Objective:To investigate the pregnancy outcome and the maternal and infant follow-up in the puer-peral period(42 days after delivery)of cesarean section with SARS-CoV-2 Omicron variant in different periods of pregnancy.Methods:330 pregnant women who were diagnosed with SARS-CoV-2 infection and delivered by ce-sarean section in Guangdong Women and Children Hospital from November 20,2022 to January 25,2023 were selected as the research subjects.They were divided into the early(80 cases),middle(151 cases)and late(99 cases)pregnancy group according to the gestational age of infection.The general information,pregnancy compli-cations and comorbidities,pregnancy outcomes,and postpartum maternal and infant follow-up of each group of pregnant women were compared.Results:The clinical classification of pregnant women was asymptomatic and mild,with 9 cases of asymptomatic and 321 cases of mild.The incidence of gestational diabetes mellitus(GDM)in the early and late group was higher than that in the middle group(P＜0.05).There was no statistically significant difference in the incidence of placental abruption,fetal growth restriction,fetal distress,amniotic fluid contamina-tion,preterm labor,postpartum hemorrhage,macrosomia,low-birth-weight infants and the maternal intensive care unit(MICU)transfer rate,newborn birth weight,neonatal asphyxia rate and NICU transfer rate among the three groups(P＞0.05).The incidence of preterm rupture of membranes in the middle group was higher than that in the late group(P＜0.05).Puerperal follow-up results showed that there was no statistically significant difference in the incidence of poor maternal uterine incision healing,poor uterine involution,vaginal microecological imbal-ance and neonatal acute upper respiratory tract infection,pneumonia,digestive system disease,cardiovascular system disease among the three groups(P＞0.05).Conclusions:The majority of pregnant women with Omicron infection during pregnancy are mild.Omicron infection in different periods of pregnancy has no significant effect on pregnancy outcome and puerperal follow-up of cesarean section.No evidence was found that GDM and prema-ture rupture of membranes are significantly associated with Omicron infection in different periods of pregnancy.

Objective:To investigate the pregnancy outcome and the maternal and infant follow-up in the puer-peral period(42 days after delivery)of cesarean section with SARS-CoV-2 Omicron variant in different periods of pregnancy.Methods:330 pregnant women who were diagnosed with SARS-CoV-2 infection and delivered by ce-sarean section in Guangdong Women and Children Hospital from November 20,2022 to January 25,2023 were selected as the research subjects.They were divided into the early(80 cases),middle(151 cases)and late(99 cases)pregnancy group according to the gestational age of infection.The general information,pregnancy compli-cations and comorbidities,pregnancy outcomes,and postpartum maternal and infant follow-up of each group of pregnant women were compared.Results:The clinical classification of pregnant women was asymptomatic and mild,with 9 cases of asymptomatic and 321 cases of mild.The incidence of gestational diabetes mellitus(GDM)in the early and late group was higher than that in the middle group(P＜0.05).There was no statistically significant difference in the incidence of placental abruption,fetal growth restriction,fetal distress,amniotic fluid contamina-tion,preterm labor,postpartum hemorrhage,macrosomia,low-birth-weight infants and the maternal intensive care unit(MICU)transfer rate,newborn birth weight,neonatal asphyxia rate and NICU transfer rate among the three groups(P＞0.05).The incidence of preterm rupture of membranes in the middle group was higher than that in the late group(P＜0.05).Puerperal follow-up results showed that there was no statistically significant difference in the incidence of poor maternal uterine incision healing,poor uterine involution,vaginal microecological imbal-ance and neonatal acute upper respiratory tract infection,pneumonia,digestive system disease,cardiovascular system disease among the three groups(P＞0.05).Conclusions:The majority of pregnant women with Omicron infection during pregnancy are mild.Omicron infection in different periods of pregnancy has no significant effect on pregnancy outcome and puerperal follow-up of cesarean section.No evidence was found that GDM and prema-ture rupture of membranes are significantly associated with Omicron infection in different periods of pregnancy.

