Cesarean delivery on maternal request and common child health outcomes: A prospective cohort study in China.

Background: Cesarean delivery vs vaginal delivery was reported to increase the risks of childhood obesity, pneumonia, anemia, and neurobehavioral disorders, but few studies were able to deal with the confounding biases associated with medical conditions indicating cesareans. This prospective cohort study aims to investigate the associations of non-medically indicated cesarean delivery on maternal request (CDMR) with these child health outcomes.

Methods: Among 17 748 liveborn infants whose mothers (primiparas) participated in a randomized controlled trial on micronutrient supplementation and pregnancy outcomes during 2006-2009 in 5 rural counties in Hebei Province, China, 6972 singletons born by full-term spontaneous vaginal delivery (SVD) and 3626 by CDMR were extracted for the assessments of obesity (weight-for-height z-score >3) and pneumonia (self-reported) at 1.

Association of cesarean delivery with anemia in infants and children in 2 large longitudinal Chinese birth cohorts.

Background: Cesarean delivery may reduce placental-fetal transfusion and thus increase the risk of early childhood anemia compared with vaginal delivery, but this notion has not been carefully studied in longitudinal cohorts.

Objective: The aim was to assess the association of cesarean delivery with anemia in infants and children in 2 longitudinal Chinese birth cohorts from different socioeconomic settings.

Design: Cohort 1 was recruited from 5 counties in northeastern China and cohort 2 from 21 counties or cities in southeastern China.

[Establishment and evaluation of enzyme-linked immunosorbent assay for measuring human IgM autoantibody to folate receptor].

Objective: To establish the method of enzyme-linked immunosorbent assay (ELISA) for measuring human IgM autoantibody to folate receptor.

Methods: Folate receptor was extracted and purified from the healthy woman placenta. The protein was coated on 96-well plates with a concentration of 5 ng/Μl.

[Impact of pregnancy terminations before 28 weeks of gestation on the overall prevalence of neural tube defects in two counties of Shanxi province].

Objective: To examine the impact of pregnancy termination before 28 weeks of gestation on the overall prevalence of neural tube defects (NTDs).

Methods: Data collected during the period of 2004 and 2010 from a birth defects surveillance system in Pingding county and Taigu county of Shanxi province were used. Number of births≥28 weeks of gestation and number of cases with major birth defects among the births were collected.

Cesarean delivery on maternal request and childhood intelligence: a cohort study.

Background: Cesarean section births have been steadily increasing over the past decade and have become an epidemic in China. Cesarean delivery on maternal request is a major contributor to this upward trend, and there has been of much concern about its impact on maternal and child health. Most of mothers believe that cesarean delivery on maternal request can improve the child's intelligence, but direct evidence is sparse.

[Questionnaire-based survey of allergic diseases among children aged 0 - 14 years in the downtown of Beijing, Chongqing and Guangzhou].

Objective: In recent years, the incidence of allergic diseases in China is increasing. With serious influence on the patients' quality of life and even life-threatening, now allergic diseases have become an important public health problem in our country. This survey aimed to obtain a general epidemic outline of children's major allergic diseases, i.

Maternal periconceptional consumption of pickled vegetables and risk of neural tube defects in offspring.

Background: Maternal exposure to nitrate, nitrite, and N-nitroso compounds from drinking water or diet has been associated with an increased risk of neural tube defects (NTDs) in some studies. Pickled vegetables contain relatively large amounts of nitrite and N-nitroso compounds. We examined the association between maternal periconceptional consumption of pickled vegetables and NTDs in Shanxi Province of northern China.

Current trends of the prevalence of childhood asthma in three Chinese cities: a multicenter epidemiological survey.

Objective: To analyze the prevalence of asthma and asthma related symptoms among children aged 0-14 years in three Chinese cities and to obtain a crude estimation of the trend of childhood asthma prevalence in China.

Methods: A cross-sectional, population-based survey of prevalence of asthma was conducted in children aged from 0 to 14 years in 3 major cities of China (Beijing, Chongqing, and Guangzhou) with different geographic locations. All the subjects were randomly selected by a multi-stage sampling method.

[Influence of hemoglobin level during early gestation on the development of cognition of pre-school children].

Objective: The purpose of this study was to evaluate the effect of hemoglobin (Hb) level during early gestation on the cognitive development of children at 4 - 6 years of age.

Methods: A total number of 3609 children were randomly selected from all the live birth infants whose mothers participated in a community intervention trial during 1993 - 1996 in 13 counties or cities in Jiangsu and Zhejiang provinces. Hb concentration during early gestation was measured at first prenatal examination and intelligence quotients (IQ), including full-scale, verbal and performance were assessed using Chinese-Wechsler Intelligence Scale for Children in 2000 - 2001 when these children had a mean age of 68 months.

[Analysis on influencing factors for stunting and underweight among children aged 3 - 6 years in 15 counties of Jiangsu and Zhejiang provinces].

Objective: To analyze the influencing factors for stunting and underweight among children aged 3 - 6 years in 15 counties of Jiangsu and Zhejiang provinces so as to provide reference for enhancing growth level among preschool children.

Methods: Data was from the 183 295 records of Children Follow-up Study Project carried out by the Institute of Reproductive and Child Heath of Peking University and the records of related perinatal health care surveillance system in rural areas of 15 counties/cities of Jiangsu and Zhejiang provinces. WHO-NCHS standard was used to assess the childhood physical level of growth.

[Study on the current status of spontaneous abortion of primigravid women in Jiaxing of Zhejiang province, China].

Objective: To study the current status of spontaneous abortion of primigravid women in Jiaxing areas of Zhejiang province of China.

