03 When should we deliver the baby

8/12/2019 03 When should we deliver the baby

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IUGR: When

should we deliver

the baby?

Ivica Zalud, MD, PhD

Professor and Acting Chair

John A Burns School of Medicine

University of Hawaii, Honolulu, USA



OBJECTIVES:

•

Define IUGR vs. SGA fetuses

•

Discuss antenatal natural history

•

Present antepartum and intrapartum

management (optimal delivery)

•

Discuss short and long term sequelae



IUGR

•

Nomenclature

: low birth weight, small for

gestational age, retarded fetal growth, small for

dates, intrauterine growth restriction

•

Definition:

–

IUGR is defined as a birth weight less than the

10

th

percentile (? 5

th

percentile or ?>2SD below

the mean) at given gestational age.

–

The fetus has not reached its growth

potential at given gestational age due to

one or more causative factors.•

Infant weight is the single most important factor

affecting neonatal mortality!



IUGR

•

ACOG: IUGR is one of the most common and

complex problems in obstetrics

•

Problems: –

Inconsistent definitions

–

Poor detection rate

–

Limited preventive and treatment options

–

Multiple associated morbidities

–

Increased likelihood of perinatal mortality

–

Impaired intellectual development, hypertension and

obesity in adulthood



IUGR: So what!

•

2

nd

leading

contributor to

perinatalmortality!!!

•

Perinatal mortality:

x6

-

10•

Intrapartum asphyxia:

up to 50%•

As many as 40% stillborns are IUGR

•

A portion of perinatal complications is

preventable

(morbidity and mortality)•

Association with

multiple sequelae

(short and long term morbidity)



IUGR

•

The fetus genetically programmed to be in

the 90

th

percentile who is born in the 20

th

percentile may be in more trouble than a

baby born to a jockey and a gymnast who

is in the 8

th

percentile!



SONOGRAPHIC FINDINGS

• Doppler studies

– Arterial: UA, MCA, uterine artery

– Venous: IVC, DV – Semi quantitative measurements:

• Waveform analysis: RI, S/D, PI

•

Absent end-diastolic flow• Reversed end-diastolic flow



Doppler

inIUGRfetuses



Umbilical Artery DopplerMeta-analyses

• Absent or reversed EDF – 80x increase inperinatal mortality (Thornton 1993 )

• UA Doppler significantly reduces IUFD

– Divon 1995 : 8 studies, 6838 Pts

– Giles 1993 : 6 studies, 4335 Pts

– Alfirevic 1995 : 12 studies, 38% reductions inperinatal mortality



Doppler in IUGR

Doppler meta analysis has shown that the use of

the UA Doppler reduces the number of:

•antenatal admissions: 44%

• inductions of labor: 29%

• C/S for NRFS: 52%

•

perinatal mortality: 38%

Alfirevic Z, Neilson JP

ACOG 1995;172;1379-87



Does Doppler improve outcomes inIUGR fetuses?

• It can, when used in conjunction withother diagnostic tools.

• Early compensatory phase (fetal hypoxia): – Biometry & arterial Doppler

• Late phase (fetal acidosis and impendingcardiovascular collapse): – Venous Doppler, FHR analysis & BPP



IUGR Challenge

• Diagnose true IUGR

• Identify markers of morbidity

• Intervene in a timely fashion



Fetal Surveillance

• Risk of NRFS is 86% when both umbilical& MCA Dopplers are abnormal

• Risk of NRFS is 4% when both umbilical &MCA Dopplers are normal

Ultrasound Obstet Gyencol 2002;19:225



TIMELINE FOR FETAL HYPOXIA

• Abnormal fetal growth

• Abnormal arterial Doppler (UA, MCA)

– ~ 2 weeks

• Abnormal venous Doppler (IVC & ductusvenosus)

– ~ 1-2 days??

