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Prevention of iatrogenic neonatal respiratory distress syndrome: Elective repeat cesarean section and spontaneous labor
Prevention of iatrogenic neonatal respiratory distress syndrome: Elective repeat cesarean section and spontaneous labor SUSAN
K.
BOWERS,
HUGH
M.
MACDONALD,
EUGENE Pittsburgh,
D.
SHAPIRO,
M.D. M.D. M.D.
Pennsylvania
Neonatal respiratory distress syndrome (RDS) is an important complication of elective repeat cesarean section. In a review of 68,880 consecutive deliveries; 1,897 women underwent elective cesarean section at a gestation estimated to be 238 weeks. Seventy-one (4.3%) of the infants of the 1,649 women who were not in labor at the time of delivery developed neonatal RDS. None of the infants of the 248 women who were in spontaneous labor at the time of delivery developed RDS (P < 0.005). There were no cases of uterine rupture in either group. Of the 71 infants who developed RDS, 29 (41%) were judged to be at term on the basis of both examination and birth weight. Misapplication of fetal ultrasound data contributed to the premature delivery of more than one third of the infants with RDS. Awaiting the onset of spontaneous labor to determine the timing of repeat cesarean section in women at term is an effective way of preventing iatrogenic neonatal RDS. (AM. J. OBSTET. GYNECOL. 143:186, 1982.)
ELECTIVE REPEAT cesarean section has been implicated as an important cause of iatrogenic prematurity, accounting for up to 9% of all admissions to the neonatal intensive care unit.‘-3 Since the primary cesarean section rate is rising,” the incidence of “iatrogenic” respiratory distress syndrome (RDS) is likely to increase. This study examines the incidence of RDS in infants delivered by elective repeat cesarean section either before or at the time of spontaneous labor.
Material and methods At Magee-Womens Hospital the clinical course of all pregnant women and their infants is reviewed at the time of discharge. The information is coded and prospectively entered into a computerized data retrieval system for later analysis. From January, 1970, through June, 1979, information on 68,880 consecutive deliveries was recorded. We reviewed the data on all women who underwent a repeat cesarean section durFrom the Departments Pediatrics, Unizwsity Received
for publication
Accepted December Reprint Sargent
166
of Obstetrics and Gynecology and of Pittsburgh School of Medicine. August
7, 1981.
3 1, 1981.
requests: Susan K. Bowen, M.D., CHCP, Drive, New Hauen, Connecticut 0651 I,
I50
ing this time period. Pregnancies complicated by diabetes mellitus, rhesus sensitization, hypertension, or preeclampsia were excluded from our analysis. In addition, women whose gestations were estimated to be less than 38 weeks at the time of cesarean section and women whose infants either were asphyxiated (5minute Apgar score 56) or had systemic bacterial infection or major congenital anomalies were also excluded. The records of the remaining women were further examined for the information that had been used to estimate the duration of gestation-menstrual history, uterine size. date of positive pregnancy test, date of quickening, date when unamplified fetal heart tones were first heard, and measurements of fetal biparietal diameter (BPD) by ultrasound. The records of all infants with RDS who were born to these mothers were reviewed further. The diagnosis of neonatal RDS required the presence of grunting, retractions, tachypnea, and an inability to maintain normal arterial blood gases in room air in conjunction with radiographic findings consistent with this diagnosis.” To avoid inclusion of infants with transient tachypnea of the newborn. only infants with respiratory distress lasting more than 48 hours were classified as haying RDS. The birth weight, gestational age as estimated by a neonatologist (no regular protocol was 0002-Y97X/82/100186+0~$00.10/0~
1982 Thr C. V.Mosb~
Co.
