596: First trimester screening markers in women with pregestational diabetes mellitus: is a correction factor needed?

Abstract

595 NIPDT registry–a critical utilization of non-invasive prenatal diagnosis test recently introduced to clinical practice Ossie Geifman-Holtzman, Janet Berman, Amen L Ness, Amy Cohen, Richard Fischer, Amanda Carre, Stuart Weiner Drexel College of Medicine, Obstetrics & Gynecology, Philadelphia, PA, Temple School of Medicine, Obstetrics & Gynecology, Philadelphia, PA, Saint Peters University Hospital, Obstetrics & Gynecology, New Brunswick, NJ, Einstein Medical Center, Genetics & Obstetrics/ Gynecology, Philadelphia, PA, Cooper University Hospital, Obstetrics & Gynecology, Camden, NJ, Thomas Jefferson University Hospital, Obstetrics & Gynecology, Philadelphia, PA OBJECTIVE: To evaluate the accuracy and utilization of noninvasive prenatal diagnosis test (NIPDT) using fetal DNA in maternal blood and to establish a multicenter registry to accomplish this aim. STUDY DESIGN: NIPDT by using fetal DNA in maternal blood to diagnose chromosomal aneuploidy is currently available and its utilization is rapidly expanding. We collected data from 6 centers and tabulated it by patient age, gestational age (GA), indication, maternal serum screen, ultrasound finding. IRB approval was obtained. We have also established the NIPDT Registry to accomplish the above goal. RESULTS: A total of 175 patients underwent testing over the past 3 months. Tests were performed at 11-13 weeks (12%), at 14-17 weeks (36%), at 18-22 (40%) weeks, and at 23-25 (12%) weeks’ gestation. The following indications were used to perform the test: Maternal age (above 35) 54% , Abnormal maternal serum screening 41%, Abnormal ultrasound finding 27% Positive family or personal history 4%. At maternal age of less than 35 about 77%, 15% and 8% were tested because of abnormal ultrasound finding, abnormal serum screen or both abnormal and others, respectively. Inconclusive results were reported to be between 3.5%-5% possible causes: testing at early GA or fetuses with hydrops. Repeat testing at a later GA yielded conclusive results except for one patient. At this time, as most tested patients are undelivered accuracy is determined based on CVS/amniocentesis results with 2% incorrect diagnosis by NIPDT, for example trisomy 18 was reported by NIPDT and was normal by FISH and Karyotype. CONCLUSION: The clinical utilization of NIPDT is rapidly expanding with significant clinical and economical implications. Larger sample size and independent evaluation of the accuracy of all results in clinical setting are clearly required and will be studied by the NIPDT Registry. Current standard of prenatal diagnosis care should continue along with critical assessment of the NIPDT results. 596 First trimester screening markers in women with pregestational diabetes mellitus: is a correction factor needed? Padmalatha Gurram, Peter Benn, Ann-Marie Prabulos, Kisti Fuller, Crawford Christine, Campbell Winston University of Connecticut, Maternal-Fetal Medicine, Farmington, CT, University of Connecticut, Clinical Genetics and developmental biology, Farmington, CT OBJECTIVE: To investigate if maternal serum pregnancy associated plasma protein-A (PAPP-A), total beta hCG and nuchal translucency (NT) measurements differ in women with pregestational diabetes (PGDM) vs. non-diabetic controls (NDC) and if so is a correction factor needed for diabetic women. STUDY DESIGN: We performed a retrospective cohort analysis of all women having a first trimester aneuploidy screen (11 to 13 6 wks) between 1/2005-12/2011 at our facility. The primary outcome was difference in PAPP-A, hCG & NT MoM (multiples of the median, corrected for maternal weight, race, gestational age [GA]) between PGDM and NDC. Women using insulin (IDDM) or oral hypoglycemics (OHG) prior to pregnancy or at the time of screening were classified as PGDM. Known aneuploidy & multifetal gestations were excluded. We also examined if any difference in PAPP-A, hCG and NT between PGDM & NDC is affected by GA or HbA1C.We compared screen positive (1:270)Down syndrome rates (DSR) between PGDM & NDC. Chi square & Mann-Whitney tests were used (significant at p 0.05). RESULTS: Of 6741 eligible patients, 103(1.5%) had IDDM & 4 (0.06%) were on OHG (excluded due to small number). Outcomes were available for 1512 patients, of which 67 (4%) developed gestational diabetes and were excluded. HbA1C was available for 43 IDDM patients. Mean maternal weight in IDDM patients was 202 lbs vs. NDC 161 lbs, (p 0.05). There was a 12% reduction of median PAPP-A & 18 % reduction of median total hCG in women with IDDM (Table). The effect of IDDM on PAPP-A & hCG did not differ with GA (p 0.05).The mean HgbA1C% was 7.3 1.5. There was no significant correlation between HbA1C and PAPP-A (Figure), hCG or NT (p 0.05). Screen positive DSR was 8.74% in IDDM vs. NDC 7.19%, (p 0.03). CONCLUSION: In women with IDDM, PAPP-A and hCG were significantly lower compared to NDC and correction factors should be considered in the aneuploidy calculation of risks for IDDM patients. This effect is not GA dependent or associated with glycemic control. Poster Session IV Academic Issues, Antepartum Fetal, Clinical Ob, Fetus, Genetics, Hypertension, Med-Surg-Diseases, Operative Ob, U/S www.AJOG.org