Obesity and recurrent miscarriage: A systematic review and meta-analysis.

The aim of this study is to perform a systematic review and meta-analysis on the relationship between excess weight and risk of recurrent pregnancy loss (RPL) and to highlight the common immunological mechanisms of these two conditions. The PubMed and MEDLINE databases were searched for publications in English available as of November 2017. The search terms used were 'recurrent pregnancy loss', 'body mass index' (BMI), 'overweight' and 'obesity'. For calculation of the odds ratio (OR) and 95% confidence intervals (CI) for miscarriage in different BMI groups, RevMan software was used (Review Manager, Version 5.3.5 for Windows; The Cochrane Collaboration). In total, 100 publications including the search terms were identified. Six studies were included for qualitative analysis, and two studies were included for quantitative analysis (meta-analysis). The association between excess weight and RPL was significant (OR, 1.34; 95% CI, 1.05-1.70; P = 0.02). The isolated analyses of the groups of obese and overweight women revealed an association only between obesity and RPL (OR, 1.75; 95% CI, 1.24-2.47; P = 0.001). The data available in the current literature revealed that obese women with a history of RPL have a high risk of future pregnancy losses, a risk which was not found among overweight women.

Maternal and pregnancy characteristics affect plasma fibrin monomer complexes and D-dimer reference ranges for venous thromboembolism in pregnancy.

BACKGROUND: D-dimers have a high negative predictive value for excluding venous thromboembolism outside of pregnancy but the use in pregnancy remains controversial. A higher cut-off value has been proposed in pregnancy due to a continuous increase across gestation. Fibrin monomer complexes have been considered as an alternative diagnostic tool for exclusion of venous thromboembolism in pregnancy due to their different behavior. OBJECTIVE: We sought to establish normal values of fibrin monomer complexes and D-dimer as a diagnostic tool for the exclusion of venous thromboembolism in pregnancy and examine the effect of maternal and obstetric factors on these markers. STUDY DESIGN: Plasma D-dimer and fibrin monomer complexes were measured by quantitative immunoturbidimetry in 2870 women with singleton pregnancies attending their routine first-trimester hospital visit in a prospective screening study for adverse obstetric outcome. Multiple regression analysis was used to determine maternal characteristics and obstetric factors affecting the plasma concentrations and converting these into multiple of the median values after adjusting for significant maternal and obstetric characteristics. RESULTS: Plasma fibrin monomer complexes increased with maternal weight and were lower in women with a history of cocaine abuse and chronic hypertension. D-dimers increased with gestational age and maternal weight and were higher in sickle cell carriers and in women of African and South Asian racial origin compared to Caucasians. CONCLUSION: Fibrin monomer complexes and D-dimers are affected by maternal and obstetric characteristics rather than only gestational age. The utility of these fibrin-linked markers as a tool for exclusion of venous thromboembolism in pregnancy might be improved by adjusting for patient-specific characteristics.

Association of gloves change and surgical site complications in elective cesarean sections of low-risk pregnancies.

BACKGROUND: The aim of this study was to assess whether the change of gloves is associated with reduced surgical site complications of elective cesarean sections in low-risk pregnancies. METHODS: A prospective and observational study was conducted, with 169 patients selected for elective cesarean sections, and divided into two groups: group 1 (N.=100) (no change of gloves); and group 2 (N.=94) (gloves changed during surgery). Fisher's Exact Test was used to test hypotheses and existence of associations between variables. The receiver operating characteristic curve (ROC) was used to determine the best value of surgical time to identify complications in the surgical site. RESULTS: There was significant effect on surgical time (group 1: 72.6 vs. group 2: 65.1 min, P=0.006). There was no association between changing gloves and the presence of complications of the surgical site. Approximately 22.5% of patients had at least one complication up to 60 days after cesarean section, with no association between the change of gloves and the presence of comorbidities during prenatal follow-up (P>0.999). Surgical time >70 min was able to correctly identify 59.1% of cases of surgical site complications up to 60 days after cesarean section with a false positive rate of 34% (area under ROC curve: 0.627, P=0.0126, 95% CI: 0.554-0.695). CONCLUSIONS: In low-risk patients submitted to elective cesarean sections, change of gloves did not reduce the incidence of complications of the surgical site. Surgical time was an independent predictor for the presence of complications of the surgical site up to 60 days after cesarean section.

