READ AND KNEW IT

1. PRETERM LABOR
Dr. NegatuT.(MD).
1

2. PRETERM LABOR
Definition
• Onset of labor prior to the
completion of 37 weeks, after the
gestational viability.
2

3. Incidence
• varies from 5-15%
• It is the number 1 cause of neonatal
morbidity and mortality and causes
75% of neonatal deaths that are not
due to congenital anomalies.
3

4. Etiology
The cause of preterm labor in 50% of
pregnancies is idiopathic.
4

5. Maternal factors
General conditions
• Race (for black Americans 16.3%, for white
Americans 7.7%)
• Age. <18, >40
• Short stature
• Weight < 45 Kg
• Strenuous work during pregnancy
• Nutritional status (obesity/ malnutrition)
• Chronic ill health
• Low socioeconomic status
• Previous induced abortion.
5

6. Medical & Obstetrical Conditions
• Anemia
• Bacterial vaginosis
• DM
• PE, Eclampsia
• Chronic HPN
• Asthma
• APH
• Interval between pregnancies
– intervals shorter than 18 months and
longer than 59 months were associated with
increased risks for both preterm
6

7. • PROM with chorioamnionitis
• Previous Hx of preterm labor
• Infections
– Pneumonia
– UTI
– Asymptomatic bacteuria
– Reproductive tract infections
– Appendicitis
– Dental infections
7

8. • Congenital abnormalities of the
uterus (septate, unicornuate/
biconuate Ux)
• Incompence of cervix
• Substance abuse (tobacco, Alcohol)
• Trauma
• Genetic
– Many preterm deliveries are familiar.
8

9. Fetal factors
• Congenital malformation (especially
those associated with fetal hydrops /
hydraminos)
• IUFD
• Multiple pregnancies
9

10. Iatrogenic /Elective PL
• Due to advance in neonatal care
there is a greater incidence of
iatrogenic or elective PL, e.g. for bad
ob. Hx like Previous stillbirth, PE, PP,
IUGR, etc.
• Miscalculation of GA also leads to
premature induction of labor.
10

11. • painful or painless uterine contractions.
• pelvic pressure
• menstrual-like cramps
• watery vaginal discharge
• pain in the low back
SIGNS & SYMPTOMS
11

12. Braxton Hicks contractions
- contractions, described as
irregular, nonrhythmical, and either
painful or painless, can cause
considerable confusion in the
diagnosis of true preterm labor
12

13. Contractions four in 20 minutes
or eight in 60 minutes plus
progressive change in the cervix
Cervical dilatation greater than 1
cm
Cervical effacement
[shortening]of 80 % or greater
13

14. PHYSICAL EXAM
• V/S [vital sign]
• Hydration
• Abdominal – FH (to see the
correlation with period of gestation),
monitoring of contractions & FHR
[fetal heart rate] auscultation.
14

15. INVESTIGATIONS
• CBC
• C-reactive protein
• U/A
• Urine culture & sensitivity
• High vaginal swab & culture
(especially for Group B
streptococcus), pH & fern test
• Speculum exam. to look for any
infection & leaking of liquor.
15

16. • Special investigations
– Enzyme immunoassay for fetal
fibronectin
• A swab is taken from posterior fornix/
external cervical os. The presence of
fibronectin in the Cx & vagina after 22 wks
& before 37 wks is diagnostic of PL.
– Exam. of urethral discharge for
gonorrhea
– Cervical swab exam. for Chlamydia
16

17. • glycoprotein produced in 20 different
molecular forms by hepatocytes, fibroblasts,
and endothelial cells, and by fetal amnion
• Present in high concentrations in maternal
blood and in amnionic fluid which play a role in
intercellular adhesion during implantation
and in the maintenance of placental
adhesion to the decidua
• detected in cervicovaginal secretions in
women who have normal pregnancies with
intact membranes at term, and it appears
to reflect stromal remodeling of the cervix
prior to labor
17

18. • fibronectin detection in cervicovaginal
secretions prior to membrane rupture was a
possible marker for impending preterm
labor
• measured using an enzyme-linked
immunosorbent assay
• values exceeding 50 ng/mL are considered
positive
• positive value for cervical or vaginal fetal
fibronectin assay, as early as 8 to 22 weeks
- powerful predictor of subsequent preterm
birth
18

19. • Pervaginal exam.
– Cx > 3cm dilated & > 80% effaced
– Presence or absence of membranes
– Presentation
• Per abdominal U/S
– Placental localization
– AFV
– Fetal well-being
– Fetal presentation
– EFW [estimated fetal weight]
19

