Effect of pre-pregnancy obesity on trimester-specific thyroid dysfunction / 上海预防医学

ObjectiveTo explore the risk of different levels of pre-pregnancy obesity on trimester-specific thyroid dysfunction. MethodsQuestionnaire information， blood samples， and urine samples from a 2017 pregnancy cohort study in Shanghai， China were collected. A total of 2 455 pregnant women were included in the analysis. Pre-pregnancy BMI was calculated based on the height and self-reported pre-pregnancy weight. Serum TSH， total thyroxine （TT4）， free thyroxine （FT4）， total triiodothyronine （TT3）， free triiodothyronine （FT3）， thyroid globulin antibody（TgAb）， and Thyroid peroxidase antibody （TPOAb） were measured using the electrochemiluminescence method. Urine iodine levels were measured using the acid digestion method. Levels of thyroid function indexes of pregnant women with different degrees of obesity during pre-pregnancy were compared， and trimester-specific thyroid dysfunction was evaluated according to the reference range of trimester-specific thyroid hormone established by this cohort. Multivariate logistic regressions analysis was used to assess the correlation between pre-pregnancy obesity and trimester-specific thyroid dysfunction. ResultsAs the degree of obesity increased， maternal levels of FT3 and TT3 gradually increased during pregnancy （P<0.001， P=0.001）， while FT4 levels gradually decreased （P=0.001）. Multivariate logistic regression analysis showed that compared with the normal weight group， pregnant women who were overweight or obesity before pregnancy had a significantly higher risk of hypothyroxinemia （OR=3.85， 95%CI： 2.08‒7.14， P<0.001） and high TT3 （OR=2.78， 95%CI： 1.45‒5.26， P=0.002） during pregnancy. ConclusionPre-pregnancy overweight or obesity can increase the risk of thyroid dysfunction during pregnancy.

Dose-response relationship between pre-pregnancy body mass index and gestational diabetes mellitus / 预防医学

Objective@#To explore the dose-response relationship between pre-pregnancy body mass index (BMI) and gestational diabetes mellitus (GDM), so as to provide insights into the cut-off values of pre-pregnancy BMI and optimizing GDM prevention and control strategies. @*Methods@#Pregnant women that admitted to Zhengzhou Central hospital in 2021 were recruited, and demographics, family history, pregnancy and delivery history and blood glucose levels during pregnancy were collected. The dose-response relationship between pre-pregnancy BMI and GDM was analyzed using restricted cubic spline (RCS) analysis. The predictive ability of pre-pregnancy BMI for GDM risk was evaluated using receiver operating characteristic (ROC) curve. @*Results@#A total of 2 279 participants were included in the study. The median age was 29.0 (interquartile range, 5.0) years. The median pre-pregnancy BMI was 21.1 (interquartile range, 3.8) kg/m2. There were 312 underweight women (13.69%), 825 women with low-normal weight (36.20%), 730 women with high-normal weight (32.03%), 345 overweight women (15.14%) and 67 obese women (2.94%).The prevalence of GDM was 17.20%. RCS analysis suggested a linear dose-response relationship between age, pre-pregnancy BMI and GDM (P<0.05). When pre-pregnancy BMI was higher than 21.1 kg/m2, the risk of GDM increased with pre-pregnancy BMI (P<0.05). When women aged over 29.0 years, the risk of GDM increased with age, and the dose-response relationship of GDM caused by pre-pregnancy BMI was stronger in the women aged over 29.0 years than in the women aged 29.0 years and below (P<0.05). The area under curve (AUC) was 0.654 (95%CI: 0.624-0.684). If the cut-off value of pre-pregnancy BMI was 23.0 kg/m2, the Youden index, sensitivity and specificity was 0.238, 0.472 and 0.766, respectively. If it was 24.0 kg/m2, the Youden index, sensitivity and specificity was 0.195, 0.342 and 0.853, respectively. If it was 21.1 kg/m2, the Youden index, sensitivity and specificity was 0.213, 0.676 and 0.537, respectively.@* Conclusions @# There is a linear dose-response relationship between pre-pregnancy BMI and GDM, and higher than 21.1 kg/m2 of the pre-pregnancy BMI could increase the risk of GDM.

Impacts of pre-pregnancy body mass index, gestational diabetes mellitus and gestational weight gain on perinatal outcomes and mode of delivery / 中国新生儿科杂志

