Abnormal Placental Findings Associated with Non-Reassuring Fetal Monitoring and Excellent Neonatal Outcomes

doi:10.4236/ijcm.2011.23053

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International Journal of Clinical Medicine, 2011, 2, 310-312

doi:10.4236/ijcm.2011.23053 Published Online July 2011 (http://www.SciRP.org/journal/ijcm)

Abnormal Placental Findings Associated with

Non-reassuring Fetal Monitoring and Excellent

Neonatal Outcomes

Gary Ventolini1, Shanthi Ramesh1, Sheela Barhan1, Ran Neiger2

1Wright State Physicians Boonshoft School of Medicine Department of Obstetrics and Gynecology, Dayton Ohio, USA; 2Perinatal

Partners, Miami Valley Hospital Berry Building, Maternal Fetal Medicine, Dayton Ohio, USA.

Email: [email protected]

Received February 29th, 2011; revised April 27th, 2011; accepted May 12th, 2011.

ABSTRACT

Objective: Obstetricians, Neonatologists, and Pathologists have studied gross histological analysis of human placentas

in search of specific alterations in placental functions that can be correlated with neonatal outcomes. Our study as-

sessed the prevalence of abnormal placental findings associated with non-reassuring fetal monitoring in labor requir-

ing emergent instrumental or cesarean delivery, followed by an excellent neonatal outcome. Study Design: One hun-

dred consecutive emergency deliveries, instrumental or cesarean, performed due to non-reassuring fetal monitoring

while in labor were retrospectively evaluated. All patien ts were low-risk for obstetric complications, and had a single-

ton, term pregnancy. They had a normal antenatal routine testing and a normal anatomy ultrasound scan at 20 to 22

weeks gestation. Results: There were 35 placentas (35%) with gross placental anomalies at the delivery triage. Addi-

tionally 7 placentas (7%) were reported to be abnormal at the patholog y examination. Conclusions: The prevalence of

abnormal placental findings in our studied popula tion was 42%.

Keywords: Abnormal Placental Findings, Excellent Neonatal Outcomes, Non-Reassuring Fetal Monitoring

1. Introduction

Obstetricians, Neonatologists, and Pathologists have

studied gross and histological analysis of human pla-

centas in search of specific alterations in placental func-

tion that can be correlated with neonatal outcomes. The

placenta provides a third party perspective regarding the

pregnancy and many maternal and fetal conditions are

evidenced by placental abnormalities [1]. Specific pla-

cental pathology is found in pregnancy loss associated

with thrombophilia, in many stillbirths and neonatal

deaths, and in cases of non-immune hydrops fetalis [2].

Many grossly and histopathological abnormal placentas

are, however, not associated with adverse neonatal out-

comes. Further attention to placental analysis including

more rigorous guidelines for pathologic diagnosis is

needed to delineate which abnormal findings are associ-

ated with adverse neonatal outcomes.

Per The College of American Pathologists (CAP)

guidelines, all human placentas should be inspected and

triaged at the delivery room and the abnormal ones

should be sent to pathology for a complete examination

using specific examination criteria as established by the

CAP. As previously determined by Ventolini et al., in a

cohort of 88 uneventful deliveries, 42% of placentas had

abnormal findings during pathological evaluation. Thir-

teen of the abnormal placentas (35.1%) showed pathol-

ogy unassociated with fetal compromise. Twenty-four of

the placentas (27.3% of the total cohort and 64.9% of the

abnormal placentas) showed findings associated with

fetal compromoise, all with APGAR scores at birth of

greater than or equal to 7 at 1 and 5 minutes. The most

common pathologies were marginal cord insertion, cho-

rioamnionitis, and abruption [3].

The purpose of our study was to assess the prevalence

of abnormal placental findings associated with non-re-

assuring fetal monitoring in labor requiring emergent

instrumental or cesarean delivery, followed by an excel-

lent neonatal outcome.