20. • Transvaginal U/S
– More accurate for cervical length
measurement.
20

21. • Amniocentesis
– To assess fetal lung maturity
– If suspicion of intrauterine infection
exists, amniotic fluid exam. is done.
• WBC count
• Glucose (low in case of infection)
• Interleukin-6 concentration (high in case of
infection)
• Gram stain & culture
• L/S ratio for maturity
21

22. The cornerstone of treatment is to avoid
delivery prior to 34 weeks, if possible.
1. Amniocentesis to detect infection
2. Steroid therapy to enhance fetal lung
maturation
3.Antimicrobials
4.Emergency or rescue cerclage
MANAGEMENT
22

23. 1. Bed rest
2. Hydration and sedation
With adequate hydration and bed rest,
uterine contractions cease in
approximately 20% of patients.
These patients, however, remain at high
risk for recurrent preterm labor.
23

24. • If the patient does not respond to
bed rest and hydration, tocolytic
therapy is instituted, provided that
there are no contraindications.
24

25. UTERINE TOCOLYTIC AGENTS
• MAGNESIUM SULFATE
• NIFEDIPINE
• PROSTAGLANDIN SYNTHETASE
INHIBITORS -indomethacin
• BETA MIMETICS
– ISOXUPRINE, RITODRINE, TERBUTALINE
25

26. UTERINE TOCOLYTIC THERAPY
• Magnesium sulfate:
– acts at the cellular level by competing with
calcium for entry into the cell at the time of
depolarization. Successful competition results in
an effective decrease of intracellular calcium ions,
resulting in myometrial relaxation.
– Drug of choice for initiating tocolytic therapy.
– Drug of choice for patients with diabetes
mellitus or heart disease.
• Side effects : Decrease tone, Hypotension,
Oliguria
26

27. • After the loading dose is given, a
continuous infusion is maintained, and
plasma levels should be determined until
therapeutic levels are reached. The
drug should be continued at therapeutic
levels until contractions cease.
27

28. • Once successful tocolysis has been
achieved, the infusion is continued for at
least 12 hours, and then the infusion rate is
weaned over 2 to 4 hours and then
discontinued. In very high risk patients
(advanced cervical dilation or continued
labor in very low birth weight cases), the
infusion can be continued until the fetus has
been exposed to glucocorticoids to enhance
lung maturity.
28

29. Nifedipine
• a calcium entry blocker
• has been shown to be an effective uterine
relaxant by inhibiting the slow, inward
current of calcium ions during the second
phase of the action potential of uterine
smooth-muscle cells.
• as an oral agent is very effective in
suppressing preterm labor with minimal
maternal and fetal side effects.
Nifedipine may gradually replace
intravenous magnesium sulfate.
29

30. Nifedipine
Side effects
• Headache
• Cutaneous flushing,
• Hypotension
• Tachycardia
30

31. PROSTAGLANDIN SYNTHETASE INHIBITORS
Indomethacin
– is the most commonly used prostaglandin
inhibitor.
– can be administered both orally and
rectally.
32

32. Indomethacin
Side effects:
• Oligohydraminos
• Premature closure of the fetal ductus
arteriosus, which in turn may lead to
neonatal pulmonary hypertension and
cardiac failure.
• Decreases fetal renal function.
• Indomethacin-exposed infants have a
greater risk of necrotizing enterocolitis,
intracranial hemorrhage.
33

33. – Ritodrine
– Terbutaline, Isoxuprine
Parenteral beta agonists
prevent preterm birth for
at least 48 hours facilitating
maternal transport and
giving of steroids
MOA:
reduce intracellular ionized
calcium levels and prevent
activation of myometrial
contractile proteins
SIDE EFFECTS:
• Pulmonary edema
34

34. Contraindications to Tocolytic
Therapy
• Severe preeclampsia,
• APH
• Chorioamnionitis,
• IUGR
• Fetal anomalies incompatible with life
• Fetal demise
• Advanced cervical dilatation
35

35. The following considerations should be given
to women in preterm labor:
1. Confirmation of preterm labor
2. For pregnancies less than 34 weeks in
women with no maternal or fetal
indications for delivery, close observation
with monitoring of uterine contractions
and fetal heart rate is appropriate, and
serial examinations are done to assess
cervical changes.
37

36. 3. For pregnancies less than 34 weeks,
glucocorticoids are given for
enhancement of fetal lung
maturation.
– 2 doses of 12 mg of
betamethasone, given
intramuscularly 24 hours apart OR
– 4 doses of 6 mg of dexamethasone
given i.m. 12 hours apart.
38

37. 5. For pregnancies less than 34 weeks
in women who are not in advanced
labor, some practitioners believe it is
reasonable to attempt inhibition of
contractions to delay delivery while
the women are given corticosteroid
therapy and group B streptococcal
prophylaxis.
40

