Postterm Pregnancy Ben Branch, DO April 2006 To enjoy this presentation completely, make sure your speakers are turned on.

Case Study: Tina S. Tina is a G5 P4 who is now at 41 3/7 weeks gestation with a male baby We know that Tina has had 4 children, all vaginally, the largest of which was 8 lbs 6 oz. No complications in prior deliveries. Tina had three term babies and one baby carried to 42 2/7.

Terminology Should we be concerned about her current gestational age? What do we call a pregnancy that has progressed past the due date? Postdates Postterm Overdue Any of the above

Postterm pregnancy “Postterm” (also called prolonged) pregnancy refers to a pregnancy that has extended to or beyond a gestational age of 42.0 weeks or 294 days from the first day of the last menstrual period We should avoid the term “post dates” pregnancy as it is loosely used and ill-defined In one study of current OB fellows, 48% defined postterm pregnancy as 41 weeks, although the ACOG definition is as above!

Causes of Postterm pregnancies By far, inaccurate dating is the most common etiology. So, get the dating correct! In the absence of inaccurate dating we do not yet understand why some pregnancies carry to 42+ gestational weeks although there is data to suggest genetics and paternity play an active role. Click to find out more about dating pregnancies

Pregnancy Dating With regards to postterm pregnancy, the EDC from a first trimester ultrasound should not differ more than 7 days from the EDC calculated by FLMP. Accurate dating is critical for determination of postterm status. Incidence of postterm pregnancy with early sonography is as low as 1.1%

What are Tina’s Risk Factors? What risk factors can you identify that put Tina at higher risk for being postterm? Multiparous Male baby Neither Both

The correct answer is B. Male Sex Other risk factors include: Primiparup Prior postterm pregnancy More rarely: fetal anencephaly and placental sulfatase deficiency Click here to see Tina’s Risk Factors

Tina’s Risk Factors Tina is a G5 P4 who is now at 41 3/7 weeks gestation with a male baby Tina has had 4 children, all vaginally, the largest of which was 8 lbs 6 oz. No complications in prior deliveries. All but one baby was born at or before term. One baby born at 42 2/7 weeks. Two risk factors, the most significant being prior postterm pregnancy

Putting it all together Tina S. is at 41 3/7 weeks GA as determined by her FLMP, which is not 42 weeks or greater She has two risk factors that she will progress to 42 or greater weeks gestation So, are we concerned? Do we need to induce her?

As we can see, the risk of perinatal mortality increases just after 40 weeks. More significantly, the risk increases almost another 35% as the pregnancy progresses after 41 weeks

Postterm pregnancies are higher risk! 90-95% of normal pregnancies will spontaneously enter labor before 42 weeks In the US, accounting for differences in postterm management styles, about 5-10% (7%) of pregnancies continue to 42 weeks GA Of all postterm pregnancies, 87% delivered spontaneously in the 42nd week. If we wait to deliver Tina at 42 weeks, the risk of an adverse event at delivery and/or in the perinatal period doubles in comparison with a term vaginal delivery.

Let’s consider the risks Click each of the divisions below to investigate Management

Delivery Adverse Events If Tina delivers as postterm, what adverse events or complications might she encounter? Just tell me already A. Shoulder dystocia B. Operative delivery C. Endometritis D. All of the above

All of the above!! Postterm Delivery Complications Maternal anxiety and exhaustion Labor dystocia Shoulder dystocia Perineal trauma Cephalopelvic disproportion Assisted delivery Operative delivery (2x as likely as term delivery) Endometritis PP hemorrhage Increased risk for thromboembolic dz

Fetal Adverse Events Just tell me already What adverse events or complications might postterm gestation have on the fetus? 1. Macrosomia 2. Congenital heart defects 3. Decreased fetal movement 4. Fetal tachycardia

Correct!! Postterm Fetal Complications Fetoplacental insufficiency Fetal growth restriction (IUGR) Macrosomic infant- risk at postterm gestation increases eight fold, approaching 10% Fetal Dysmaturity Syndrome- Triad of long, thin malnourished infant with flaking skin and meconium stained skin (20% of postterm gestations)

Incorrect!! TRY AGAIN

Postterm Infant Complications Which of these are more likely to occur in a postterm baby? A. Meconium Aspiration Syndrome B. Hypoglycemia C. Fevers D. None of the above

CORRECT! More Postterm Infant Complications: Perinatal mortality twice that at term (4-7/1,000 vs 2-3/1,000) Potential for low birth weight infant (associated with increased perinatal mortality) Poor fetal growth places infant at risk for IUGR, oligohydramnios and cord compression Meconium Aspiration Syndrome more likely, places at risk for hyaline membrane development and subsequent pulmonary HTN and respiratory failure Postterm status is an independent risk factor for low 5 minute APGARS

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 point? Expectant management Admit Tina for induction of labor at 41 3/7 weeks How do we decide?

