Transcript Preterm Labor

Preterm Labor
Ahmed Barefah
Ahmed Al-Ghamdi
Mohammed Al-Talhi
Definition
Preterm labor is the presence of
contractions of sufficient strength
and frequency to effect
progressive effacement and
dilation of the cervix between 20
and 37 weeks' gestation
WHO
Preterm Labor
Incidence : 9-11%
• Spontaneous
: 40-50%
• PROM
: 25-40%
• Obstetrically indicated : 20-25%
Preterm Labor
Most mortality and
morbidity is experienced
by babies born before 34
weeks.
Major Risks Of Preterm Delivery
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Death
Respiratory distress syndrome
Hypothermia
Hypoglycaemia
Necrotising enterocolitis
Jaundice
Infection
Retinopathy of prematurity
Intraventricular hemorrhage
Can preterm
labor be
predicted?
Prediction
1. Assessment of risk factors
2. Vaginal examination to assess the
cervical status
3. Ultrasound visualization of
cervical length and dilatation
4. Detection of foetal fibronectin in
cervicovaginal secretions
1-Risk Factors
While the exact cause of
preterm labor is often
unknown, there is strong
evidence that intrauterine
infection may play a role in
very early preterm labor.
1-Risk Factors
Bacterial Vaginosis
 Bacterial vaginosis increased the
risk of preterm delivery >2-fold .
 Risks were higher for those
screened at <16 weeks than those
at <20 weeks of gestation
1-Risk Factors
Other Risk Factors
Multiple pregnancy: risk >50%
Previous preterm delivery: risk 20- 40%
Cigarette smoking: risk 20-30%
Cervical incompetence
Uterine abnormalities
1-Risk Factors
Other Risk Factors
Young age of mother - less than 16 years of age.
•Lower socioeconomic class.
Reduced body mass index (BMI) - BMI less than
19.0.
Antiphosphlipid syndrome.
Obstetric complications, including hypertension in
pregnancy,antepartum haemorrhage, infection,
polyhydramnios, foetalabnormalities.
2-Vaginal examination
Digital examination is the traditional
method used to detect cervical
maturation, but quantifying these
changes is often difficult.
3-Vaginal U/S
Vaginal ultrasonography
allows a more objective
approach to examination
of the cervix.
Prevention
Prevention of Preterm Labor
Women at increased risk of
preterm delivery may be
identified by various risk
factors in the obstetric
history and treated.
General measures
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Tobacco cessation
Improved nutritional status
Aggressive treatment of UTIs
Patient education
17 Hydroxy -Progesterone Caproate
Prophylactic use of 17 hydroxy
progesterone caproate to prevent
preterm labor revealed a significant
decrease in preterm birth .
Weekly injection or daily suppositories
Treatment Of Vaginosis
Treatment of asymptomatic abnormal
vaginal flora and bacterial vaginosis
with oral clindamycin early in the
2nd trimester significantly reduces
the rate of late miscarriage and
spontaneous preterm birth.
Diagnosis
Diagnosis
3 criteria to document PTL(20-37w)
1-Regular uterine contractions occur
at 4/20 min. or 8/60 min. Plus:
progressive change in the cervix.
2- Cervical dilatation > 1 cm
3- Effacement >
_ 80%.
Vaginal U/S+ Fibronectin Test
Suspected preterm labor with no
cervical changes :
Negative fetal fibronectin +
Cervical length > 30 mm
the likelihood of delivering in the next week
is less than 1%.
Thus most women with a negative test can
safely be sent home without treatment.
Treatment
•Inhibition of labor
• Corticosteroid
• Antibiotics
•Others.
Inhibition Of Labor
•Bed rest :DVT
•Hydration &sedation
• Tocolytics
Most Efforts to Prevent
Preterm Labor Not Effective
Until effective strategies are found, efforts
should be aimed at preventing newborn
complications by :
• Corticosteroids
• Antibiotics against group B strep
• Avoiding traumatic deliveries.
• Delivery in a center with experienced
resuscitation teams and neonatal intensive
care
Is Tocolysis Better Than No
Tocolysis For Preterm Labour?
• It is reasonable not to use tocolytic
drugs, as there is no clear evidence
that they improve outcome. However,
tocolysis should be considered if the
few days gained would be put to good
use, such as completing a course of
corticosteroids, or in utero transfer
Tocolytics
Most authorities do not
recommend use of tocolytics
at or after 34 weeks' .
There is no consensus on a
lower gestational age limit for
the use of tocolytic agents.
