Release Notes & History🔗

Release 2.0🔗

Key Changes in 2.0🔗

• New participant cohorts included: multiple birth participants and postnatal recruits (PNR)
• +40 new instruments across 10 domains
• Expanded MRI & EEG data (processed derivatives for more participants, no QC restriction on raw BIDS)
• Major data fixes and harmonization updates across multiple domains

Participant Population🔗

HBCD enrolls at least 25% of participants with more than minimal substance use during pregnancy, including opioids (Si et al. 2024). Enrollment strategies aim to yield a study population representative of individual and geographic characteristics of pregnant and postpartum individuals (18 years or older) in the U.S., including an adequate comparison group for substance-exposed individuals (Nelson et al. 2024).

Inclusion & Exclusion Criteria🔗

Items listed below are filtered/excluded from release data unless stated otherwise
Participants	DCC participants excluded Only CH Profiles included - Exclusion by PSCID prefix (PI, QI, XI, YI) Only 'Active' participants included Only selected 'Multiple Birth' profiles are included (based on clean-up procedures) Only selected 'Postnatal Recruitment' profiles are included (based on clean-up procedures) No sites excluded as of 2.0 Participant exclusion if 'Brain Rating' is 'Abnormal' Participant excluded due to 'Examiner' not 'REDCap' on REDCap surveys (possible modification of data between REDCap and LORIS, or data entered directly into LORIS)
Visits	Only data from visits whose status is set to ‘LaunchPad Complete’ up to '2025-07-01' for 2.0 release and '2026-07-01' for 3.0 release (YYYY-MM-DD) Forced insertion/exclusion of participants (based on 'LaunchPad Complete' date after July 1, 2024 exceptions granted for 1.0 release only)
Instruments	ERICA — mh_cg_erica_{fcm_adm_}{3_7m|7_9m} GABI Setup/Receipt — nt_pa_gabi_{setup|rcpt} MRI Data & Scan Summary — mri_ra_chkl_{data|scan} NIH Baby Toolbox — ncl_ch_nbtb Participant & RA Feedback — adm_cg_fb / adm_ra_fb Urgent Events & Participant Alerts — adm_fd_urgent / admin_alert
Variables	Informant (informant), Validity (validity), Duration (duration), and Window Difference (window_difference) Open text, descriptive, and line variables Impossible or selected Extreme/Outlier values filtered out Select Item/Score-level fields (hardcoded per instrument)

New Cohorts & Instruments🔗

Release data now include multiple birth participants (multiple participants from the same birth, e.g. twins) and postnatal recruits (PNR) who joined the study after the child is born (complete a modified V01 and V02). Participant IDs for multiples and PNR are provided in the HBCD Private Release Notes - see Multiple Birth Participants under Visit Information for details.

A number of new instruments were incorporated into R2.0 as well. Click to expand infobox below to view the full list.

MRI & EEG Updates🔗

• Raw BIDS data now includes all available data, not restricted to data that only passed raw data quality control.
• Raw and processed data included for additional participants and visits.
• MRI scanner details now included in the session-level Scans TSV files, including: ScannerManufacturer, ScannerModel, ScannerSoftwareVersion, and ScannerSerialNumber.
• New procedures were implemented to remove processed MRI data with serious data quality issues (see details).

Resolved Known Issues🔗

Domain	Updates
General	• Standardized Parquet precision by regenerating all data in a single step (type_data = double)
Demographics	Basic Demographics (sed_basic_demographics) • Removed invalid screen_mother_race response option (2 = Hawaiian) • Removed ACS Child Multi-Race (duplicate coding to child_ethnoracial_acs_by_multi_ethnicity) • Removed Child Multi-Ethnicity V01 data Visit Data (par_visit_data) • Set withdrawal dates for participants who did not withdraw to null (from 12/26/1999) • Removed V02 urine toxicology substance use flags (urine not collected at V02) • Corrected TLFB substance use flags for missing V02 visits ('no' → null)
Biospecimen & Omics	Urine Toxicology • Restored missing values for cotinine (*_results_bio_c_cot_u) incorrectly set to 0 (N = 18)
Neurocognition & Language	SPM-2 (ncl_cg_spm2__inf) • Added age fields (gestational, adjusted, candidate) • Added missing status scores
Pregnancy & Exposure	APA 1/2 (pex_bm_apa_anger_*) • Added missing T-scores and total scores for Anger subscale TLFB (pex_ch_tlfb) • Added age variables (gestational / adjusted / candidate age)
Social & Environmental	eHITS (sed_bm_ehits) • Corrected score calculations (score, total_score)

Release History🔗

Prior release notes are available via prior versions of this site as follows (also accessible via flyout menu).

Version	Release Date	Release Notes
1.0	2025-06-26	View Release Notes
1.1	2025-10-10	View Release Notes