Table 1 Key human studies informing Heartland Study hypotheses

Urinary glyphosate concentration in pregnant women in relation to length of gestation

(Lesseur et al., 2022)

Glyphosate and AMPA

163

Biomarkers in Second trimester urine samples

Shortened length of gestation in spontaneous births

Glyphosate: HR = 1.31, (95%CI 1.00–1.71)

AMPA: HR = 1.32 (95%CI: 1.00–1.73)

Prenatal exposure to organophosphate and pyrethroid insecticides and the herbicide 2,4-dichlorophenoxyacetic acid and size at birth in urban pregnant women

(Balalian et al., 2021)

2,4-D

270

Urinary biomarkers of 2,4-D

Inverse association between concentration and head circumference

2,4-D was associated with smaller head circumference in the second (β =  − 1.57; (95%CI: − 2.74, − 0.39) and third (β =  − 1.74, (95%CI: − 2.98, − 0.49) categories of concentration in comparison to the first category

Prenatal exposure to pesticides and risk of preeclampsia among pregnant women: Results from the ELFE cohort

(Enderle et al., 2021)

Herbicides

17,376

Self-reported home application

Pre-eclampsia

Women receiving antihypertensive treatment for pre-eclampsia compared to women without pre-eclampsia (aOR = 2.20, (95%CI: 1.23, 3.93)

Maternal urinary levels of glyphosate during pregnancy and anogenital distance in newborns in a US multicenter pregnancy cohort

(Lesseur et al., 2021)

Glyphosate and AMPA

94

Second trimester urine biomarker

Anogenital distance in female offspring

After adjusting for confounders, increased AMPA was associated with longer AGD in female infants, β = 1.96, (95%CI 0.44, 3.5)

Prenatal Exposure to Glyphosate and Its Environmental Degradate, Aminomethylphosphonic Acid (AMPA), and Preterm Birth: A Nested Case–Control Study in the PROTECT Cohort (Puerto Rico)

(Silver et al., 2021)

Glyphosate and AMPA

247

Multiple second trimester urine biomarkers

Increased odds of preterm birth

aORs for an interquartile range increase in exposure at Visit 3 were 1.35 (95% CI: 0.99, 1.83) and 1.67 (95% CI: 1.26, 2.20) for GLY and AMPA, respectively

Prenatal and infant exposure to ambient pesticides and autism spectrum disorder in children: population based case–control study

(Ehrenstein et al., 2019)

Glyphosate

41,292

GIS, California Pesticide Use records

Autism spectrum disorder

ASD: Glyphosate OR = 1.16, (95% CI 1.06, 1.27); ASD with intellectual disability: Glyphosate OR = 1.33 (95%CI 1.05,1.69)

Atrazine Contamination of Drinking Water and Adverse Birth Outcomes in Community Water Systems with Elevated Atrazine in Ohio, 2006–2008

(Almberg et al., 2018)

Atrazine

14,445

Mean gestational and trimester-specific atrazine concentrations were calculated from EPA water quality monitoring data

Term low birth weight

aOR 1.27 (95% CI 1.10, 1.45)

Glyphosate exposure in pregnancy and shortened gestational length: a prospective Indiana birth cohort study

(Parvez et al., 2018)

Glyphosate

71

Urine biomarkers of exposure

Shortened length of gestation

GLY urine levels were significantly correlated with shortened gestational lengths (r =  − 0.28, p = 0.02)

Exposure to pistachio pesticides and stillbirth: a case–control study

(Razi et al., 2016)

Proximity to pistachio orchards as a proxy for organo-phosphate pesticide exposure

375

Self-report

Stillbirth

In mothers living in pistachio gardens the OR = 14.1 (95% CI, 3.3, 63.4)

In mothers exposed to sprayed pesticides, the OR = 5.0 (95% CI, 1.2, 28.6)

County-level pesticide use and risk of shortened gestation and preterm birth

(Winchester et al., 2016)

