Pregnancy outcome in the patient with a nonreactive nonstress test and a positive contraction stress test

Pregnancy outcome in the patient with a nonreactive nonstress test and a positive contraction stress test

The pregnancy outcomes for 41 patients with high-risk pregnancies who had undergone antepartum fetal heat-l rate testing between July 5, 1977, and April 10, 1980, and demonstrated a nonreactive nonstress test (NST) and a positive contraction stress test (CST) were reviewed. The estimated gestational ages of the time of the positive CST ranged from 28 to 44 weeks’ gestation. Of the 41 pregnant women with a positive CST, 30 were allowed to labor. The remaining 11 patients underwent immediate cesarean section (8) or were managed expectantly because of immature phospholipid profiles (3). In the laboring group, 60.0% had evidence of late decelerations. Cesarean section for persistent late decelerations was necessary in 33.3%. The overall cesarean section rate for the positive CST group was 58.5%. The neonatal outcome for these 41 pregnancies demonstrated 29.3% of fetuses to be growth retarded and 17.1% of fetuses to have congenital abnormalities. The overall perinatal mortality rate was 7.3%. This investigation further substantiates the increased fetal and neonatal risks associated with a nonreactive NST and a positive CST. Induction of labor with direct fetal monitoring should be attempted in a term gestation where the cervix is ready for induction of labor and where rapid intervention by cesarean section is possible. (AM. J. OBSTET. GYNECOL. 139:11, 1981.)

ELTAI. k3EAR.r RATE (FHR) testing shown to he ;I valuable adjunct in the manqemcnt of rhe high-risk pregnancy.‘, ” The goal of this biophysical technique is to identify those fetuses at risk tot- ~lrerol’lac.erlt;lI insufficiency. Currently, the nonhtl-ess test (NST) has been used as the primary approach for assessing fetal u.ell-being. \Vhen primaril! thr NST is used, a nonreacrive (NR) NST has been .-\NTLI’.ARTl’M

has

bec,n

associated with a higher perinatal mortality rate and intrapartum fetal distress than a reactive NST.’ However, further evaluation with the contraction stress test (CST) is required to improve its predictive accurac);. Whenever the CST is used, the positive CST, which is manifested as repetitive late decelerations of the FHR, carries the gravest prqnosis for the fetus. Previous investigations of the pregnancy cWcome in patients with a positive CST along have shown higher incidences of‘ intrapartum fetal distress and perinatal death.“, ’ Braly and Freeman” have shown an even poorer outcome in those pregnancies with a positive CST that is not reactil’e. A recent review by Gauthier and associates” of’ their exper-ience Icith patients bvho exhibited a NR KST and a positive CST has shown a similar relationship. Therefore. an investigation was undertaken at our illst.itution to review and report the clinical outcome and course of those pregnancies in our NS7‘ population who had a NR NST and a positive CST. Material and methods Since July 5. 1977, all pregnancies at high-risk for uteroplacental insufficiency haire been evaluated by antepartum FHR testing. The indications for antepartum evaluation by the NST were postdates (242 weeks’ ges11

12

Slomka

Table

and Phelan

I. (Ilinical

exhibited

of’ those

profile

a NKNS’l’-posit i!

pl-egrmncies

tl\lg~lc~tx~l

which

e (Xl‘

pr’ewnt),

therr

:tlJo\c.

llo~\c\~cr~.

it’tlre

tiitr7

ir~itrr~1trrr~it~

( tlie

I~OLII-5.

It the

,igemctit lo\\

(:S’I‘

lx1tient fluid

(:SI

\\;is

tc;is Ixtacd

01 t:tllitrg

the

atrrrriotic \vri4

ag:;iirr

lv;t\

tlvli\v~-c,ci

iri&xtc~tl

~~qxitc’d

posiri\c.

\\illiiIr

:1trCl joint

i!+

srrtJwclirc~r1t

err cstr iol tl~~rt~r ririrr;itioris.

\alucs.

