Low first-trimester PAPP-A in IVF (fresh and frozen-thawed) pregnancies, likely due to a biological cause

PURPOSE

The purpose of this study is to confirm a difference in the first-trimester screen maternal biochemistry and false-positive rates (FPR) between pregnancies conceived spontaneously and those conceived via assisted reproductive technologies (ART).

METHODS

Retrospective analysis of the complete population of women (17,889 pregnancies) who had undergone first-trimester screening between January 2004 and September 2009 at three private ultrasound clinics in Queensland, Australia was used in the study. The age, gestation, method of conception, ultrasound markers, biochemistry markers (PAPP-A, fβ-hCG), and type of biochemical analyzer platform (Brahms Kryptor, Immulite 2000) data was collated. Univariate analysis of variance (ANOVA), Spearman's rank nonparametric correlation analysis, and Binary Logistic Regression analysis were used to analyze data. Spontaneous pregnancies were used as controls. Results were considered significant when the p value was less than 0.05.

RESULTS

After exclusions, 16,363 singleton pregnancies, including 1543 conceived via ART, were analyzed. Results from the two biochemistry platforms, Brahms Kryptor and Immulite 2000 were significantly different (p < 0.001); thus, the data was divided for analysis purposes. PAPP-A was universally significantly lower in IVF pregnancies compared to spontaneously conceived pregnancies (p < 0.001). Using the Brahms Kryptor platform, ICSI was associated with significantly decreased PAPP-A (p < 0.046), and a significantly increased FPR (p = 0.012).

CONCLUSIONS

Consistent with previous studies IVF pregnancies had significantly lower PAPP-A levels supporting the need to appropriately adjust the combined first-trimester screening (cFTS) risk algorithm for IVF conceptions. The Brahms Kryptor and Immulite 2000 platforms are significantly different; however, the universally lower PAPP-A findings support the hypothesis that the lower PAPP-A is due to a biological cause.

IFPA meeting 2015 workshop report II: mechanistic role of the placenta in fetal programming; biomarkers of placental function and complications of pregnancy

Workshops are an integral component of the annual International Federation of Placenta Association (IFPA) meeting, allowing for networking and focused discussion related to specialized topics on the placenta. At the 2015 IFPA meeting (Brisbane, Australia) twelve themed workshops were held, three of which are summarized in this report. These workshops focused on various aspects of placental function, particularly in cases of placenta-mediated disease. Collectively, these inter-connected workshops highlighted the role of the placenta in fetal programming, the use of various biomarkers to monitor placental function across pregnancy, and the clinical impact of novel diagnostic and surveillance modalities in instances of late onset fetal growth restriction (FGR).