3

3

3

3

www.AJOG.org SMFM Abstracts
16 TRANSVAGINAL ULTRASOUND FINDINGS AND MODE OF DELIVERY IN PLACENTA
PREVIA PATRIZIA VERGANI1, ILARIA POZZI1, SARA ORNAGHI1, MASSIMILIANO GRECO1,
FRANCESCA MARIA RUSSO1, ILARIA FOLLESA1, 1University of Milano-Bicocca, Depart-
ment of Obstetrics and Gynecology, Monza, Milan, Italy

OBJECTIVE: There is consensus that a placenta previa that totally or partially
overlies the internal os requires delivery by caesarean, however the mode of delivery
when the placenta lies in proximity to the internal os is more controversial. Three
retrospective studies concluded that a placental edge-os distance greater than 20
mm permitted a safe vaginal delivery. Conversely there is no concordance about the
treatment of women with a placental edge-os distance between 0 and 20 mm. We
have related transvaginal ultrasound findings with mode of delivery and outcomes
in cases of complete or partial placenta previa.

STUDY DESIGN: Retrospective review of 114 consecutive singleton pregnancies
with placenta previa confirmed by a transvaginal ultrasound performed at �28 days
of delivery. Excluded were cases with a placental-to-internal os distance of 21-30
mm (n�16). Cases in which the placental edge overlapped the internal cervical
(n�42) underwent cesarean section (CS). The other cases were allowed to labor
and included Group 1 (n�24) with a placental edge-to-internal os distance of 1-10
mm and Group 2 (n�29) with a distance of 11-20 mm. Likelihood of CS and other
obstetric variables were compared using Chi-Square and One-Way ANOVA where
appropriate.

RESULTS: Mean scan-to-delivery interval was 10 days. The Group 1 and 2 dif-
fered for maternal age (35�4 vs 33�3 years, p�0.02) but had similar rates of
nulliparity (58% vs 62%). Rates of CS (75% vs 31%, OR�6.7, 95% CI 2-22) and
rates of bleeding before labor (29% vs 3%, OR�11.5, 95% CI 1.6-76.7) were sig-
nificantly higher in Group 1 than Group 2. Blood loss at delivery (662�466 vs
510�547 mL, p�0.29) and rate of severe postpartum hemorrhage (21% vs 10%,
OR � 2.3, 95% CI 0.5-9.7) were similar in the 2 groups.

CONCLUSION: Patients with marginal placenta previa and a placental edge-
to-os distance �10 mm should be allowed to labor as more than two-thirds will
deliver vaginally without increased risk of hemorrhage.

0002-9378/$ - see front matter
doi:10.1016/j.ajog.2008.09.344

17 UMBILICAL CORD GASES AND NEURO-DEVELOPMENTAL DISABILITY IN VERY
PRETERM BIRTHS ALAN TITA1, JOSEPH BIGGIO1, SUZANNE P. P. CLIVER1, FRED
BIASINI2, RICHARD RECTOR2, WILLIAM ANDREWS1, 1University of Alabama at Birming-
ham, Obstetrics and Gynecology, Birmingham, Alabama, 2University of Alabama
at Birmingham, Psychology, Birmingham, Alabama

OBJECTIVE: To assess the relationship between umbilical artery acid-base sta-
tus and major neurodevelopmental disability at age 6 years among very preterm
births (VPTB).

STUDY DESIGN: Secondary analysis of a prospective cohort of 457 VPTBs be-
tween 23 and 32 weeks= from 1996-2001. Arterial cord gas parameters �10th %tile
for pH (�7.1), base excess (� �8.6 mEq/L), bicarbonate (�21 mEq/L), PO2 (�29
mm Hg) and � 90th percentile for PCO2 (�77 mm Hg) were considered abnor-
mal. Neurodevelopmental disability was defined as IQ �70, or the composite of
IQ�70, cerebral palsy, blindness, deafness or other major deficits (abnormal bal-
ance, impaired coordination, dystonia and seizure disorder). Logistic regression
was used to adjust for race and parental IQ and (in additional analyses) for gesta-
tional age (GA).

RESULTS: 261 of 375 survivors with mean GA of 28.8 weeks were evaluated at
mean age of 6.8 years. In unadjusted analyses, GA (inversely) and abnormal pH,
base excess and pC02, but not bicarbonate or pO2, were associated with long-term
disability. Multivariable analyses with and without adjustment for GA (as a contin-
uous variable) are presented in the table. Not shown, each 1 week increase in GA,
was associated with a 25-28% significant decrease in adjusted risks of IQ�70 and
composite major disability. Children with cord gas abnormalities had higher rates
of disability within sub-groups of earlier and later GA.

CONCLUSION: The risk of long-term major neurodevelopmental disability as-
sociated with abnormal cord pH and base excess remains considerably increased
(over 2-fold) after accounting for the strong association with GA. However, a much
larger cohort would be needed to conclusively assert the suggested association be-
tween cord gas abnormalities and long-term disability.

