Demographic and clinical characteristics of study participants
| Characteristics | Mother with IBD | Control mother | P value |
| N | 40 | 81 | – |
| Mean age at recruitment (year, mean±SD) | 32.9±4 | 32.9±3.7 | 0.35 |
| Jewish ethnicity (%) | 35 | 13.8 | 0.008 |
| Nulliparous (%) | 62.5 | 40.7 | 0.024 |
| Exposure to antibiotics during pregnancy (%) | 20.5 | 24.1 | 0.67 |
| Peripartum antibiotics (%) | 65.5 | 52.1 | 0.25 |
| Use of assisted reproductive technology (%) | 9.9 | 13.2 | 0.59 |
| Gestational diabetes/type 1 DM (%) | 3.9 | 5.7 | 0.67 |
| Biologic drugs during pregnancy (%) | 50 | – | – |
| Thiopurines during pregnancy (%) | 28 | – | – |
| Prior surgery (%) | 16 | – | – |
| Disease remission during pregnancy (%) | 70 | – | – |
| Characteristics | Infants born to mothers with IBD | Infants born to control mothers | P value |
| N | 26 | 53 | |
| Male gender (%) | 69.2 | 39.6 | 0.013 |
| Mean gestational age at delivery (weeks, mean±SD) | 39.5±1.08 | 39.3±1.67 | 0.36 |
| Delivered by C-section (%) | 46.2 | 30.2 | 0.16 |
| Preterm birth (%) | 5.7 | 0.0 | 0.55 |
| Birth weight (kg, mean±SD) | 3.41±0.38 | 3.29±0.52 | 0.82 |
| Low birth weight (%) | 0 | 3.8 | 0.31 |
| Exclusive breast feeding (%) | 50 | 39.6 | 0.073 |
| Exclusive formula (%) | 15.4 | 3.7 | |
| Mixed feeding (%) | 34.6 | 56.6 | |
| Exposure to antibiotics after birth (%) | 3.8 | 9.4 | 0.66 |
| Exposure to probiotics after birth (%) | 11.5 | 13.2 | 0.83 |