Background Some of the non‐criteria autoantibodies, especially non‐conventional antiphospholipid (aPL) antibodies, were present with high prevalence in sporadic miscarriages and recurrent pregnant loss. However, whether these autoantibodies are associated with miscarriage patients without apparent causes remain unclear. Methods The subjects were recruited from the female patients visiting the Infertility Center at the Beijing Obstetrics and Gynecology Hospital from January 2017 to March 2018. The women who experienced one sporadic miscarriage (n = 89) or recurrent pregnancy loss (n = 125) were enrolled. The control participants (n = 59) were those women with normal pregnancy history and with no miscarriage or thrombosis experience. The collected serum specimens from above patients and controls were subjected to the 13 non‐criteria autoantibody examinations, targeting non‐conventional phospholipids, thyroid, sperm, endometrial, and anti‐nuclear antigens. Results When compared with the controls, the following non‐criteria antibodies stood out in present study with significantly increased frequency and were listed in the order of decreasing positive rates: aPE IgM (40.0%), ANA (15.2%), aEM IgG (13.6%), aPE IgG (12.8%), and aPT IgM (10.4%). Except for ANA, the presence of aPE IgM, aEM IgG, aPE IgG, and aPT IgM was not associated with positivity of LA tests. In receiver operating characteristic analyses, the combined aPE IgG and aEM IgG biomarker panel had the best discriminating power between miscarriage patients and healthy controls. Conclusion Our findings suggested that the non‐criteria could be included as part of the pregnancy loss evaluation when apparent causes are absent, and the conventional aPLs tests failed to provide interpretations.

Background Preeclampsia (PE) prediction has been shown to improve the maternal and fetal outcomes in pregnancy. We aimed to evaluate the PE prediction values of a series of serum biomarkers. Methods The singleton pregnant women (20–36 gestational weeks) with PE‐related clinical and/or laboratory presentations were recruited and had the blood drawn at their first visits. The following markers were tested with the collected serum samples: soluble fms‐like tyrosine kinase 1 (sFlt‐1), placental growth factor (PlGF), thrombomodulin (TM), tissue plasminogen activator inhibitor complex (tPAI‐C), complement factors C1q, B, H, glycosylated fibronectin (GlyFn), pregnancy‐associated plasma protein‐A2 (PAPP‐A2), blood urea nitrogen (BUN), creatinine (Cre), uric acid (UA), and cystatin C (Cysc). Results Of the 196 recruited subjects, 25% (n = 49) developed preeclampsia before delivery, and 75% remained preeclampsia negative (n = 147). The serum levels of sFlt‐1, BUN, Cre, UA, Cysc, and PAPP‐A2 were significantly elevated, and the PlGF level was significantly decreased in the preeclampsia‐positive patients. In the receiver operating characteristics (ROC) analyses, the area under the curves were listed in the order of decreasing values: 0.73 (UA), 0.67 (sFlt‐1/PlGF), 0.66 (Cysc), 0.65 (GlyFn/PlGF), 0.64 (PAPP‐A2/PlGF), 0.63 (BUN), 0.63 (Cre), and 0.60 (PAPP‐A2). The positive predictive values of these serum markers were between 33.1% and 58.5%, and the negative predictive values were between 80.9% and 89.5%. Conclusions The serum markers investigated in current study showed better performance in ruling out than ruling in PE. Absence of pre‐defined latency period between blood draw and the onset of PE limits the clinical utility of these markers.

Background: Preeclampsia is a common obstetric multisystem disorder causing maternal and fetal morbidity and mortality; it’s been shown that the prediction improves preeclampsia outcomes in pregnancy. However, the current serum biomarkers had low clinical application values and still lack validation studies. Here we aimed to evaluate the preeclampsia prediction values of a series of serum biomarkers in Chinese pregnant women of > 20 weeks of gestation. Methods: Singleton pregnant women with preeclampsia-related clinical and/or laboratory presentations were recruited and had blood drawn at their first visits. The prospective cohort was further divided into preeclampsia-positive and preeclampsia-negative groups based on the follow-up results. The following markers were tested using the collected serum samples: soluble fms-like tyrosine kinase-1 (sFlt-1); placental growth factor (PlGF); thrombomodulin (TM); tissue plasminogen activator inhibitor complex (tPAI-C); compliment factors C1q, B, and H; glycosylated fibronectin (GlyFn); pregnancy-associated plasma protein-A2 (PAPP-A2); blood urea nitrogen (BUN); creatinine (Cre); uric acid (UA); and cystatin C (Cysc). Results: A total of 196 women with suspected preeclampsia were recruited with follow-up medical records. Twenty-five percent (n=49) of the recruited subjects developed preeclampsia before delivery, and 75% remained preeclampsia-negative (n=147). The serum levels of sFlt-1, BUN, Cre, UA, Cysc and PAPP-A2 were significantly elevated, and the PlGF level was significantly decreased in the preeclampsia-positive patients. In the receiver operating characteristics (ROC) analyses, the area under the curves were listed in the order of decreasing values: 0.73 (UA), 0.67 (sFlt-1/PlGF), 0.66 (Cysc), 0.65 (GlyFn/PlGF), 0.64 (PAPP-A2/PlGF), 0.63 (BUN), 0.63 (Cre), and 0.60 (PAPP-A2). With the cut-off values obtained from the ROC analyses, the positive predictive values of these serum markers were between 33.1% and 58.5%, and the negative predictive values were between 80.9% and 89.5%. Conclusions: Although several serum markers were found to be significantly changed with current prospective cohort, their limited predictive values in preeclampsia development posed potential barrier in clinical implementation. Further studies with larger cohort are warranted to further reveal the clinical utilities of the serum markers in preeclampsia prediction.