Post-term Pregnancy Management

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Post-term Pregnancy Management

• Oana Marcu DO
• Swedish Family Medicine
• 10/11/05

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Objectives Low Risk Pregnancy

• What is Post-term Pregnancy
• Why is it worrisome?
• Risks to Mom and Babe
• Antenatal monitoring
• When to Induce
• How to Induce
• Induction Timeline

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What is PTP and why is it worrisome?

• PTP is gestation gt 42wks
• Prevalence is 10 of all US pregnancies
• Slightly Increased risk of PTP in women who are
  primips or a product of PTP
• 2-3x higher if woman has a prior history of
  post-term delivery

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EDC Dating

• Management relies on ACCURATE DATING!
• Clinical dating by LMP
• Early ultrasound Cochrane retrospective study
• Comparing date by LMP and US rule
• Clinically follow uterine sizing, fundal height,
  quickening and FHTs for consistency

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Risks Mom to Babe

• Perinatal (still births and neonatal deaths)
  Mortality 2-3/1,000 deliveries at 40wks, doubles
  at 42 wks and is 4-6x greater at 44wks.
• Perinatal Morbidity related to fetal growth and
  uteroplacental insufficiency
• Maternal Risks CPD, labor trauma during
  delivery, PP hemorrhage, Acute C/S

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Antenatal Monitoring

• Monitor with the goal of detecting early signs of
  fetal distress and preventing fetal death
• Lack of evidence for the benefit of monitoring
• Option 1 AFI at 41 wks and biweekly NST
• Option 2 BPP at 41wks
• AFI gt5, BPP 8-10 (normal) 6/8 equivocal
• Both have high false positive and low false
  negative rates

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When to Induce Indications

• Urgent / High Priority
• Non-reassuring status
• Chorioamnionitis
• PPROM at 35wks
• Severe Pre-eclampsia
• IUGR below 3
• IDDM with complications or gt40wks
• Anyone gt42wks

• Medium Priority
• Maternal medical d/o
• Fetal malformation
• Mild pre-eclampsia
• IUGR below 10
• IDDM gt 38wks
• AFI 5-8
• Multiple gestation gt38wks
• Hx of demise

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Contraindications

• Placenta Previa and Vasa
• Previous C/S LTCS or classical
• Fetal position breech, transverse, mentum
• Maternal HTN
• Polyhydramnios
• Abnormal FHTs

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When to Induce Research

• AAFP 2005 elective induction at 41 wks proposed
  to reduce rates of adverse fetal and maternal
  complications.
• CMPPT largest RCT (1992)
• Cochrane Review 19 RCT (2004)
• Meta-analysis of 16 RCT (2003)
• ACOG induction at 43wks (1989) but 1997 does not
  describe an upper GA for expectant management but
  does rec monitoring by 42 wks.
• SOGC routine induction at 41wks (1997)
• Not all authorities agree in routine intervention

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41 wks vs. Expectant Management

• Standard of care remains expectant management
  with antenatal monitoring at 41wks and Induction
  at 42 wks.
• 42 wks by expert opinion- as risks to fetus and
  mom increase with GA
• Excellent communication with patient is
  essential!

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Non-Medical Labor Stimulators

• Hot baths, long walks, spicy food
• Castrol oil cocktail, enemas
• Black and blue cohosh
• Sex, nipple stimulation
• Stripping the membrane by provider starting at
  term- Cochrane review reduced duration of
  pregnancy and continuing beyond 41 wks

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Is the cervix favorable?

• Bishop lt 6 Unfavorable so
• Mechanical Cervial Ripening
• Stripping of membranes
• Laminaria
• Transcervial Foley Catheter- speculum exam, ring
  forcepts, 30cc foley (14-26 French), sterile
  saline
• Monitor FHT for reactivity, insert foley through
  cervial internal os, RN to inflate and tape to
  inner thigh- remove within 24hrs

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Prostaglandins

• Misoprostol (Cytotec)
• Cost 25 cents
• Gel Capsules 25mcg pv
• Stored at room temp
• Pt suppine for 30mins, 2 hr NST or until FHT
  reactive and lt 7 ctx in 15 mins
• Repeat q4hrs max150mcg

• Cervidil
• Cost 200
• Capsule with string, 10mg control released, must
  be stored in freezer
• Pt suppine for 2hr, continously monitor FHT
• Repeat q12hrs

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Prostaglandins

• Misoprostol
• Risk of Hyerstimulation
• (gt7 ctx in 15mins)
• Cant remove med!!!
• If Hyperstimulation then no more miso or Pitocin!

