1. Post Term Pregnancy

2. The student at the end of this lecture should be able to :
Diagnose post term pregnancy in suspected case.
Determine the consequences of prolongation of pregnancy beyond the expected date.
Planning delivery in a post term pregnancy depending on fetal well being and bishop score.
Describe labor in postterm pregnancy

3. Post term pregnancy: Post term pregnancy (prolonged): is that
pregnancy persist beyond 42 weeks (294
days) from the onset of last menstrual
period.
Incidence : 6 – 12 % of all pregnancies .

4. The risks of post term pregnancy :
Are because of Postmaturity(dysmaturity) syndrome :
Occuring in 20-30% of post term pregnancies
related to aging and infarction of the placenta
result into placental insufficiency.
Intrauterine hypoxia may be manifested as meconium staining.
Fetus with postmaturity syndrome may have loss
of subcutaneous fat ,long finger nails ,dry peeling
skin and abundant hair.

5. Other wise the fetus grow in uterus to
a point of macrosomia ; may results in
abnormal labor ,shoulder dystocia , birth
trauma and increased incidence of caesarean
section .

6. Etiology :
Initiation of human labour is by complex
maternal and fetal factors .The cause of
postdate pregnancy is unknown in most
instances and occurs in healthy pregnancy.
Rare association is with : Anencephalic
pregnancy (hypoplastic Adrenal gland),
placental sulfatase deficiency and
extrauterine pregnancy.

7. Diagnosis:
The diagnosis is difficult . Accurate dating of
gestation is the key for diagnosis and
perinatal management .
There are factors to be evaluated in dating
a pregnancy to determine whether it’s
a misdated or postdated pregnancy .

8. Factors evaluated in dating pregnancy
Accurate date of Lmp.
Uterus size by (bimanual Pelvic examination 1st trimester(
Uterus size/date discrepancy during antenatal care.
Gestational age when the fetal heart tones first heard (doppler ultrasound at weeks).
Gestational age when the fetal heart first heard
(DeLee stethoscope weeks).
Date of quickening(18-20 w in primi in multi)
Sonographic parameters (bipariatal diameter
between weeks)
If there is no concordance between 2 factors this mean
the patient have poor date .

9. Management of post term pregnancy
Antepartum management ; Decision of delivery :
If the patient is <42 weeks with engaged
head and favorable cervix then labour should
be induced .
Patient with <42 week and unfavorable
cervix:
Twice weekly NST and BPP.
AFI amniotic fluid index (sum of 4 pocket of liquor in 4 quadrant).

10. -until the cervix is favorable .
If the result is reassuring then follow up and
delivery is indicated :
-until the cervix is favorable .
-result is abnormal (deceleration, AFI is
oligohydramnia <=5) .
-Fetal macrosomia .
-43 weeks regardless of other factors
because of increased perinatal morbidity
and mortality .

11. Patient present late in gestation with the
label of prolonged pregnancy in question,
expectant approach is acceptable and risk of
intervention with delivery of preterm infant
must be considered .

12. Intrapartum management :
Continuous electronic fetal monitoring
during induction of labour.
Membranes should be ruptured early in labour to assess the color of amniotic fluid and to apply internal electrodes.
If there is fetal distress (fetal blood sampling) then C.S. is indicated .