2. Materials and Methods

One hundred consecutive emergency deliveries, instru-

mental or cesarean, performed due to non-reassuring

fetal monitoring while in labor were retrospectively

Abnormal Placental Findings Associated with Non-reassuring Fetal Monitoring and Excellent Neonatal Outcomes 311

evaluated. The study was approved by the Institutional

Review Board and took place at a large tertiary hospital

between January 2003 and December 2008. All patients

were low-risk for obstetric complications, and had a

singleton, term pregnancy. In addition they had a normal

antenatal routine testing and a normal anatomy ultra-

sound scan at 20 to 22 weeks gestation.

The patients were admitted to the hospital in active

labor. Their fetal monitoring tracings on admission were

all reactive as well as the admission routine prenatal

laboratory parameters were within normal limits. Fur-

thermore, on admission history, they recollected having

no changes in fetal behavior the 48 hours prior to admis-

sion. They were all non-smokers and their urinary drug

toxicology screen was negative on admission.

As labor progressed, the patient’s fetuses manifested

intolerance to labor, characterized by repeat prolonged

decelerations and/or repeat late decelerations that required

emergent instrumental delivery and/or cesarean delivery.

Their fetal intolerance was not preceded by uterine hyper-

stimulation or by regional anesthesia placement and not

fully resolved by fetal intrauterine resuscitation.

All the neonates were delivered with APGAR scores

of equal or more than 7 at 5 minutes of birth, normal

arterial and venous umbilical blood cord gases and un-

eventful nursery stay. All the placentas were triaged at

the delivery room, the ones revealing any anomaly at

gross assessment, were sent to pathology for examina-

tion. Statistical analysis was performed with GraphPad

Software (GraphPad Software, San Diego, CA)

3. Results

Twenty eight patients (28%) had an instrumental deliv-

ery: 12 deliveries (12%) were vacuum assisted and 16

deliveries (16%) were forceps assisted. Seventy two

patients (72%) had a cesarean delivery (see Table 1).

There were 35 placentas (35%) with gross placental

anomalies at the delivery triage. The placental findings

were: 7 (7%) had opaque amniotic membranes, 6 (6%)

with velamentous cord insertion, 6 (6%) had a long um-

bilical cord (105 cm), 6 (6%) presented with foul smell-

ing amniotic membranes, 4 (4%) had a short umbilical

cord, 4 (4%) with retro placental hemorrhage and 2 (2%)

with acute abruption. Additionally 7 placentas (7%)

were reported to be abnormal at the pathology examina-

tion as follow: chorioamnionitis, funisitis, and true knots

(see Table 2).

4. Discussion

The placenta serves as vital resource in evaluating neo-

natal and maternal outcomes following delivery for non

reassuring fetal heart monitoring. The placenta contains

nine months of data available that could be gathered

through careful pathologic evaluation regarding etiolo

Table 1. Mode of delivery.

Instrumental Patients

Abnormal

Placentas Normal P Value

Vaccum Assisted 12 4 8 0.48

Forceps Assisted 16 5 11 0.35

Cesarean 72 33 39 0.66

Total 100 42 58

Table 2. Placental findings.

Placentas Triage Macroscopy

Path Microscopy

Path

6 Velamentos

cord insertion Agreed 6 2 Fibrin deposits

1 Small infarct

Opaque

amniotic

membranes

Agreed 7

1 Funisitis

2 Micro calcifications

2 Meconium stain

Long

umbilical

cord

Agreed 6

Mean length

112 cm (103 - 120)

1 Funisitis

1 Vasculopathy

Foul smelling

amniotic

membranes

Agreed 5 5 Chorioamniotis

1 Meconium stain

4 Short

umbilical cord

Agreed 2

(clots not seen at

examination)

1 Old infarct

1 Micro calcifications

2 Fibrin deposits

Retro

placental

hemorrhage

Agreed 4 None

2 Acute

abruption Agreed 2 1 Recent infarct

7 Normal Agreed 7

2 Chorioamniontis

1 Mecomium stain

3 Fibrin deposits

1 Funisitis

gies of immediate insults requiring delivery, as well as a

timeline of chronic events leading to fetal intolerance to

labor. In placental pathology, few diagnoses are immedi-

ately apparent: generally only those, which are hemato-

genously disseminated, like infectious organisms or some

specific inborn errors of metabolism. However, on closer

examination, histopathological evidence of choriamnion-

tiis including one specific finding of umbilical cord in-

flammation (funisitis) is associated with fetal sepsis.