Objective:To investigate the pregnancy outcome and the maternal and infant follow-up in the puer-peral period(42 days after delivery)of cesarean section with SARS-CoV-2 Omicron variant in different periods of pregnancy.Methods:330 pregnant women who were diagnosed with SARS-CoV-2 infection and delivered by ce-sarean section in Guangdong Women and Children Hospital from November 20,2022 to January 25,2023 were selected as the research subjects.They were divided into the early(80 cases),middle(151 cases)and late(99 cases)pregnancy group according to the gestational age of infection.The general information,pregnancy compli-cations and comorbidities,pregnancy outcomes,and postpartum maternal and infant follow-up of each group of pregnant women were compared.Results:The clinical classification of pregnant women was asymptomatic and mild,with 9 cases of asymptomatic and 321 cases of mild.The incidence of gestational diabetes mellitus(GDM)in the early and late group was higher than that in the middle group(P＜0.05).There was no statistically significant difference in the incidence of placental abruption,fetal growth restriction,fetal distress,amniotic fluid contamina-tion,preterm labor,postpartum hemorrhage,macrosomia,low-birth-weight infants and the maternal intensive care unit(MICU)transfer rate,newborn birth weight,neonatal asphyxia rate and NICU transfer rate among the three groups(P＞0.05).The incidence of preterm rupture of membranes in the middle group was higher than that in the late group(P＜0.05).Puerperal follow-up results showed that there was no statistically significant difference in the incidence of poor maternal uterine incision healing,poor uterine involution,vaginal microecological imbal-ance and neonatal acute upper respiratory tract infection,pneumonia,digestive system disease,cardiovascular system disease among the three groups(P＞0.05).Conclusions:The majority of pregnant women with Omicron infection during pregnancy are mild.Omicron infection in different periods of pregnancy has no significant effect on pregnancy outcome and puerperal follow-up of cesarean section.No evidence was found that GDM and prema-ture rupture of membranes are significantly associated with Omicron infection in different periods of pregnancy.

Objective:To investigate the pregnancy outcome and the maternal and infant follow-up in the puer-peral period(42 days after delivery)of cesarean section with SARS-CoV-2 Omicron variant in different periods of pregnancy.Methods:330 pregnant women who were diagnosed with SARS-CoV-2 infection and delivered by ce-sarean section in Guangdong Women and Children Hospital from November 20,2022 to January 25,2023 were selected as the research subjects.They were divided into the early(80 cases),middle(151 cases)and late(99 cases)pregnancy group according to the gestational age of infection.The general information,pregnancy compli-cations and comorbidities,pregnancy outcomes,and postpartum maternal and infant follow-up of each group of pregnant women were compared.Results:The clinical classification of pregnant women was asymptomatic and mild,with 9 cases of asymptomatic and 321 cases of mild.The incidence of gestational diabetes mellitus(GDM)in the early and late group was higher than that in the middle group(P＜0.05).There was no statistically significant difference in the incidence of placental abruption,fetal growth restriction,fetal distress,amniotic fluid contamina-tion,preterm labor,postpartum hemorrhage,macrosomia,low-birth-weight infants and the maternal intensive care unit(MICU)transfer rate,newborn birth weight,neonatal asphyxia rate and NICU transfer rate among the three groups(P＞0.05).The incidence of preterm rupture of membranes in the middle group was higher than that in the late group(P＜0.05).Puerperal follow-up results showed that there was no statistically significant difference in the incidence of poor maternal uterine incision healing,poor uterine involution,vaginal microecological imbal-ance and neonatal acute upper respiratory tract infection,pneumonia,digestive system disease,cardiovascular system disease among the three groups(P＞0.05).Conclusions:The majority of pregnant women with Omicron infection during pregnancy are mild.Omicron infection in different periods of pregnancy has no significant effect on pregnancy outcome and puerperal follow-up of cesarean section.No evidence was found that GDM and prema-ture rupture of membranes are significantly associated with Omicron infection in different periods of pregnancy.