Pesticides

7,940,794

California Pesticide Use records

Preterm birth, low birthweight percentile

Counties with higher pesticide use were associated with higher PTB (low 8.59 ± 0.11%, moderate 9.25 ± 0.07%, high 10.0 ± 0.06%, p's < 0.001) and shorter gestations (low 39.197 ± 0.014 weeks, moderate 39.126 ± 0.011 weeks, high 39.049 ± 0.011 weeks, p's < 0.001)

Maternal Residential Atrazine Exposure and Risk for Choanal Atresia and Stenosis in Offspring

(Agopian, Cai, et al., 2013)

Atrazine

4092

USGS estimated residential atrazine exposure

Choanal atresia and stenosis

Mothers with high levels of residential atrazine exposure had an increased risk of choanal atresia or stenosis with an aOR = 1.79, (95% CI 1.17, 2.74)

Maternal Residential Atrazine Exposure and Gastroschisis by Maternal Age

(Agopian, Langlois, et al., 2013)

Atrazine

95,551

USGS estimated residential atrazine exposure

Gastroschisis

Risk for gastroschisis in offspring was significantly increased for women ≥ 25 years with high levels of residential atrazine exposure compared to low aOR = 1.97, (CI: 1.19–3.26)

Atrazine Exposure in Public Drinking Water and Preterm Birth

(Rinsky et al., 2012)

Public drinking water atrazine data

71,768

Public drinking water data

Preterm birth

Increase in the odds of preterm birth noted in those women living in counties with the highest level of atrazine exposure, OR = 1.26, (95% CI 1.19, 1.32)

Drinking-water herbicide exposure in Indiana and prevalence of small-for-gestational-age and preterm delivery

(Ochoa-Acuña et al., 2009)

Drinking water nitrate and atrazine levels

24,154

Indiana geocoding logs

Small for gestational age

Mean atrazine concentrations over the entire pregnancy > 0.644 microg/L were associated with higher SGA prevalence than in the control group, adjusted PR = 1.14, (95% CI 1.03, 1.24)

Pre- and post-conception pesticide exposure and the risk of birth defects in an Ontario farm population

(Weselak et al., 2008)

Self-Reported dicamba use

3,412

Self-report

Birth defects

Pre-conception exposure to dicamba in males increased the risk of birth defects, OR = 2.42, (95% CI 1.06, 5.53)

Pesticide Exposure and Self-Reported Gestational Diabetes Mellitus in the Agricultural Health Study

(Saldana et al., 2007)

Self-reported pesticide use

11,273

Self-report from FFH

Gestational diabetes mellitus

Women who reported agricultural pesticide exposure (mixing or applying pesticides to crops or repairing pesticide application equipment) during pregnancy were more likely to report GDM, OR = 2.2 (95% CI 1.5, 3.3)

Spontaneous Abortion in Spouses of Greenhouse Workers Exposed to Pesticides

(Petrelli et al., 2003)

Occupational exposure to greenhouse atrazine

184

Self-report

Spontaneous abortion

The OR adjusted for age, smoking, and education of both partners and for spouse’s type of work and time between the pregnancy and the interview yielded an OR = 11.8, CI: 2.3–59.6

Birth malformations and other adverse perinatal outcomes in four U.S. wheat-producing states

(Schreinemachers, 2003)

Geographically estimated chlorophenoxy herbicide exposures

43,634

Geographic estimation

Birth malformations

Significant increases in birth malformations were observed for the circulatory/respiratory category for the combined sexes, OR = 1.65, (95% CI 1.07, 2.55)

An exploratory analysis of the effect of pesticide exposure on the risk of spontaneous abortion in an Ontario farm population

(Arbuckle et al., 2001)

Self-reported pesticide use

3,936

Self-report

Late spontaneous abortions

We observed moderate increases in risk of early abortions for preconception exposures to phenoxy acetic acid herbicides (OR) = 1.5, 95% CI, 1.1–2.1