3. DEFINITIONS
PRE TERM PREGNANCY
DELIVERY BEFORE 37 WEEKS OF GESTATION
TERM PREGNANACY
GP FROM 37 TO 41 + 6 days WEEKS
POSTERM PREGNANCY
GP FROM 42 WEEKS ONWARDS
4. PRETERM LABOUR
Preterm labour is defined by WHO as Onset of
labour prior to the completion of 37 weeks of
gestation, in a pregnancy beyond 20 wks of
gestation.
Preterm labour is considered to be established if
regular uterine contractions can be documented
atleast 4 in 20 minutes or 8 in 60 minutes with
progressive change in the cervical score in the form
of effacement of 80% or more and cervical
dialatation >1cm.
5. CONT’
This condition tends to be over diagnosed and over
treated.
Nearly 50-60% of preterm births occur following
spontaneous labour.
30% due to preterm premature rupture of
membranes
Rest are iatrogenic terminations for maternal or fetal
benefit.
6. Half of all neonatal morbidity occurs in preterm
infants.
Inspite of all major advances in obstetric and
neonatal care, there has been no decrease in
incidence of preterm labour over half a century.
On the contrary , it has been increasing in the
developed countries as more and more high risk
mothers dare to get pregnant.
7. Incidence
Preterm birth occurs in 5-12% of all pregnancies and
accounts for majority of neonatal deaths and nearly
half of all cases of congenital neurological disability,
including cerebral palsy.
A neonate weighing 1000- 1500 g today has ten
times greater chance of surival then what it had in
1960s.
The focus is hence shifting to early preterm
births(<32 weeks) which account for 1-2% of all
births but contribute to 60% of perinatal mortality
and nearly all neurological morbidity.
8. One of the major reasons for increase in incidence of
premature births is the increase in numbers of
multiple pregnancies , particularly higher order
pregnancies, resulting from the use of fertility drugs
and assisted reproduction.
9. PRETERM LABOUR
5 -> 4 -> 4
Mildly preterm 32 – 36 weeks
Very preterm 28 – 31 days weeks
Extremely preterm 24 – 27 weeks
12. RISK FACTORS
MAJOR NON MODIFIABLE
Last birth preterm: 20% risk
Last two birth preterm : 40%risk
Twin pregnancy: 50% risk
Uterine abnormalities
Cervical Anomalies
Factors in current pregnancy
13. Non modifiable , Minor
Parity 0 or >5
Ethnicity(Black)
Poor socioeconomic status
Education
Teenagers having second or subsequent babies
14. Modifiable
Smoking :2x risk of PPROM
Drug abuse : especially cocaine
BMI <20
Inter Pregnancy interval: <1year
19. PREVENTION
Rx of BV
Cervical Cerclage
Selective Reduction of pregnancy numbers
Progesterone ?
20. PREDICITON
Cervical length
TVS improves diagnostic accuracy
Normal length 35 mm
In asymptomatic women with singleton pregnancy
Cervix <15 mm long : risk of delivering before 32 weeks is 4%
Cervix <5 mm long: risk of delivering before 32 weeks is 78%
In symptomatic woman with singleton pregnancy
Cervix <15mm long : risk of delivering within 7 days is 50%
Cervix >15 mm long: risk of delivery within 7 days is <1%
21. cont
Fetal Fibronectin(fFn)- glue like protein at
choriodecidual interface
fFN test offers rapid assessment of risk in symptomatic women
with minimal cervical dilatation,
fFN is protein not usually present in cervicovaginal secretions
at 22-36weeks
fFN positive test indicates that women is likely to deliver
fFN predicts preterm birth within 7 – 10 days of testing
Implying disruption of choriodecidual interface
22. TOCOLYTIC AGENTS AND STEROIDS
Used to prevent labour and delivery
May prolong pregnancy but not more than 72 hours
Useful for fetal lung maturity by maternal IM steroids
Transportation of mother to a facility with neonatal intensive
care
23. IMPORTANT TOCOLYTIC DRUNGS
TOCOLYTIC DRUGS SIDE EFFECTS
MAGNESIUM SULFATE
Competitive inhibitors of calcium
Overdose treated by IV ca gluconate
Resp depression
Muscle weakness
Pulmonary edema
Beta- Adrenergic agonist
Terbutaline
HTN and tachycardia
Hypokalemia
Hyperglycemia
24. cont
Calcium channel Blocker
Dec. intracellular Calcium
e.g nifidipine ,
Hypotension
Myocardial depression
Tachycardia
Prostaglandin synthetase inhibitor
Dec. smooth muscle contractility
e.g. Indomethacin
Fetal complications like
oligohydramnios, premature closure of
ductus and necritising enterocolitis
have restricted their use.