Methods: We analyzed the data from both perinatal healthcare surveillance program and spontaneous abortion, collected in Jiaxing areas by the Institute of Reproductive and Child Health, Peking University. The study population consisted of 14 769 primigravid women (excluding induced abortion, ectopic pregnancy and molar pregnancy as outcomes) attempting to become pregnant who registered between 1993 and 1995.

[Correlation on hemoglobin concentration and the development of cognition among pre-school children].

Objective: Our purpose was to evaluate the association between hemoglobin concentration (Hb) and cognitive ability of children at 4 - 6 years of age in 21 counties/cities in China.

Methods: A total number of 7331 children born during 1993 - 1996 were randomly selected from 21 counties or cities in Hebei, Jiangsu and Zhejiang provinces. Hb concentration of children were measured followed by three tests including full-scale, verbal and performance intelligence quotient (IQ) test performed by Chinese-Wechsler Intelligence Scale for Children, one year later.

[Prospective cohort study of pregnancy-induced hypertension and risk of preterm delivery and low birth weight].

Objective: To determine the association between pregnancy-induced hypertension(PIH) and risk of preterm delivery (PD) and low birth weight (LBW).

Methods: A prospective cohort was established based on 131 867 women who delivered a singleton baby in seven cities or counties in Zhejiang province, China, during the period of 1995 - 2000. The exposure group included 14 278 women who were diagnosed as PIH, and the non-exposure group included 117 589 women.

[Birth weight distribution among premature infants and related social factors].

Objective: To understand the distribution of birth weight among premature infants and the associated social factors.

Methods: The study population consisted of 97 537 women who delivered singleton live birth of 20 to 41 gestational weeks in 4 counties/cities, Jiangsu and Zhejiang provinces, China from 1995 to 2000. Chi-square test was employed to test the difference of proportions between respective groups.

[Association between pregnancy-induced hypertension, cesarean delivery and perinatal mortality: a prospective study].

Objective: To examine the relationship between pregnancy-induced hypertension (PIH) and risks of perinatal mortality.

Methods: A population-based, retrospective cohort study was conducted based on 134 858 women registered in a perinatal health care surveillance system and delivered singleton births between 1995 to 2000 in Zhejiang province, China. Multivariate logistic regression models were employed to estimate the relative risk (OR) and 95%CI.

[The relationship between prepregnancy body mass index and the occurrence of pregnancy induced hypertension].

Objective: To examine the relationship between prepregnancy body mass index (BMI) and the risk of pregnancy-induced hypertension (PIH) in Chinese population.

Methods: Data were collected in 6 counties/cities covered by Perinatal Health Care Surveillance System which was part of the Sino-American cooperative project on neural tube defects prevention established in 1992. The study population consisted of 83 159 women who attended premarital or preconception medical physical examination and delivered single live births with at least 20 gestational weeks from 1995 to 2000 in Jiaxing area.

[Relations between pre-pregnancy body mass index, gestational weight gain, and the occurrence of neonatal asphyxia].

Objective: To assess the relationship between pre-pregnancy body mass index (BMI), weight gain during pregnancy, and the risk of neonatal asphyxia.

Methods: Data was collected in 6 countiedeities covered by Peri-natal Health Care Surveillance System which was part of a Sino-American cooperative project on neural tube defects prevention established in 1992. The study population consisted of 83,030 women who attended premarital/preconception medical physical examination program and had delivered single live birth with at least 20 gestational weeks from 1995 to 2000 in Jiaxing area, Zhejiang province.

[Association of pregnancy-induced hypertension with small-for-gestational-age babies].

Objective: To examine the association between pregnancy-induced hypertension (PIH) and small-for-gestational-age babies (SGA) in a Chinese population.

Methods: Subjects were women who delivered a singleton baby (gestational weeks: equal to or greater than 28, and less than 42) in four cities or counties in Jiangsu and Zhejiang provinces, China, during the period of 1995 - 2000. A total number of 93 743 women were included.

[Prevalence of preterm birth among singletons in 10 counties (cities) of China, 1993-2005].

Objective: To describe the secular trends and epidemiological characteristics of preterm birth among singletons in 10 counties (cities) of China during 1993-2005.

Methods: We analyzed data on 542 923 women (gestational age > or =28 weeks) collected through Perinatal Healthcare Surveillance System established by the Institute of Reproductive and Child Health, Peking University. Chi-square tests were employed to test the differences in prevalence of preterm birth among different groups.

[Study on the third trimester hemoglobin concentrations and the risk of low birth weight and preterm delivery].

Objective: To investigate the association between third trimester hemoglobin (Hb) concentrations and the risk of low birth weight and preterm delivery in a Chinese population.

Methods: Subjects were women who delivered in four cities/counties in Jiangsu and Zhejiang provinces, China, during the period of 1995 - 2000. Incidence of low birth weight and preterm delivery was calculated and compared among groups of women with different levels of Hb during the third trimester.

[The current status and the changing patterns of perinatal health care in some southern and northern areas of China, 1994 - 2000].

Objective: To understand the current status and its changing patterns of perinatal health care in some southern and northern areas of China from 1994 to 2000.

Methods: Data was collected in 13 counties/cities covered by Perinatal Health Care Surveillance System which was part of the Sino-American cooperative project on neural tube defects prevention, established in 1992. The study population consisted of 368 589 women who delivered single live births of at least 20 gestational weeks from 1994 through 2000.

[The extent and relative changes of equities in utilization of prenatal care among women in some areas of China].

Objective: To assess the extent and relative changes of the equities in prenatal care utilization among women with different educational attainment in some areas of China.

Methods: Data were collected in 13 counties/cities covered by Perinatal Health Care Surveillance System established by Institute of Reproductive and Child Health, Peking University. The study population consisted of 103 704 women who delivered single live births in 1994 and 2000.