The China Family-Based Birth Cohort: A Study of Both Assisted Reproductive Technology and Spontaneous Pregnancies

Abstract

Background: More than 1·0% of all births in China are through Assisted reproductive technology (ART). Concern is mounting over the safety of ART and the health impacts of ART on maternal and fetal health. Well-designed longitudinal cohort aiming to address the concern is yet sparse. The China National Birth Cohort (CNBC) Study is a family-based and prospective birth cohort study consisting of both Assisted reproductive technology (ART) pregnancies and spontaneous pregnancies. Which was set to comprehensively describe the incidence of birth outcomes from ART and spontaneous-conceived pregnancies and to systematically evaluate the environmental and genetic factors that may influence the birth outcomes of these pregnancies. Methods: CNBC was launched at 22 centers (located in 15 cities of China) in November 2016, and aims to complete recruitment of 10,000 couples who plan to have invitro fertilization or intra-cytoplasmic sperm injection (IVF/ICSI) treatments and 10,000 couples who have spontaneous pregnancies. The cohort data is collected from the biological parents and the offspring from the ART centers and obstetrics departments, respectively. Findings: By December 2018, CNBC had recruited 10,954 ART families and 10,618 spontaneous conceived families. Questionnaires (demographic, occupational, behavioral, environmental, nutritional and psychosocial factors, etc.), clinical data (obstetric and pediatric examination, and laboratory tests, etc.), and biospecimens (blood, urine, cord blood, follicular fluid, sperm, and seminal plasma, etc.) were collected respectively before embryo transfer, at the 1st, 2nd and 3rd trimester during pregnancy, and approximately 42 days, 6 months, 12 months, and 36 months after birth. Interpretation: The CNBC provided comprehensive data and bio-specimen resources from ART-received pregnancy and spontaneous pregnancy family, which will help identify the risk factors for ART pregnancies, and to elucidate heterogeneity of maternal and child health consequences between ART- and spontaneous-conceived populations. The CNBC data will be available on line, and researchers can apply with formal proposals. Funding: China National Key Research & Development (RD The Key Project of National Natural Science Foundation of China; The Innovation Capability Development Project of Jiangsu Province. Declaration of Interest: The authors declare that they have no conflict of interest. Ethical Approval: This study was approved by the institutional review board of CNBC, and written informed consent was obtained from all subjects.