P-418

The role of preparatory cycles in ovum recipients: A retrospectivestudy. S. H. Jun, C. Racowsky, J. H. Fox, M. D. Hornstein. Brigham andWomen’s Hosp, Boston, MA.

Objective: Preparatory cycles for egg donation recipients are often per-formed to demonstrate endometrial adequacy of the recipient before under-going the actual egg donation cycle. This study was undertaken to see ifpreparatory cycles affected in vitro fertilization (IVF) outcome in ovumdonation recipients.

Design: A retrospective study examining 94 consecutive ovum donationrecipients undergoing their first egg donation cycle at Brigham and Wom-en’s Hospital between January 1998 and September 2000.

Materials/Methods: Out of 94 ovum recipients included in this study, 52of them underwent preparatory cycles. These cycles were carried out withLupron, estrogen and progesterone. Endometrial biopsies were performedon days 10–12 of progesterone supplementation and endometrial dating ofat least 23 days was considered adequate. In some of the patients undergoingpreparatory cycles, the endometrial stripe was measured by transvaginalultrasound on days 18–21 of estrogen therapy. The main outcome measurewas an ongoing pregnancy of at least 12 weeks gestation or a live birth.

Results: Pregnancy rates in women with and without preparatory cycleswere 40.4% (21/52) and 47.6% (20/42), respectively. Among ovum recip-ients who underwent preparatory cycles, the percentages of adequate endo-metrial biopsies in pregnant versus nonpregnant groups were 76.2% (16/21)and 83.3% (25/30), respectively. In patients with endometrial stripes$7mm by transvaginal ultrasound, 88.9% (24/27) of the biopsies were con-sidered adequate. And in those,7 mm, 72.7% (8/11) were consideredadequate. All results showed no statistical significance.

Conclusions: The practice of performing preparatory cycles in egg do-nation recipients is used on the assumption that confirmation of endometrialadequacy may result in improved pregnancy rates. This study failed todemonstrate improved pregnancy rates in women undergoing preparatorycycles for egg donation. In addition, our results showed that there was nocorrelation between adequate endometrial biopsies and higher pregnancyrates as well as no significant association between histologic findings andendometrial thickness in women who underwent both biopsy and ultra-sound. More studies in the future will be necessary to further support ourfindings.

P-419

Cytogenetic study of couples and their children born after intracyto-plasmic sperm injection (ICSI). L. Martelli, A. C. Nassr, V. M. Motta,R. L. Baruffi, L. A. Laureano, J. G. Franco. Ctr for Human ReproductionSinhaJunqueira Maternity Fdn, Ribeirao Preto, Brazil.

Objective: Cytogenetic study is an important tool in the investigation offertility and chromosomal abnormalities are considered to be major con-tributors to the genetic risks of the ICSI procedure. The rate of abnormalkaryotypes in infertile couples and in pregnancies conceived through ICSIis presumably increased, with the incidence ranging from 0.5 to 7.3%,depending on the sample and especially on the methodology used bydifferent groups. The aim of the present study was to determine the inci-dence of chromosomal abnormalities in couples and their children born afterICSI using a protocol of cytogenetic investigation.

Design: A cytogenetic investigation in couples and their children bornafter ICSI procedure.

Materials/Methods: The sample consisted of 45 couples undergoing ICSI(Group I) and 70 children (36 boys and 34 girls) born to them after thisprocedure (Group II). The mean age of the women was 34 years (range27–46 yr) and the mean age of the men was 41 years (range 27–61).Chromosomal analysis was performed on cultures of peripheral bloodlymphocytes by standard methods including GTG, CBG and high resolutionbandings. The protocol included the analysis of 100 metaphases per case formosaicism exclusion. The F.I.S.H. technique was used when necessary.

Results: In Group I, two men and two women (4/905 4.4%) presenteda major chromosome aberration. One case showed a 46,X,del (Yq) karyo-type and three cases presented gonosomal mosaicisms: one patient with47,XYY/46,XY and two patients with 45,X/47,XXX/46,XX. In Group II,three children (3/705 4.2%) showed abnormal karyotypes: one 45,X, onemosaic 47,XY,1mar/46,XY and one structural aberration, 46, X, del (Yq),

transmitted by the father. Structural variants (15ps1) or polymorphismsinvolving the centromeric heterochromatin of chromosomes 1, 9 and Y weredetected in 9 cases (10%) of Group I and in 9 cases (12.8%) of Group II.

