fertilises an egg with no DNA
- shows up as snowstorm sign on USS
define a partial molar pregnancy and what is seen on USS
- 2 sperm cells fertilise an egg with DNA
- USS shows foetal tissue in the uterus + snowstorm
postpartum contraceptive advice
- no contraception is needed for 21 days postpartum.
- lactational amenorrhoea can only be used up to 6 months postpartum and if mum is exclusively breastfeeding and remains amenorrhoeic
name an absolute contraindication for vaginal birth after C-section
a classic c-section - vertical scar.
signs of hypokalaemia on ECG
U waves,
small or absent T waves,
prolonged QT and PR intervals along with
ST depression.
what is ovarian hyper stimulation syndrome
OHSS is a known side effect of fertility treatments, which is characterised by an increase in ovarian size and shifting of fluid which can result in ascites and pleural effusions
Mx of OHSS
- Treatment is largely supportive, with fluid replacement as appropriate, and drainage of ascites/pleural effusions if required.
- thromboprophylaxis as pts are in a hyper coagulable state
use of wells score in pregnancy
The Wells score is not validated for use in pregnant women.
D-dimers are not helpful in pregnant patients, as pregnancy is a cause of a raised D-dimer.
when is a pregnancy classed as post term
42 weeks onwards
what is offered to women that are 41 weeks pregnant
- 1st and 2nd line
- a membrane sweep
- induction of labour with prostaglandin E2.
- other options include cervical ripening baloon OR artificial rupture of membrane + oxytocin flush
pre-eclampsia minor RFs
THINK NUMBERS
- >40 maternal age
- BMI >35
- multiple pregnancy
- first pregnancy
- pregnancy interval > 10 yrs
- fam hx of pre-eclampsia
pre-eclampsia major RFs
- chronic kidney disease
- chronic HTN
- prior pregnancy with pre-eclampsia
- T1DM or T2DM
- autoimmunity: antiphospholipid syndrome or SLE
what is associated with obstetric cholestasis
Obstetric cholestasis is associated with an increased risk of stillbirth.
1st line Mx of shoulder dystocia
McRobert’s manœuvre
what is shoulder dystocia
Failure of the anterior shoulder to pass under the pubic symphysis after delivery of the foetal head.
zavenelli
Zavenelli is performed by returning the foetal head to the pelvis for delivery via caesarean section.
shoulder dystocia complications
Maternal
PPH
Extensive vaginal tear(3rdand 4thdegree)
Psychological
Neonatal
Hypoxia
Fits
Cerebral palsy
Injury to brachial plexus + Erb’s palsy
absolute CI’s for external cephalic version
- Caesarean section is already indicated for other reason
- Antepartum haemorrhage has occurred in the last 7 days
- Non-reassuring cardiotocograph
- Major uterine abnormality
- Placental abruption or placenta praevia
- Membranes have ruptured
- Multiple pregnancy
what condition can increase risk of miscarriage
antiphopholipid syndrome
RFs for miscarriage
- ↑ maternal age >35
- Previous miscarriage
- Lifestyle: smoking, alcohol and recreational drug use during pregnancy
- prior gynae surgery
- Uncontrolled DM or thyroid disorders
- anti-phospholipid syndrome and S L E
how is antiphospholipid syndrome managed to reduce risk of miscarriage
anti platelet + anticoagulant
aspirin + LMWH
how long should a woman avoid pregnancy for after MTX
3 months
serial bHCG in intrauterine pregnancy and in ectopic
Serial serum β-hCG:2 samples taken 48 hours apart with a rise of:
- < 63%suggestive of ectopic pregnancy.
- > 63% = intrauterine.
- <50% = miscarriage.
what do you do if a woman has a pregnancy of unknown location
- Early gestation pregnancies may be hard to see on USS so take a serum bHCG level and repeat in 48 hours.
- a rise of >63% is expected in intrauterine pregnancy.
- if the serum HCG is over 1500IU/L, a pregnancy should be visible on an USS.
- if not visible, this indicates MTX Mx
RFs for breech presentation
polyhydramnios - they have more space to move
multiple pregnancy - less space to move
T/F
anti-D prophylaxis is needed for ECV
true
1st line downs syndrome screening
combined test
- Bloods: Pregnancy associated plasma protein A + bHCG
- USS for nuchal translucency [>6mm = +ve]
booking clinic weeks and investigations
- ideally <10 weeks but between 8-12 weeks.
tests:
- HIV
- Syphillis
- Hep B
- Red cell autoantibodies
- Rh status
- blood group
- FBC for anaemia
- screening for thallasemia
- high risk women screened for sickle cell
when would you offer a women OGTT
- if she has 1 RF for GDM, offer at 24-28 weeks.
- if she’s previously had GDM:
- offer ASAP after booking clinic
- offer again at 24-28 weeks gestation if the first was normal
complications of polyhydramnios
- cord prolapse
- placental abruption
- PROM
- preterm labour + delivery
- malpresentation of foetus
potters syndrome
a fetal condition which presents with pulmonary hypoplasia and various structural malformations as a result of compression in utero
What is pulmonary hypoplasia + why does it occur
- Pulmonary hypoplasia = underdevelopment of the lungs
- in oligohydramanios there is reduced amniotic fluid which is essential for the development of the fetal lungs.