Volume Number
143 2
used), duration of hospitalization, and clinical course of these infants were also reviewed. The data were statistically analyzed by use of chi-square and Student’s t tests .li
Prevention
Table I. Acute morbidity iatrogenic RDS
of iatrogenic
of infants
neonatal
RDS
187
with
Results There were 1,897 women who underwent elective repeat cesarean section at 238 weeks estimated gestation who met the study criteria. Two hundred and forty-eight (13%) of these women were in spontaneous labor at the time of delivery and there were no cases of RDS in their infants. There were 1,649 women (87%,) who were not in labor at the time of delivery and 71 (4.3%:) of their infants developed RDS (x’ = 10.7; P < 0.005). There were no cases of uterine rupture in either group. Review of the records of the 71 women whose infants developed RDS revealed that 100% lacked documentation of the date at which unamplified fetal heart tones were first heard, 92% lacked documentation of the date of quickening, 90%’ lacked documentation of a positive pregnancy test, and 24% lacked documentation of uterine size at the first prenatal visit. In addition, in 37%’ of these women the documented uterine size was inconsistent with the date of the last menstrual period (LMP) and the inconsistency was ignored. Finally, measurement of the fetal BPD by ultrasound to confirm the fetal gestational age was performed in only 45%) of these 7 1 women. Of the 32 women who did undergo ultrasound examinations to assess fetal gestational age, the information obtained was not used appropriately in 20 cases (63%). Eight of the 20 women were uncertain of the date of their LMP yet fetal BPD was not measured until the third trimester. Of the 12 women for whom a single midtrimester sonogram was done, cesarean section was rescheduled to an earlier date for six because the sonogram suggested that the fetal gestational age was greater than that calculated from the LMP and the scheduled cesarean section date was not reassessed for six women despite a sonogram suggesting that the fetal gestational age might be as much as 3 weeks less than that calculated from the date of the LMP. Of the 71 infants who developed neonatal RDS, the gestational age as assessed by the pediatrician was found to be ~38 weeks in 42 infants (59%) (mean birth weight, 2,707 gm: range, 1,905 to 3.460 gm) and 238 weeks in 29 infants (41%) (mean birth weight, 3,206 gm: range, 2,620 to 4,180 gm). The mean birth weights of the infants in these two groups were significantly different (Student’s t test = 5.35; P < O.OOI), tending to corroborate the gestational assessments. A summary of the acute morbidity of these infants is
Inspired O2 fraction > 0.40 Phototherapy for hyperbilirubinemia Constant positive airway pressure Mechanical ventilation Chest tube for pneumothorax Mean duration of hospitalization
24 (57%)
20 (69%)
10 (24%)
9 (31%)
8 (19%) 5 (12%) 1 (2%)
6 (21%) 1 (3%) 3 (10%)
10.1 days
9.1 days
shown in Table I. Although both the premature and the term infants experienced considerable morbidity, there were no significant differences between these two groups in either the use of any of the treatment modalities or in the mean duration of hospitalization. One infant (gestational age <38 weeks) had an intraventricular hemorrhage and seizures. All of the infants were alive at the time of hospital discharge.
Comment Iatrogenic prematurity, with its concomitant neonatal complications, has been identified as the major risk of elective repeat cesarean section.’ Consequently, obstetricians have sought ways to confirm the fetal gestational age at different times during pregnancy. Clinical variables, such as date of the LMP, uterine size at the first prenatal visit, date of quickening, date when the unamplified fetal heart tones were first heard, and date of an early positive pregnancy test, correlate well with the gestational age of the fetus.N. g In this series, most of the 71 infants who developed RDS did not have the benefit of the appropriate use of these variables to confirm their delivery dates. Measurement of the fetal BPD by ultrasound is also useful for confirming or determining fetal gestational age. lo Some authors have suggested that careful documentation of fetal gestational age by use of ultrasound in conjunction with clinical parameters and amniocentesis may reduce the frequency of iatrogenic RD.%“, ‘I For optimal accuracy serial measurements should be obtained beginning in the second trimester. With fetal BPD measurements obtained before 26 weeks and again between 30 and 33 weeks, the gestational age of the fetus can be accurately estimated to within 3 days of the true gestation. I0 However, a single fetal BPD value obtained during the second trimester can predict fetal gestational age only with an accuracy of * 11 days (a range of 22 days): therefore, although a single mid-