38. 6.For pregnancies at 34 weeks or beyond,
women with preterm labor are
monitored for labor progression and
fetal well-being
7.For active labor, an antimicrobial is
given for prevention of neonatal group B
streptococcal infection.
41

39. 1. Labor
• Continuous electronic monitoring is
preferred
• Fetal tachycardia, especially with
ruptured membranes, is suggestive of
sepsis
42

40. 2. Prevention of neonatal group B
Streptococcal infections
• Either penicillin G or ampicillin
intravenously every 6 hours until
delivery for women in preterm
labor(ACOG)
43

41. 3. Delivery
Staff proficient in resuscitative
techniques commensurate with the
gestational age of the newborn and fully
oriented to any specific problems should
be present.
44

42. 4. Prevention of neonatal intracranial
hemorrhage
• Preterm newborns have germinal matrix
bleeding that can extend to more serious
intraventricular hemorrhage
• It was hypothesized that cesarean delivery to
obviate trauma from labor and vaginal delivery
might prevent these complications
• Avoidance of active-phase labor is impossible
in most preterm births because the route of
delivery cannot be decided until the active
phase labor is firmly established
45

43. Prevention of PL[preterm L]
PRIMARY PREVENTION
• Preventing pregnancy in teenagers
• Prevent smoking
• Prevent reprod. TI/ STIs
• Access to FP methods to prevent unwanted
& frequent pregnancies.
• Preconceptional counseling
• Improve the nutrition & general health of
the women
• Decrease factors causing stress & give
adequqte rest.
46

44. Prevention of PL
SECONDARY PREVENTION
• Identification of preg. Women who
are risk & their close surveillance.
Includes:
– Pt education to enable them to detect
early symptom of PL (rhythmic
backache, pelvic pressure, heavier
vaginal discharge, vag. Spotting & abd.
cramps) and also instruct to reduce
physical & sexual activity.
47

45. – Medical therapy include tocolytic drugs,
progesteron therapy, ATBs , cortisone
– Circlage if cervical incompetence is
present’
48

46. Premature Ruptures
Of Membranes
(PROM)
49

47. Definitions
PROM - Spontaneous rupture of membranes
before onset of labor after 28 completed
weeks.
LATENCY PERIOD - interval between PROM &
onset of labor.
PROLONGED PROM - ROMs for more than 12
hrs.
TERM PROM - ROM after 37 weeks.
PRETERM PROM – ROM before 37 wks
VERY PRETERM PROM – between 28-30 wks.
50

48. Definitions
CHORIAMNIONITIS (CA)
• Clinical CA has the following signs:
– Fever > 380C
– Uterine tenderness
– Foul smelling AF
– Increasing WBC count
– Maternal or fetal tachycardia
• Subclinical
– Diagnosed by AF study in the absenceof
the above mentioned signs.
51

49. Etiology
• The exact cause is not known.
• Associations with:
– Incompetent Cx
– Overdistended Ux (Polyhydraminos,
multiple pregancies)
– Inherent membrane defects (genetic
conditions, low maternal serum copper,
vit. C deficiency)
52

50. Etiology
– Infections
• Asymptomatic bacteriuria
• UTI
• Lower GTI
• Bacterial vaginosis
• Intrauterine infections
• Chorioamnonitis
– Seminal fluid releasing collagenase
like enzyme
– Maternal connective tissue
disorders
53

51. Etiology
– 2nd & 3rd trimester bleeding
– ECV
– Amniocentesis
– Trauma
– Maternal smoking
– Low socioeconomic status
– Family history
54

52. Diagnosis
• Symptoms :
– Sudden gush of fluid from the vagina/
continued leakage
• Hx :
– Duration of leakage
– Quantity of the discharge
– Type of discharge (clear/ blood stained/
green-colored)
– Consistency of the fluid
– Presence of vernix
55

53. Diagnosis
• Hx :
– Presence & duration of pain
– LMP for GA
– Fetal movement
– Any Hx suggestive of infections
– A detailed present & past obs., medical
& surgical Hx may help find the
pathological cause.
56

54. Examination
• GPE, Hydration & monitoring of vitals
• Abdominal examination
– Confirm GA by measuring the FH which
may be small for dates
– Look for uterine tenderness
– Determine fetal lie
– Auscultate Fetal heart sounds
57

55. Examination
• Speculum exam.
– Extent of cervical dilatation & effacement
– Cord prolapse
– Fetal presenting part
– Liquor may be seen draining through Cx os &
pooling of the amniotic fluid in post. fornix.
– If no discharge is seen, the pt is asked to
cough, apply slight fundal pressure or perform
Valsava maneuver & leak is observed.
– The fluid is collected.
Pad chart ;if no free fluid
– A clean sterile pad is given to pt, the pad is
observed after 1 hr.
– >Drawback: Vulval pads can be moisted with urine or vaginal
discharge which can be mistaken with the amniotic fluid
58