Objective:To study the impacts of pre-pregnancy body mass index (BMI), gestational diabetes mellitus (GDM) and gestational weight gain (GWG) on perinatal outcomes and mode of delivery.Methods:From November 2016 to December 2017, single-pregnancy women in early pregnancy (<13 weeks) regularly checked-up at our hospital were enrolled in this prospective cohort study and followed up until delivery. They were assigned into four groups according to pre-pregnancy BMI: obese group (≥28.0 kg/m 2), overweight group(24.0-<28.0 kg/m 2), normal group (18.5-<24.0 kg/m 2) and underweight group(<18.5 kg/m 2). A 75-g oral glucose tolerance test was performed at 24-28 weeks of pregnancy to screen for GDM. The optimal GWG was 11.0-16.0 kg for underweight group, 8.0-14.0 kg for normal group, 7.0-11.0 kg for overweight group and 5.0-9.0 kg for obesity group. The effects of pre-pregnancy BMI, GDM and GWG on perinatal outcomes and delivery mode were evaluated using multivariate logistic regression methods. Results:A total of 802 pregnant women were included. The incidences of pre-pregnancy overweight and obesity were 21.8% and 8.9%, respectively. The incidence of GDM was 14.1%. 57.2% of the participants experienced excessive GWG. The incidences of macrosomia, low birth weight and premature birth were 7.1%, 2.7% and 2.2%, respectively. The incidence of Cesarean delivery (C-section) was 37.7%. Pre-pregnancy obesity [adjusted odds ratio ( AOR)=4.355, 95% confidence interval ( CI) 1.900-9.980] and excessive GWG ( AOR=3.799, 95% CI 1.796-8.034) were independent risk factors for macrosomia. Excessive GWG was a protective factor for low birth weight ( AOR=0.279, 95% CI 0.084-0.928) and inadequate GWG was a risk factor for low birth weight ( AOR=10.954, 95% CI 3.594-33.382) and premature birth ( AOR=8.796, 95% CI 2.628-29.438). Compared with the normal group, overweight group had an increased risk of C-section ( AOR=1.817, 95% CI 1.119-2.949). Compared with pregnant women without pre-pregnancy overweight/obesity, GDM nor excessive GWG, any combination of two of the above-mentioned three factors increased the risks of macrosomia ( AOR=3.908, 95% CI 1.630-9.370) and C-section ( AOR=2.269, 95% CI 1.325-3.886). The risks of macrosomia and C-section were the highest when all three factors existed. Conclusions:Pre-pregnancy obesity and excessive GWG are independent risk factors for macrosomia and pre-pregnancy overweight is a risk factor of C-section. Exposure to any two of the three factors (pre-pregnancy overweight/obesity, GDM and excessive GWG) increases risks of macrosomia and C-section and the highest risk is observed when all three factors are present.

The Risk of Spontaneous Preterm Birth according to Maternal Pre-pregnancy Body Mass Index in Twin Gestations

BACKGROUND: Maternal obesity is a well-known risk factor for both total preterm birth (PTB) and spontaneous PTB in singleton gestation, whereas this association is not well determined in multiple pregnancy. The objective of this study was to determine the risk of spontaneous PTB according to the pre-pregnancy body mass index (BMI) in twin gestations. METHODS: The association between the risk of PTB and pre-pregnancy BMI was determined in women pregnant with twins between 2004 and 2014. Pre-pregnancy BMI values were divided into three groups (underweight/normal/overweight and obese). PTB was classified as spontaneous PTB (following preterm premature rupture of membranes, preterm labor, or cervical insufficiency) or medically indicated PTB (cesarean section or induction of labor because of maternal/fetal indications). RESULTS: A total of 1,959 women were included in the analysis, and the percentages of total PTB and spontaneous PTB were 13.1% and 9.3%. The percentages of total PTB and spontaneous PTB in three groups were 14.1%, 11.9%, 16.3%, respectively, and 11.0%, 8.0%, 12.5% (P < 0.05 between normal and overweight/obese women). The risks of total and spontaneous PTB in overweight/obese women were higher than those in women with normal weight, even after adjustment for prior history of PTB, age, maternal height, parity, in vitro fertilization-embryo transfer (IVF-ET) (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.01–2.03; OR, 1.58; 95% CI, 1.05–2.36). CONCLUSION: The risks of both total and spontaneous PTB were significantly greater in the overweight/obese group than in the normal BMI group.

Relationships between maternal pre-pregnancy body mass index, pregnancy weight gain and gestational diabetes / 中国基层医药

Objective To analyze the association between pre-pregnancy body mass index,pregnancy weight gain and gestational diabetes(GDM).Methods The pre-pregnancy body mass index,pregnancy weight gain and the incidence data of 345 gestational diabetes with full-term primiparae were analyzed.Results The GDM ratio of low-weight,ideal weight group,over-weight was 2.78％,2.96％,16.04％,respectively over-weight GDM pregnancy was significantly higher than the ideal weight group( x2 =4.269,P ＜0.05),and GDM over-weight before pregnancy was significantly higher than the low weight group the incidence of GDM,the difference was statistically significant( x2 =17.299,P ＜0.01 ) ;Pregnant women in different pregnancy weight gain A( ＜ 11.0kg),B( 11.0 ～ 17.9kg),C( 18.0～24.9kg),D(≥25.0kg) range,the GDM were 0％,1.75％,6.60％,11.02％,that GDM of A,B,C,D group were statistically different( P ＜ 0.05 ).Rate of weight gain during pregnancy on pregnancy size was proportional to the impact of diabetes.Conclusion Pre-pregnancy body mass index,pregnancy weight gain had clinical significance in evaluation of gestational diabetes.