Review the literature We know that the likelihood of adverse events, complications, and perinatal mortality increases after 41 weeks and again more significantly after 42 weeks. Perinatal mortality was decreased without increasing C sxn and other adverse outcome rates when induction of labor (IOL) was initiated at or during week 41 (Crowley et al) Cesarean rate in postterm pregnancies induced before 42 weeks was actually decreased in comparison with expectantly managed postterm pts. (Sanchez et al) The ideal time for IOL is currently being investigated in a Cochrane Review* What does ACOG recommend? Uterine dysfunction leading to higher rates of C sxn Am J Obstet Gynecol. 1988 Feb;158(2):334-8. PMID: 3277431 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 Recommendations Trend in the past 10 years has been for IOL at 41 completed weeks gestation (42 0/7, 294 days, EDD + 14 days) At MUSC Family Medicine, we try to arrange induction between 41 0/7 and 41 3/7 weeks. If the induction happens later, we have a BPP done between those dates to ensure no complications. However, if favorable cervix in the face of no other complications OR evidence of fetal compromise OR oligohydramnios, delivery should be effected 2004 ACOG Practice Guidelines

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

Tina S. Induction At her office visit, Tina is examined. Her cervix is closed and very posterior. You ask her to come to the hospital the next night for cervical ripening. Tina is admitted at 41 3/7 weeks for induction of labor. The next morning, the cervix is soft and 2 cm dilated. She is having irregular contractions. Pitocin is started for labor augmentation. At next check, she is 5 cm. You perform an AROM. Four hours later, she is fully dilated and ready to push.

Tina S. DELIVERY During the delivery, the intern noticed the dreaded turtle head sign. Fortunately, he had reviewed his ALSO manual the day before and knew the HELPERR mnemonic and dystocia maneuvers. With assistance the intern was able to finally deliver the baby by Ruben’s maneuver, but the intern heard a “pop” during the delivery of the anterior shoulder. The baby boy weighed 9 lb 10 oz and caused a grade 1 midline laceration which approximated well and was allowed to heal by primary intent. The newborn exam was completely normal, but the intern was concerned about what three potential injuries to the baby?

Our intern’s worries Neurologic injury, such as Erb’s palsy Orthopedic injury, such as clavicular or humeral fracture Torticollis is common in shoulder dystocia infants. In some cases, a “pop” is heard which the delivering physician believes is the clavicle being fractured. However, this sound can commonly be the tearing of muscle fibers in the sternocleidomastiod muscle on the ipsilateral side of the dystocia secondary to the downward traction used in delivery. This muscle injury causes a hematoma to develop with in the first 48 hours of life and the infant may subsequently develop torticollis. Treatment lies in early diagnosis and early physical therapy consult for manual therapy to prevent facial asymmetry and postural changes in the infant. References

References Sielski, Lori A. “Postterm Infant.” Up to Date Online. MUSC Library. 2006. 11 Apr 2006 www.utdol.com Norwitz, Errol R. “Postterm Pregnancy.” Up to Date Online. MUSC Library. 2006. 11 Apr 2006 www.utdol.com Crowley P. Interventions for preventing or improving the outcome of delivery at or beyond term. The Cochrane Database of Systematic Reviews 1997, Issue 1. Art. No.: CD000170. DOI: 10.1002/14651858.CD000170. 6 Apr 2006 Gülmezoglu AM, Crowther CA. Induction of labour for improving birth outcomes for women at or beyond term. (Protocol) The Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: CD004945. DOI: 10.1002/14651858.CD004945. 6 Apr 2006 ACOG Practice Bulletin. Clinical management guidelines for obstetricians-gynecologists. Number 55, September 2004 (replaces practice pattern number 6, October 1997). Management of Postterm Pregnancy.

References Sanchez-Ramos L, Olivier F, Delke I, Kaunitz AM. Labor induction versus expectant management for postterm pregnancies: a systematic review with meta-analysis. Obstet Gynecol 2003; 101:1312–1318. Macrosomia--maternal characteristics and infant complications. AUSpellacy WN; Miller S; Winegar A; Peterson PQ SOObstet Gynecol 1985 Aug;66(2):158-61. G¸lmezoglu AM, Crowther CA. “Induction of labour for improving birth outcomes for women at or beyond term.” (Protocol) The Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: CD004945. DOI: 10.1002/14651858.CD004945. Thomsen, JR. “Sternomastoid Tumor of Infancy.” Ann Otol Rhinol Laryngol. 1989 Dec;98(12 Pt 1):955-9.