188
Bowers, MacDonald, and Shapiro
trimester fetal BPD that suggests a gestational age which is either much less or much greater than was expected should raise doubts about the accuracy of the date of the mother’s LMP, it should not be used as the sole determinant of the delivery date. A single fetal BPD value obtained after 29 weeks of gestation is predictive of fetal gestational age only to within 3 weeks, and thus has no value for determining the timing of an elective repeat cesarean section.‘” Some investigators have suggested that the use ot ultrasound to assess fetal gestational age may actualh increase the risk of overestimating fetal maturity.” Atthough both accuracy and sophistication in the use ot ultrasound improved during the study period, the misappbcatlon of ultrasound data was indeed an irnportant factor leading to premature delivery in our series. Of the 20 infants with RDS whose mothers experienced inappropriate application of fetal ultrasound, 17 were in the group of infants who were subsequently .judged to be premature b\- examination and birth weight. Although a term gestation is defined as 2% werk~, the fetal lungs may not be fully mature until after week 38 of gestation.“’ In this study 29 of’ the 71 inlants (41%) with RDS wereJudged to be at a gestational age of at feast 38 weeks on the basis of both esamination and birth weight. Others have reportecl a similar percentage of cases of iatrogenic RDS occurring in term infants.’ Furthermore, since the morbiditr, from iatrogenic RDS in term infants is substantial, and since even a confirmed gestational age of 23X rveeks does not guarantee that an infant will not develop RDS, additional assurance of fetal pulmonary maturity is necessary prior to elective delivery by repeat cesareait section. It has been suggested that women scheduled for elective cesarean section, particularly those whose expected date of confinement is uncertain:’ should mldergo amniocentesis near term, with delay of deli\,er\ until
the
lecithinisphingomyelin
that the fetal lungs are mature.”
(L/S)
ratio
This alone
indicates
gtlarantee
of fetal
pulmonary
maturity,
however,
at least orle large series. RDS occurred infants in whoin a prior L/S ratio indicated tit\
.I-’ In
tions
addition,
front
the
risk
nual
cost
We
to elective ~oultl
that
befijre
~\omen not
fetal OCCUI~
complica-
irepot-ted
mav
cesarean
to be as
be reduced
sectioii,
witI
the
onset
a repeat
is an efttctive
rn;ltltritv,
since
in infants
xc-host
the current
nrl-
of $150,000.
aw.aiting
performing
at tcrnl
suring
risk
be in excess
suggest
labor
this
Ital
been
Finallv, the financial costs of are substantial: if all \+omen at OUI~ into have an amniocentesis with an I./S
the procedtlre kutiorr were prior
serious
has
high 3s 17 . ” altbouqh ~ t be aid of’ ultrasound.”
ratio
or
amniocentesis
since
in 3.7’j; of fetal matu-
in
of spontanenus
cesarcan
alternate our
data
&OM
mothers
of‘ as-
that
were
in
section
nlethod
RDS
did
iu spontanc-
ous labor at the time the\ underwent a repeat cesarean section, ‘l’hr major poterltial risk of this ‘rpproach is
literine
rupttirc,
in O.:i’;;
of women
low
traiis\‘crsc
tleli\,er
the
risk
1vci.e
in labor. Other
of. oper-sting
possibl\
tients
\vho
‘I‘be
, xii ax
risk
cesarean
of
~verks‘
indicate
ttlat
accurate
not
;I single
potential
b!,
allowed
to
risk
cdse
itI 0111
ot
uterine
problems \\.ith
inclucte
a full
stomach
of cnd:)riietritis
iri lx-
labor at tlrc time 01 cesal.ean section.
KDS
in infants
is substantial. gestational
the
awaiting ant1
were
L’4X n’omen
on a 1~‘oman
age.
spontaneous
I”-edictor
maternal
lvbo in the
inc r-eased
irr
sectiorr
be 23X
women
,li Hobvev~r,
occurred section
CCWIT~II
incisioir
occurrecl.
and.
to have
a pre\,ious
cervical
c\.ho
rupture
eras reported
w+tb
vagiIxill1
srries
ai,
which
repeat
l‘be
data
onset
from
stud\
at term iiiaturit\
section from
to
our
of‘ labor
pulmon;ir\
cesareari
uiorbidit\
bv electike in irttatits,judged
of fetal
repeat fetal
hoi-11 even
tbih
and
that
approach
is iii the is
minimal. rl’e
are
Heubdch.
vie\\, of secretarial
the
indebted
to
111-s. S. CZaritis.