56. Exam. of collected AF
• Gross Exam.
– Clear, blood stained or cream/ green
color
– Foul smelling
59

57. Diagnostic tests in PROM
• Nitrazine paper test
pH of the vagina : 4.5 – 6.0
pH of the AF : 7.1 – 7.3
– It changes color from yellow green to dark blue at pH >
6.5
• False +ve
– Blood contamination
– Semen contamination
– Alkaline antiseptics
– Bacterial vaginosis
– Tap water
• False –ve
– Minimal residual fluid
60

58. Diagnostic tests in PROM
• Ferning – a drop of AF when placed
on a clean slide & allowed to dry
demonstrates ferning (microscopic
crystallization) due to interaction of
AF proteins & salts
• False +ve
– Cervical mucus
– NaCl solution
61

59. Special investigations
• Amniocentesis – a dilute solution of
1 ampule of indigo carmine dye is
injected in to the AF & a pad is kept
at vulva. A leak of blue fluid in to
the vagina confirms Dx.
• High vag. swab for culture &
sensitivity (for Dx of infection) &
fetal fibronectin (to Dx
prematurity)
62

60. • 0.1% nile blue sulphate test – the
collected fluid can be centrifuged &
examined for fetal cells staining with the
dye. The cells appear orange due to the
presence of exfoliated fat cells from the
sebaceous glands of the fetus.
• Culture & sensitivity of AF (for infection)
63

61. • U/S
– GA
– Amount of AF- reduced/ absent
– Fetal presentation, number
– EFW
– Placental localization & maturity
• CBC, CRP (to predict development of
chorioamnionitis)
• Urine exam. – routine, microscopy &
culture.
64

62. Complications
• Preterm labor: with the risk of
prematurity.
• Infection: chorio-amnionitis,
septicemia and fetal pneumonia.
• Fetal deformities and distress: due
to oligohydramnios.
65

63. Management
• All pts suspected of PROM should be
admitted.
• Investigations on admission
– CBC
– Urine: routine/ microscopy exam.
– Urine: Culture & sensitivity
– 2 swabs – a high vaginal swab & a
cervical for culture & sensitivity
• Determine GA for deciding further
management.
66

64. Management
• General Principles
1. Confirm the diagnosis
2. Determine GA
3. Evaluate for intra amniotic infection
4. Evaluate for the presence of labor
5. Evaluate fetal condition
67

65. • Indications for immediate delivery
– Pt in labor
– Clinical chorioamnionitis
– Fetal distress
– Features suggesting cord compression
or cord prolapse
– Gross fetal congenital abnormalities
– Immunocompromised host
– Pregnancy complications indicating
delivery (heart disease, DM)
68

66. Management of Term PROM
PROM
Labor
IAI
FD
IUFD
YES DELIVERY
NO
Contraindication for VD YES CS
NO
Cx status
Favorable
DELIVERY
Unfavorable
Prostaglandin
Priming
Possible
YES
PG
DELIVERY
NO
Observe for
6-30 hr
Spon.
Labor
YES
NO
FOLLOW
INDUC-
TION 69

67. PROM
Gramstain + Cervical culture
U/S
For GA, EFW, Presentation, BPP
Labor, FD,IAI, IUFD
YES NO
DELIVER
NO >34 wk
<34 wk
Hospitalization
Monitor for IAI
(Clinical, AF anlysis)
Hospitalization
Antibiotics
Monitor for IAI
+ Steroids
Management of
PPROM
70

68. ATB use in PROM
Advantages
• Increases latency period
• Decreases the incidence of maternal
& neonatal morbidity & mortality
71

69. ATB use in PROM
Indications
Prophylactic
• PPROM with expectant management (<34
weeks)
– Ampicillin 2 gm iv QID/ 48 hrs
– Erythromycin 500mg iv/ 48hrs
+
– Amoxacillin 500mg PO TID for 5-7 days if
delivery doesn’t occur
– Erythromycin 500 mg PO QID for 5-7 days if
delivery doesn’t occur
• At time of delivery with prolonged PROM
– Ampicillin 2 gm iv till delivery
72

70. ATB use in PROM
Therapeutic
• Clinical IAI
– Ampicillin 2gm iv QID for 7-10 days
– Gentamycin 80mg iv TID for 7-10 days
– Clindamycin 900mg iv TID for 7-10 days
• IF Clindamycin is not available
– Chloramphenicol 1000mg iv QID or
– Metronidazole 500mg iv TID
• Single agent treatment
– Ceftriaxone 1gm iv BID
73

71. THE END
74