.I\

l)1tltrroriJCttr-

<‘\lx’(

i;~ll\

\\itlr

tlrc

11c’011;11;11 lC(oItl\

of

~otrsttlt;1tiorr

trcoti;1tologi~ts. ITiti;lll\

. all

tlJosc~ lxiticrjts

the

tn~ltelx;lI

\\ith

;t NK

;1t1d SS’I;i~ic1

po.siti\v

;I

(IS 1 wc’tc

~lll~ll\/CYI. Table

II.

in those

1ndications

f’ol- antepar-turn

pregnancies

with

FHR

testing

a NRNST-positive

Results

CS?‘

Rrt~zecrr

Jtrl!

tvorn~rr t’osttlates Suspected 1 U(GR be-eclarripsia Chronic hypertension l’revious fetal death Di~1lJcres rnellitrrs (Classes AnerrG

I ti I4 ti 4 4 3 I

R to D)

33.3 29.2 12.5 8.3 8.3 6.3 2. I

{

ss-rs

;ltld

positive

clinically

clatiotl

suspected

(I LGK).

intrauterine

chronic

clialxtes

rnellittrs.

(II’FD),

or-

liy~ertension,

previous

(:S’I‘

rlccx;ised

l’etal reu~rd

e:1~l1 NSI‘

a~~tl c:s7

in twl

bet-c

talwti

1~11~ ititerpretatior~ prwertcr

ti\-itk, scril-xd.7

our blrcnever.

;I(

dor1e

of FHR

iirid

position

and

tdootl

‘I-he

according

pressttrx

(Sl‘s

to the

\vcr-c

to

per~toI~IIletl

met hod

the cej-\is wis

;1 positi\.e war based

tlcw7ihetl

(X5.1‘ was ohtairrctl. on fetal matttrit\

WAS suitable

c-orrsidcr-c,d

for

indrrction

Ix

otr fetal

c-linic ;1II\

rn;Ilrrre.

dir-cc-r

riot be ;ipplied.

FIfK

ws:1re,11J

r~~oriitor-ir1g wc.tic~n

\v;is

h;trltl, if the cervix follo\viIrg ;1mrriotom\ morritorirrg lxtticrit

10

tlrr.

irr the

111 c’ir.ses lvlrcrc nioc~errtcis

coultl done

iv;ts

\‘t’rtes, later-;11

letal

amniotic

tabor wx

phospholipid for-

lxtticntx

411~1 Xi

\vceks’

1.76’7 :{.(i’,

Ss’l

I-4 positi\,c

I

atrtt

(5

CL

l’s wc’i v

wc’~.c’ c rgxr-c,ttc

NST

betwc~tt

;mtl

demonsrr-;1tetl pt-ofilcs

~gest;1tion

\vt’tx~

arltl

riliecl.

Id)\ lvho

tlo apparent

ltt ttrc

gestxiorj.

the

NS’I

antI

it1tlttc

tiorr

witlr

w:1~

Ifuitl phospholipid :ISS:~~ [I./S] ratio 2 2: 1, plrospl1cjti.

;lntl NSI’\.

II.

rrtrc-lial

b\as ;tpprx~priat~

.\t

rlIix

!\‘;1s ii0 ititt

stic

\v;~\

wcr.v \II(.

<1 .i-rrritrtttcbitlr

wec,I\s’

,yet;1tiotr

ICIC~~\C..

~1tt~srclttc’rrfl\ t-cslxyri\~vl\.

swtiorr in l;rl~~~r lot. lx,t+tcirt c-eplialopcl\ic disl)rlJlJor-riorr.

‘I SK C’L itlcrtc

\,igirr;rll\ ;\ly;tI

l)ositi\cs

idrti-

1ttrcl~~i-u~~rrt

alJ;1t~t~trri

tlcli\ct-cd

\\itlr

3X wecLs,

\\;ti

cthit,itt~tl

linrc,

to tx

ctrsl)i~i~,trs

1\.15

NS’l’x

patictjrs

36 ;1nd

rlic

g~~~t;ttioti;iI

clr;tlh

(:.$I

OIIC ~3 xgitr

(ISI.. Tlrcrc

frt;tl

x~orrtl

Iwo

At

(:$I‘.

