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www.AJOG.org SMFM Abstracts

14 ADDITION OF PERFLUOROCARBON TO ENHANCE PULMONARY GROWTH TO TRACHEALOCCLUSION IN A RABBIT MODEL FOR FETAL LUNG DEVELOPMENT ELISA DONE1,LÉONARDO GUCCIARDO1, LOURENCO SBRAGIA1, XENIA ROUBLIOVA1, STEFFI MAYER1,VERONIKA BECK1, JAN DEPREST1, 1Katholieke Universiteit Leuven, Faculty of Medi-cine, Centre for Surgical Technologies, Leuven, Belgium

OBJECTIVE: Fetal tracheal occlusion (TO) prevents egress of lung fluid, stretch-ing fetal airways hence causing lung growth. Addition of adjuncts increasing airwaystretch may cause additional growth. We investigated the effect of intratrachealperfluorocarbon (PFC) in fetal rabbits.

STUDY DESIGN: Cornual end fetuses were randomly assigned at 27 d(term�31d) to 6 groups: Tracheal Occlusion (TO; n�7), TO with addition of0.5mL PFC (TO�PFC; n�7) or saline (TO�Sal; n�7), SHAM (neck dissection;n�7). Neighbouring fetuses were used as internal normal controls (CTR; n�28).At term, fetuses were delivered by C-section to assess wet lung-to-body weight ratio(LBWR), lung volume/body weight ratio (LVBWR), airway morphometry: linearintercept (Lm-index inversely related to alveolar size), mean terminal bronchiolardensity (MTBD-index of number of alveoles) and alveolar septal thickness (Lmw).Number of proliferating cells was determined using PCNA immunostain.

RESULTS: LBWR was higher in TO groups than in CTR or SHAM fetuses.Additional PFC but not saline added to LBWR. LVBWR followed the same trendswith larger volumes for TO�PFC. Linear intercept and alveolar wall thickness weresignificantly lower in TO�PFC compared to others whereas the MTBD remainedthe same. The number of PCNA-positive cells was not different between group-s.(Table1)

CONCLUSION: TO increases lung size and volume by term. Adding PFC or salineunder the occlusion increases that even more. PFC causes increased air space sizeand thinner septa compared to TO and TO�saline but this was without measurableincreases in number of proliferating cells.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2008.09.644

15 THE EFFECT OF BMI AND OBESITY ON MATERNAL AND CORD BLOODBETAMETHASONE CONCENTRATIONS CYNTHIA GYAMFI1, 1for the Eunice KennedyShriver National Institute of Child Health and Human Development MFMU Net-work, Bethesda, Maryland

OBJECTIVE: Body mass index (BMI, kg/m2) is known to affect the volume ofdistribution of medications, particularly when they are delivered by the intramus-cular route. Antenatal corticosteroids have never been studied in relation to ma-ternal obesity. Thus, we evaluated whether maternal prepregnancy BMI or obesityaffect maternal serum or cord blood betamethasone concentrations.

STUDY DESIGN: Participants receiving betamethasone in the active group of adouble-blind randomized placebo-controlled trial of weekly antenatal corticoste-roids who delivered within one week of steroid administration were identified. Weanalyzed maternal serum and cord blood betamethasone concentrations by BMI,and then compared obese women, defined as a BMI 30, to non-obese women,defined as BMI �30. We controlled for the number of courses received, days sincethe last course, plurality, and gestational age at delivery.

RESULTS: Of 53 mothers that delivered within one week of betamethasoneadministration with available serum and maternal BMI information, 41 of thosewere non-obese and 12 were obese. Mean maternal serum betamethasone concen-trations were 6.7 ng/mL and 8.5 ng/mL for non-obese and obese women, p�0.74,respectively. Cord blood betamethasone concentrations were available for 43 neo-nates, from 35 non-obese and 8 obese mothers. These concentrations were alsosimilar in both groups, 3.4 ng/mL versus 3.8 ng/mL, p�0.82. After controlling forthe factors listed above, there was not a linear relationship between BMI and beta-methasone concentrations, p�0.52.

Supplemen

CONCLUSION: Neither increasing maternal BMI nor obesity affect serum orcord blood betamethasone concentrations.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2008.09.645

16 PREVALENCE OF COMPLICATIONS IN TWIN TWIN TRANSFUSION SYNDROMEFOLLOWING SELECTIVE FETOSCOPIC LASER PHOTOCOAGULATION:A SINGLE CENTEREXPERIENCE. MOUNIRA HABLI1, ANNETTE BOMBRYS1, DAVID LEWIS1, FOONG.YEN LIM2,WILLIAM POLZIN3, TIMOTHY CROMBLEHOLME2, 1University of Cincinnati, Cincinnati,Ohio, 2Cincinnati Children’s Hospital Medical Center, Fetal Care Center, Cincin-nati, Ohio, 3Good Samaritan Hospital, Cincinnati, Ohio

OBJECTIVE: Previously high rates (7%-28%) of complications following selec-tive fetoscopic laser photocoagulation(SFLP) were reported. The aim of this studyis to report the prevalence of early and late complications of twin twin transfusionsyndrome(TTTS) following SFLP in a single center

STUDY DESIGN: A retrospective chart review of all patients treated with SFLPfor TTTS at a single center from 9/2005-2/2008. Complications following SFLP arecategorized as early (occurred in �7 days) and late( � 7days). Pregnancy outcome,survival and complications following SFLP including recurrent TTTS (recurrenceof polyhydramnios-oligohydramnios sequence), amniotic band syndrome(ABS),chorioamniotic separation(CAS), iatrogenic monoamnionicity, and twin anemia-polycythemia syndrome(TAPS) (defined as high MCA Dopplers suggestive of ane-mia) were recorded. Data are presented as mean�SD or n(%).

RESULTS: A total of 137 TTTS cases (135 twins,2 triplets) were treated by SFLPduring the study period. Mean gestational age(GA) at procedure was 20.9�2.5weeks and at delivery was 34.5�4.6 weeks. 2/62(3%) with anterior placentation hadtransplacental trocar placement. We found a range 2 to 7% of early complicationsand 1.5-7% of late complications following SFLP(table).There were 2(1.5%) casesof monoamnionicity and 2(1.5%) recurrent TTTS treated with SFLP. There were18(13%) IUFD involving both twins. Overall survival of one or all fetuses was211/276(76.4%).

CONCLUSION: Our findings suggest a lower complication rate as compared toprior reported data. This data is important in patients counselling. It also empha-sizes the importance of close follow up and surveillance for early recognition andmanagement of such complications.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2008.09.646

t to DECEMBER 2008 American Journal of Obstetrics & Gynecology S177