• Cervidil
• Risk of Hyerstimulation
• Special Indications
• Oligo and IUGR
• Can be pulled out!!!
• Cant use Oxytocin for 30mins after removal

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Oxytocin Induction

• Bishop score gt or equal to 6 Favorable
• Goal gt7 ctx per 15mins
• Low Dose Active Management
• Start oxytocin at 6 milliunits/min and go up by 6
  q20 mins (max 36)
• If labor is not progressing appropriately, place
  IUPC and evaluate montevideo units

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Induction Timeline

• Routine stripping membranes at 37wks
• 40wks sign consent and educate increased risk if
  C/S (2-3x for primip), longer labor, higher
  chance of instrumented delivery
• 41 wks AFI / NST and call induction line
• 41 ½ wks NST
• 41wks check cervix- calculate bishop

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Induction Timeline

• Induction Line 386-3286
• Info needed reason for induction, SVE and date
  done, EDC and method for dates, attending on that
  day, GBS status, pt home phone number
• Educate pt on the process (answer the phone)
• Fax Induction orders and confirm records
• Triage for cervical ripening the night before
  planned induction!

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Case

• 28 yr G2P0 with uncomplicated pregnancy at 40 1/7
  wks- getting more uncomfortable, c/o hand
  numbness and difficulty sleeping. Baby moving
  well, no contractions or SROM.
• BP 120/78 Urine trace prt and neg glucose
• FH 41, SVE 1cm/thick/high- posterior
• What is your plan for monitoring and follow-up?

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Case

• Educate her on the process and planning of
  induction
• Schedule her for AFI and NST at 41 wks and
  another NST at about 41 ½ wks.
• See her in your clinic again in 41 1/7 wks
  evaluate tests and check SVE, calculated Bishop
  score and call induction line, confirm that all
  records are
• The night before planned induction meet her at
  triage for cervical ripening

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Take Home Points

• Essential to have accurate dating
• PTP is associated with increased maternal and
  fetal risks especially intrauterine fetal death
• Antenatal monitoring at 41wks AFI and NST
  biweekly, or BPP
• Plan ahead for cervical ripening and scheduling
  the induction

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References

• Briscoe D, Nguyen H, Mancer M, Gautam N.
  Management of Pregnancy Beyond 40 wks Gestation,
  Am Fam Physician 2005 711935-41.
• Crowley P. Interventions for precenting or
  improving the outcome of delivery at or beyond
  term. Cochrane database Syst Rev 2004(3)
  CD00170.
• Hannah ME, Hannah WJ, Hellmann J. Induction of
  labor compared with serial natenatal monitoring
  in post-term pregnancy. A RCT. The Canadian
  Multicenter Post-term Pregnancy Trial Group. N
  Engl J Med 10023261587-92.
• Hollis B. Prolonged pregnancy.Curr Opin Obstet
  Gynecol 2002 12203-7.
• Mongelli M, Wilcox M, Gardosi J. Estimating the
  date of confinement ultrasonographic biometry
  versus certain menstral dates, Am J Obstet
  Gynecol 1996174(1 pt 1)278-81.
• Neilson JP. Ultrasound for fetal assessment in
  early pregnancy. Cochrane Database Syst Rev
  2004-3) CD00182.
• Lindell A, Lecture Prolonged Pregnancy. SFM
  didactics 2003
• Sanchez-Ramos L. Olivier F, Delke I, Kaunitz AM.
  Labor induction versus expectant mangement for
  postterm pregnancies a systemic review with
  meta-analysis. Obstet Gynecol 20031011312-8.