Table 2: Maternal/paternal details

Display only CDE items recommended as ESSENTIAL when studying: Pregnancy and infant outcomes Longer term childhood outcomes

CDE Item	Definition	Recommended data format and suggested values	Essential to collect when studying pregnancy and infant outcomes	Essential to collect when studying longer term childhood outcomes	Source	Purpose	Notes
Maternal date of birth	Mother's date of birth	Date (dd/mm/yyyy)	Yes	Yes	Directly reported	Dataset creation Derivation (age at LMP)	Availability depends on local law/data collection and storage permissions.
Maternal age at last menstrual period (LMP)	Mother's age (in years) on the first day of the last menstrual period prior to the pregnancy	Integer	Yes	Yes	Directly reported	Sub-setting Risk factor	Availability depends on local law/data collection and storage permissions.
Household income	The total annual household income (mother and partner before any tax or other deductions).	Value 1: Integer* Value 2: Currency (when >1 country)	No	Yes	Directly reported	Sub-setting Risk factor	An important measure of socioeconomic status. *This may be considered an overly intrusive question for some study participants. Alternative options for collecting the data could be to ask participants to state whether household income is above or below a national or regional average, or alternatively to use income brackets representing quintiles of the national/regional distribution. Post-collection processing to determine if above or below the national average for that country likely required. Studies running in a single country with comparable incomes between study subjects could utilize this as a continuous variable or use other markers of socioeconomic status (e.g. residential area). International studies will require standardisation.
Maternal education	Highest level of education achieved by the mother	Options: a) No formal education, b) Primary school (First school/Up to around 11 years)), c) Secondary school (Second school/Up to around 16 years), d) College (Sixth form/Up to around 18 years), e) University (18+ years), f) Unknown	No	Yes	Directly reported	Sub-setting Risk factor	Post collection processing required to determine if above or below the national average for the maternal country. Studies running in a single country could utilize this as a continuous variable. International studies will require standardisation.
Paternal education	Highest level of education achieved by the father	Options: a) No formal education, b) Primary school (First school/Up to around 11 years)), c) Secondary school (Second school/Up to around 16 years), d) College (Sixth form/Up to around 18 years), e) University (18+ years), f) Unknown	No	No	Directly reported	Sub-setting Risk factor	Post collection processing required to determine if above or below the national average for the maternal country. This may not be available in all cases but should still be collected where possible.
Maternal IQ	Intellectual ability of the mother	Value 1: Integer Value 2: Name of measurement tool (free text)	No	No*	Directly reported	Sub-setting Risk factor	*Not essential but highly recommended as an important co-variable risk factor in studies assessing child neurodevelopment. Intellectual ability of the mother as measured by a formal, clinically validated tool accepted for measuring adult IQ in the country of data collection. This data should be considered for both educational and cognitive longer term childhood outcomes.
Maternal ethnicity	The ethnicity of the mother	Options (see notes): a) Aboriginal b) Australian, c) American Indian, d) Arab, e) Black/African, f) Central Asian, g) East Asian, h) Hispanic, i) Hawaiian or Pacific Islander, j) Inuit, k) South American l) Native, m) South Asian, n) White, o) Mixed Race, p) Other, q) Unknown	No	No	Directly reported	Sub-setting Risk factor	There are no internationally accepted and validated ethnicity or racial categories which cover all ethnic groups or races around the world. Those proposed in the Recommended data format and suggested values column are thought to represent the most common general terms that are applied when referring to the different ethnicities or races around the world. However, this list should be adapted to ensure any important ethnic/racial differences which exist in the general population where the study is being conducted can be considered in statistical analyses.
Consanguinity	The father of the baby is a first or second degree relative of the mother	Value 1: a) Yes, b) No, c) Unknown If "Yes", Value 2: Text (details)	No	Yes	Directly reported	Sub-setting Risk factor	Only the categorical response can be used in data sub-setting or as a risk factor statistic. May be useful to improve analysis of infant first year outcomes like growth and congenital anomaly data.
Maternal Height	Height (cm) of the mother at the time of conception	Integer	No*	Yes**	Directly reported	Derivation (BMI) Risk factor	Important to collect if BMI not collected (for derivation), may also be valuable for assessing birth weight for gestational age using personalised growth charts (see Table 10) Convert from feet and inches, etc. *Relevant to longer term child growth outcomes but not neurodevelopmental outcomes.
Maternal Weight pre-pregnancy	Actual or approximate weight (kg) of the mother at or around the time of conception	Integer	No*	No*	Directly reported	Derivation (BMI)	*Important to collect if BMI not collected (for derivation), may also be valuable for assessing birth weight for gestational age using personalised growth charts (see Table 10) Convert from stones and pounds, etc.
Maternal BMI pre-pregnancy	Maternal BMI at the time of conception (kg/m2)	Integer	Yes	Yes	Derived (Maternal height and maternal weight pre-pregnancy)	Risk factor
Maternal country of residence	Country in which the mother resides at the time of reporting	Value: ISO 3166 Alpha-2 codes	No	Yes	Directly reported	Sub-setting Population standardisation Risk factor	The diagnosis and assessment of longer-term child outcomes (e.g. neurodevelopment) may differ across regions and countries. Studies running in a single country may wish to utilise data
Smoking in pregnancy	Maternal smoking of tobacco during pregnancy	Value 1: a) Yes, b) No, c) Unknown If "Yes", Value 2: Text (details of use, including timing, duration and amounts)	No*	Yes	Directly reported	Risk factor	*Not essential for data analysis but highly recommended as these are important co-variable risk factors Only the categorical response can be used in data sub-setting. Level of nicotine exposure may correlate with longer term outcomes.
Alcohol in pregnancy	Maternal alcohol consumption during pregnancy	Value 1: a) Yes, b) No, c) Unknown If "Yes", Value 2: Text (details of use, including timing, duration and amounts)	No*	Yes	Directly reported	Risk factor	*Not essential for data analysis but highly recommended as these are important co-variable risk factors Only the categorical response can be used in data sub-setting. Level of alcohol exposure may correlate with longer term outcomes.
Illicit drugs in pregnancy	Maternal recreational drug use in pregnancy (details of drugs, approximate daily amount ingested, duration of use in pregnancy)	Value 1: a) Yes, b) No, c) Unknown If "Yes", Value 2: Text (details of use, including timing, duration and amounts)	No*	Yes	Directly reported	Risk factor	*Not essential for data analysis but highly recommended as these are important co-variable risk factors Only the categorical response can be used in data sub-setting. Level of exposure may correlate with longer term outcomes.
Folic acid use	Maternal folic acid use in pregnancy	Value 1: a) None, b) Started pre-conception, c) Started first trimester, d) Started after first trimester, e) Unknown If not "None" or "Unknown" - Value 2: a) 400 micrograms (μg), b) 5 mg, c) Other (dose - text)	No*	Yes	Directly reported	Risk factor	*Not essential for data analysis but highly recommended as these are important co-variable risk factors Level of folate exposure may be essential for certain longer term outcomes.