I). Edelstone,
and J. Harger
manuscript assistance.
and
Ms.
.J. Fa)
E.
Mueller-
for critical f’or
re-
excellent
is not a
REFERENCES 1. Goldenberg, R. L., and Nelson, K.: latrogenic respirator) distress syndrome: An analysis of obstetric events preceding delivery of infants who develop respiratory distress syndrome, Abf. J. OBSTET. GYNECOL. 123:617, 1975. 2. Hack, M., Fanaroff, A. A., and Klaus, M. H.: Neonatal respiratory distress following delivery: A preventable disease? AM. J. OBSTET. GYNECOL. 126:43. 1976. 3. Flaksman, R. J., Vollman, J. H., and Benfield. D. G.: Iatrogenic prematurity due to elective termination of- incomplicated pregnancy: A major perinatal health care problem, AM. J. OBSTET. GYNECOL. 132:885, 1978. 4. Bottoms, S. F., Rosen, M. G., and Sokot, R. J.: The in-
5.
6. 7.
8.
trcase in the ccsarcan birth r-ate. N. Engl. J. Med. 320:559, 1980. Baker, D. H.. and Berdon, W. E.: The neonate and young infant: The chest, irt Caffey, J., editor: Pediatric S-ra) Diagnosis, ed. 7, Chicago, 1978, Year Book Medical Pub lishers, pp. 1655-1661. Colton, T.: Statistics in Medicine, Boston, 1971, Little, Brown & Co. Shy, K. I(., Log&o. J, P., and Karp, L. F.: Evaluation of elective repeat cesarean section as a standard of care: ,413 application ot‘ decision analysis, AM. J. OBSTET. GYNECOL. 139:123. 1981. Hertz, R. H.. Sokol, R. ,J., Knole, J. D.. et al.: Clinical
Prevention
9.
10.
11.
12
13.
estimation of gestational age: Rules for avoiding preterm delivery, AM. J. OBSTET. GYNECOL. 131:395, 1978. Frigoletto, F. D.. Jr., Phillipe, M.. Davies, I. J., and Ryan, li. J.: Avoiding iatrogenic prematurity with elective repeat cesarean section without the routine use of amniocentesis, AM. J. OBSTET. GYNECOL. 137:521, 1980. Sabbagha, R. E.: Biparietal diameter and gestational age. in Sabbagha, R. E., editor: Diagnostic Ultrasound Applied to Obstetrics and Gynecology, Hagerstown, Md., 1980, Harper & Row, Publishers, pp. 79-92. Toffle, R. C., Macfee, M. S.. and Porreco, R. P.: The management of. elective, repeat cesarean section, J. Reprod. Med. 21:377. 1978. Cowett. R. M., and Oh, W.: Foam stability predictions of respiratory distress in infants delivered by repeat cesarean section, N. Engl. J. Med. 295~1222, 1976. Usher, R. H.. Allen, A. C., and McLean, F. 1-I.: Risk of
of iatrogenic
neonatal
RDS
189
respiratory distress syndrome related to gestational age, route of delivery, and maternal diabetes, AM. J. OBSTET. GYNECOL. 111:826, 1971. 14. Donald, I. R., Freeman, R. K.. Goebelsmann, U., et al.: Clinical experience with the amniotic fluid lecithin/ ;pd;i?ngomyelin ratio, AM. J. OBSTET. GYNECOL. 115:547, 15. Rome, R. M., Clover, J. I., and Simmons, S. C.: The benefits and risks of amniocentesis for the assessment of fetal lung maturity, Br. J. Obstet. Gynaecol. 82:662, 1975. 16. Picker. R. H.. Robertson. R. D.. Pennington, I. C., et al.: A safe method of amniocentesis for lecithuin/sphingomyelin determination in late pregnancy using ultrasound, Obstet. Gynecol. 47:722, 1976. 17. Merrill. B. S., and Gibb, C. E.: Planned vaginal delivery following cesarean section, Obstet. Gynecol. 52:50, 1978.
K.
BOWERS,
HUGH
M.
