1. Preterm labor and Post-term delivery
E.Naghshineh M.D

2. It is estimated that 50% of all major
neurologic handicaps in children result from premature births.

3. Average gestational period= 280±14days
Term labor= weeks
Preterm labor= weeks

4. Activation of the parturition process results in:
membrane activation
Cervical ripening
an increase in myometrial responsiveness to endogenous and exogenous signals.

5. Initiating events: Decidual hemorrhage (abruption)
Mechanical factors (over distention of uterus, cervical incompetence)
Hormonal changes (fetal or maternal stress)
Sub clinical/clinical infection (1/3 –earliest GA)

6. Hormonal withdrawal of the uterine inhibitor hormone progesterone
In Humans:
no great increase in cortisol from the fetal adrenal gland before labor
nor has a dramatic decrease in progesterone

7. Oxytocin
Oxytocin is a universal initiator of labor are its ability to induce labor when given exogenously, and the increase in blood levels that accompanies labor in most species.

8. Oxytocin levels are higher in umbilical artery blood
than in umbilical vein or maternal blood . . .

9. The fetus is a source of oxytocin production
The concentration of oxytocin receptors
is a major reason for increased
contractility of the uterus and release
during labor.

10. Prostaglandins
Cytokines

11. INFECTION symptomatic nongenital infections
, such as acute pyelonephritis and
pneumonia

12. hypothesis
microbes or their products such as endotoxin enter the uterine cavity during pregnancy, most commonly ascending from the lower genital tract.
Blood-borne infection from a nongenital
focus occurs less commonly.

13. Microbes or their products then interact, most likely with the decidua or possibly with the membranes, producing prostaglandins or directly leading to uterine muscle contraction. This interaction is most likely mediated through a cytokine cascade.
As a result, there is cervical dilation, entry of more
microbes into the uterus, and continuation of "the viscous cycle" resulting in premature birth.

14. subclinical infection
1.The prevalence of histologic chorioamnionitis is increased among preterm births

15. Clinical infection
2.Clinical infections is increased in mothers and neonates after preterm birth.
Sepsis and meningitis are increased 3 to 10 fold in preterm infants. .

16. 3.There are associations of preterm birth with various maternal lower genital infections or microbes.
Active chlamydial infection
Heavy GBS colonization
Trichomonas vaginalis

17. 4.Positive cultures of the amniotic fluid/membranes/decidua are found in some patients in premature labor.

18. The most widely discussed route of upper genital tract infection in preterm labor is an ascending path through the vagina and cervix

19. EPIDEMIOLOGY OF PRETERM LABOR
Currently, 11.8% of women deliver preterm.
The vast majority of preterm deliveries are a result of preterm labor (50%), premature rupture of the Membranes (33%), or cervical incompetence.

20. Major preterm labor risk factors
Prior preterm labor X
Multiple gestation X
African-American race X
Low socioeconomic status X

21. Minor preterm labor risk factors
Modifiable risks Nonmodifiable risks
Poor maternal weight gain Extremes of age (<17 or >40)
Physically demanding work Prior multiple abortions
Smoking History of DES exposure
Anemia History of uterine abnormality
Bacteriuria Short stature
Bacterial vaginosis Low prepregnancy weight
Maternal systemic infections
: pyelonephritis

22. Risk Scoring Systems
Contraction Monitoring
Salivary Estriol
Screening for Bacterial Vaginosis
Fetal Fibronectin
Cervical Evaluation
a history consistent with cervical incompetence
PPROM prior to 32 weeks gestation
history of cold-knife conization
diethylstilbestrol exposure uterine
uterine anomaly

23. PRETERM LABOR DEFINITION
Uterine contractions (>4 contractions per 20 minutes) and cervical dilation (>2 cm in a nullipara and >3 cm in a multipara) and cervical effacement (>80%) or uterine contractions and cervical change.

24. TREATMENT OF PRETERM LABOR
Hormone treatment
Alcohol treatment
Beta-mimetics
MgSO 4
Antiprostaglandins
Anti-oxytocics
Ca channel blockers

25. Absolute contraindications to tocolytic therapy
Severe preeclampsia
Severe abruptio
Severe bleeding any cause
Frank chorioamnionitis
Fetal death
Fetal anomaly incompatible with life
Severe fetal growth restriction
Mature lung studies
Maternal cardiac arrythmias

26. Relative contraindications to tocolytic therapy
Mild chronic hypertension
Mild abruptio
Stable previa
Maternal cardiac disease
Hyperthyroidism
Uncontrolled diabetes mellitus
Fetal distress
Fetal anomaly
Mild intrauterine growth restriction
Cervix >4 cm

27. Maternal side effects related to MgSO4
Common
Flushing
Sense of warmth
Headache
Nystagmus
Nausea
Dizziness
Lethargy
Serious
Pulmonary edema
Neuromuscular blockage
Osteopenia

28. Prolonged Pregnancy
Postterm pregnancy, is one that has lasted longer than 42 weeks or 294 days beyond the first day of the last menstrual period

29. Postdatism implies pregnancy lasting beyond the estimated due date at 40 weeks.
Postdatism: 3% to 12% of all pregnancies.
The term "postmature" is reserved for the pathologic syndrome in which the fetus experiences placental insufficiency and resultant intrauterine growth restriction.

30. Prolonged pregnancies are at risk for macrosomia resulting in shoulder dystocia and fetal injury, oligohydramnios, meconium aspiration, intrapartum fetal distress, and stillbirth.
Maternal risks include trauma, hemorrhage, and labor abnormalities

31. The most common cause of a prolonged pregnancy is inaccurate dating.
Early ultrasound dating
Placental sulfatase deficiency is an X-linked disorder that affects male fetuses.

32. Maternal risk factors for prolonged pregnancy include;
primiparity,
previous prolonged pregnancy,
young maternal age.

33. AMNIOTIC FLUID
Commonly used ultrasound techniques include the four-quadrant AFI and the largest vertical pocket

34. ANTENATAL TESTING
CST, NST, and BPP

35. THE FETUS
Postmature infant was characterized by peeling, parchmentlike skin, wasted appearance and meconium staining of skin, membranes, and the cord

36. The postmaturity syndrome described by Clifford is seen in only a small percentage of prolonged pregnancies.
By far the most common complication is macrosomia resulting in dystocia with associated brachial plexus injuries and fractures.

37. MANAGEMENT The risk of stillbirth increases as gestational age
Induction and expectant management have similar outcomes, and either is suitable for managing the uncomplicated prolonged gestation.

38. PREVENTION
Separation of the membranes from the lower uterine segment (membrane sweeping) is a safe and inexpensive method of inducing labor, although its effectiveness is most likely operator-dependent.

39. INDUCTION OF LABOR
In the presence of a favorable cervix, induction after 41 weeks is reasonable.

40. Towards a safe motherhood