Objective:To investigate the pregnancy outcome and the maternal and infant follow-up in the puer-peral period(42 days after delivery)of cesarean section with SARS-CoV-2 Omicron variant in different periods of pregnancy.Methods:330 pregnant women who were diagnosed with SARS-CoV-2 infection and delivered by ce-sarean section in Guangdong Women and Children Hospital from November 20,2022 to January 25,2023 were selected as the research subjects.They were divided into the early(80 cases),middle(151 cases)and late(99 cases)pregnancy group according to the gestational age of infection.The general information,pregnancy compli-cations and comorbidities,pregnancy outcomes,and postpartum maternal and infant follow-up of each group of pregnant women were compared.Results:The clinical classification of pregnant women was asymptomatic and mild,with 9 cases of asymptomatic and 321 cases of mild.The incidence of gestational diabetes mellitus(GDM)in the early and late group was higher than that in the middle group(P＜0.05).There was no statistically significant difference in the incidence of placental abruption,fetal growth restriction,fetal distress,amniotic fluid contamina-tion,preterm labor,postpartum hemorrhage,macrosomia,low-birth-weight infants and the maternal intensive care unit(MICU)transfer rate,newborn birth weight,neonatal asphyxia rate and NICU transfer rate among the three groups(P＞0.05).The incidence of preterm rupture of membranes in the middle group was higher than that in the late group(P＜0.05).Puerperal follow-up results showed that there was no statistically significant difference in the incidence of poor maternal uterine incision healing,poor uterine involution,vaginal microecological imbal-ance and neonatal acute upper respiratory tract infection,pneumonia,digestive system disease,cardiovascular system disease among the three groups(P＞0.05).Conclusions:The majority of pregnant women with Omicron infection during pregnancy are mild.Omicron infection in different periods of pregnancy has no significant effect on pregnancy outcome and puerperal follow-up of cesarean section.No evidence was found that GDM and prema-ture rupture of membranes are significantly associated with Omicron infection in different periods of pregnancy.

Objective:To investigate the pregnancy outcome and the maternal and infant follow-up in the puer-peral period(42 days after delivery)of cesarean section with SARS-CoV-2 Omicron variant in different periods of pregnancy.Methods:330 pregnant women who were diagnosed with SARS-CoV-2 infection and delivered by ce-sarean section in Guangdong Women and Children Hospital from November 20,2022 to January 25,2023 were selected as the research subjects.They were divided into the early(80 cases),middle(151 cases)and late(99 cases)pregnancy group according to the gestational age of infection.The general information,pregnancy compli-cations and comorbidities,pregnancy outcomes,and postpartum maternal and infant follow-up of each group of pregnant women were compared.Results:The clinical classification of pregnant women was asymptomatic and mild,with 9 cases of asymptomatic and 321 cases of mild.The incidence of gestational diabetes mellitus(GDM)in the early and late group was higher than that in the middle group(P＜0.05).There was no statistically significant difference in the incidence of placental abruption,fetal growth restriction,fetal distress,amniotic fluid contamina-tion,preterm labor,postpartum hemorrhage,macrosomia,low-birth-weight infants and the maternal intensive care unit(MICU)transfer rate,newborn birth weight,neonatal asphyxia rate and NICU transfer rate among the three groups(P＞0.05).The incidence of preterm rupture of membranes in the middle group was higher than that in the late group(P＜0.05).Puerperal follow-up results showed that there was no statistically significant difference in the incidence of poor maternal uterine incision healing,poor uterine involution,vaginal microecological imbal-ance and neonatal acute upper respiratory tract infection,pneumonia,digestive system disease,cardiovascular system disease among the three groups(P＞0.05).Conclusions:The majority of pregnant women with Omicron infection during pregnancy are mild.Omicron infection in different periods of pregnancy has no significant effect on pregnancy outcome and puerperal follow-up of cesarean section.No evidence was found that GDM and prema-ture rupture of membranes are significantly associated with Omicron infection in different periods of pregnancy.

