Polyethyleneimine (PEI), a cationic polymer vehicle, forms a complex with DNA which then can carry anionic nucleic acids into eukaryotic cells. PEI-based transfection is widely used for transient transfection of plasmid DNA. The efficiency of PEI-based transfection is affected by numerous factors, including the way the PEI/DNA complex is prepared, the ratio of PEI to DNA, the concentration of DNA, the storage conditions of PEI solutions, and more. Considering the major influencing factors, PEI-based transfection has been optimized to improve its efficiency, reproducibility, and consistency. This protocol outlines the steps for ordinary transient transfection and lentiviral production using PEI. © 2017 by John Wiley & Sons, Inc.

Background: There is no clear clinical conclusion on whether assisted reproductive technology (ART) increases maternal and child risk and affects infant birth and development. This study aimed to perform a multiple regression analysis of the perinatal maternal and infant conditions in an assisted reproductive singleton pregnancy and the physical development and complications of such infants at 6 months old.Methods: This study enrolled 145 singleton pregnant women who were admitted to Luohe Central Hospital between December 2017 and December 2019 to undergo in vitro fertilization and embryo transfer as a research group, and 160 singleton pregnant women who were naturally conceived at the same time and delivered at our hospital were selected as the control group. The relevant data of the patients were collected, and the perinatal conditions, neonatal complications, physical development and NBN score of infants aged 6 months were compared between the two groups. Multivariate logistic regression was used to analyze risk factors for perinatal complications in assisted reproduction singleton pregnancy.Results: The incidence of complications in the perinatal period in the study group was significantly higher than that in the control group (P<0.05). However, there was no significant difference in the incidence of complications such as very low birth weight, respiratory distress, neonatal hemolysis, hyperbilirubinemia, hypoglycemia, infectious pneumonia and neonatal asphyxia between the two groups (P>0.05). Likewise, at 6 months of age, the infants in the research group showed no significant difference to the control group in physical development indicators, including weight, head circumference, body mass index, height and NBN score (P>0.05). The analysis of the unconditional multivariate logistic regression model revealed hypertension during pregnancy, placental previa, premature membrane rupture, gestational age <32 weeks, and very low birth weight as risk factors that affect perinatal complications in patients with assisted reproductive singleton pregnancy (P<0.05). Conclusions:The incidence of complications in perinatal patients with assisted reproductive singleton pregnancy is higher than that of natural singleton pregnancy, but there is no significant difference in physical development, NBN score and complications of 6 months old infants.