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SMFM Abstracts

COST ANALYSIS OF DOWN SYNDROME SCREENING BY MATERNAL AGE WITH O R W I T H O U T THE TRIPLE SCREEN GARRY TURNER l, ADAM BORGIDA 1, MICHAEL BARSOOM 1, MICHAEL DEROCHE 1, PETER BENN 2, JAMES EGAN3; qJniversi ty of Connect icut , Obstetrics and Gyne- cology, Farmington, CT; :~University of Connecticut, Pediatrics, Farmington, CT: 3St. Francis Hospital and Medical Center, Obstetrics a n d Gynecology, Hartfbrd, CT

OBJECTIVE: To assess the cost effectiveness of antenatal screening for Down syndrome (DS) using maternal age cut-offs f rom 15 to 49 with or without the triple screen (TS).

STUDY DESIGN: Using Final Natality Statistics, the n u m b e r livebirths (LB) for 1999 were stratified by maternal age from 15 to 49 years old. Age- specific maternal LB were multiplied by the age-specific DS risk to estimate the number of DS LB assuming no antenatal intervention. Cost assmnptions were: TS-$120; ultrasound-S300; amniocentesis (anmio) with karyotype-$1,200: p r egnancy termination-S2,000: a n d excess litetime cost of a DS newborn- $500,000. We assumed that the procedure-related loss for amnio was 1:200 and that 100% of risk positive women chose anmio. Efficacy was based on: DS cases detected, p rocedure related losses, cost /DS case detected and total cost of screening. Total cost included: screening and termination costs (86% chose terminat ion) and litetime costs of LB DS cases. Two cost analyses were performed: 1 ) age cut-offs f rom age 15 to 49 (AGE); 2 ) age cut-offs from age 15- 49 with TS for all women younger than the age cut-off (AGE&TS).

RESULTS: Cost per DS case detected by AGE was lowest at $555,044 at age 29. Using AGE&TS the cost was lowest at $284,555 at age 49 (Figure). The ratio of DS cases detected to procedure related losses crossed 1 at age 30 for AGE and 32 for AGE&TS.

CONCLUSION: The more cost effective antenatal DS screening protocol was the AGE&TS at all ages up to 49. Figure Cost per DS case detected

" ~ $ 1 , 5 O O , O O O ........................................................................... -~ ............................

"o~: $1/000;000

. . . . . . . q , . . . . . -

Materna l A g e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . . . . . . . . . . . . . i . . . . . . . . . . . . . . . . . . . .

I ~ Materna l A g e cut -o f f ~ Materna l age and Triple...s_green...i

December 2001 A m J Obstet Gynecol

510 C H O R I O N I C VILLUS SAMPLING PRECEDING MULTIFETAL PREG- NANCY REDUCTION: DOES INTERVAL BETWEEN PROCEDURES ALTER OUTCOME? THOMAS JENKINS l, RICHARD GREENE 2, GEORGE DAVIS 3, MARK EVANS 4, RONALD WAPNERS; 1Thomas Jefferson University, Maternal-Fetal Medicine, Phi ladelphia , PA; 2Thomas Jefferson University, Maternal Fetal Medicine, Philadelphia, PA; 3Vanderbilt University, Maternal- Fetal Medicine, Nashville, TN: 4MCP H a h n e m a n n University, Obste t r ics / Gynecology, Philadelphia, PA; 5MCP H a h n e m a n n University, Obstetrics and Gynecology, Philadelphia, FA

OBJECTIVE: Chorionic villus sampling (CVS) pr ior to multifetal preg- nancy reduct ion (MFPR) has been shown to be safe, eificacious, and offers the oppor tuni ty to knowingly preserve only euploid fetuses. The effect of the interval between CVS and MFPR has not been previously studied.

STUDY DESIGN: We reviewed our MFPR database between 1 /89 and 1/2000. During that time period, patients were offered MFPR "after CVS based upon results of the direct p repara t ion (<9days), or waiting until the final culture was available (>9 days). The interval between procedures and fetal loss was assessed. A power analysis estiumtes that 1298 patients per arm would be required to test for a 50% difference in fetal loss.

RESULTS: CVS was per formed on 363 of 1163 MFPR patients dur ing the interval. Outcome data were available for 317 patients (87%). Seventy-three patients (23%) had MFPR within 48 hours, and 233 (73.5%) within 9 days of CVS. Groups did not differ with respect to maternal age, starting or ending fetal number, or nmnber of tetuses sampled. Total loss rates within 8 weeks of MFPR, or <24 weeks gestat ion were 17 /317 (5.4%), and 22 /317 (6.9%), respectively. Loss rates within 4 and 8 weeks of MFPR, and <24 weeks gestation are presented below. A subanalysis of cases between 1996-2000 was per formed to minimize any potential changes in technique (n = 175). Results did not diffel:

CONCLUSION: Loss rates following MFPR per formed within 9 days of CVS are higher but not statistically different than those per to rmed after final CVS results are available. Further study of this relationship is required.

