Page Last Updated: October 16, 2025

Pregnancy & Infant Health Instruments🔗

Health V1 & V2 Instruments🔗

Instrument	Acronym	Construct	Table Name
Health V1- Health History	Healthhx	Pre-pregnancy and pregnancy health	`pex_bm_health_preg__healthhx`
Health V1- Exposures & Vaccines	Vacc	Vaccines in pregnancy	`pex_bm_health_preg__exp__vacc`
Health V1- Chronic Conditions	Chroncond	Chronic conditions/STIs in pregnancy	`pex_bm_health_preg__chroncond`
Health V1- Illness	Illness	Illness in pregnancy	`pex_bm_health_preg__illness`
Health V1- ER Admissions	ERhosp	ER or hospitalization in pregnancy	`pex_bm_health_preg__erhosp`
Health V1- Medications	Meds	Medications in pregnancy	`pex_bm_health_preg__meds`
Health V2- Pregnancy	Healthv2 Preg	Health updates up to delivery	`pex_bm_healthv2_preg`
Health V2- Infancy	Healthv2 Inf	Delivery and birth outcomes	`pex_bm_healthv2_inf`

Amidst powerful societal expectations to ‘do what’s best for the baby’ during pregnancy (i.e. by stopping substance use), up to half of pregnancies in the United States are unintended with 1 in 5 unwanted (Bearak et al. 2020). This discrepancy contributes to implicit bias against pregnant individuals who use substances as ‘not caring about their babies’ which is neither humane, nor evidence based (Massey et al., 2022). While cessation of substance use during pregnancy is universally recognized as optimal, the ability to make this “parental” sacrifice varies substantially between birthing individuals and within individuals between their different pregnancies (Level et al., 2024). Failure to recognize this inherent heterogeneity in pregnancy intention stigmatizes substance users who did not intend to want to become pregnant. Summarily, inclusion of pregnancy intention as a covariate in all studies that characterize prenatal substance exposure (in the absence of a strong justification otherwise) is thus strongly recommended to acknowledge myriad experiences of birthing parents who participated in HBCD who made this research possible.

Coding challenges were identified for the following systems:

ICD codes (via BioPortal) – reasons for medication use, ER visits, and hospitalizations
WHO symptom codes – symptom reporting
RxNORM – medication names

Difficulties arose both for participants (describing symptoms/medications) and for HBCD staff (locating the correct term in the databases). The following instruments were impacted by coding issues:

Instrument	Coding Issues
Health V1- Illness	• Illnesses captured via BioPortal ICD or WHO symptom codes • Participants had difficulty naming conditions • Staff had difficulty locating correct codes
Health V1- ER Admissions	• Reasons captured via BioPortal ICD codes • Coding difficult for use of ER for normal care visits (no diagnosis) • False alarms (e.g., suspected water break) often coded as “don’t know”
Health V1- Medications	• Medication names from RxNORM; reasons from BioPortal ICD • No option for preventive use → aspirin (to prevent preeclampsia) moved to prenatal vitamin section a few months into the study • PRN (“as needed”) medications inconsistently reported • Some medications were coded with dose, but this was not asked and should not be used
Health V2- Pregnancy	Same ICD (via BioPortal) and RxNORM issues as V1
Health V2- Infancy	Same ICD (via BioPortal) and RxNORM issues as V1

Out-of-range values were filtered (i.e. changed to "n/a") for the following Health V2- Infancy (pex_bm_healthv2_inf) fields:

Field Name	Field Description	Valid Range
`pex_bm_healthv2_inf_001__01`	Weight at birth (oz)	≤ 16
`pex_bm_healthv2_inf_001__02`	Weight at birth (lbs)	≤ 66
`pex_bm_healthv2_inf_002`	Length at birth (inches)	12 - 51
`pex_bm_healthv2_inf_002__01`	Calculated length at birth (cm)	30 - 130