Objective:To investigate the pregnancy outcome and the maternal and infant follow-up in the puer-peral period(42 days after delivery)of cesarean section with SARS-CoV-2 Omicron variant in different periods of pregnancy.Methods:330 pregnant women who were diagnosed with SARS-CoV-2 infection and delivered by ce-sarean section in Guangdong Women and Children Hospital from November 20,2022 to January 25,2023 were selected as the research subjects.They were divided into the early(80 cases),middle(151 cases)and late(99 cases)pregnancy group according to the gestational age of infection.The general information,pregnancy compli-cations and comorbidities,pregnancy outcomes,and postpartum maternal and infant follow-up of each group of pregnant women were compared.Results:The clinical classification of pregnant women was asymptomatic and mild,with 9 cases of asymptomatic and 321 cases of mild.The incidence of gestational diabetes mellitus(GDM)in the early and late group was higher than that in the middle group(P＜0.05).There was no statistically significant difference in the incidence of placental abruption,fetal growth restriction,fetal distress,amniotic fluid contamina-tion,preterm labor,postpartum hemorrhage,macrosomia,low-birth-weight infants and the maternal intensive care unit(MICU)transfer rate,newborn birth weight,neonatal asphyxia rate and NICU transfer rate among the three groups(P＞0.05).The incidence of preterm rupture of membranes in the middle group was higher than that in the late group(P＜0.05).Puerperal follow-up results showed that there was no statistically significant difference in the incidence of poor maternal uterine incision healing,poor uterine involution,vaginal microecological imbal-ance and neonatal acute upper respiratory tract infection,pneumonia,digestive system disease,cardiovascular system disease among the three groups(P＞0.05).Conclusions:The majority of pregnant women with Omicron infection during pregnancy are mild.Omicron infection in different periods of pregnancy has no significant effect on pregnancy outcome and puerperal follow-up of cesarean section.No evidence was found that GDM and prema-ture rupture of membranes are significantly associated with Omicron infection in different periods of pregnancy.

Objective:To investigate the impact of abnormal patterns of 75 g oral glucose tolerance test (OGTT) in the second trimester on the risk of large for gestational age (LGA) newborn deliveries.Methods:General clinical data and OGTT results of 66 290 pregnant women who received regular prenatal care and delivered in Guangdong Maternal and Child Health Hospital from December 24, 2016 to July 26, 2022 were collected. According to the results of OGTT, the pregnant women were divided into 8 groups: normal blood glucose group (normal fasting blood glucose, 1-hour and 2-hour after oral glucose, 54 518 cases), gestational diabetes mellitus (GDM) 0 group (only abnormal fasting blood glucose, 1 430 cases), GDM 1 group (only abnormal blood glucose at 1-hour after oral glucose, 2 150 cases), GDM 2 group (only abnormal blood glucose at 2-hour after oral glucose, 3 736 cases), GDM 0+1 group (both fasting blood glucose and 1-hour after oral glucose were abnormal, 371 cases), GDM 0+2 group (both fasting blood glucose and 2-hour after oral glucose were abnormal, 280 cases), GDM 1+2 group (abnormal blood glucose at 1-hour and 2-hour after oral glucose, 2 981 cases) and GDM 0+1+2 group (abnormal fasting blood glucose, 1-hour and 2-hour after oral glucose, 824 cases). Multivariate logistic regression was used to analyze the effects of different abnormal OGTT patterns on LGA. In addition, the blood glucose measurements at the three time points of OGTT were combined and used as continuous variables in the receiver operating characteristic (ROC) curve to evaluate the predictive value of each blood glucose measurement mode for LGA and the area under the curve (AUC) was compared.Results:(1) Multivariate logistic regression analysis showed that the risks of LGA were significantly increased in GDM 0 group ( OR=1.76, 95% CI: 1.50-2.08; P<0.001), GDM 0+1 group ( OR=2.29, 95% CI: 1.72-3.04; P<0.001), and GDM 0+1+2 group ( OR=1.98, 95% CI: 1.61-2.43; P<0.001). (2) ROC curve analysis showed that fasting blood glucose, 1-hour after oral glucose, 2-hour after oral glucose, fasting+1-hour after oral glucose, fasting+2-hour after oral glucose, 1-hour+2-hour after oral glucose, and fasting+1-hour+2-hour after oral glucose had certain predictive value for LGA (all P<0.001). The AUC of fasting blood glucose measurement was higher than that of 2-hour blood glucose measurement in predicting LGA, and the difference was statistically significant ( P<0.05). There was no significant difference in the AUC between fasting blood glucose and other blood glucose measurement modes for predicting LGA (all P>0.05). Conclusions:In the abnormal OGTT patterns, pregnant women with abnormal fasting blood glucose, abnormal fasting+1-hour after oral glucose, and abnormal fasting+1-hour+2-hour after oral glucose have an increased risk of LGA. Fasting blood glucose measurement is of great significance for the prediction of LGA, and could be used as an optimal indicator to evaluate the risk of LGA in clinical practice.

Objective:To investigate the pregnancy outcome and the maternal and infant follow-up in the puer-peral period(42 days after delivery)of cesarean section with SARS-CoV-2 Omicron variant in different periods of pregnancy.Methods:330 pregnant women who were diagnosed with SARS-CoV-2 infection and delivered by ce-sarean section in Guangdong Women and Children Hospital from November 20,2022 to January 25,2023 were selected as the research subjects.They were divided into the early(80 cases),middle(151 cases)and late(99 cases)pregnancy group according to the gestational age of infection.The general information,pregnancy compli-cations and comorbidities,pregnancy outcomes,and postpartum maternal and infant follow-up of each group of pregnant women were compared.Results:The clinical classification of pregnant women was asymptomatic and mild,with 9 cases of asymptomatic and 321 cases of mild.The incidence of gestational diabetes mellitus(GDM)in the early and late group was higher than that in the middle group(P＜0.05).There was no statistically significant difference in the incidence of placental abruption,fetal growth restriction,fetal distress,amniotic fluid contamina-tion,preterm labor,postpartum hemorrhage,macrosomia,low-birth-weight infants and the maternal intensive care unit(MICU)transfer rate,newborn birth weight,neonatal asphyxia rate and NICU transfer rate among the three groups(P＞0.05).The incidence of preterm rupture of membranes in the middle group was higher than that in the late group(P＜0.05).Puerperal follow-up results showed that there was no statistically significant difference in the incidence of poor maternal uterine incision healing,poor uterine involution,vaginal microecological imbal-ance and neonatal acute upper respiratory tract infection,pneumonia,digestive system disease,cardiovascular system disease among the three groups(P＞0.05).Conclusions:The majority of pregnant women with Omicron infection during pregnancy are mild.Omicron infection in different periods of pregnancy has no significant effect on pregnancy outcome and puerperal follow-up of cesarean section.No evidence was found that GDM and prema-ture rupture of membranes are significantly associated with Omicron infection in different periods of pregnancy.

Objective To construct lipid nanoparticles(lipopeptide-lipid nanoparticle,LP-LNP)with novel lipopeptides as adjuvants,and initially explore their synergistic effect on mRNA vaccines.Methods Two novel lipopeptides,SS-10 and SQ18,were designed and synthesized.Microfluidic technology was used to encapsulate lipopeptides in different proportions,as well as mRNAs encoding enhanced green fluorescent protein(eGFP),firefly luciferase(F-luc),and ovalbumin(OVA)into lipid nanoparticles to construct an mRNA delivery system with novel lipopeptides as adjuvants(LP-LNP).The particle size and polydispersity coefficient of LP-LNP were measured using dynamic light scattering.The activation effect on Toll-like receptors 2(TLR2)was detected using HEK-BlueTM mTLR2 reporter cells to screen the optimal lipopeptide ratio.The preferred LP-LNP-eGFP-mRNA was transfected into HEK293T cells,and the expression of eGFP was observed under a fluorescence microscope.In vivo imaging was used to investigate the expression level of LP-LNP-F-luc-mRNA in mice.Flow cytometry was used to evaluate the ability of LP-LNP-OVA-mRNA to induce the maturation of dendritic cells(DCs)in draining lymph nodes and cross-presentation of antigens after immunization.Results Lipopeptides SQ18 and SS-10 were incorporated into LNP at 0.50％and 0.75％molar ratios,respectively,to obtain LP-LNP with uniform particle size,high encapsulation efficiency,and good in vitro safety.The ability of this formulation to activate TLR2 was significantly stronger than the positive control Pam2CSK4(P＜0.01).The preferred LP-LNP obtained effective in vitro transfection,and LP-LNP prepared with SQ18 at 0.50％molar ratio had significantly better in vivo transfection efficiency than traditional LNP(P＜0.01),and significantly promoted the maturation of DCs in draining lymph nodes and cross-presentation of antigens(P＜0.05).Conclusion LP-LNP with novel lipopeptides as adjuvants can enhance the delivery capacity of mRNA and further improve the immune effect of mRNA vaccines.