Table Pregnancy losses versus interval o f C'VS to MFPR, n (%)

_<48 >48 -<9 >9 HOURS HOURS O.R. DAYS DAYS O.R.

loss_<4wks 3 (4.1) 5 (2.0) 2.0 (0.5, 8.9) 7 (3.0) 1 (1.2) 2.5 (0.3, 21.2) from MFPR

loss_<8wks 7 (9.6) 1O (4.1) 2.5 (0.9, 6.8) 15 (6.4) 2 (2.4) 2.8 (0.6, 12.6) from MFPR

loss<24wks 7 (9.6) 15 (6.1) 1.6 (0.6.4.1) 18 (7.7) 4 (4.8) 1.7 (0.6, 5.1) gest.

509 ELEVATED FIRST TRIMESTER MATERNAL SERUM FREE BETA-HCG IS N O T ASSOCIATED WITH ADVERSE PREGNANCY O U T C O M E YIFAT O C H S H O R N 1, SIGAL HEIFETZ 2, OFER LEHAVI 1, MICHAEL KUPFER- MINC 3, ARIEL MAN~, YUVAL YARON1; 1Sourasky Medical Center, Prenatal Diagnosis Unit, Genetic Institute, Tel Aviv: "-'Sheba Medical Centei; Ob/Gyn , Ramat Gan; 3Tel Aviv University, Obstetrics and Gynecology, Tel Aviv

OBJECTIVE: Elevated second tr imester inaternal serum [~-human chor ionic gonado t rop in (I%hCG) is associated with adverse p r egnancy outcomes such as gestational hypertension and fetal growth restriction (FGR). The purpose of this study was to evaluate whether first t r imester maternal sermn free I~hCG is also associated with such adverse outcomes.

STUDY DESIGN: The study included 1686 patients with singleton preg- nancies who underwent first trimester screening using nuchal translucency, free ~ h C G and PAPP-A. The incidences of various pregnancy outcomes were evaluated according maternal serum free ~-hCG levels. A fi'ee ~-hCG cut-off value of 3.0 MoM was used.

RESULTS: 33 aneuploid fetuses were detected. 156 patients had elevated free ~hCG, however no significant increase was fbund in these patients for any of the outcomes evaluated (Table). No other statistically significant cut-off value tbr free I3-hCG was detected.

CONCLUSION: We conclude that unlike second trimester [3-hCG, first trimester free [~-hCG is not a predictor of adverse pregnancy outcomes.

Table

FREE ~-HCG FREE ~-HCG _<3 MUM >3 MUM

(N = 1530) (N = 156)

Aneuploidy 2.0% 1.9% Preterm labor 5.2% 5.8% FGR 3.8% 5. l% Gest. hypertension 3.0% 3.2% Placental abrupt ion 0.1% 0% Oligohydramnios 0.6% 0.6% Miscarriage 1.4% 0.6% IUFD 0.1% 0% Total (excluding aneuploidy) 14.1% 15.4%

511 NORMAL RANGE OF CREATINE KINA,~iE BRAIN ISOENZYME (BB-CK) ACTIVITY IN PLASMA OF FETUSES DURING THE SECOND TRIMESTER EMMANUEL BUJOLD ~, ANTHONY JOHNSON 1, PATRICIA DEVERS l, JAN- ICE GOLDMAN 2, EVIE RUSSELL 1, STANLEY M. BERRy1; 1Wayne State University, Obstet r ics /Gynecology, Detroit, MI; 2Wayne State University, Pathology, Detroit, MI

OBJECTIVE: The detect ion of elevated % BB-CK in cord b lood f rom severely affected neonates lead to the suggestion that prenatal diagnosis of malignant osteopetrosis may be possible by fetal blood sampling (FB8) (J Bone Miner Res 1996;11:1438-1443). Therefore, we sought to establish a normal range of % BB-CK in the h u m a n fetus between 19 and 22 weeks.

STUDY DESIGN: Afiquots of frozen banked fetal plasma t rom indicated cordocenteses done between 19 and 22 weeks f rom 1993 and 2001 were analyzed. Total CK activity and % BB-CK were determined by electrophoretic separation of isoenzymes of creatine kinase on plasma. Comparison of % BB- CK between each week of gestation was per formed using Kruskal-Wallis test.

RESULTS: We found that % BB-CK activity was comparable between each week of gestatioual age, P= .656 (see Table).

CONCLUSION: We have established that the % BB-CK is cons tant between 19 and 22 weeks. These findings may now provide a means for the prenatal diagnosis of malignant osteopetrosis.

Table Level of total CK activity and % BB-CK in the cord blood at 19-22 wk

T O T A L CK (IU/L) % BB-CK

GEST. AGE MEDIAN MEDIAN (WEEKS) N (Q1-Q3) (Q1-Q3)

19 14 89.5 (58.5-131) 5.6 (4.2-9.1) 20 27 72.0 (52,0-96.5) 6.4 (5.2-9.8) 21 15 64.0 (43,5-81.5) 6.5 (5.3-9.4) 22 8 82.0 (60.8-105) 5.3 (4.7-8.0) Total 64 70.5 (50.0-99.8) 6.2 (4.7-9.0)