0002-9378/$ - see front matter
doi:10.1016/j.ajog.2008.09.345
Suppleme
18 POLYSUBSTANCE ABUSE BY WOMEN IN A METHADONE TREATMENT PROGRAM
INCREASES THE RISK FOR PRETERM BIRTH CHRISTOPHER ALMARIO1, NEIL
SELIGMAN1, EDWARD HAYES1, KEVIN DYSART2, VINCENZO BERGHELLA1, JASON BAXTER1,
1Thomas Jefferson University, Obstetrics and Gynecology, Philadelphia, Pennsyl-
vania, 2Thomas Jefferson University/Nemours Foundation, Neonatology, Phila-
delphia, Pennsylvania

OBJECTIVE: To determine whether the increased rate of preterm birth (PTB)
among women in a methadone treatment program is associated with supplemen-
tation of methadone with additional substances.

STUDY DESIGN: Case-control study of opiate-addicted gravid women in a
methadone treatment program. We defined cases and controls as those with a
preterm or term delivery, respectively. Women who delivered a live-born neonate
between 2000-2006 were included. We defined “supplements to methadone” to
include alcohol (by self report) and any illicit drugs, except marijuana, found on a
urine drug screen within two weeks of delivery. Odds ratio (OR) and 95% confi-
dence interval (CI) for PTB were calculated for each substance individually and
multiple substances used together.

RESULTS: We analyzed 258 opiate-addicted gravid women on methadone. The
rate of PTB was 29.1%. The most commonly used “supplements” to methadone
were opiates (16.7%), cocaine (13.6%), benzodiazepines (12.0%), alcohol (7.8%),
and barbiturates (1.2%). We found no elevated risk for PTB in women who solely
supplemented methadone with the above individual substances when compared to
those not supplementing. Those using methadone with two or more “supplements”
near the time of delivery were at increased risk for PTB, and there appeared to be an
additive effect (Table). Tobacco use was high (86.1%) and therefore not included as
a “supplement” in our model.

CONCLUSION: Opiate-addicted gravid women on methadone treatment who
supplement with illicit drugs or alcohol are at increased risk for PTB, and the risk is
dependent on the number of “supplements” used.

No. of “supplements” to methadone Preterm birth OR (95% CI)

1 1.0 (0.5-2.1)
2 3.3 (1.4-7.5)
3� 6.1 (1.5-25.4)

0002-9378/$ - see front matter
doi:10.1016/j.ajog.2008.09.346

19 IS THERE ANY RELATION BETWEEN DEVELOPMENT OF NON REASSURING FETAL
HEART RATE PATTERN AND ACUTELY INCREASED UTERINE ARTERY VASCULAR FLOW
RESISTANCE DURING DINOPROSTONE USE IN POSTTERM PREGNANCIES? DENIZ
KARCAALTINCABA1, DERYA AKDAG1, OMER KANDEMIR1, SEDA GUVENDAG-GUVEN1,
SERDAR YALVAC1, ALI HABERAL1, 1Etlik Women’s hospital, Ankara, Turkey

OBJECTIVE: Development of non reassuring fetal heart rate pattern(NRFHRP)
during labour is common indication for emergency Cesarian section. Sustained
release form of dinoprostone is frequently used for induction of labour in posterm
pregnancies. In this prospective cohort study we aimed to investigate relation be-
tween development of NRFHRP and changes in doppler parameters of fetal and
uterine arteries during induction of labor with vaginal dinoporostone .

STUDY DESIGN: Totally 141 postterm pregnancies(who completed 41 gesta-
tional weeks) were included. Patients(n�108) who had successful spontaneous
vaginal delivery were recruited as control group and patients( n�15) who under-
went c sections due to NRFHRP were recruited as study group. Remaining 16
patients who underwent cesarian section because of other causes were excluded
from final analysis. Associated risk factors were recorded. Doppler param-
eters(RI,PI, s/d) of umbilical, middle cerebral and uterine arteries were measured
before and 4-6 hours after dinoprostone application during relaxation period of
contractions.

RESULTS: There was no statiscal difference with regard to age and gestational
week between study and control groups. Results of basal doppler analysis of uterine
and fetal arteries were not statistically different. After vaginal dinoprostone appli-
cation there was statistically significant increase in uterine arteryRI(uaRI) in study
group(0.15) compared to control group(0.1) (p�0.004). ReceiverOperatingChar-
acteristic(ROC) curve identified an uaRI increase value of 0.11 as optimal threshold
for prediction of NRFHRP with 73.3%sensitivity and 69.4%specificity. Logistic
regression analysis demonstrated that increase of uaRI was predictive for NRFHR-
P(odds ratio(CI) 6.6(1.8-24.6))

CONCLUSION: Increased uaRI more than 0.11 after sustained release of dino-
prostone in postterm pregnancies may allow earlier prediction of development of
NRFHRP. Increased uaRI associated with dinoprostone use may lead poor perfu-
sion of fetoplasental unit during labour which may be possible cause of emergency
cesarean section.

0002-9378/$ - see front matter
doi:10.1016/j.ajog.2008.09.347
nt to DECEMBER 2008 American Journal of Obstetrics & Gynecology S99

sara_ornaghi
Highlight