MACDONALD,
EUGENE Pittsburgh,
D.
SHAPIRO,
M.D. M.D. M.D.
Pennsylvania
Neonatal respiratory distress syndrome (RDS) is an important complication of elective repeat cesarean section. In a review of 68,880 consecutive deliveries; 1,897 women underwent elective cesarean section at a gestation estimated to be 238 weeks. Seventy-one (4.3%) of the infants of the 1,649 women who were not in labor at the time of delivery developed neonatal RDS. None of the infants of the 248 women who were in spontaneous labor at the time of delivery developed RDS (P < 0.005). There were no cases of uterine rupture in either group. Of the 71 infants who developed RDS, 29 (41%) were judged to be at term on the basis of both examination and birth weight. Misapplication of fetal ultrasound data contributed to the premature delivery of more than one third of the infants with RDS. Awaiting the onset of spontaneous labor to determine the timing of repeat cesarean section in women at term is an effective way of preventing iatrogenic neonatal RDS. (AM. J. OBSTET. GYNECOL. 143:186, 1982.)
ELECTIVE REPEAT cesarean section has been implicated as an important cause of iatrogenic prematurity, accounting for up to 9% of all admissions to the neonatal intensive care unit.‘-3 Since the primary cesarean section rate is rising,” the incidence of “iatrogenic” respiratory distress syndrome (RDS) is likely to increase. This study examines the incidence of RDS in infants delivered by elective repeat cesarean section either before or at the time of spontaneous labor.
Material and methods At Magee-Womens Hospital the clinical course of all pregnant women and their infants is reviewed at the time of discharge. The information is coded and prospectively entered into a computerized data retrieval system for later analysis. From January, 1970, through June, 1979, information on 68,880 consecutive deliveries was recorded. We reviewed the data on all women who underwent a repeat cesarean section durFrom the Departments Pediatrics, Unizwsity Received
for publication
Accepted December Reprint Sargent
166
of Obstetrics and Gynecology and of Pittsburgh School of Medicine. August
7, 1981.
3 1, 1981.
requests: Susan K. Bowen, M.D., CHCP, Drive, New Hauen, Connecticut 0651 I,
I50
ing this time period. Pregnancies complicated by diabetes mellitus, rhesus sensitization, hypertension, or preeclampsia were excluded from our analysis. In addition, women whose gestations were estimated to be less than 38 weeks at the time of cesarean section and women whose infants either were asphyxiated (5minute Apgar score 56) or had systemic bacterial infection or major congenital anomalies were also excluded. The records of the remaining women were further examined for the information that had been used to estimate the duration of gestation-menstrual history, uterine size. date of positive pregnancy test, date of quickening, date when unamplified fetal heart tones were first heard, and measurements of fetal biparietal diameter (BPD) by ultrasound. The records of all infants with RDS who were born to these mothers were reviewed further. The diagnosis of neonatal RDS required the presence of grunting, retractions, tachypnea, and an inability to maintain normal arterial blood gases in room air in conjunction with radiographic findings consistent with this diagnosis.” To avoid inclusion of infants with transient tachypnea of the newborn. only infants with respiratory distress lasting more than 48 hours were classified as haying RDS. The birth weight, gestational age as estimated by a neonatologist (no regular protocol was 0002-Y97X/82/100186+0~$00.10/0~
1982 Thr C. V.Mosb~
Co.
