Prolonged pregnancy
د.ﺳﮭﺎ وﺗﻮت
Definition: any pregnancy last for 42 weeks or more (ie:294
days or more).
It cause an anxiety for both woman& obstetrician. It’s not
pathological& should be differentiated from post maturity
syndrome( which is resemble IUGR).
Fetal risk of post term pregnancy:
1.fetal hypoxia &acidosis
2.increase PNM& morbidity
3.neonatal seizure& prenatal death
4.macrosomic baby &need for C/S.
5.shoulder dystocia & birth trauma like skull fracture &brachial
plexuses injury
6. muconium stain syndrome
7.increase incidence of sudden infant death syndrome
8. increase incidence of cerebral pulsy & intraventicular
hemorrhage.
Maternal risk of post term pregnancy:
1.increase operative delivery
2. increase incidence of post partum hemorrhage
3. increase incidence of prolonged labor with it’s complication
like fetal distress, maternal distress, obstructed labor, rupture
uterus ,pph & maternal infection.
4.increase maternal anxiety &psychological morbidity.
Incidence
:
About 4-14% of pregnancies are post term & tis incidence is
reduced significantly when dating of pregnancy is done by first
trimester U/S.
Etiology
:
The causes of prolonged pregnancy is unclear& it may represent
a simple biological variation.
The most common causes are: 1. nillparous woman
2.primigravida
3. obese one
4. previous history of post term pregnancy lead to increase
incidence by 30%.
5.a relative adrenocortical insufficiency may contribute to the
delay in the onset of labor& an increase incidence of
intrapartum hypoxia or even fetal death.
6.genetic factor as a woman delivery post term pregnancy in her
first pregnancy, had an increase risk of further post term
pregnancy.
7.an encephalic baby & placental sulfatase deffeceincy.
Management
:
Clinical guideline in the management of prolonged pregnancy:
1. after 41 weeks gestation, if the date is certain ,the woman
should offered an elective delivery.
2. if the cervix is un favorable, cervical ripening should be
undertaken by PG analog.
3. if an expectant management is chosen ,assessment of fetal
health should be initiated.
4. from 42 weeks ,woman who decline induction of labor,
should be offered an antenatal monitoring consist of twice
weekly CTG& U/S estimation f AFI.
So at managing woman with post term pregnancy:
1.sweeping of membrane at 40 weeks.
2.induction of labor at 41 weeks associated with decrease
incidence of :
a . PNM& morbidity.
b. muconium staining
c. NO. of C/S.
3.close fetal surveillance, if the mother refuse induction of
labor& this is done by:
1. cick count
2. NST
3. contraction stress test
4. U/S for AFI.
5. biophysical profile.
6. Doppler study.
But none of these investigation are so sensitive to detect
intrauterine fetal hypoxia& we should inform the patient.
