Preterm Labour, PROM, and Prolonged Pregnancy Flashcards
How helpful is maternal risk scoring in predicting premature deliveries?
- Terrible
- Fail to identify up to 70% so of limited use
What is the most important risk factor for pre-term labour?
- Prior preterm birth
A woman comes in the preterm contractions concerning for preterm labour which two tests can help predict if she will deliver?
1) Fetal fibronectin
- glycoprotein that maintains integrity of chorionic-decidual interface
2) Cervical length (U/S)
- > 30mm has high negative predictor value
What is the definition of true labour?
Regular, painful contractions of increasing intensity
Associated with:
- progressive dilatation and effacement of the cervix
- OR progression of station
What is tocolysis?
Suppression of labour
What is the goal of tocolysis?
- Delay delivery
- Typically does not inhibit pre-term labour completely but can buy time to transfer to appropriate center and administer steroids
What are the contraindications to tocolysis?
1) Maternal Factors
- HTN
- DM
- Heart disease
- (pre)eclampsia
- chorioamnionitis
2) Fetal Factors
- erythroblastosis fetalis (Rh incompatability leading to fetal hemolysis)
- severe congenital abnormality
- fetal distress/demise
- IUGR
What agents are used for tocolysis?
1) Calcium channel blocker (nifedapine)
2) Prostaglandin synthesis inhibitor (Indomethacin)
What drug is used to enhance fetal pulmonary maturity? How is it given?
- Betamethasone valerate
- Given IM, looks like goal is to give 24mg total can by done in two ways
a) 12mg q24h x 2 doses
b) 6mg q12h x 4 doses
What is a maternal contraindication to corticosteroid use for fetal pulmonary maturity?
- Active TB
What is cervical cerclage?
- Placement of cervical sutures at the level of the internal os
When is the best time to perform cervical cerclage?
- 12 to 14 weeks
When will cervical cerclage sutures be taken out?
- Elective removal at 37 weeks
- OR removed immediately at the onset of pre-mature labour to reduce the risk of cervical laceration and uterine rupture
What is premature rupture of membranes?
- rupture of membranes prior to labor at any gestational age
What is prolonged rupture of membranes?
- rupture of membranes for greater than 24 hours without the onset of labour
What investigations can be done to investigate a potential PROM?
1) Speculum exam
- pooling of fluid in posterior fornix
- valsalva to exacerbate
- sterile (avoid introducing infection)
2) Nitrazine test
- pH test, nitrazine paper turns blue (basic)
3) Ferning
- High salt in amniotic fluid
- when fluid evaporates leaves fern pattern of salt
How would you manage a PPROM at under 24 weeks?
- Consider termination
- Very poor outcome due to pulmonary hypoplasia
How would you manage a PPROM at 26-34 weeks?
expectant management
- prematurity complications are significant
How would you manage a PPROM at 34-36 weeks
- Grey zone
- approximate risk = between RDS and neonatal sepsis
What is the definition of prolonged pregnancy?
- pregnancy greater than 42 weeks
How would you counsel a term patient about when you may induce labour in a normal pregnancy?
- Offer IOL after 41 weeks if vaginal delivery is not contraindicated
Why is prolonged pregnancy a bad thing?
- Higher perinatal mortality due to progressive placental insufficiency
- increased risk of meconium aspiration and infection
- postmaturity syndrome
What is the definition of intrauterine fetal death?
Fetal death in utero after 20 weeks
50% of intrauterine fetal deaths are idopathic. What are the secondary conditions that can lead to this outcome?
1- HTN 2- DM 3- Erythroblastosis fetalis 4- Congenital abnormality 5- Placental or umbilical cord issues 6- Infection 7- Antiphospholipid antibody syndrome
What serum blood test would you expect to see with intrauterine fetal death?
- Increased AFP
- made in liver of fetus, escapes in certain conditions such as NT defect (or death)
What would you expect to hear on history and physical exam of a patient with intrauterine fetal death
- decreased perception of movement
- SFH not increasing
- Absent fetal HR on doppler
- No FHR on US (needed for diagnosis)
How do you manage a patient with intrauterine fetal death?
- Under 12 weeks D&C
- 13 + weeks, may require IOL
What investigations are done following intrauterine fetal death? 3 categories
Think secondary causes:
1) Maternal: screen for DM, Infection, autoimmune
2) Fetal: karyotype, autopsy, amniotic fluid culture for infection
3) Placental: Pathology and culture
