obs - preterm delivery Flashcards
what aree the gestational limts for preterm delivery?
24-37 weeks
extremely preterm - less than 28 wks
very preterm - 28-32 wks
what aree the gestational limts for late miscarriage?
Late miscarriage occurs between 16 and 23 + 6 weeks
a fetus may be born alive from 23 weeks but has very little chance of survival
what are the complications of preterm birth?
Fetal: Intensive care admission Cerebral palsy Death Chronic lung disease Blindness Minor disability At 24 weeks: 1/3 handicapped, 1/3 die
Maternal: Infection Severe illness Endometritis CS rate
What are the causes of preterm labour?
rsik factors?
Causes: Pre-eclampsia Placental abruption Iatrogenic Antepartum haemorrhage: placental abruption, praevia Infections - STI
Risk factors: - Multiple pregnancy Previous hx Extremes of maternal age Short inter-pregnancy interval Maternal medical diseases e.g. renal failure, DM IUGR Lower socioeconomic class - Polyhydramnios uterine abnormalities; fibroids etc cervical incompetence - eg LLETZ
what invx would you do to ivx to determinee likeliihood of preterm labour?
TVUS - cervical length
- an effaced cervix would suggest pending delivery
unlikely ptd if cerviix >15mm
Fetal fibronectin (if uneffaced cerviix) - would be +ve
list some prevention strategies for preterm labour?
Usually given to women that are high risk eg previous PTD:
1a. Cervical cerclage (elective or rescue)
OR
1b. Progesterone supplementation/suppositories
- in early pregnancy
- Treat infections eg uti
- Fetal reduction - get rid of some foetuses if mutliple pregnancy
- Treat Polyhydramnios: Amniioreduction or NSAIDS (monitor baby carefully)
- Treta medical disease
what are some contraindications to cervical cerclage?
Infection
Contractions
a 32 weeks pregnanct woman comes in with Dull suprapubic ache and discharge. she also has a fever. how would you ivx and what are your dfx?
Dfx: PTD
o Digital vaginal examination performed unless Ruptured Membranes (feel for cervical effacement)
o Sterile speculum - check if cervical os is opened
Effaced or dilating cx confirms diagnosis of PTD
o Vaginal swab - look for infecitous cause
CRP high in chorioamnionitis
High WCC if infection (BUT raised if given steroids)
Other hx that can show:
Painful contractions
Rupture of membranes
APH
How is Preterm labour managed?
Prevention: cerclage or progesterone suppository
Steroids and tocolysis:
Maternal corticosteroids < 36 weeks (fetal lung development)
Tocolysis:
Nifedipine or atosiban (oxytocin-receptor antagnonist) to delay rather than stop PTL - allow steeroid to take effect. dont use for >24h
Delivery:
birth in unit with intensive neonatal care faclities
Vaginal delivery
C-section if indicated
How is chorioamniotiis as a cause of PTD managed?
Choriomanionitis: IV abx and immediate delivery
why is vaginal deliviery preferred in PTD?
Vaginal delivery reduces the incidence
of neonatal respiratory distress syndrome
DEFINE PRETERM PRELABOUR RUPTURE OF MEMBRANES?
Membranes rupture before labour at <37 weeks
list the complicatoins of PPROM?
Preterm Delivery follows within 48h in 50% of cases
Chorioamnionitis or funisitis (cord infection) is common
Prolapse of umbilical cord
Absence of liquor (usually <24 weeks) -> Fetal lung distress
A 29 week pregnant woman presents with contractions, abdominal pain, fever, tachycardia, uterine
tenderness and coloured/offensive liquor.
what is your dfx?
Chorioamnioniitis
this can precede or follow PPROM
A woman presents at 31 weeks pregnant following a gush of clear fluid followed by further leaking
dfx?
how would you ivx? what findings are diagnostic ?
DFX: PPROM
1st - physical exam of fetal lie and presentation
- speculum: pooling of lfuid in posterior fornix = DIAGNOSTIC
also cervical effacement, length
If still unsure, can do the following:
USS: less liquor. can be normal though
Infection: high vaginal swab, FBC for WCC and CRP
Fetal well-being monitored by CTG
o Persistent fetal tachycardia = infection
How is PPROM treated?
- Oral erythromycin - if risk of infection
- corticosteroids < 36 weeks
- IV MgSO4 bolus - neuroprotection : 24-29 wks
Monitor for PTD & chorioamnionitis
Admission:
Imperial NHS trust: admit until 28 weeks, after which 2-3x
per week outpatient monitoring until delivery.
Delivery:
Aim for delivery at 37 weeks in most cases
A 33-year-old primigravida woman of 32 weeks gestation presents to the Emergency Department with premature rupture of membranes. There have been no complications of the pregnancy so far and the woman is normally fit and well. How is she best managed?
In the case of confirmed PPROM (pooling in fornix found):
Admit her IV steroids (takes 24 hrs after 2nd dose to work so 48hrs) Examine: cervical favourability (likelihood of spontaneously going into labour alone). if unfavourable cervix, Oral Abx - erythromycin for 10 days
monitor for signs of chorioamnionitis
Regular fetal monitoring - ctg
Induce at 36 weeks - consider at 34
in which situations would tocolysis be indicated?
- To slow the progress of labour in preterm labour (when there is no fetal compromise eg expeditious delivery is not immediately indicated). delays delivery for 24 hours. allows steroids (and mgso4) to have an effect.
Hyperstimulation (contractions that increase risk of fetal compromise)
Cord prolapse - in preparation for c-section after manual attempts have been applied
List some examples of tocolytics.
which are less used now?
Nifedipine - 1st line (not licenced but used)
MgSO4
Indomethacine
No longer used:
Terbutaline (beta mimetics)
Ritodrine
why is terbutaline not used anymore?
risk of adverse events outweighs the benefit
maternal and fetal side effects, such as
maternal tachycardia, hyperglycemia, and palpitations
arrhythmias and pumonary oedema
has lead to deaths
which events in preterm labour would contraindicatee tocolysis?
bleeding
infection
fetal compromise
what is the guidancee about prescribing IV corticosteroids for preterm labour?
offer it for women under 34 weeks (discuss risks and benefits with them)
consider for women 32 - 35+6 wks
up to when is MgSO4 givene for neuroprotection and how?
up to 34 weeks
given as IV Bolus
in an obstetric emergency where an IV bolus/infusion of BP med is needed, which would you choose?
Hydralazine
cant give the others as IV