Administration & Quality Control🔗

Administration🔗

Instrument	Child-Specific	Respondent	Administration	Visits	Completion
Healthhx	No	Pregnant Participant	Self-Administered	V01	5 min
Vacc	No	Pregnant Participant	Self-Administered	V01	3 min
Chroncond	No	Pregnant Participant	Self-Administered (in person)	V01	3 min
Illness	No	Pregnant Participant	HBCD Study Staff (in-person)	V01	3 min
ERhosp	No	Pregnant Participant	HBCD Study Staff (in-person)	V01	5 min
Meds	No	Pregnant Participant	HBCD Study Staff (in-person)	V01	5 min
Healthv2 Preg	No	Birth Parent	HBCD Study Staff (in person)	V02	10 min
Healthv2 Inf	Yes	Birth Parent or Primary Caregiver on Child	HBCD Study Staff (in person)	V02	10 min

Quality Control🔗

For all pregnancy and infant health instruments listed on this page, quality control was performed by reviewing response distributions for outliers.

Instrument Details🔗

Healthhx	Pre-pregnancy and pregnancy health outcomes, including: gravidity and parity, height and weight, pregnancy intentions, use of assisted reproductive technology, start of prenatal care, prenatal vitamin or aspirin use, secondhand smoke
Vacc	Vaccines in pregnancy, including receipt of common vaccines in pregnancy and trimester received.
Chroncond	Information on chronic conditions and sexually transmitted infections (STIs) during pregnancy, including whether they are ongoing or resolved.
Illness	Illness in pregnancy, including start and stop dates and whether the person had a fever.
ERhosp	ER visit(s) or hospitalization(s) during pregnancy, including occurrence(s) and reason(s).
Meds	Medications used during pregnancy (since last menstrual period), including prescription and over-the-counter medications. It includes details such as the name of the medication, its indication, frequency of use, and start/stop dates.
Healthv2 Preg	Health updates for the birth parent between enrollment and delivery, including: prenatal vitamin use, aspirin intake, infections and illnesses, vaccinations, medication use (ongoing and newly prescribed), pregnancy complications (e.g., gestational diabetes), labor and delivery details (e.g., delivery method, location, and hospital stay duration)
Healthv2 Inf	Delivery and birth outcomes, including: infant characteristics (birth weight & length, duration of hospital stay); newborn conditions (birth defects, genetic diagnoses); medical interventions including NICU admission and length of stay, intubation, adverse outcomes (e.g. bronchopulmonary dysplasia, congenital syphilis), medications (name, indication, status), healthcare access, and specialist visits; and newborn hearing test results

References🔗

Bearak, J., Popinchalk, A., Ganatra, B., Moller, A.-B., Tunçalp, Ö., Beavin, C., Kwok, L., & Alkema, L. (2020). Unintended pregnancy and abortion by income, region, and the legal status of abortion: estimates from a comprehensive model for 1990-2019. The Lancet. Global Health, 8(9), e1152–e1161. https://doi.org/10.1016/S2214-109X(20)30315-6

Level, R. A., Zhang, Y., Tiemeier, H., Estabrook, R., Shaw, D. S., Leve, L. D., Wakschlag, L. S., Reiss, D., Neiderhiser, J. M., & Massey, S. H. (2024). Unique influences of pregnancy and anticipated parenting on cigarette smoking: results and implications of a within-person, between-pregnancy study. Archives of Women’s Mental Health, 27(2), 301–308. https://doi.org/10.1007/s00737-023-01396-z

Massey, S. H., Neiderhiser, J. M., Shaw, D. S., Leve, L. D., Ganiban, J. M., & Reiss, D. (2012). Maternal self concept as a provider and cessation of substance use during pregnancy. Addictive Behaviors, 37(8), 956–961. https://doi.org/10.1016/j.addbeh.2012.04.002

Massey, S. H., Estabrook, R., Lapping-Carr, L., Newmark, R. L., Decety, J., Wisner, K. L., & Wakschlag, L. S. (2022). Are empathic processes mechanisms of pregnancy’s protective effect on smoking? Identification of a novel target for preventive intervention. Social Science & Medicine (1982), 305(115071), 115071. https://doi.org/10.1016/j.socscimed.2022.115071

Schoenaker, D. A. J. M., Ploubidis, G. B., Goodman, A., & Mishra, G. D. (2017). Factors across the life course predict women’s change in smoking behaviour during pregnancy and in midlife: results from the National Child Development Study. Journal of Epidemiology and Community Health, 71(12), 1137–1144. https://doi.org/10.1136/jech-2017-209493