572: The use of multiplex ligation-dependent probe amplification (MLPA) versus karyotype analysis in the investigation of pregnancy loss

Abstract

amplification (MLPA) versus karyotype analysis in the investigation of pregnancy loss Danielle O’Leary, Keelin O’Donoghue Cork University Maternity Hospital, University College Cork, Obstetrics and Gynecology, Cork, Ireland OBJECTIVE: Karyotyping is important in pregnancy loss as about 6% of stillborn babies will have a chromosomal abnormality, while in couples with recurrent miscarriage, chromosomal abnormalities of the embryo account for 30-60% of further miscarriages. Some abnormalities are potentially recurrent and can be tested for in future pregnancies. Traditionally cytogenetic investigation of pregnancy loss is performed by culture of chorionic villi and karyotype analysis on fetal material. This technique has a high failure rate (reported at 1040%), associated with misdiagnosis due to overgrowth of maternal tissue and is also labour intensive. The technique of multiplex ligation-dependent probe amplification (MLPA) reportedly has a higher success rate, ranging from 85-95%, and a quicker reporting time. We aimed to compare the success rate and time taken for reporting with MLPA and karyotype analysis and to compare the number of normal and abnormal results and indications for testing for both techniques. STUDY DESIGN: Tissue samples sent for MLPA testing between October 2011-June 2012 and for karyotype analysis in the corresponding months in 2010-2011 were recorded. Reports were examined and time taken for processing and results calculated. RESULTS: 102 tissue samples were sent for MLPA testing, compared to 60 samples for karyotype analysis. Indications included investigation of unexplained stillbirth (26/162), late miscarriage (53/162) and recurrent miscarriage (76/162). The success rate of MLPA analysis was higher at 89%, in contrast to 73% for karyotype analysis. MLPA had a quicker reporting time, on average 9.2 days compared to 16.3 days. CONCLUSION: Our findings confirm the higher success rates and quicker reporting time with MLPA analysis versus karyotype by tissue culture. The lower cost per sample is also advantageous in times of sparse resources. From these data, we recommend the continued use of MLPA analysis as the cytogenetic investigation of choice in pregnancy loss. 573 Extremely high risk of fetal death and severe perinatal complications associated with simultaneously elevated AFP and very low unconjugated estriol David Krantz, Burton Rochelson, Jon Carmichael, Terrence Hallahan, Nidhi Vohra, Stephanie Augustine PerkinElmer, NTD Labs, Melville, NY, North Shore Long Island Jewish Heath System, Maternal Fetal Medicine, Manhassett, NY OBJECTIVE: To determine the risk of severe anomalies and perinatal complications in pregnancies associated with a simultaneously elevated AFP and very low unconjugated estriol (UE3). STUDY DESIGN: A total of 6,365 second trimester ONTD/Down syndrome screening tests from a single hospital performed between March 2010 and February 2012 were analyzed. Outcomes were obtained from pregnancies with simultaneously elevated AFP ( 2 MoM) and a very low UE3 ( 1 %ile). RESULTS: There were 139 elevated AFP results (2.2%) and 72 (1.1%) very low UE3 results. After excluding 1 case of anencephaly, 9 patients had simultaneously elevated AFP and very low UE3 results. There were 3 cases of fetal loss and 2 cases of pregnancy termination due to severe fetal anomalies or severe pregnancy complications. In the remaining 4 cases, 3 pregnancies were associated with IUGR and admittance to the NICU and one pregnancy was associated with oligohydramnios and small placenta but did not require admittance to NICU. CONCLUSION: Both elevated AFP and low UE3 are known to be associated with increased risk of fetal anomalies and pregnancy complications. Based on this case series, when both of these results occur simultaneously the pregnancy is at significant risk for severe fetal anomalies, fetal death and NICU admission at birth. Even if severe anomalies are not immediately diagnosed in these patients, continued close monitoring of the pregnancy until delivery is still warranted.