Volume Number
143 2
used), duration of hospitalization, and clinical course of these infants were also reviewed. The data were statistically analyzed by use of chi-square and Student’s t tests .li
Prevention
Table I. Acute morbidity iatrogenic RDS
of iatrogenic
of infants
neonatal
RDS
187
with
Results There were 1,897 women who underwent elective repeat cesarean section at 238 weeks estimated gestation who met the study criteria. Two hundred and forty-eight (13%) of these women were in spontaneous labor at the time of delivery and there were no cases of RDS in their infants. There were 1,649 women (87%,) who were not in labor at the time of delivery and 71 (4.3%:) of their infants developed RDS (x’ = 10.7; P < 0.005). There were no cases of uterine rupture in either group. Review of the records of the 71 women whose infants developed RDS revealed that 100% lacked documentation of the date at which unamplified fetal heart tones were first heard, 92% lacked documentation of the date of quickening, 90%’ lacked documentation of a positive pregnancy test, and 24% lacked documentation of uterine size at the first prenatal visit. In addition, in 37%’ of these women the documented uterine size was inconsistent with the date of the last menstrual period (LMP) and the inconsistency was ignored. Finally, measurement of the fetal BPD by ultrasound to confirm the fetal gestational age was performed in only 45%) of these 7 1 women. Of the 32 women who did undergo ultrasound examinations to assess fetal gestational age, the information obtained was not used appropriately in 20 cases (63%). Eight of the 20 women were uncertain of the date of their LMP yet fetal BPD was not measured until the third trimester. Of the 12 women for whom a single midtrimester sonogram was done, cesarean section was rescheduled to an earlier date for six because the sonogram suggested that the fetal gestational age was greater than that calculated from the LMP and the scheduled cesarean section date was not reassessed for six women despite a sonogram suggesting that the fetal gestational age might be as much as 3 weeks less than that calculated from the date of the LMP. Of the 71 infants who developed neonatal RDS, the gestational age as assessed by the pediatrician was found to be ~38 weeks in 42 infants (59%) (mean birth weight, 2,707 gm: range, 1,905 to 3.460 gm) and 238 weeks in 29 infants (41%) (mean birth weight, 3,206 gm: range, 2,620 to 4,180 gm). The mean birth weights of the infants in these two groups were significantly different (Student’s t test = 5.35; P < O.OOI), tending to corroborate the gestational assessments. A summary of the acute morbidity of these infants is
Inspired O2 fraction > 0.40 Phototherapy for hyperbilirubinemia Constant positive airway pressure Mechanical ventilation Chest tube for pneumothorax Mean duration of hospitalization
24 (57%)
20 (69%)
10 (24%)
9 (31%)
8 (19%) 5 (12%) 1 (2%)
6 (21%) 1 (3%) 3 (10%)
10.1 days
9.1 days
shown in Table I. Although both the premature and the term infants experienced considerable morbidity, there were no significant differences between these two groups in either the use of any of the treatment modalities or in the mean duration of hospitalization. One infant (gestational age <38 weeks) had an intraventricular hemorrhage and seizures. All of the infants were alive at the time of hospital discharge.
Comment Iatrogenic prematurity, with its concomitant neonatal complications, has been identified as the major risk of elective repeat cesarean section.’ Consequently, obstetricians have sought ways to confirm the fetal gestational age at different times during pregnancy. Clinical variables, such as date of the LMP, uterine size at the first prenatal visit, date of quickening, date when the unamplified fetal heart tones were first heard, and date of an early positive pregnancy test, correlate well with the gestational age of the fetus.N. g In this series, most of the 71 infants who developed RDS did not have the benefit of the appropriate use of these variables to confirm their delivery dates. Measurement of the fetal BPD by ultrasound is also useful for confirming or determining fetal gestational age. lo Some authors have suggested that careful documentation of fetal gestational age by use of ultrasound in conjunction with clinical parameters and amniocentesis may reduce the frequency of iatrogenic RD.%“, ‘I For optimal accuracy serial measurements should be obtained beginning in the second trimester. With fetal BPD measurements obtained before 26 weeks and again between 30 and 33 weeks, the gestational age of the fetus can be accurately estimated to within 3 days of the true gestation. I0 However, a single fetal BPD value obtained during the second trimester can predict fetal gestational age only with an accuracy of * 11 days (a range of 22 days): therefore, although a single mid-
188
Bowers, MacDonald, and Shapiro
trimester fetal BPD that suggests a gestational age which is either much less or much greater than was expected should raise doubts about the accuracy of the date of the mother’s LMP, it should not be used as the sole determinant of the delivery date. A single fetal BPD value obtained after 29 weeks of gestation is predictive of fetal gestational age only to within 3 weeks, and thus has no value for determining the timing of an elective repeat cesarean section.‘” Some investigators have suggested that the use ot ultrasound to assess fetal gestational age may actualh increase the risk of overestimating fetal maturity.” Atthough both accuracy and sophistication in the use ot ultrasound improved during the study period, the misappbcatlon of ultrasound data was indeed an irnportant factor leading to premature delivery in our series. Of the 20 infants with RDS whose mothers experienced inappropriate application of fetal ultrasound, 17 were in the group of infants who were subsequently .judged to be premature b\- examination and birth weight. Although a term gestation is defined as 2% werk~, the fetal lungs may not be fully mature until after week 38 of gestation.“’ In this study 29 of’ the 71 inlants (41%) with RDS wereJudged to be at a gestational age of at feast 38 weeks on the basis of both esamination and birth weight. Others have reportecl a similar percentage of cases of iatrogenic RDS occurring in term infants.’ Furthermore, since the morbiditr, from iatrogenic RDS in term infants is substantial, and since even a confirmed gestational age of 23X rveeks does not guarantee that an infant will not develop RDS, additional assurance of fetal pulmonary maturity is necessary prior to elective delivery by repeat cesareait section. It has been suggested that women scheduled for elective cesarean section, particularly those whose expected date of confinement is uncertain:’ should mldergo amniocentesis near term, with delay of deli\,er\ until
the
lecithinisphingomyelin
that the fetal lungs are mature.”