• Abnormal NST / BPP score



PREGNANCY MANAGEMENT

• The crux of management: hazards ofprematurity vs. threat of IUFD

•Referral to maternal fetal medicinesubspecialist – targeted ultrasound andcounseling

• Search for etiology: fetal, placental,maternal




• Fetal karyotype (2-5% abnormal – Creasy& Resnik 1999)

• NST, BPP, CST, UA Doppler

• Serial biometry (q 3-4 weeks) – watch

head growth



PREGNANCY MANAGEMENT• Abnormal UA Doppler

– Decreased diastolic flow• Increase frequency of testing; consider deliver >37

weeks

– Absent end diastolic flow• Steroids; consider delivery at 34 weeks

– Reversed end diastolic flow• Steroids: consider delivery at 32 weeks

Am J Obstet Gynecol. 2012 Apr;206(4):300-8.



Berkley E, Chauhan SP, Abuhamad A.

Doppler assessment of the fetus with intrauterine growth restriction.


• Relevant studies were identified usingPubMed (US National Library of Medicine,

1983 through 2011) publications inEnglish, which describe the peripartumoutcomes of IUGR according to Doppler

assessment of:•umbilical arterial

•middle cerebral artery

•ductus venosus.






• R andomized and quasi-randomizedstudies: UA Doppler significantlydecreases the likelihood (1.2% vs 1.7%;

RR, 0.71; 95% confidence interval, 0.52-0.98).

• labor induction

• cesarean delivery• perinatal deaths

• Antepartum surveillance with UA Doppler

should be started when the fetus is viable






• Although Ductus venous, MCA and othervessels have some prognostic value forIUGR fetuses, there is a lack of

randomized trials showing benefit.

• Doppler studies of vessels other than theUA, as part of assessment of fetal well-being in pregnancies complicated byIUGR, should be reserved for research

protocols.



Delivery• The optimal timing of delivery depends on

the underlying etiology of the growthrestriction (if known) as well as theestimated gestational age.

• The patient makes informed decision



Delivery

•

Altering the timing of delivery for fetuseswith aneuploidy or congenital infectionmay not improve the outcome.

• In some cases patients may electnonintervention.

• Some women may choose to forgodelivery of a severely growth-restrictedfetus at 25 weeks of gestation even if

there is an increased risk of fetal death.



Delivery

•

Management may be enhanced by anindividualized and multidisciplinaryapproach.

• When intervention for perinatal benefit is

the preferred option, antenatal fetalsurveillance may help guide the timing ofdelivery.

•IUGR alone is not an indication forcesarean delivery and the route of deliveryshould be based on other clinicalcircumstances.



GRIT Trial

• The only published randomized trial toassess the timing of delivery of the earlypreterm (<34 weeks) IUGR fetus.

• Pts whose OBs were uncertain whetherdelivery would be beneficial, wererandomized: – early delivery group (delivery within 48 hours)

or

– expectant management group (with

antepartum surveillance until it was felt thatdelivery should not be delayed any longer).

BJOG 2003;110:27 – 32 Lancet 2004;364:513 – 20 AJOG 2011;204:34.e1 – 34.e9



GRIT Trial

• The rates of betamethasone administrationwere the same in both groups.

• Perinatal survival was similar.

• At the 6 – 12-year follow-up there were nodifferences in cognitive, language, behavior,or motor abilities of the children born towomen in the early-delivery group versus

those in the expectant management group.

BJOG 2003;110:27 – 32 Lancet 2004;364:513 – 20 AJOG 2011;204:34.e1 – 34.e9



DIGIT Trial

• In the Disproportionate IntrauterineGrowth Intervention Trial at Term,women with singleton gestations at or

beyond 36 weeks with suspected IUGRwere randomized: – undergo delivery or

–

expectant management with delivery onlyif some other indication arose.

BMJ 2010;341:c7087.



DIGIT Trial

•

There were no differences in compositeneonatal outcome between these twogroups.

• The study cohort was not large enoughto determine whether individualoutcomes, such as perinatal death,

were affected by the differentmanagement approaches.