Effect of grade 3 placenta <36 weeks of pregnancy on perinatal outcomes.

BACKGROUND: The aim of this study was to assess whether the presence of grade 3 placenta <36 weeks of pregnancy is associated with adverse perinatal outcomes. METHODS: Retrospective cohort study in which patients were separated into the following three groups: 1) grade 3 placenta <36 weeks, 2) grade 3 placenta >36 weeks, 3) no occurrence of grade 3 placenta throughout pregnancy. The χ2 and general linear model tests were used to compare adverse perinatal outcomes. Binary logistic regression model was used to estimate the odds ratio (OR) for adverse perinatal outcomes. Receiver operating characteristic (ROC) curve was used to determine the cut-off of the middle cerebral artery Pulsatility Index (MCA PI) in the detection of births <37 weeks in grade 3 placentas <36 weeks. RESULTS: Significant association was observed between grade 3 placenta <36 weeks and birth <37 weeks (P<0.001), birth weight <10th percentile (P=0.001), 5-min Apgar Score <7 (P=0.014), admission to neonatal intensive care unit (P<0.001), and fetal death (P=0.002). Grade 3 placenta <36 weeks was significant predictor for birth <37 weeks (OR: 2.6; 95% CI: 1.74-3.92), pre-eclampsia (OR: 1.8; 95% CI: 1.02-3.27), birth weight <10th percentile (OR: 2.1; 95% CI: 1.39-3.10), fetal death (OR: 5.6; 95% CI: 1.65-18.78), and composite perinatal outcomes (OR: 2.2; 95% CI: 1.51-3.17). The MCA PI showed an area under ROC curve of 0.641 (95% CI: 0.546-0.728) in the detection of births <37 weeks. CONCLUSIONS: Grade 3 placenta <36 weeks was associated with a higher prevalence of adverse perinatal outcomes.

Physiopathology of late-onset fetal growth restriction.

Fetal growth restriction (FGR) is defined as the inability of the fetus to reach its potential for genetic determination. FGR can have several causes, including genetic syndromes, chromosomal diseases, and infections; however, a vast majority of cases are probably attributed to impaired uterine and placental circulation. The relationships between abnormal placental development and FGR are complex, and studies are generally few, presenting confounding factors. Damage to the uteroplacental circulation associated with vasculogenesis and villus angiogenesis dysfunction are the main factors involved in subsequent FGR. The main receptors involved in FGR include hypoxia-inducible factor (HIF 1, 2, and 3), vascular endothelial growth factor (VEGF), placental growth factor (PlGF), vascular endothelial growth factor C (VEGF-C), soluble Flt-1, soluble endoglin (Seng), angiopoietin-1 and -2 (Ang-1 and Ang-2), tyrosine kinase receptor 1 (Flt-1), tyrosine kinase receptor 2 (Flt-2), vascular endothelial growth factor receptor (VEGFR) 1, 2 and 3, kinase domain receptor (KDR), and vascular endothelial growth factor receptor A (VEGFR-A). Furthermore, failure in trophoblastic invasion and remodeling of spiral arteries has been associated with FGR owing to poor placental perfusion. There are several possible causes for poor remodeling of spiral arteries, which probably vary on a case-to-case basis. Changes in the placental form, macroscopic and microscopic vascular lesions, inflammation, and genetic changes are also related to FGR. Based on gestational age at diagnosis, FGR can be classified as early- (˂32 weeks) and late-onset (≥32 weeks). Moreover, there exist several theories regarding possible pathophysiological differences between early- and late-onset FGR, with some postulating that it the same disease but at different stages or severity. Another hypothesis suggests that the change in the trophoblastic invasion of spiral arteries would be milder. In this article, we address the main mechanisms described in the pathophysiology of FGR and, later, the specific findings in late-onset FGR.