by BGI Genomics

Geographical distribution of the cohort. Credit: BGI Genomics

A new pregnancy health cohort study involving over 20,000 families has identified common complications, high-risk groups, and geographical trends through biological samples collected across China.

The research, led by BGI Genomics in collaboration with medical centers from 12 cities in China, was published in the European Journal of Epidemiology in November 2024.

The cohort, launched in 2022 and still ongoing, aims to provide advanced insights into maternal and child health. By June 2024, researchers had collected more than 161,000 biological samples—such as blood, urine, and vaginal fluid—at crucial stages of pregnancy (early, mid, late, and postpartum). This comprehensive dataset supports cutting-edge research in multi-omics and the Developmental Origins of Health and Disease (DOHaD), focusing on how early-life factors influence long-term health outcomes.

Trends in maternal age, weight, and regional differences

The average age for participants is above 29, reflecting a growing trend toward older motherhood. Weight gain during pregnancy has become a concern, with the proportion of women with a pre-pregnancy BMI over 30 increasing from 5.57% to 22.16% by delivery, while those with BMIs between 25 and 30 tripled. These trends highlight the need for better weight management throughout pregnancy.

Baseline information for different regions. Credit: BGI Genomics

Regional differences were also observed. The result found that 41% of participants were shorter than 160 cm, while 24% were taller than 165 cm, with northern provinces such as Liaoning and Inner Mongolia having the tallest women. The cesarean section rate reached 39.76%, slightly higher than in previous years.

Educationally, 68.59% of participants held a bachelor's degree, underscoring the value of education. Guangdong recorded the highest number of women with two or more children (12.22%), possibly linked to its stronger economy and higher fertility rates.

Common pregnancy complications and high-risk groups

The study reported several common pregnancy complications. Premature rupture of membranes (PROM) affected 18.29% of participants, increasing the risk of infection and preterm labor.

Gestational diabetes mellitus (GDM) was diagnosed in 16.74%, raising the chances of complications such as macrosomia and preeclampsia. Additionally, 8.44% of women experienced hypothyroidism, and preterm birth occurred in 4.92% of cases, requiring specialized care for underdeveloped infants.

Prevalence of common pregnancy complications. Credit: BGI Genomics

High-risk groups were identified. Women with assisted reproductive technology (ART) had higher rates of preterm birth and preeclampsia, underscoring the need for careful monitoring. Mothers aged 35 and older faced increased risks for preterm delivery and GDM, with Shandong having the highest number of older mothers.

The study also identified regional disparities, with Guangdong reporting 266 cases of thalassemia out of 1,503 participants, while in other regions, only 79 cases were found among 3,339 women. Additionally, researchers found nine cases of fetal chromosomal abnormalities and four cases of fetal genetic disorders, emphasizing the importance of prenatal genetic screening.

Future research and follow-up

Prospective, multi-center, multi-omics birth cohorts offer the opportunity to study the field of DOHaD, and this study provides a comprehensive approach to studying the developmental origins of health and disease. The second phase of this study is underway, with a systematic analysis of five types of pregnancy-related diseases.

Researchers plan to map blood indicator curves over time and pinpoint the gestational weeks when diseases are diagnosed. This dynamic approach, leveraging multiple sampling points, will help uncover hidden relationships between phenotypes and the progression of omics data throughout pregnancy.

Dr. Zhou Si, chief scientist from the Institute of Intelligent Medical Research (IIMR) at BGI Genomics, emphasized, "The study extensively collected diverse data and biological samples, making this cohort an ideal candidate for DOHaD field and multi-omics research. We aim to provide valuable insights into the developmental origins of health and disease, particularly within the context of Chinese populations."

More information: Si Zhou et al, A prospective multicenter birth cohort in China: pregnancy health atlas, European Journal of Epidemiology (2024). DOI: 10.1007/s10654-024-01157-x

Journal information: European Journal of Epidemiology 

Provided by BGI Genomics