Postterm PregnancyPostterm Pregnancy

Ben Branch, DOBen Branch, DO

April 2006April 2006

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Case Study: Tina S.Case Study: Tina S.

Tina is a G5 P4 who is Tina is a G5 P4 who is now at 41 3/7 weeks now at 41 3/7 weeks gestation with a gestation with a malemale babybaby

We know that Tina has We know that Tina has had 4 children, all had 4 children, all vaginally, the largest of vaginally, the largest of which was 8 lbs 6 oz. which was 8 lbs 6 oz. No complications in No complications in prior deliveries. Tina prior deliveries. Tina had three term babies had three term babies and one baby carried and one baby carried to 42 2/7.to 42 2/7.

TerminologyTerminology

Should we be Should we be concerned about concerned about her current her current gestational age?gestational age?

What do we call a What do we call a pregnancy that has pregnancy that has progressed past progressed past the due date? the due date?

A.PostdatesB.PosttermC.OverdueD.Any of the above

Postterm pregnancyPostterm pregnancy

““Postterm” (also called Postterm” (also called prolonged) pregnancy refers prolonged) pregnancy refers to a pregnancy that has to a pregnancy that has extended to or beyond a extended to or beyond a gestational age of 42.0 gestational age of 42.0 weeks or 294 days from the weeks or 294 days from the first day of the last menstrual first day of the last menstrual period period

We should avoid the term We should avoid the term “post dates” pregnancy as it “post dates” pregnancy as it is loosely used and is loosely used and ill-definedill-defined

In one study of current OB In one study of current OB fellows, 48% defined fellows, 48% defined postterm pregnancy as 41 postterm pregnancy as 41 weeks, although the ACOG weeks, although the ACOG definition is as above!definition is as above!

Causes of Postterm Causes of Postterm pregnanciespregnancies

By far, inaccurate By far, inaccurate dating is the most dating is the most common etiology. So, common etiology. So, get the dating correct!get the dating correct!

In the absence of In the absence of inaccurate dating we inaccurate dating we do not yet understand do not yet understand why some pregnancies why some pregnancies carry to 42+ carry to 42+ gestational weeks gestational weeks although there is data although there is data to suggest genetics to suggest genetics and paternity play an and paternity play an active role.active role.

Click to find out more about dating pregnancies

Pregnancy DatingPregnancy Dating

With regards to postterm pregnancy, With regards to postterm pregnancy, the EDC from a first trimester the EDC from a first trimester ultrasound should not differ more than ultrasound should not differ more than 7 days from the EDC calculated by 7 days from the EDC calculated by FLMP. FLMP.

Accurate dating is critical for Accurate dating is critical for determination of postterm status.determination of postterm status.

Incidence of postterm pregnancy with Incidence of postterm pregnancy with early sonography is as low as early sonography is as low as 1.1%1.1%

What are Tina’s Risk What are Tina’s Risk Factors?Factors?

What risk factors What risk factors can you identify can you identify that put Tina at that put Tina at higher risk for higher risk for being postterm?being postterm?A.Multiparous

B.Male babyC.NeitherD.Both

The correct answer is B. Male The correct answer is B. Male SexSex

Other risk factors include:Other risk factors include: PrimiparupPrimiparup

Prior postterm pregnancyPrior postterm pregnancy

More rarely: fetal anencephaly and More rarely: fetal anencephaly and placental sulfatase deficiencyplacental sulfatase deficiency

Click here to see

Tina’s Risk Factors

Tina’s Risk FactorsTina’s Risk Factors

Tina is a G5 P4 who is now at 41 3/7 weeks Tina is a G5 P4 who is now at 41 3/7 weeks gestation with a gestation with a male babymale baby

Tina has had 4 children, all vaginally, the Tina has had 4 children, all vaginally, the largest of which was 8 lbs 6 oz. No largest of which was 8 lbs 6 oz. No complications in prior deliveries. All but complications in prior deliveries. All but one baby was born at or before term. one baby was born at or before term. One One baby born at 42 2/7 weeks.baby born at 42 2/7 weeks.