Conclusions: The results obtained after cytogenetic investigation of cou-ples submitted to ICSI agree with those reported in the literature, demon-strating that the most frequent chromosome-related causes of infertility aresex chromosome abnormalities. The percentage of de novo chromosomalaberrations in the children of the present series was 2.85%; however,additional studies are needed to state that there is a higher prevalence ofgonosomal aberrations after treatment with ICSI. The protocol used toexclude mosaicism in the two Groups rules out the hypothesis that the causeof the increased frequency of sex chromosome aneuploidy is due to parentalmosaicism.

P-420

Frequency of monozygotic twinning associated with in vitro fertiliza-tion and embryo transfer (IVF-ET). W. L. Gentry, M. A. Henry, E. S.Critser. Advanced Fertility Group, Indianapolis, IN; Reproductive Care ofIndiana, Indianapolis, IN; Clarian Health Partners, Indianapolis, IN.

Objective: To assess the frequency of monozygotic twinning after IVF-ET.

Design: A retrospective review of all in vitro fertilization proceduresresulting in an embryo transfer procedure from January 1, 1997 throughDecember 31, 2000.

Materials/Methods: One thousand and sixty five IVF-ET records werereviewed. Each record was classified as to day of transfer (day 3 vs. day5/6). Ultrasound data confirming an intrauterine gestational sac was used todetermine intrauterine pregnancy (IUP). Number of documented beatinghearts was compared to number of gestational sacs to indicate the presenceof a monozygotic twin. Data were analyzed by Fisher’s Exact Test.

Results: Six hundred and six transfers were performed on day 3, resultingin 213 (36%) IUPs. Four hundred and fifty nine transfers were performed onday 5/6, resulting in 236 (51%) IUPs. There was only one documentedmonozygotic twin amongst pregnancies established with day 3 transfer ascompared to 16 monozygotic pregnancies resulting from day 5/6 transfer(p , .01). One of the 16 monozygotic pregnancies involved a monozygotictriplet. Day 5/6 transfers which included at least one top quality blastocysthad a higher (p, .01) pregnancy rate (112/168; 66%) as compared to day5/6 transfers with no top quality blastocysts (102/206; 49.5%). Monozygotictwin rates tended (p, .06) to be lower when the transfer included a topquality blastocyst (4/112; 3.5%) as compared to transfers with no top qualityblastocysts (11/202; 10.7%). Day 5/6 transfers with no blastocysts had alower pregnancy rate (22/85; 26% IUP) with one (1/22;4.5%) monozygoticpregnancy.

IVF-ET IUPMonozygotic

twinning

Day 3 696 213 (36%) 1 (0.5%)Day 5/6 459 236 (51%) 16 (6.7%)

Conclusions: These data suggest that current practice involving day 5/6embryo transfer may have a greater risk for monozygotic pregnancies. Eachprogram should rigorously evaluate their own data in order to best counselpatients for risks associated with multiple pregnancy.

P-421

Luteal phase estradiol (E2) and progesterone (P) profiles differ betweenconception and non-conceptionin-vitro fertilization-embryo transfer(IVF-ET) cycles utilizing pituitary down-regulation. S. Ben-Ozer, S.Eisenkop, M. Vermesh. The Ctr for Fertility and Gynecology, Tarzana, CA;Women’s Cancer Ctr, Tarzana, CA.

Objective: 1) To characterize the relationship between luteal E2 and Pdynamics and cycle outcome and 2) to identify a luteal E2 level or E2:Pratio predictive of pregnancy in IVF-ET utilizing pituitary down-regulation.

Design: A prospective clinical study of patients undergoing IVF at ourinstitution between 8/00–11/00. 74 patients satisfied the inclusion criteria[age #43 years, weight within 20% of ideal, fresh IVF-ET with own

S252 Abstracts Vol. 76, No. 3, Suppl. 1, September 2001