25. MATERNAL STEROIDS
Reduces the rates of respiratory distress,
intraventricular hemorrhage and neonatal death
Given as IM injection two doses 12-24 hrs apart.
Maximum benefit is seen after 48 hours.
26. MANAGEMENT OF PRETERM LABOUR
Confirm labour using three criteria listed above.
Rule out contraindications of tocolysis
Administer IV line
Start MgSO4 tocolysis with 5g IV for 20 min, then
2g/h
Adminster maternal IM betamethasone to stimulate
type II pneumocyte
27. Clear plan about
Mode of delivery
Monitoring in labour
Presence of pediatrician
In antibiotics in labour
28. PRETERM PRELABOUR OF MEMBRANES
(PPROM)
Rupture of fetal membranes occurring before 37 wks
of gestation.
It complicates about 3 % of pregnancies and
contributes to one third of preterm births
30. Diagnosis of PPROM
History of sudden escape of watery amnoitic fluid.
Oligohydramnios on US
Pooling of amniotic fluid in posterior vagina
A sterile speculum examination confirms that the fluid is
coming through the os.
Nitrazine test: turns blue from yellow if amniotic fluid leak.
Fern test
Ultrasound examination shows oligohydramnios
Amnisure test(immunochromatographic method) detects trace
amounts of placental microglobulin (PAMG-1)
31. Differential diagnosis
It needs to be differentiated from stress urinary incontinence
and profuse normal vaginal discharge.
UTI
Vaginal Infection
32. Management of PPROM
Correct and prompt diagnosis is imperative for
optimum management.
PPROM remote from term: Conservative management
is advisable, provided acute cord complications like
prolapse and compression, placental abruption and
fetal distress have been excluded. Oligohydramnios is
not an indication.
Antibiotics: help to prolong latency and improve perinatal
outcomes.
Corticosteroids: should be given to patients between 24 and 34
weeks of gestation.
33. PPROM nearer to term(34-36 wks):
It is preferable to induce labour unless fetal lung
maturity or gestational age is doubtful
Serial transabdominal amnioinfusions in<26 wks
pregnancies with PPROM and severe
oligohydramnios in selected women reduce the risk
of pulmonary hypoplasia and improve neonatal
survival.
34. POST-TERM PREGNANCY
Any pregnancy that exceeds 42 weeks from the first
day of last menstrual period in women with regular
28 day cycles
Aka Postdate pregnancy and prolonged pregnancy
35. INCIDENCE
The generally quoted incidence of PT pregnancy is
10%
Incidence is decreasing b/c of better estimation of
duration of gestation and timely induction of labour.
36. RISK FACTORS
Past history of prolonged pregnancy
Family history
Race (White>black)
Anencephaly
Congenital adrenal hyperplasia
Extra uterine pregnancy
38. Fetal Complications
Macrosomia Syndrome
Occurs when placental function is maintained(80% cases)
Results in healthy but large fetus
Amniotic fluid is normal
Inc risk of C-section b/c of prolonged and arrested labour
Shoulder dystocia
39. Dysmaturity syndrome
When placental function deteriorates (20% cases)
Placental insufficiency results in reduction of metabolic and
respiratory support to fetus
Amniotic fluid is decreased
Inc risk of C-section b/c of non reassuring fetal heart rate
patterns
Oligohydramnios results in umbilical cord compression
40. MATERNAL COMPLICATIONS
Anxiety
Is commonly seen postdate pregnancy b/c of worry of inc. in
gestation period from the EDD
Prolonged labour
Chances increases significantly and also the risk of
instrumental delivery
C-section
Risk of C-section is also greatly increased
42. CONFIRAMTION OF GESTATIONAL AGE
In a booked case confirmation of gestational age is
easily determined
In an unbooked case , diagnosis of post term
pregnancy poses a major challenge.
43. DETERMINATION OF GESTATIONAL AGE
HISTORY
LMP
EARLY U/S
FAMILY HISTORY
HX OF NTDs
EXAMINATION
SFH
BISHOP SCORING
45. CONSERVATIVE MANAGEMENT
50% women going beyond 42 weeks of gestation
experience spontaneous labour in 4-5 days
Poor bishop score
Good fetal health + adequate placental function
46. INDUCTION OF LABOUR
1. Favorable cervix
2. Oligohydramnios
3. Fetal macrosomia
4. Non reactive NST