preterm labor pain chapter for medical students

1. Preterm Labor
Saeed esmailian
Kerman University of Medical Sciences

2. DefinitionDefinition
regular uterine contractions
by progressive cervical dilation and/or
effacement at less than 37 weeks

4. Significance
 Preterm birth is the leading direct cause of neonatal death
(death in the first 28 days of life).
 It is responsible for 27 percent of neonatal deaths
worldwide, comprising over one million deaths annually
 The risk of neonatal mortality decreases as gestational age
at birth increases, but the relationship is nonlinear (figure 1
 preterm birth is the second most common cause of-death
(after pneumonia) in children younger than 5 years.

5. Survival in Premature Infants
survival chance is directly proportional to the maturity
26 wks – 80%
27 wks – 90%
28-31 wks – 90 to
95%
32-33 wks – 95%
34-36 wks –
approaches term
survival rates

7. Complications of PrematurityComplications of Prematurity
 RDS
 IVH
 Feeding difficulties/NEC
 Apnea
 PDA
 Infection
 Jaundice
 Hypothermia
 Neurobehavioral
 ROP
 Anemia

8. Prevalence
 Worldwide
11 percent (range 5 percent [parts of Europe] to 18 percent
[parts of Africa]),
15 million children each year (range 12 to 18 million)
 United States in 2011, 11.73 percent

15. RiskRisk
factorsfactors

19. Signs and symptomsSigns and symptoms
1. Painful or painless uterine contractions
2. Menstrual-like cramping
3. Mild, irregular contractions
4. Low back ache
5. pressure sensation in the vagina
6.6. Vaginal dischargeVaginal discharge of mucus, which may
be clear, pink, or slightly bloody (ie,
mucus plug, bloody show)

20. Diagnostic critiriaDiagnostic critiria
Uterine contractionUterine contraction 4 in 20 mins
8 in 60 mins with cervical change
Cervical dilatation > 1 cm
Cervical effacement > 80%

21. Initial evaluation
 Maternal vital signs:
(temperature, blood pressure, heart rate, respiratory rate)
 Fetal monitoring:
fetal heart rate and contraction (frequency /duration /intensity)
 Uterine contractions are evaluated continuously using a contraction
monitor, palpation, and the patient’s subjective assessment.
 patient’s past and present obstetrical and medical history and GA
 Examination of the uterus
firmness, tenderness, fetal size, and fetal position.

22. Initial evaluation
 Speculum examination
using a wet non-lubricated speculum
 cervical dilation and effacement
 uterine bleeding (abruptio placenta or placenta previa)
 fetal membranes, ( intact or ruptured)
 fetal fibronectin (fFN).
 bactrial culture (B streptococcal,gonorrhea and chlamydia)

23. Fetal Fibronectin
 Fetal Fibronectin (fFN)- it is a glue like protein
binding choriodecidual membrane
 Present in vaginal secretions between 23-34 weeks
and signifies onset of labor
 Bedside test can be done – if negative it rules out
preterm labor in next two weeks
 P/V examination gives false positive result for 24
hours
Between 24-32 weeks
fFN – 25ng/ml + cervical length of 25 mm
shows significant risk

24. Initial evaluation
 Ultrasound examination
 Assess amniotic fluid index.
 Determine (+/ - 3 weeks) gestational age.
 Transvaginal scan for cervical length.
 Normal cervical length = 35 mm
 Significant cervical length = 25 mm
 Funnelling of membrane

25. Management
1. BBetamethasone (24- 34w)etamethasone (24- 34w)
2.2. Tocolytic drugs (before 34w)Tocolytic drugs (before 34w)
for up to 48 hours
3.3. AntibioticsAntibiotics ( GBS chemoprophylaxis, Appropriate
antibiotics to women with positive urine culture results)
 Bed rest (+)
 Hydration (-)
 Emergency cerclage (+)

26. Glucocorticoid
 BetamethasoneBetamethasone
12mg IM stat and 24 hours later
Effective: 24 hours after initial dose
Effect up to 7 days
Adverse effect:
 Pulmonary edema
 Infection
 Difficult glucose control in DM women

28. Tocolytic drugsTocolytic drugs

31. Magnesium SulfateMagnesium Sulfate
Calcium antagonist
Cleared almost by renal excretion
4 g loading dose 2 g/hr continuous dose
Therapeutic range:
 4~7 mEq/L
 1 mEq/L = 1.2 mg/dl = 0.5 mmol/L
Deep tendon reflex disappear
 10 mEq/L
Respiratory arrest
 12 mEq/L

34. Beta-Adrenergic Agonist
 RitodrineRitodrine
 Beta-adrenergic receptor desensitization
 Side effect:
 Pulmonary edema
 Hyperglycemia
 Arrhythmia

35. Prostaglandin Inhibitors (Nsaid(
 IndomethacinIndomethacin
< 48 hours
< 30-32 weeks' gestation)
Not > 200mg/day.
 Side effect:
 Oligohydramnios (reversible)

36. Prostaglandin Inhibitors (Nsaid(
Capsule 25mg oral
Amp 50mg
Rectal Supp 100 mg
50 mg Loading dose
Then 25-50mg /6hs

37. Calcium Channel Blockers
 Nifedipine (adalat)Nifedipine (adalat)
Higher delaying of delivery for >48 H.
Lower risk of RDS &Neonatal jundice.
Lower admission to NICU
Fewer maternal adverse effects
 Side effect:
 Hypotension
 Decrease uteroplacental perfusion

38. Dose:
20mg initial
10-20 mg /4-6 h
Available forms
Adalate capsule : 10mg
Adalate retard Tablet: 20 mg

39. Atosiban
 Nonapeptide oxytocin analogue
 Competitive antagonist of oxytocin-induced contractions
 Side effect:
 Nausea, vomiting, headache, dizziness, money loss
 18000 NTD/day

42. Reffrences

43. thanks