GBS infection in pregnancy
- Abx prophylaxis offered during labour - penicillin [2d line = vancomycin in allergy]
- if untreated poses risk to mum and baby - sepsis, pneumonia + meningitis
RFs for neonatal GBS infection
- Positive GBS culture in current or previous pregnancy
- Previous birth resulting in neonatal GBS infection
- Pre-term labour
- Prolonged rupture of membranes
- Intrapartum fever >38 degrees Celsius
- Chorioamnionitis
RFs for preterm delivery which is MC
- MC = infection. Introduced iatrogenically, ascending up the genital tract or retrograde from peritoneum
- uterine over distension - polyhydramnios, multiple pregnancy or uterine abnormality
- Cervical weakness, 1º due to prior procedures [C-sections at full dilatation, LlETZ, cone biopsy]
Preterm labour Mx - labour started but membranes intact
- CSX: lung maturation + reduce risk of NEC. 2 IM injections to mother 24hrs apart
- MgSO4 - reduce risk of cerebral palsy
- tocolytics to delay birth and increase time for lung maturation. Nifedipine
test used to assess risk of preterm delivery
foetal fibronectin assesses the risk of delivery after pre-term labour starts - a positive test = increased risk of delivery in the next 7-14 days.
stages of labour
First stage – from the onset of labour (true contractions) until 10cm cervical dilatation
Second stage – from 10cm cervical dilatation until delivery of the baby
Third stage – from delivery of the baby until delivery of the placenta
signs of onset of labour
Show (mucus plug from the cervix)
Rupture of membranes
Regular, painful contractions
Dilating cervix on examination
What happens during the first stage of labour
Cervical dilatation and effacement (thinning). The “show” (mucus plug that normally prevents bacteria from entering uterus, is passed, falling out and creating space for baby to pass through.
What are the 3 phases of the first stage of labour
Latent - 0 to 3cm dilatation. ~0.5cm/hour with irregular contractions
Active - 3 to 7cm dilatation. ~1cm/hour with regular contractions
Transition phase - 7 to 10cm dilatation. ~1cm per hour with regular strong contractions.
What are the 7 cardinal movements of labour
- Engagement
- Descent
- Flexion
- Internal rotation
- Extension
- Restitution and external rotation
- Expulsion
DEFINE
Prelabour rupture of membranes
Preterm prelabour rupture of membranes
Prolonged rupture of membranes
Prelabour - Amniotic sac ruptures before onset of labour after 37 weeks gestation.
Preterm prelabour - Prior to labour and before 37 weeks
Prolonged - Rupture more than 18 hours
RFs for IUGR
- chronic HTN
- preeclampsia
- maternal smoking or substance abuse
- multiple pregnancy
- Hx of IUGR
- diabetes
- antiphospholipid syndrome
how is uterus size measured?
symphysis fundal height AFTER 24 weeks
P-PROM Mx
- antibiotics should be given for 10 days following premature preterm rupture of membranes, or until the woman is in established labour, whichever is sooner
- Prophylactic Erythromycin 250 mg QDS for 10 days
- Induction of labour may be offered from 34 weeks to initiate the onset of labour.
- Corticosteroids if between 34 and 34+6 weeks gestation.
neonatal complications of maternal chlamydia infection;
- if the infection ascends from the vagina, it causes chorioamnionitis, which can cause the membranes to rupture early.
- If a baby is delivered vaginally while the mother has active chlamydia infection, it can be transmitted and cause conjunctivitis and pneumonia
chorioamnionitis.The most common organisms implicated in chorioamnionitis are
- group B streptococcus - e.g. Streptococcus agalactiae
- E.coli
c-section categories
Category 1: Immediate threat to life of mother and baby. Decision to delivery time is 30 minutes.
Category 2: No imminent threat to life but required urgently due to compromise of mother or baby. Decision to delivery is 75 minutes
Category 3: Deliver is required but mother and baby are stable
Category 4: Elective Caesarean
what can be given alongside ECV to improve success rate
Beta-mimetic agents such as terbutaline can enhance the success rate of external cephalic version by relaxing the uterus, although they may cause side effects like tachycardia, palpitation, and flushing
Uterine hyper-stimulation is defined as + cause
- greater than 5 contractions occurring within 10 minutes
- it is due to administration of prostaglandins or oxytocin for induction of labour.
how does a Choriocarcinoma present
Mx?
- b-hCG that doesn’t fall after removal of a molar pregnancy
- Tx = methotrexate based chemo
Presentation of polymorphic eruption of pregnancy
- typically present in the third trimester.
- It occurs as itchy red patches and often first appears on the abdomen, particularly over striae
methods of foetal size Ax
USS to measure
- Estimated fetal weight (EFW)
- Fetal abdominal circumference (AC)
define SGA and severe SGA
- SGA = foetal size below the 10th gentile
- severe SGA = foetal size below the 3rd gentile
ideal rate of contractions during labour
4-5 contractions every 10 minutes
- any slower and labour won’t progress
- any faster and could –> foetal compromise.
name a complication and configuration of multiple pregnancy
twin-twin transfusion syndrome where 1 baby receives most of the blood flow and the other starves
- MC seen in mono chorionic diamniotic pregnancies.
how is polyhydramnios and oligohydramnios defined
by amniotic fluid index:
- >24cm or 2000ml = polyhydramnios
- <5cm or 200ml = oligohydramnios