(L/S)
ratio
This alone
indicates
gtlarantee
of fetal
pulmonary
maturity,
however,
at least orle large series. RDS occurred infants in whoin a prior L/S ratio indicated tit\
.I-’ In
tions
addition,
front
the
risk
nual
cost
We
to elective ~oultl
that
befijre
~\omen not
fetal OCCUI~
complica-
irepot-ted
mav
cesarean
to be as
be reduced
sectioii,
witI
the
onset
a repeat
is an efttctive
rn;ltltritv,
since
in infants
xc-host
the current
nrl-
of $150,000.
aw.aiting
performing
at tcrnl
suring
risk
be in excess
suggest
labor
this
Ital
been
Finallv, the financial costs of are substantial: if all \+omen at OUI~ into have an amniocentesis with an I./S
the procedtlre kutiorr were prior
serious
has
high 3s 17 . ” altbouqh ~ t be aid of’ ultrasound.”
ratio
or
amniocentesis
since
in 3.7’j; of fetal matu-
in
of spontanenus
cesarcan
alternate our
data
&OM
mothers
of‘ as-
that
were
in
section
nlethod
RDS
did
iu spontanc-
ous labor at the time the\ underwent a repeat cesarean section, ‘l’hr major poterltial risk of this ‘rpproach is
literine
rupttirc,
in O.:i’;;
of women
low
traiis\‘crsc
tleli\,er
the
risk
1vci.e
in labor. Other
of. oper-sting
possibl\
tients
\vho
‘I‘be
, xii ax
risk
cesarean
of
~verks‘
indicate
ttlat
accurate
not
;I single
potential
b!,
allowed
to
risk
cdse
itI 0111
ot
uterine
problems \\.ith
inclucte
a full
stomach
of cnd:)riietritis
iri lx-
labor at tlrc time 01 cesal.ean section.
KDS
in infants
is substantial. gestational
the
awaiting ant1
were
L’4X n’omen
on a 1~‘oman
age.
spontaneous
I”-edictor
maternal
lvbo in the
inc r-eased
irr
sectiorr
be 23X
women
,li Hobvev~r,
occurred section
CCWIT~II
incisioir
occurrecl.
and.
to have
a pre\,ious
cervical
c\.ho
rupture
eras reported
w+tb
vagiIxill1
srries
ai,
which
repeat
l‘be
data
onset
from
stud\
at term iiiaturit\
section from
to
our
of‘ labor
pulmon;ir\
cesareari
uiorbidit\
bv electike in irttatits,judged
of fetal
repeat fetal
hoi-11 even
tbih
and
that
approach
is iii the is
minimal. rl’e
are
Heubdch.
vie\\, of secretarial
the
indebted
to
111-s. S. CZaritis.
I). Edelstone,
and J. Harger
manuscript assistance.
and
Ms.
.J. Fa)
E.
Mueller-
for critical f’or
re-
excellent
is not a
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