BMJ 2010;341:c7087.



Delivery: NICHD, SMFM, ACOG

•

Existing data and expert consensus, a joint conference of the NICHD , SMFMand ACOG suggested the following twotiming strategies:

1) Delivery at 38 0/7 – 39 6/7 weeks ofgestation in cases of isolated fetal

growth restriction

Obstet Gynecol 2011;118:323 – 33.




2) Delivery at 34 0/7 –

37 6/7 weeks ofgestation in cases of IUGR with additionalrisk factors for adverse outcome

– oligohydramnios

– abnormal umbilical artery Doppler – maternal risk factors

– comorbidities

Obstet Gynecol 2011;118:323 – 33.




3) Delivery before 34 weeks• At a center with a NICU and, ideally, afterconsultation with a maternal – fetal specialist.

•Corticosteroids should be administeredbefore delivery (improved preterm neonataloutcomes).

•For cases in which delivery occurs before 32

weeks of gestation, magnesium sulfate shouldbe considered for fetal and neonatalneuroprotection

Obstet Gynecol 2011;118:323 – 33.




• 37 or more: delivery if NRFS; electivedelivery after 38-39 weeks




• 34-37 weeks – Management individualized

– Antepartum testing: NST/AFI twice weekly,UA Doppler

– Non-reassuring status: evaluate for delivery

– Oligohydramnios and abnormal UA Doppler:more frequent antepartum testing but not

delivery (unless non-reassuring status)




• <34 weeks: – Expectant management if reassuring fetal

status – Rx steroids for fetal benefits

– Antepartum testing: NST/AFI & BPP twiceweekly, daily kick counts, UA Doppler

– Abnormal UA Doppler: daily NST and at leasttwice weekly BPP for up to 2 weeks

–

Non-reassuring status: evaluate for delivery



IUGR

• What are benefits of UA Doppler?

• Significant reduction of laborinduction (RR 0.89), C/S (RR 0.9)

and perinatal deaths (RR 0.71) –

number needed to to treat: 203

Alfirevic et all. Cochrane Database 2010



TERM IUGR

• Mode of delivery – Based entirely on standard obstetric practice

– No evidence to support routine C/S

– Consideration for C/S if non-reassuring antepartumtesting with an unfavorable cervix

– Labor induction with or without cx ripening

• Continuous electronic fetal monitoring

• FHR monitor: Increased risk for decreased variability and late

decelerations

• Meconium

– Optimum: Tertiary care centers with MFM and NICUavailable



LONG-TERM OUTCOME

• Depend on underlying cause

• Poor cognitive function

• Adverse neurological outcome in childhood

• Impaired gross motor development,hyperactivity, poor concentration, lower

IQ, speech and reading disabilities(Gembruch & Gortner 1998 )

• Cerebral palsy



LONG-TERM OUTCOME

• David Barker, epidemiologist from England

– Fetal origin of adult diseases: The risk ofcoronary artery disease, stroke and hypertension

– Intrauterine conditions could programdevelopment of the cardiovascular system later inlife

– Infants with birth weight less than 5.5 lb had a 3x

increase in death due to coronary artery diseaselater in life.

• Other risks:

– Abdominal obesity, type 2 diabetes mellitus,

hyperlipidemia





KEY POINTS:

• IUGR alone is not an indication for cesareandelivery.

• The optimal timing of delivery depends on the

underlying etiology of the growth restriction (ifknown) as well as the estimated gestational age.

• Proposed Performance Measure (ACOG)% of patients with suspected IUGR in whom a plan for assessmentand surveillance of fetal growth and well-being is initiated, if deliveryis not pursued at the time of diagnosis



KEY POINTS:

• In managing IUGR pregnancies, timing ofdelivery is the most critical step.

• The challenge is to balance the risk ofprematurity with the risk of IUFD,

neonatal morbidity and mortality and longterm neurodevelopmental delay.



Hawaii, USA

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03 When should we deliver the baby