Choice Of Tocolytic Drug
B –Sympathomimetic
(Ritodrine)
Magnesium sulphate
Indomethacin
Nifedipine = Epilate
Atosiban= Tractocile
Choice Of Tocolytic Drug
If a tocolytic drug is used, ritodrine no
longer seems the best choice.
Atosiban or nifedipine appear
preferable as they have fewer adverse
effects and seem to have comparable
effectiveness.
B -Sympathomimetic Agents.
• Maternal: pulmonary edema, myocardial
ischemia, arrhythmia, and even maternal
death.
• Fetal : arrhythmia, cardiac septal
hypertrophy , hydrops, pulmonary edema,
and cardiac failure. hypoglycemia,
periventricular-intraventricular
hemorrhage, and fetal and neonatal death.
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Magnesium Sulfate
Magnesium sulphate is ineffective
at delaying birth or preventing
preterm birth, and its use is
associated with an increased
mortality for the infant.
Nitric Oxide Donors
There is insufficient evidence to
support the routine
administration of nitric oxide
donors (nitroglycerin )in the
treatment of preterm labor.
Indomethacin
Compared with ritodrine there is
insufficient evidence for any
differential effect on delay in
delivery, but indomethacin does
seem to have fewer maternal
adverse effects than the betaagonists
Indomethacin
Fetal risk:
Premature closure of the ductus.
Renal and cerebral vasoconstriction.
Necrotising enterocolitis
Common with high dose and
prolonged exposure.
Indomethacin
Indomethacin can be
used as a second-line
tocolytic agent in early
gestational age preterm
labors.
Indomethacin
Indomethacin may be a firstline tocolytic in:
• Associated polyhydramnios :
( to have renal effects of
indomethacin)
Atosiban: Tractocil
Atosiban, a synthetic
peptide, is a competitive
antagonist of oxytocin at
uterine oxytocin
receptors.
Atosiban: Tractocil
Atosiban - compared with beta-agonistshas:
Little difference in the effect of these agents on
delayed delivery
Fewer maternal adverse effects than beta-agonists,
such as chest pain, palpitations , tachycardia ,
hypotension , dyspnoea ,vomiting , and headache.
Nifedipine
Nifedipine- compared with ritodrine has:
Higher delaying of delivery for >48 H.
Lower risk of RDS &Neonatal jundice.
Lower admission to NN ICU
Fewer maternal adverse effects
Nifedipine
When tocolysis is indicated for women in
preterm labor, calcium channel blockers
are preferable to other tocolytic agents
compared, mainly betamimetics.
Nifedipine
20mg initial
10-20 mg /4-6 h
Epilate capsule
:10mg
Epilate retard Tablet: 20 mg
Maintenance Tocolysis Is Not
Recommended For Routine Practice.
There is insufficient evidence for any
firm conclusions about whether or not
maintenance tocolytic therapy
following threatened preterm labor is
worthwhile. Therefore maintenance
therapy cannot be recommended for
routine practice.
Corticosteroids
Antenatal corticosteroids are associated
with a significant reduction in rates of
RDS, neonatal death and
intraventricular haemorrhage, although
the numbers needed to treat increase
significantly after 34 weeks' gestation.
Corticosteroids
The optimal treatment-delivery
interval for administration of
antenatal corticosteroids is
after 24 hours but < 7 days after
the start of treatment.
Corticosteroids
Two 12 mg doses of betamethasone
given IM 24 hours apart, Or
Four 6 mg doses of dexamethasone
given IM 12 hours apart
Antibiotics
Group B Streptococci (GBS) Prophylaxis
All patients in preterm labor are
considered at high risk for
neonatal GBS sepsis and
should receive prophylactic
antibiotics regardless of
culture status.
Group B Streptococci (GBS) Prophylaxis
The goal of this strategy is
to prevent neonatal
sepsis, and not to
prevent preterm birth.
Conclusions
Various strategies that have been
used to prevent or treat preterm
labor, haven't proven effective.
Tocolysis should be considered only
for 2 days- if needed - for
corticosteroids therapy , or in utero
transfer to a tertiary center .
Conclusions
If a tocolytic drug is
used, ritodrine no
longer seems the
best choice.
Conclusions
Other drugs with fewer adverse effects and
comparable effectiveness are now
recommended
Atosiban or nifedipine have been
recommended
endomethacin may be used as a 2nd line
tocolytic or if there is polyhydramnios
Conclusions
Maintenance tocolytic
therapy has no proven
effect.
It cannot be recommended
for routine practice.
Thank You
team A