TwoTwo risk factors, the most significant risk factors, the most significant being prior postterm pregnancybeing prior postterm pregnancy

Putting it all togetherPutting it all together

Tina S. is at 41 3/7 weeks GA as Tina S. is at 41 3/7 weeks GA as determined by her FLMP, which is not determined by her FLMP, which is not 42 weeks or greater42 weeks or greater

She has two risk factors that she will She has two risk factors that she will progress to 42 or greater weeks progress to 42 or greater weeks gestationgestation

So, are we concerned? Do we need So, are we concerned? Do we need to induce her?to induce her?

As we can see, the As we can see, the risk of perinatal risk of perinatal mortality increases mortality increases just after 40 weeks.just after 40 weeks.

More significantly, More significantly, the risk increases the risk increases almost another 35% almost another 35% as the pregnancy as the pregnancy progresses after 41 progresses after 41 weeksweeks

Postterm pregnancies are Postterm pregnancies are higher risk!higher risk!

90-95% of normal pregnancies will 90-95% of normal pregnancies will spontaneously enter labor before 42 weeksspontaneously enter labor before 42 weeks

In the US, accounting for differences in In the US, accounting for differences in postterm management styles, about 5-10% postterm management styles, about 5-10% (7%) of pregnancies continue to 42 weeks GA(7%) of pregnancies continue to 42 weeks GA

Of all postterm pregnancies, 87% delivered Of all postterm pregnancies, 87% delivered spontaneously in the 42spontaneously in the 42ndnd week. week.

If we wait to deliver Tina at 42 weeks, the If we wait to deliver Tina at 42 weeks, the risk of an adverse event at delivery and/or in risk of an adverse event at delivery and/or in the perinatal period the perinatal period doublesdoubles in comparison in comparison with a term vaginal delivery.with a term vaginal delivery.

Let’s consider the risksLet’s consider the risks

Complications/Adverse Events

At Delivery Fetal Effects Infant Effects

Outcomes Outcomes Outcomes

Management

Click each of the divisions below to investigate

Delivery Adverse EventsDelivery Adverse Events

If Tina delivers as If Tina delivers as postterm, what postterm, what adverse events or adverse events or complications might complications might she encounter?she encounter?

Just tell me alread

y

A. Shoulder dystocia

B. Operative delivery

C. Endometritis

D. All of the above

All of the above!!All of the above!!Postterm Delivery ComplicationsPostterm Delivery Complications

Maternal anxiety and exhaustionMaternal anxiety and exhaustion Labor dystociaLabor dystocia Shoulder dystociaShoulder dystocia Perineal traumaPerineal trauma Cephalopelvic disproportionCephalopelvic disproportion Assisted delivery Assisted delivery Operative delivery (2x as likely as term delivery) Operative delivery (2x as likely as term delivery) EndometritisEndometritis PP hemorrhagePP hemorrhage Increased risk for thromboembolic dzIncreased risk for thromboembolic dz

Fetal Adverse EventsFetal Adverse Events

What adverse events What adverse events or complications might or complications might postterm gestation postterm gestation have on the fetus?have on the fetus?

1. Macrosomia1. Macrosomia

2. Congenital heart 2. Congenital heart defectsdefects

3. Decreased fetal 3. Decreased fetal movementmovement

4. Fetal tachycardia4. Fetal tachycardia

Just tell me alread

y

Correct!!Correct!!Postterm Fetal Complications Postterm Fetal Complications

Fetoplacental insufficiencyFetoplacental insufficiency Fetal growth restriction (IUGR)Fetal growth restriction (IUGR) Macrosomic infant- Macrosomic infant- risk at postterm risk at postterm

gestation increases gestation increases eight foldeight fold, , approaching 10%approaching 10%

Fetal Dysmaturity Syndrome-Fetal Dysmaturity Syndrome- Triad of Triad of long, thin malnourished infant with flaking long, thin malnourished infant with flaking skin and meconium stained skin (skin and meconium stained skin (20%20% of of postterm gestations)postterm gestations)

Incorrect!!Incorrect!!