According to Rhone et al., in review of 100 sequential

placentas, 75% were submitted to pathology for review

by CAP protocol with 50% having findings consistent

with inflammation [4]. Fetal clinical indicators of infec-

tion were associated with placental findings of chorioam-

nionitis, while maternal clinical indicators were not, em-

phasizing the utility of placental examination in identi-

fying unknown material infection.

Also of interest are pathological findings of endothe-

lial damage to fetal vessels secondary to infection or

vascular insults in the placenta resulting in fetal side

infarctions that can be a hallmark of neonatal embolic

Abnormal Placental Findings Associated with Non-reassuring Fetal Monitoring and Excellent Neonatal Outcomes

312

disease. Roberts et al. [5] reported that “fetal thrombotic

vasculopathy,” referring to inflammatory damages to

vessels secondary to infection or vascular insult and

related placental findings is often cited in a legal context

[6-8], however, further research is need to determine

prognostically how these findings affect long-term neo-

natal outcome.

Our study found 35% of placentas with gross abnor-

malities associated with potential for adverse fetal con-

sequences including opaque or foul smelling amniotic

membranes; velamentous cord insertion, long umbilical

cord, and short umbilical cord, acute abruption, and retro

placental hemorrhage. Additionally 7 placentas (7%)

were reported to be abnormal at the pathology examina-

tion as follow: chorioamnionitis, funisitis, and true knots.

Such abnormalities were associated with reassuring

neonatal outcomes as measured by APGAR scores of

more than 7 at 5 minutes of birth, normal arterial and

venous umbilical blood cord gases and uneventful nurs-

ery stay. What is unknown is the degree to which these

placental anomalies, while not associated with abnormal

fetal development, effect placental perfusion, leading to

fetal intolerance of labor.

A recent classification system of cerebral palsy calls

for an assessment of the timing and etiology of brain

injury [9]. The placental examination is an underused

resource for addressing these important questions. An

expert assessment of the placental pathology can provide

temporally and mechanistically specific data not avail-

able from any other source. An analysis of 125 placentas

from term infants with cerebral palsy, neonatal encepha-

lopathy, and other neurodisabilities compared with 200

term placentas from healthy infants, found four lesions:

fetal thrombotic vasculopathy, chronic villitis with oblit-

erative vasculopathy, chorioamnionitis with intense cho-

rionic vasculitis, and meconium associated vascular ne-

crosis to be statistically significantly increased in af-

fected infants when controlled for confounding factors.

Further analysis demonstrated that the lesions were

equally common in affected infants with normal or ab-

normal umbilical blood gases and 5 min APGAR scores

[10]. While this data is limited, it does demonstrate a

placental abnormality as seen on histological examina-

tion as correlated with neonatal outcome.

5. Comments

The prevalence of abnormal placental findings in our

studied population was 42%. Placental anomalies could

contribute to non-reassuring tracings that require emer-

gent delivery. Further delineation of specific placental

abnormalities in relationship to adverse neonatal out-

comes requires increased collaboration between Obste-

tricians, Pathologists, and Neonatologists with diligent

analysis of placentas both grossly and histologically.

6. Key Points

 All human placentas should be inspected and triaged

at the delivery room and the abnormal ones should be

sent to pathology for a complete examination

 The placenta provides a third party perspective re-

garding the pregnancy and many maternal and fetal

conditions are evidenced by placental abnormalities.

 Placental anomalies could contribute to non-reas-

suring tracings that require emergent delivery.

 The prevalence of abnormal placental findings in our

studied population was 42%

 The most common pathologies were marginal core

insertion, chorioamnionitis and abruption

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