COJ (I .III~I

\v;1s tortrrtl f-0~.

intant

b\crit (csare:irr ~r~itiorjs :iritl

3 I

I tJ 1~11 o\~J(‘c 1. I IJ(.

t~~~rir~1irrit1g 36

;rt

tli;ihvle\.

tl1e I,tyt

subscclttcnt

, arid

~r‘o~~llr-1~etar~tled !i. ‘l‘lic

;1m-

of’labor

I)

ol~t.1itiirrg

tl1c IXlhV

\lrc

;I l)oGlive clistrxx

(:l;iss

;I tight

whose

gestz1tiorr.

01 f’et;il

( I). It1 tlit (.S-1s

;1f.tcr

(‘;iLr4c* of tllr

lxttient

At 36 weeks’

other

li;ttl

At ~ltltops~‘.

infant

irit~r-l~J~c.t,iti~,114

114 Irc~rrr

tlwt

\l-itli

of se\ ct c f~ct;tl ~co~J;II-~\.

the

norY~lal.

uitlr

ti~t,il

\ ;I[ ZS

,q’ot~l~

(:S 1 \\;1s tlonc

the

2-l IIO~IIY

to

pJxyrJ;rJJc~b

(31

posilivc

pr~~cltrcl~~cl

ititlic:1tive

.-It tlvliw*r\.

(~I‘hv it1 tlic

illltl

3t-;

;rrrrtJiotic

( I). :1trtl poGti\cL

less ttiari lJi%jr-

L’,‘c 2nd

positi\,.

c~or~sec~uti\c~

tlitfi~~ulties

.I :I-+-wcT~

clsc’.

srispiciotts

l~r c~rotil~

lJol~trl;rfiorr.

,I rqxxt

irr ;1 lxiticrrr

ocutt7wl

apl”“I‘“i

III.)

in cat-h two

III).

had

is irr~ltrtled

in Tahlc

bith

i,esttlts

who

orIt‘

the

tlJi<

imrri;1ttrt~~~

( T‘;ihle

patient

(Z),

t cst1lrs

of loi

(XI’7

;IIX’

tlr;iti

euwption

iritlic~ations o\c~;iII

gcat;itiorr,

ILlFl>

TVitlr NS’I‘

tcatirrg

mow

of‘otrr~

hour5

prxy~arlcy

l1;id

positi\,e

tlistwss Z-4

E‘HK

lxitierrls

had

;1t !!H bvceks’

m:ittrt.it\

I9XO.

SK

(41.5’%)

;1r1tep;1r~trttrr

the

;t primaI3

cltrcstioIr;1l~lr,

>I

to tltose

LVC~I-C’ticgxti\e

.rgt’,

f’or. Se\-eral

one

c~sti~iol

position.

If’ l~trtrrIonar~~

fluid

c~ttt~orirc

Rat

example, of labor or‘

LY;IS irrtltr~~~l

rcc-r1n~tx7rt

nratur.ity

w;1s pet~fi1rmetl.

tlemoIrstr;1ted I)) (letit)lil~isl~lliti~~~~li~~lin

On

g5txtiori

‘I‘ec-l1tric;il

siiit;ible for itrtlrrclioIr of. l:1bor, and ;1pplic;iriotI of tlirec t FHK

fetal let’t

initnecli;rtcly.

For

woks’

;111tl

\2;;1s x~orrr-

m;trrner. fi)r- intluc~tion

simil;rr-

weeks

If a ftrrs

f!eliveI-v

plishetl iii the nrost espeditious if the c,ct-vi\ w;is riot srtit;tt)le

10,

ttntler-xteztt

to IJ;l\~c

e\~aluatiorJ.

E‘OLII~ patients

tlcwas

subsecluerrt and whethet

of’lahor.

for. gr-orip,

\Iitlrin

deper1ds

it] I-espotxse

April

I). A tot81 of

II.

c&iriiptic

no fet;il

xso~i~~tes.~

~Vtrwcwr n~:1n;1gcr~~erit

the

\2’;1s

iritrr\als. lvhich

SST.

wcrc‘ xti\it\.