TRY AGAIN

Postterm Infant Postterm Infant Complications Complications

Which of these are more likely to Which of these are more likely to occur in a postterm baby?occur in a postterm baby?

A. Meconium Aspiration SyndromeA. Meconium Aspiration Syndrome

B. HypoglycemiaB. Hypoglycemia

C. FeversC. Fevers

D. None of the aboveD. None of the above

CORRECT!CORRECT!More Postterm Infant More Postterm Infant

Complications:Complications: Perinatal mortality twice that at termPerinatal mortality twice that at term (4-7/1,000 vs (4-7/1,000 vs

2-3/1,000)2-3/1,000) Potential for Potential for low birth weight infantlow birth weight infant (associated (associated

with increased perinatal mortality)with increased perinatal mortality) Poor fetal growthPoor fetal growth places infant at risk for IUGR, places infant at risk for IUGR,

oligohydramnios and cord compressionoligohydramnios and cord compression Meconium Aspiration SyndromeMeconium Aspiration Syndrome more likely, more likely,

places at risk for hyaline membrane development places at risk for hyaline membrane development and subsequent pulmonary HTN and respiratory and subsequent pulmonary HTN and respiratory failurefailure

Postterm status is an independent risk factor for Postterm status is an independent risk factor for low 5 minute APGARSlow 5 minute APGARS

Incorrect!!Incorrect!!

TRY AGAIN

Did you review the adverse events and complications associated with postterm status for the delivery, the fetus, and the infant?

NO

Maybe

YES

What are our options at this What are our options at this point?point?

Expectant management Expectant management Admit Tina for induction of labor at Admit Tina for induction of labor at

41 3/7 weeks41 3/7 weeks How do we decide?How do we decide?

Review the literatureReview the literature

We know that the likelihood of adverse events, We know that the likelihood of adverse events, complications, and perinatal mortality increases after 41 complications, and perinatal mortality increases after 41 weeks and again more significantly after 42 weeks.weeks and again more significantly after 42 weeks.

Perinatal mortality was decreased Perinatal mortality was decreased without increasingwithout increasing C sxn C sxn and other adverse outcome rates when induction of labor and other adverse outcome rates when induction of labor (IOL) was initiated at or during week 41 (Crowley et al)(IOL) was initiated at or during week 41 (Crowley et al)

Cesarean rate in postterm pregnancies induced before 42 Cesarean rate in postterm pregnancies induced before 42 weeks was actually weeks was actually decreaseddecreased in comparison with in comparison with expectantly managed postterm pts. (Sanchez et al)expectantly managed postterm pts. (Sanchez et al)

The ideal time for IOL is currently being investigated in a The ideal time for IOL is currently being investigated in a Cochrane ReviewCochrane Review

What does ACOG recommend?What does ACOG recommend?Click the paper for some new and interesting news!

New research suggests that parity may be an important consideration in the decision to induce postterm patients. In one study, primiparous women that were induced before 42 weeks had a higher rate of adverse events, primarily C section deliveries, than did their multiparous counterparts. This is likely due to uterine dysfunction. ACOG has not changed their recommendations with regards to this limited study to date.

ACOG Postterm Management ACOG Postterm Management RecommendationsRecommendations

Trend in the past 10 years has been for Trend in the past 10 years has been for IOLIOL at 41 at 41 completed weeks gestation (42 0/7, 294 days, completed weeks gestation (42 0/7, 294 days, EDD + 14 days)EDD + 14 days)

At MUSC Family Medicine, we try to arrange At MUSC Family Medicine, we try to arrange induction between 41 0/7 and 41 3/7 weeks. If the induction between 41 0/7 and 41 3/7 weeks. If the induction happens later, we have a BPP done induction happens later, we have a BPP done between those dates to ensure no complications.between those dates to ensure no complications.

However, if favorable cervix in the face of no other However, if favorable cervix in the face of no other complications complications OR OR evidence of fetal compromise evidence of fetal compromise OROR oligohydramnios, delivery should be effected oligohydramnios, delivery should be effected

2004 ACOG Practice Guidelines2004 ACOG Practice Guidelines

Make your decisionMake your decision

Tina is 41 3/7 weeks, by Leopold’s you estimate the fetus to be cephalic in presentation and are unsure of the estimated fetal weight, she has an unfavorable cervix by Bishop’s score. She is very uncomfortable and having lots of body pains. Our ACOG recommendations tell us we can induce her or we can expectantly manage her pregnancy. Which would you like to do?Expectant Management Induction of Labor

Expectant ManagementExpectant Management

If you and the patient desire to wait If you and the patient desire to wait until 42 0/7 for induction of labor, bi-until 42 0/7 for induction of labor, bi-weekly modified BPP (NST and U/S weekly modified BPP (NST and U/S for AFI) is recommended for fetal for AFI) is recommended for fetal assessment. assessment.

Tina S. InductionTina S. Induction At her office visit, Tina is examined. Her cervix is At her office visit, Tina is examined. Her cervix is

closed and very posterior. You ask her to come to closed and very posterior. You ask her to come to the hospital the next night for cervical ripening. the hospital the next night for cervical ripening. Tina is admitted at 41 3/7 weeks for induction of Tina is admitted at 41 3/7 weeks for induction of labor. labor.

The next morning, the cervix is soft and 2 cm The next morning, the cervix is soft and 2 cm dilated. She is having irregular contractions. dilated. She is having irregular contractions. Pitocin is started for labor augmentation.Pitocin is started for labor augmentation.

At next check, she is 5 cm. You perform an At next check, she is 5 cm. You perform an AROM. Four hours later, she is fully dilated and AROM. Four hours later, she is fully dilated and ready to push.ready to push.

Tina S.Tina S.DELIVERYDELIVERY

During the delivery, the intern noticed the dreaded During the delivery, the intern noticed the dreaded turtle head sign.turtle head sign.

Fortunately, he had reviewed his ALSO manual the Fortunately, he had reviewed his ALSO manual the day before and knew the HELPERR mnemonic and day before and knew the HELPERR mnemonic and dystocia maneuvers. With assistance the intern was dystocia maneuvers. With assistance the intern was able to finally deliver the baby by Ruben’s maneuver, able to finally deliver the baby by Ruben’s maneuver, but the intern heard a “pop” during the delivery of the but the intern heard a “pop” during the delivery of the anterior shoulder.anterior shoulder.

The baby boy weighed 9 lb 10 oz and caused a grade The baby boy weighed 9 lb 10 oz and caused a grade 1 midline laceration which approximated well and was 1 midline laceration which approximated well and was allowed to heal by primary intent.allowed to heal by primary intent.

The newborn exam was completely normal, but the The newborn exam was completely normal, but the intern was concerned about what intern was concerned about what three potential injuries three potential injuries to the baby?to the baby?

Our intern’s worriesOur intern’s worries NeurologicNeurologic injury, such as Erb’s palsy injury, such as Erb’s palsy OrthopedicOrthopedic injury, such as clavicular or humeral injury, such as clavicular or humeral

fracturefracture TorticollisTorticollis is common in shoulder dystocia infants. In is common in shoulder dystocia infants. In

some cases, a “pop” is heard which the delivering some cases, a “pop” is heard which the delivering physician believes is the clavicle being fractured. physician believes is the clavicle being fractured. However, this sound can commonly be the tearing of However, this sound can commonly be the tearing of muscle fibers in the sternocleidomastiod muscle on muscle fibers in the sternocleidomastiod muscle on the ipsilateral side of the dystocia secondary to the the ipsilateral side of the dystocia secondary to the downward traction used in delivery. This muscle downward traction used in delivery. This muscle injury causes a hematoma to develop with in the first injury causes a hematoma to develop with in the first 48 hours of life and the infant may subsequently 48 hours of life and the infant may subsequently develop torticollis. Treatment lies in early diagnosis develop torticollis. Treatment lies in early diagnosis and early physical therapy consult for manual and early physical therapy consult for manual therapy to prevent facial asymmetry and postural therapy to prevent facial asymmetry and postural changes in the infant.changes in the infant.

