[Effects of interpregnancy interval on pregnancy outcomes of subsequent pregnancy: a multicenter retrospective study].

Objective: To explore the effects of interpregnancy interval (IPI) on pregnancy outcomes of subsequent pregnancy. Methods: A multicenter retrospective study was conducted in 21 hospitals in China. Information of age, height, pre-pregnancy weight, IPI, history of diseases, complications of pregnancy, gestational age of delivery, delivery mode, and pregnancy outcomes of the participants were collected by consulting medical records of pregnant women who had two consecutive deliveries in the same hospital during 2011 to 2018. The participants were divided into 4 groups according to IPI:<18 months, 18-23 months, 24-59 months and ≥60 months. According to the WHO's recommendation, with the IPI of 24-59 months group as a reference, to the effects of IPI on pregnancy outcomes of subsequent pregnancy were analyzed. Stratified analysis was further carried out based on age, history of gestational diabetes mellitus (GDM), macrosomia, and premature delivery, to explore the differences in the effects of IPI on pregnancy outcomes among women with different characteristics. Results: A total of 8 026 women were included in this study. There were 423, 623, 5 512 and 1 468 participants in <18 months group, 18-23 months group, 24-59 months group and ≥60 months group, respectively. (1) The age, pre-pregnancy body mass index (BMI), history of cesarean section, GDM, gestational hypertension and cesarean section delivery rate of <18 months group, 18-23 months group, 24-59 months group and ≥60 months group were gradually increased, and the differences were statistically significant (P<0.05). (2) After adjusting for potential confounding factors, compared with women in the IPI of 24-59 months group, the risk of premature delivery, premature rupture of membranes, and oligohydramnios were increased by 42% (OR=1.42, 95%CI: 1.07-1.88, P=0.015), 46% (OR=1.46, 95%CI: 1.13-1.88, P=0.004), and 64% (OR=1.64, 95%CI: 1.13-2.38, P=0.009) respectively for women in the IPI≥60 months group. No effects of IPI on other pregnancy outcomes were found in this study (P>0.05). (3) After stratified by age and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of oligohydramnios for women with advanced age (OR=2.87, 95%CI: 1.41-5.83, P=0.004); and <18 months could increase the risk of premature rupture of membranes for women under the age of 35 (OR=1.59, 95%CI: 1.04-2.43, P=0.032). Both the risk of premature rupture of membranes (OR=1.58, 95%CI: 1.18-2.13, P=0.002) and premature delivery (OR=1.52, 95%CI: 1.07-2.17, P=0.020) were significantly increased in the IPI≥60 months group. After stratified by history of GDM and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would lead to an increased risk of postpartum hemorrhage for women with a history of GDM (OR=5.34, 95%CI: 1.45-19.70, P=0.012) and an increased risk of premature rupture of membranes for women without a history of GDM (OR=1.44, 95%CI: 1.10-1.90, P=0.009). After stratified by history of macrosomia and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months could increase the proportion of cesarean section for women with a history of macrosomia (OR=4.11, 95%CI: 1.18-14.27, P=0.026) and the risk of premature rupture of membranes for women without a history of macrosomia (OR=1.46, 95%CI: 1.12-1.89, P=0.005). After stratified by history of premature delivery and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of premature rupture of membranes for women without a history of premature delivery (OR=1.47, 95%CI: 1.13-1.92, P=0.004). Conclusions: Both IPI≥60 months and <18 months would increase the risk of adverse pregnancy outcomes in the subsequent pregnancy. Healthcare education and consultation should be conducted for women of reproductive age to maintain an appropriate IPI when they plan to pregnant again, to reduce the risk of adverse pregnancy outcomes in the subsequent pregnancy.

[Effect of glucose on Akt2 mRNA and methylation level and the association between early-pregnancy Akt2 mRNA level in peripheral blood and pre-pregnancy BMI and GDM].

Objective: To explore the effect of glucose on Akt2 gene methylation and mRNA level in the trophoblast cell line HTR8/SVneo and the association between first-trimester Akt2 mRNA level in peripheral blood and pre-pregnancy body mass index (BMI) and gestational diabetes mellitus (GDM). Methods: The cell model of intrauterine hyperglycemia in pregnant women with GDM was established, and divided into 5 groups based on the different glucose concentrations (2.5, 5.0, 10.0, 25.0, and 40.0 mmol/L). The mRNA levels of Akt2 gene were detected by real-time quantitative PCR, and the methylation levels of Akt2 gene promoter region were detected by mass spectrometry. According to pre-pregnancy BMI and diagnosis of GDM, 60 pregnant women who had given birth at Peking University First Hospital during December 2014 to July 2016 were classified into overweight non-GDM group, overweight GDM group, obese non-GDM group and obese GDM group. Real-time quantitative PCR analyses were used to detect the levels of Akt2 mRNA in first-trimester peripheral blood of the 4 groups. Results: (1) Level of Akt2 mRNA significantly rose with the glucose concentration of medium increased, showing concentration dependency (all P<0.05). Compared with the 25.0 mmol/L group, the following methylation levels changed significantly (all P<0.05): cytosine-phosphate-guanine (CpG) 10, CpG23, and CpG24.5 of Akt2 gene promoter region in the 5.0 mmol/L group, CpG23 and CpG24.5 in the 2.5 mmol/L group, and CpG10 in the 10.0 mmol/L group. Compared with the 5.0 mmol/L group, CpG10 in the 40.0 mmol/L group showed methylation change (P<0.05). (2) Compared with the overweight non-GDM group [1.04(0.90~1.26)], overweight GDM group [2.10(1.85~2.28)] and obese GDM group [1.68(0.82~2.43)] all had higher Akt2 mRNA levels and the differences were statistically significant (all P<0.05). Compared to obese GDM group [1.68(0.82~2.43)], the level of Akt2 mRNA was higher in overweight GDM group [2.10(1.85~2.28)] and lower in obese non-GDM group [1.00(0.71~2.17)], but the differences were not statistically significant (all P>0.05). Conclusions: Glucose might affect Akt2 mRNA level by changing the methylation of Akt2 gene promoter region, and the change might appear in the first trimester of pregnant women with GDM, especially for women with lower pre-pregnancy BMI.

[Analysis of the maternal glucolipid metabolism in twin pregnancies complicated by gestational diabetes mellitus].

Objective: To explore the characteristics of maternal glucose and lipid metabolism in twin pregnancies complicated by gestational diabetes mellitus (GDM). Methods: The clinical features of twin and singleton pregnancies complicated by GDM, which delivered in Peking University First Hospital from January 1st, 2012 to December 31st, 2017 were retrospectively analyzed. A total of 286 twin pregnancies with GDM (GDM-T group) were collected, and 572 singleton pregnancies complicated by GDM (GDM-S group) which were matched by delivery time in a ratio of 1∶2 among all singleton pregnancies with GDM. The characteristics of maternal glucolipid metabolism in the second trimesters of pregnancy was compared between two groups. Results: (1) Compared with GDM-S group, the maternal delivery age were lower [(32±4), (33±4) years] and prepregnancy body mass index (BMI) were higher [(24±4), (23±4) kg/m(2)] in GDM-T group, the differences were statistically significant (all P<0.05). The incidence of chronic hypertension was found no significant difference (P=0.581). (2) The 3 points of glucose values in 75 g oral glucose tolerance test (OGTT) and OGTT-area under curve (AUC) had no significant difference between GDM-T and GDM-S group.When compared with GDM-S group, the maternal glycosylated hemoglobin levels [(5.41±0.35)%, (5.32±0.28)%], the insulin resistance index (4.07±0.77, 2.63±1.50) and the proportion of insulin use (7.7%, 4.4%) were all significantly higher in GDM-T group (all P<0.05). The values of triglyceride [(3.4±1.4), (2.6±1.2) mmol/L], total cholesterol [(6.3±1.1), (6.0±1.0) mmol/L], low density lipoprotein cholesterol [(3.3±0.9), (3.1±0.8) mmol/L] were significantly higher and values of high density lipoprotein cholesterol [(1.7±0.4), (2.0±0.5) mmol/L] were significantly lower in GDM-T group than GDM-S group (all P<0.05). (3) There was no significant difference in the incidence of gestational hypertension between the two groups (P>0.05). When compared with GDM-S group, the incidences of preeclampsia and small for gestational age were both significantly higher (13.3% vs 2.4%; 28.7% vs 1.7%) and the incidence of large for gestational age was significantly lower in GDM-T group (4.5% vs 15.2%; all P<0.05). Conclusions: The insulin resistance is aggravated in twin pregnancies and the characteristics of lipid metabolism are different between singleton and twin pregnant women complicated by GDM, and there are more complications in twin GDM pregnancies.

Identification of forensically important beetles (Coleoptera: Histeridae) in China based on 16S rRNA and Cyt b.

Exact identification of an insect sample is usually the first essential step in a forensic entomological analysis. However, the morphological similarity of beetles in the level of species usually poses a challenge for forensic scientists within their routine work. As a supplementary to traditional morphological method, molecular genetics identification turns out to be simple and time-saving. A molecular identification method involving a 288-bp segment of the 16S ribosomal RNA (16S rRNA) gene and a 334-bp segment of the cytochrome b (Cyt b) gene from 23 histerid beetles specimens, collected from 7 locations in 6 Chinese provinces, was evaluated. The 16S rRNA and Cyt b genes are sequenced to examine the ability of the region, resolve species identities and enrich the local databases. The monophyletic branches of the phylogenetic tree showed the potential of the markers in identifying beetles within families. Combined analysis is a more accurate approach for species identication than independent analysis.

Identification of the forensically important sarcophagid flies Boerttcherisca peregrina, Parasarcophaga albiceps and Parasarcophaga dux (Diptera: Sarcophagidae) based on COII gene in China.

Accurate species identication is a crucial step in forensic entomology, as the insect collected on a corpse can provide useful information for estimation of postmortem interval (PMI). The utility of the forensically important Sarcophagidae (Diptera) for crime scene investigation has been severely restricted, as morphological identification is difficult, especially the identification of females and larvae. In this study, a method for using mitochondrial DNA (mtDNA) sequence data and phylogenetic analysis was performed to distinguish the three Chinese sarcophagid species: Boerttcherisca peregrina (Robineau-Desvoidy, 1830) Parasarcophaga albiceps (Meigen, 1826) and Parasarcophaga dux (Thompson, 1869) (Diptera: Sarcophagidae). DNA was extracted and analyzed by a 189 bp fragment of cytochrome coxidase subunit II (COII) gene. The monophyletic branches of the phylogenetic tree reveal that this marker is suitable for discrimination between these species, providing high support for separation on congeneric species. Therefore, the molecular method applied to the sarcophagid species identification is feasible.