U’Om;ltl

lo-minute

the

xwlcrations

4;1t11c’ da!..

iriterpwld

l)r”~tratIt

fetal

iii .I‘ahle

I~IT

iristittrtioti has ken previotrd~ a NR NST was obtained. ;I (Xl‘

for

the

tnottitoi~z

and

. each iit

of’

FHR

(‘l’ahle

Sevcrmcn

itidic;itiotr

death

Corwmetrics

1 I :! tetal

the

in the semi-Fowler’5

rnc3bttt-eriierit5 the

;md

to cotttinttousl\

l)wing

niovement.

tiJtlrltl

1.11~ irr~lic~~1tioIrs

retar-

fetal

gird

pr~eyn;ttrcic.~

smol\rr-r.

pi+edanipsia,

intraitterinc

‘1~~11~s IO 1 H. 1 I I. I lOA<:, wxl

yw!vth

I!)lif.

-i 1 ue1-e

t-eu~rxled.

li5tetl tation).

3.

hi+-I-isk

C’

01 ;I 9~ or.~’ 411’

(:%I

\ ‘11 3 1

lr;itJ

1(~1~1i\~ I,otl1 ~111~lcr~.

I;1tc cl~t~~i~r~l~~ri\el\.

Pregnancy

Table

III.

Pregnancy

outcome

in patients

outcome

with a NRNST-positive

after

nonreactive

CST by clinical

NST and positive

CST

13

management Labor

Immature phospholipid fwofile

Ikvn Pregnancies (No.) Mods of d&wry:

Vaginal Spontaneous Forceps Cesarean section Meconium Abnormal cord position *Includes t IUFD.

patient

with

No labor

F&l

distress

No fetal dL~lrf?F.\ *

7 ‘otnl

3

8

12

18

41

It

0

1

17

2 1

8 3

1 11 6

15 13 2 ?I 3

24 13

2

2

2

6

12

1

positive

CST

at 28 and 36 weeks’

gestation.

Of‘ the 38 pregnancies which were considered mature, either clinically or by phospholipid assay, all were delivered within 24 hours of the NR NST and positive CST. Of these, eight underwent direct cesarean section for the following indications: “uninducible” cervix (4), breech presentation (2). and repeat cesarean section (2) (Table I II). Of the 30 patients who were allowed to labor, which includes the pregnancy discussed earlier with positive CS’l‘s at 28 and 36 weeks’ gestation, direct FHR monitoring was applied in each case (Table III). Meconiurn-stained amniotic Huid was detected intrapartum in nine patients (30.0%). During labor, late decelerations of the FHR were observed in 18 (60.0%). and cesarean section for persistent late declerations, despite position change and oxygen administration, was necessary in 10 instances (3X:4’%) (Table IV). In the patients with persistent FHR late decelerations, 80% (8 of 10) had absent or minimal FHR variability. One cesarean section for fetal distress was done because of sustained FHR bradycardia. and one patient developed late decelerations in the second stage of labor and was delivered by midforceps. At delivery, abnormal cord positions were recorded in eight instances (26.7%). In summary, cesarean section was performed in 24 of -11 pregnancies (58.5%). Of those patients who labored, 11 of :30 required immediate cesarean section for fetal distress. Meconium-stained amniotic Huid and abnormal cord positions were present in 31.7% and 29.3%. respectively. ‘l‘he f’etal outcome for the entire NR NST-positive CST group are listed in Table V. While the overall incidence of growth-retarded babies was 29.2%, the fetal distress group had the highest rate of growthretardecl babies (7.5.0’2). In addition, the fetal distress group had the highest incidence of neonatal complicariotis and the lowest mean birth weight. The overall perinatal mortality rate was 7311,000, with two neonatal deaths (Potter’s syndrome, diaphragmatic hernia)

Table IV. Intrapartum FHR patterns with induction of labor

Itern

Pregnancies (No.) Decrease in baseline variability

Fetal dislms

in patients

No f&al di,strm

Total

12 8

18 3

2

4

6

30

11

of <5 bpm

Variable decelerations (severe) La& rleceleratzon.~:

Mild Moderate Severe

Combined late decelerations and decreased baseline variability

2

5

5 5

1 0

7 6 5

8

0

x

and one IUFD. Finally, congenital abnormalities present in seven infants (17.1%,) (Table VI).

were

Comment Whenever a physician is faced with a patient who has a NR NST and a positive CST, the route of‘ delivery is his primary concern. In most instances, these patients, as in this series, undergo antepartum FHR testing because of hypertensive disorders of pregnancy, postdates, or suspected ICJGR.‘-” Therefore, it is no surprise that the majority of the babies delivered are growth retarded. The incidence in various series ranges from ?3703 to 41.470.’ However, the problem remains as to the best mode of deliver\. In clinical situations where the cervix is unfavorable for induction of labor, there is a breech presentation, or the patient has had a previous cesarean section, the decision to proceed directly to cesarean section is easy. Induction of labor, under these circumstances, would not be without the potential for additional maternal and fetal risk. As a result of this decision to l”-oceed directly to cesarean section, a higher overall cesarean section rate which, depending on the series. ranges from 57.7% to 84y03 is encountered in these cases.

14

Slomka

and Phelan

Pregnancy

(:ST.

In

mediate rect

FHR

I I(;R

those

insritutions

cesarean

section,

monitoring

with

is justifiable.

c.an 1~ iI~~lrratcl\

the

an attempt diagnosed,

capability at labor

In those primary

cases

outcome

for

irn-

section

with

di-

when

where

appears this

should

after

nonreactive

to he the

antepartum

consider

the

NST and positive

procedure FHR

of choice.

pattern

possibility

CST

Finally,

is observed.

of‘ a11 anomalous

15

one fetus.

cewrean

REFERENCES

I. Lee. C. I’.: Fetal activity acceleration determination for rhe evaluation of fetal reserve. Obstet. Gynecol. 48: 19. 197li. 2. Evrrtson. I,. R.. Gauthier. R. J.. Schifrin, B. S., and Paul. R. !I.: Antepartum fetal heart rate testing. 1. Evolution of the

rwnstress

test.

AM. J. ORSTET.

GYNECOL.

133:29,

1979.

3. Freeman, R. K., Goebelsmann. U., Nochimson. D., and (:rtl ulo, C:.: An evaluation of the significance of a positive oxvrocin challenge test. Obstet. Gynecol. 47:8, 1976. -1. Odcndaal, H. J,: The fetal and labor outcome of 102 po\irive contraction stress tests. Ohster. Gynecol. 54:X11. 1979. .i. Braly, P.. and Freeman, R. K.: The significance of fetal heart rate reactivity with a positive oxytocin challenge test. Ohsret. Gvnecol. 50:689. 1977. 6. Gaurhier, R. J.; Ever&on, L. R., and Paul, R. H.: Anteparturn fetal heart rare testing. II. Intrapartum fetal heart observation and newborn outcome following a positive contraction stress test. AM. J. OBSTET. GYNECOL. 133:34. 19i’l.

7. Phelan. AM.

J. P.: Diminished

J. OBSTET.

GYNECOL.

fetal

reactivity

136:230,

with

smoking.

1980.

8. Ray, M.. Freeman. R., Pine, S., and Hesselgesser. R.: Clinical experience with the oxyrocin challenge test. AM. J. OBSTET.

GYNEcot..

114:

1. 197”.

9. Gabbe, S. G., Freeman, R., and Goehelsmann, I..: EvahIation of the contraction stress test hefnre 33 weeks’ gestation, Obstet. Gynecol. 523649, 197X. 10. Keegan, K. A., and Paul, R. H.: Antepartum fetal heart rate testing. IV. The nonstress test as a primary approach, AM. J. OBSTET. GYNECOL. 136:75. 1980. 1 I. Sandenbergh, H. A., and Odendaal. H. J.: Clinical experience with the contraction stress test. S. Afr. Med. J. 51:660. 12.

1977.

Garite, T. J., Luizey, E. M., Freeman. ter, W. : Fetal heart rate patterns fetuses with congenital anomalies. 716, 1970.

R. Ii., and Dorchesand fetal distress in Ohstet. Gynecol. 53: