Maternal Pre-conception Body Mass Index and Fasting Plasma Glucose With the Risk of Pre-term Birth: A Cohort Study Including 4.9 Million Chinese Women.

Background: To evaluate the associations of pre-conception body mass index (BMI), fasting plasma glucose (FPG) alone and their combination with pre-term birth (PTB) risk. Methods: We conducted a population-based retrospective cohort study with 4,987,129 reproductive-aged women, who participated in National Free Pre-Pregnancy Checkups Project in 2013-2016 and had a singleton delivery before December 2017 in China. All data analyses were conducted in 2018-2021. Results: A total of 339,662 (6.81%) women had pre-term deliveries. Compared with women with normal weight and normal glucose, underweight and normal weight were associated with PTB among hypoglycemia women, the adjusted odd ratios (aORs) were 1.24 (95% CI: 1.05-1.48) and 1.16 (95% CI: 1.07-1.25), respectively; underweight, overweight and obesity were associated with PTB among women with normal glucose, the aORs were 1.09 (95% CI: 1.08-1.10), 1.06 (95% CI: 1.05-1.07) and 1.08 (95% CI: 1.05-1.12), respectively; all the BMI groups were significantly associated with PTB among women with pre-diabetes or diabetes (P < 0.05). The dose-response relationships of BMI with PTB varied in different FPG level, with U-shaped curve in normal glucose and pre-diabetes women, J-shaped in diabetes women, L-shaped in hypoglycemia women. For FPG with PTB, the dose-response relationships were U-shaped in normal weight, overweight, and obesity women, and L-shaped in underweight women. Conclusion: We found that the associations of PTB with BMI varied with levels of FPG, and associations of PTB with FPG varied with levels of BMI. There was a synergistic effect on PTB risk due to abnormal weight and glycemia besides a conventional main effect derived from either of them. Achieving desirable weight and glucose control before conception should be advised.

Nicorandil reversed homocysteine-induced coronary microvascular dysfunction via regulating PI3K/Akt/eNOS pathway.

OBJECTIVE: Nicorandil exerts a protective effect against coronary microvascular dysfunction in acute myocardial infarction (AMI) patients. However, the mechanism and effect of nicorandil in hyperhomocysteinemia (HHcy) AMI patients remain unclear. METHODS: C57/BL6 mice with mild to moderate HHcy and human coronary artery endothelial cells (HCAECs) cotreated with HHcy (1 mmol/L) for 24 h and hypoxia for 6 h were selected as models. Small animal ultrasound detection was used to compare cardiac function. CD31 immunofluorescence staining and tomato lectin staining were used to assess the number of microcirculation changes in vivo. MTT, tube formation and western blotting assays were used to evaluate the effect of nicorandil on HCAECs and the PI3K/Akt/eNOS pathway. RESULTS: The results showed that nicorandil improved cell viability and p-PI3K/PI3K, p-Akt/Akt, and p-eNOS/eNOS expression in the vitro HHcy and hypoxia models. The beneficial effects of nicorandil on HCAECs could be inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and the nitric oxide synthase (NOS) inhibitor L-NAME. In vivo, nicorandil improved the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) in the post-HHcy + MI model, and the levels of CD31 and tomato lectin expression were higher in the nicorandil treatment group. The effectiveness of nicorandil was inhibited in the PI3K and L-NAME groups. CONCLUSION: The results suggest that nicorandil improves Hcy-induced coronary microvascular dysfunction through the PI3K/Akt/eNOS signalling pathway.

Preconception Hb concentration with risk of spontaneous abortion: a population-based cohort study in over 3·9 million women across rural China.

OBJECTIVE: Evidence on the relationship between maternal Hb concentration and spontaneous abortion (SA) risk is limited and conflicting. The purpose of the study was to evaluate whether maternal preconception anaemia or high Hb concentration is associated with risk of SA. DESIGN: A population-based cohort study established between 2013 and 2017. SETTINGS: Local maternal and child care service centres in each county. PARTICIPANTS: In total, 3 971 428 women aged 20-49 years, who participated in National Free Pre-Pregnancy Checkups Project from 2013 to 2016 and successfully got pregnant before 2017 in rural China. RESULTS: A total of 101 700 (2·56 %) women were recorded having SA, with highest SA rate in women with severe anaemia (4·58 %). Compared with women with Hb of 110-149 g/l, the multivariable-adjusted OR for SA was 1·52 (95 % CI: 1·25, 1·86) for women with Hb < 70 g/l, 0·92 (0·84, 1·01) for 70-99 g/l, 0·80 (0·77, 0·83) for 100-109 g/l, 1·11 (1·08, 1·15) for 150-159 g/l, 1·12 (1·04, 1·20) for 160-169 g/l and 1·02 (0·93, 1·12) for ≥ 170 g/l, respectively. An approximate U-shaped curve for the risk of SA with Hb concentrations was observed when Hb concentrations less than 145 g/l, above which the association plateaued (Pnon-linear < 0·001). CONCLUSIONS: Severe anaemia and high Hb concentration before pregnancy were associated with an increased risk of SA. Women with mild anaemia prior to pregnancy had lower risk of SA. Underlying mechanisms need to be further studied.

The association of husbands' smoking with wives' dysglycemia status: A cross-sectional study among over 10 million Chinese women aged 20-49.

BACKGROUND: We comprehensively evaluated the association between husbands' smoking amount and wives' dysglycemia status. METHODS: We conducted a cross-sectional study which recruited 12 023 714 reproductive couples who participated in the National Free Pre-Pregnancy Checkups Project (NFPCP) between 2015 and 2016 in China. Multivariable logistic models were used to estimate odds ratio (OR) and 95% CI. Subgroup analysis and stratified analysis were further performed to investigate potential effect modification. RESULTS: Compared to the neither-smoker group, the multivariable-adjusted ORs for diabetes mellitus (DM) among women was 1.09 (95% CI, 1.07-1.10), 1.04 (95% CI, 0.87-1.23), and 1.28 (95% CI, 1.17-1.41) in the husband-smoker, wife-smoker, and both-smokers groups, respectively. An increased risk of DM was also observed for women whose husbands smoke 1 to 10 (OR, 1.06; 95% CI, 1.04-1.07), 11 to 20 (OR, 1.13; 95% CI, 1.11-1.15), and over 20 cigarettes per day (OR, 1.25; 95% CI, 1.17-1.31). The prevalence of wives' DM showed significant linear trends with husbands' smoking amount (Pfor trend < .001). A similar growth tendency was also observed between husband smoking amount and impaired fasting glucose (IFG) prevalence with ORs of 1.04 (95% CI, 1.04-1.05), 1.05 (95% CI, 1.04-1.06), and 1.09 (95% CI, 1.06-1.11) for 1-10, 11-20, and over 20 cigarettes per day, respectively. The relationship between husbands' smoking amount and wives' IFG/DM prevalence appear to be modified by body mass index (BMI). CONCLUSIONS: This study shows significant relationships between husbands' smoking and wives' risk of IFG/DM, and this result exists in both a categorical and dose-response manner. This association is modified by BMI. Family-oriented smoking interventions may both reduce husbands' active smoking and wives' risk of DM.

Pre-pregnancy maternal fasting plasma glucose levels in relation to time to pregnancy among the couples attempting first pregnancy.

STUDY QUESTION: What is the relationship between pre-pregnancy maternal glucose levels and fecundability in Chinese couples? SUMMARY ANSWER: Elevated pre-pregnancy maternal glucose levels were associated with fecundability, as reflected by prolonged time to pregnancy (TTP) among the couples with no prior gravidity. STUDY DESIGN, SIZE, DURATION: Based on the National Free Pre-conception Check-up Projects supported by the Chinese government, 2 226 048 eligible couples attempting first pregnancy and participating in the project from 2015 to 2016 were included. They were followed-up for 1 year or until they reported pregnancy. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: The Kaplan-Meier method was used to estimate the cumulative pregnancy rate in each menstrual cycle, and the discrete-time analogue of the Cox models was used to estimate the fecundability odds ratios (FORs) and 95% CIs by different pre-pregnancy maternal glucose levels (impaired fasting glucose (IFG) or diabetes as compared to normal). MAIN RESULTS AND THE ROLE OF CHANCE: The cumulative pregnancy rate for 12 cycles of the normal fasting plasma glucose (FPG) level group was 42.29%, significantly higher than that of the IFG (35.52%) and diabetes groups (31.52%). After adjusting for confounding factors, the FORs were 0.82 (95% CI: 0.81-0.83) and 0.74 (95% CI: 0.72-0.76) for the IFG and diabetes groups, respectively, as compared to the normal group. The association between pre-pregnancy maternal FPG levels and the FORs was non-linear, and the optimal FPG level for greatest fecundability (shortest TTP) was 3.90-4.89 mmol/L. LIMITATIONS, REASONS FOR CAUTION: The findings from this register-based cohort study require cautious interpretation given that information bias would be inevitable for single FPG measurements and for TTP calculations that were based on telephone follow-up information. Additionally, because couples who achieved pregnancy during their first menstrual cycle in the study were excluded, the pregnancy rates reported were low and possibly biased. WIDER IMPLICATIONS OF THE FINDINGS: The current report suggests that elevated pre-pregnancy maternal glucose levels were associated with prolonged TTP. Early evaluation and preventive treatment for female partners with IFG or diabetes in a pre-pregnancy examination are necessary. STUDY FUNDING/COMPETING INTEREST(S): Funding was provided by the National Key Research and Development Program of China (grants No. 2016YFC1000300 and 2016YFC1000307), the National Natural Science Foundation of China (grant No. 81872634), the CAMS Innovation Fund for Medical Sciences (grant No. 2018-I2M-1-004), the National Human Genetic Resources Sharing Service Platform (grant No. 2005DKA21300) and the National Population and Reproductive Health Science Data Center (grant No. 2005DKA32408), People's Republic of China. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Preconception blood pressure and time to pregnancy among couples attempting to conceive their first pregnancy.

BACKGROUND: The association of abnormal blood pressure levels (including hypertension and prehypertension) with reduced fecundability among young childbearing-age couples is not yet elucidated completely. OBJECTIVE: The purpose of this study was to investigate the association between abnormal preconception blood pressure level and time to pregnancy among couples who are attempting to conceive their first pregnancy. STUDY DESIGN: A total of 2,234,350 eligible couples (with no previous gravidity and whose female partners were 20-49 years old) participated in the National Free Preconception Check-up Projects from January 1, 2015, to December 31, 2016. Each couples' preconception blood pressure levels were measured, and time to pregnancy was recorded. Cox models for discrete survival time were used to estimate fecundability odds ratios and their corresponding 95% confidence intervals after adjustment for age, ethnicity, educational level, occupation, household registration, region, tobacco exposure, alcohol intake, body mass index, duration of marriage of the couples, and fasting plasma glucose levels of the female partner. RESULTS: Compared with normotensive women, those women with hypertension (systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg) had a 21% lower pregnancy rate (fecundability odds ratio, 0.79; 95% confidence interval, 0.78-0.81). A similar finding was found among men (fecundability odds ratio, 0.89; 95% confidence interval, 0.88-0.90). Prehypertension (systolic blood pressure between 120 and 139 mm Hg, and/or a diastolic blood pressure between 80 and 89 mm Hg) in both male and female partners was associated slightly with reduced fecundability odds ratios. Compared with couples in which both partners were normotensive, the pregnancy rate was reduced by 27% (fecundability odds ratio, 0.73; 95% confidence interval, 0.69-0.77) among couples in which both partners had hypertension. CONCLUSION: Abnormal preconception blood pressure levels were associated with prolonged time to pregnancy among couples who were attempting to conceive their first pregnancy; the mechanism is worth further investigation.

The association between ambient PM2.5 exposure and the risk of preterm birth in China: A retrospective cohort study.

BACKGROUND: The relationship between PM2.5 exposure and preterm birth remains unclear. OBJECTIVES: To explore the effect of exposure to PM2.5 on preterm birth in China. METHODS: The birth outcomes of 426,246 pregnant women enrolled between January 2014 and December 2014 in NFPCP (National Free Pre-pregnancy Checkups Project) were collected, and their individual PM2.5 exposure values were estimated from the China National Environmental Monitoring Centre. The time of gestational exposure to PM2.5 was divided into four periods (the first trimester, the second trimester, the third trimester and the entire pregnancy). The average concentration and the corresponding quartiles of PM2.5 were calculated in these periods by the daily average PM2.5 data. Cox proportional hazards regression was used and he effects of maternal age, education level, occupation, second-hand smoking, alcohol use, pre-pregnancy BMI, baby's sex, number of previous pregnancies, coastal areas and season of conception were adjusted for. RESULTS: A total of 426,246 singleton births were included, among which 35,261 (8.3%) were preterm birth. Effect of each 10µg/m3 increase of PM2.5 on preterm birth was most significant during the third trimester (HR, 1.06; 95%CI, 1.06-1.07), and also significant during the first trimester (HR, 1.04; 95%CI, 1.03-1.04), the second trimester (HR, 1.02; 95%CI, 1.02-1.02) and the entire pregnancy (HR, 1.06; 95%CI, 1.05-1.06). Compared with the lowest quartile of PM2.5, other quartiles increased the risk of preterm birth, and were most significant during the third trimester (HR, 1.87; 95%CI, 1.69-2.06). Subgroup analysis showed that compared with other subgroups, women who were older than 30years, had low education level, worked as farmers, had male baby, had previous pregnancies, not live in coastal areas and pregnant in winter were more sensitive to PM2.5 exposure. CONCLUSIONS: Ambient PM2.5 exposure during pregnancy played an important role in the pregnancy process and increased the risk of preterm birth.

[The method and efficacy for screening neonatal tetanus in high risk areas in China].

OBJECTIVES: To establish a method for screening neonatal tetanus (NT) in high risk areas in China using multi-sources data. METHODS: We adopted six NT-related indicators from National Notifiable Disease Report System (NNDRS) and National Maternal and Child Health Annual Report System, to calculate weighted high-risk score at prefecture level in 2010 and 2011. And we selected the top 30 high risk cities, and compared the scores with the actual NT incidence ranking and WHO scoring. RESULTS: The highest areas distributed in the Southwest of China with poor and minority population, and the Southeast part with high density of migrants. In the leading 30 prefectures with high score between the methods of weighted high-risk scoring and reported NT incidence ranking, there were 8 different. In comparison of the results of the methods of weighed high-risk scoring and WHO scoring, 276 prefectures in 340 distributed were divided into the same ranking groups, with Kappa coefficient 0.56 (P < 0.01). The Chi-Square association coefficient was 0.74 (P < 0.01), which showed a high correlation. But there were 10 different prefectures in the leading 36 prefectures between the two methods. CONCLUSION: The weighted scoring method included several possible factors influencing NT incidence and took their weights into consideration. Thereby, compared with WHO scoring method, this method could be more appropriate for the reality in China.