POSTTERM PREGNANCY

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• POSTTERM PREGNANCY
• AZZA ALYAMANI
• OBSTETRICS GYNICOLOGY
• Department
• King Khalid University

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• Introduction
• Post term pregnancy is a common situation.
  It
• cause anxiety for both women and obstetricians
• because it perceived as being a cause of
  increased
• risk to the fetus.
• Post term pregnancy per se is not a
  pathological
• condition and should not be confused with the
• post maturity syndrome described by Clifford in
• 1954.

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• Definitions

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• Post term ( prolonged pregnancy )
• it is 42 completed weeks or more ( 294
  days).
• this definition is accepted by both WHO
  FIGO.
• Post maturity syndrome
• it is IUGR with associations of
  ,meconium
• stained amniotic fluid ,
  oligohydramnios , fetal
• distress , loss of subcutaneous fat and
  dry
• cracked skin reflecting placental
  insufficiency.
• Past date
• past the calculated EDD before 42
  weeks.

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• Incidence
• 5 -10
• Dating by the last menstrual period (LMP)
  alone ,
• has a tendency to overestimate the GA .
• While the use of early ultrasound alone , to
  calculate
• GA , significantly reduced the incidence of post
  term
• pregnancy . Ia

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• Importance
• Fetal and Neonatal risks
• It is likely that the majority of
  morbidity and mortality associated with post
  term pregnancy, arises because of post maturity.
• Post term pregnancies are
  associated with excess perinatal morbidity
  mortality .
• Delivery at 42 week is associated
  with a doubling of the perinatal mortality rate ,
  unlike
• the 37 -41 week period in which antepartum
• deaths contribute about 2/3 of the total .

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• When lethal congenital abnormalities
  are
• excluded ,intrapartum fetal death is 4 times
  more
• common, and
• neonatal death is 3 times more
  common in infant s born after 42 weeks.

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• In addition , meconium staining of the
  amniotic
• fluid and the likely of intrapartum fetal
  hypoxia
• were much more common in post term
• pregnancies compared to those delivered at 40 ws.
• This result in fetal acidosis , neonatal
  seizures
• perinatal death . Post term pregnancy is also a
• risk factor for birth trauma and shoulder
  dystocia.

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• B) Maternal risks of post term pregnancies
• increased operative delivery , hemorrhage
  and
• maternal infection.
• in addition , psychological morbidity as
• increased maternal anxiety .

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• Etiology
• Not Clear
• It is common in
• primigravida
• previous post term
  pregnancy. 30
• The cause may be due to
• 1. low cortisol levels with post term fetal
  distress.
• 2. relative adrenocortical insufficiency leading
  to
• delay in the onset of labor increased risk
  of
• intrapartum hypoxia or death.

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• Support for this theory is that
• infants delivered following a post term
  pregnancies
• are at increased risk of
• sudden infant death syndrome.
• death up to 2 years of age.

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Fetal Assessment
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• Monitoring Post term Pregnancy
• The perinatal mortality does not
  significantly rise
• until 42 ws. gestation ,thus there is no need to
  offer
• fetal monitoring prior to this gestation, if it
  is not
• offered at term .
• There is no consensus about the
  appropriate
• surveillance to post term pregnancy and no clear
• evidence exists to support that fetal monitoring
• can reduce the perinatal mortality.

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• simple fetal monitoring is as effective as
  more
• sophisticated monitoring of post term
  pregnancies
• The use of Doppler analysis of various
  arterial
• systems as uterine , umbilical ,middle
  cerebral
• and descending aorta in uncomplicated post
  term
• pregnancies is not different from that in
  term
• pregnancies.

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• Therefore
• the recommended fetal monitoring
• in post term pregnancy
• is

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• a) Amniotic fluid measurement
• Liquor volume fall after term , thus
  AFI does
• not improve perinatal outcomes , thus the mean
• pool depth (MPD) is the tool of choice for
  monitoring
• liquor in post term pregnancy. Ib
• b) CTG
• Simple monitoring with NST and
  liquor assessment holds an advantage over the
  formal
• biophysical profile scoring.

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• It is therefore ,vital that each woman is
  treated
• on an individual basis and counseled regarding
• the risks of post term pregnancy.

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• Management

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• (1) induction of labor at 41 weeks
• to reduce perinatal mortality , meconium
  staining
• of the amniotic fluid and small decrease
  in
• caesarean section rate . 1a
• (2) conservative management
• with close fetal surveillance, this can
  reduce
• excess operative delivery in women who
  will
• opt to for conservative management .

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• Other interventions
• a. nipple stimulation
• but have not been shown to be of benefit .
  
• b. sweeping the membranes
• at or beyond 40 weeks appear to
  significantly
• reduce the incidence of post term
  pregnancy
• and should be offered to all women.

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• Key points
• 1. the use of early ultrasound dating ,
  reduces the
• incidence of postterm pregnancy.
• 2. induction of labor after 41 weeks
  reduces perinatal
• mortality rates without increasing
  CS rates.
• 3. sweeping the membranes significantly
  reduces the
• incidence of postterm pregnancy .
• 4. no clear evidence that fetal monitoring
  can reduce the
• perinatal mortality in postterm
  pregnancy.
• 5. the use of NST and liquor assessment
  in monitoring
• postterm pregnancy twice weekly is
  recommended in
• women who prefer conservative
  management with
• fetal surveillance.

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THANK YOU