References

ReferencesReferences

Sielski, Lori A. “Postterm Infant.” Sielski, Lori A. “Postterm Infant.” Up to DateUp to Date Online. Online. MUSC LibraryMUSC Library. . 2006. 11 Apr 2006 2006. 11 Apr 2006 www.utdol.comwww.utdol.com

Norwitz, Errol R. “Postterm Pregnancy.” Norwitz, Errol R. “Postterm Pregnancy.” Up to DateUp to Date Online. Online. MUSC MUSC LibraryLibrary. . 2006. 11 Apr 2006 2006. 11 Apr 2006 www.utdol.comwww.utdol.com

Crowley P. Interventions for preventing or improving the outcome Crowley P. Interventions for preventing or improving the outcome of delivery at or beyond term. of delivery at or beyond term. The Cochrane Database of The Cochrane Database of Systematic ReviewsSystematic Reviews 1997, Issue 1. Art. No.: CD000170. DOI: 1997, Issue 1. Art. No.: CD000170. DOI: 10.1002/14651858.CD000170. 6 Apr 200610.1002/14651858.CD000170. 6 Apr 2006

Gülmezoglu AM, Crowther CA. Induction of labour for improving Gülmezoglu AM, Crowther CA. Induction of labour for improving birth outcomes for women at or beyond term. (Protocol) birth outcomes for women at or beyond term. (Protocol) The The Cochrane Database of Systematic ReviewsCochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: 2004, Issue 4. Art. No.: CD004945. DOI: 10.1002/14651858.CD004945. 6 Apr 2006CD004945. DOI: 10.1002/14651858.CD004945. 6 Apr 2006

ACOG Practice BulletinACOG Practice Bulletin. Clinical management guidelines for . Clinical management guidelines for obstetricians-gynecologists. Number 55, September 2004 obstetricians-gynecologists. Number 55, September 2004 (replaces practice pattern number 6, October 1997). Management (replaces practice pattern number 6, October 1997). Management of Postterm Pregnancy.of Postterm Pregnancy.

ReferencesReferences

Sanchez-Ramos L, Olivier F, Delke I, Kaunitz AM. Labor induction Sanchez-Ramos L, Olivier F, Delke I, Kaunitz AM. Labor induction versus expectant management for postterm pregnancies: a versus expectant management for postterm pregnancies: a systematic review with meta-analysis. systematic review with meta-analysis. Obstet Gynecol 2003Obstet Gynecol 2003; ; 101:1312–1318. 101:1312–1318.

Macrosomia--maternal characteristics and infant complications. Macrosomia--maternal characteristics and infant complications. AUSpellacy WN; Miller S; Winegar A; Peterson PQ SOObstet AUSpellacy WN; Miller S; Winegar A; Peterson PQ SOObstet Gynecol 1985 Aug;66(2):158-61.Gynecol 1985 Aug;66(2):158-61.

G¸lmezoglu AM, Crowther CA. “Induction of labour for improving G¸lmezoglu AM, Crowther CA. “Induction of labour for improving birth outcomes for women at or beyond term.” (Protocol) birth outcomes for women at or beyond term.” (Protocol) The The Cochrane Database of Systematic Reviews Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: 2004, Issue 4. Art. No.: CD004945. DOI: 10.1002/14651858.CD004945.CD004945. DOI: 10.1002/14651858.CD004945.

Thomsen, JR. “Sternomastoid Tumor of Infancy.” Thomsen, JR. “Sternomastoid Tumor of Infancy.” Ann Otol Rhinol Ann Otol Rhinol Laryngol.Laryngol. 1989 Dec;98(12 Pt 1):955-9. 1989 Dec;98(12 Pt 1):955-9.