{
  "abstract": "Introduction We sought to define the burden of obesity in the first trimester in pregnant women with IBD and its influence on adverse pregnancy outcomes.Methods We extracted ICD-10 coded data on pregnancies in women with and without IBD between 1/9/20 and 13/11/25. Body mass index (BMI) was assessed in the first trimester. Adverse pregnancy outcomes were gestational diabetes, pre-eclampsia, emergency Caesarean section, still birth (after 24 weeks of pregnancy), prematurity (delivery before 37 weeks’ gestation), high or low birth weight (>4000g and <2500g), and venous thromboembolism (VTE).To determine if IBD is an additive risk factor for an adverse pregnancy outcome, we matched each pregnancy at week 24 in women with IBD to 6 in women without IBD, according to age at conception, BMI and number of prior births.Results There were 68.3% (168/246) and 62.4% (17364/27845) births in women with and without IBD, respectively. Of these 0% and 0.4% were still births. The median BMI in women with and without IBD was not different. Older age (OR 0.99 [95% CIs 0.98-0.99] p<0.001); non-white ethnicity (OR 0.56 [95% CIs 0.49-0.64] p<0.001) and lower social deprivation (OR 0.99 [95% CIs 0.99-0.99] p<0.001) were associated with a lower risk of obesity; whereas urban living (OR 1.10 [95% CIs 1.03-1.17] p=0.008) was associated with a higher risk of obesity.A dose-dependent risk of gestational diabetes, pre-eclampsia, prematurity, emergency Caesarean section, high birth weight and VTE (table 1) was associated with increasing class of obesity.21.2% (53/250 [95% CIs 16.4-26.9%]) of pregnant women living with IBD were obese. In our matched cohort, there was no difference in the risk of an any adverse pregnancy outcome in women living with and without IBD, irrespective of disease activity (OR 0.69 [95% CIs 0.47-1.01] p=0.06). There was no additional risk in women living with both IBD and obesity compared to those living with obesity without IBD (OR 1.17 [95% CIs 0.49-2.72] p=0.7). 35.5% (86/242) were deemed to be at risk of VTE, but only 9.5% (23/242) were prescribed low molecular weight heparin (LMWH). Based on 2025 international consensus statement all women with IBD should be treated with aspirin, to mitigate the risk of preeclampsia, but only 33.2% (65/196) were.Conclusions Counter-intuitively, one in five pregnant women with IBD were living with obesity in the first trimester. Obesity was associated with a dose-dependent increase in adverse pregnancy outcomes: a diagnosis of IBD per se was not an additive risk factor. Two thirds of patients at risk of pre-eclampsia and VTE were not treated with aspirin or LMWH.Abstract P242 Table 1Normal weight/ overweight (BMI 18.5-29.9)Class 1 obesity (BMI 30-34.9)Class 2 obesity (BMI 35-39.9)Class 3 obesity (BMI >40)P valuePositive oral glucose tolerance test (OGTT)6.74% (159/2360)7.43% (142/1912)8.08% (81/1002)12.41% (82/661)<0.001Pre-eclampsia4.00% (4118/12169)6.00% (159/2651)9.85% (129/1310)9.05% (74/818)<0.001Emergency Caesarean section14.88% (1803/12119)16.74% (434/2593)19.71% (254/1289)23.74% (189/796)<0.001Premature delivery (<37 weeks)6.87% (850/12366)7.31% (193/2641)8.35% (109/1305)9.20% (75/815)0.024High birthweight (>4000g)10.27% (1244/12118)12.46% (323/2593)12.49% (161/1289)15.58% (124/796)<0.001Low birthweight (<2500g)5.91% (716/12118)6.67% (173/2593)5.66% (73/1289)5.15% (41/796)0.35Venous thromboembolism1.34% (167/12438)2.00% (53/2651)2.37% (31/1310)2.32% (19/818)0.003",
  "authors": [
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "Christopher Roberts"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "Rebecca Smith"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "Safwat Odeh"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "Vida Caines"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "Claire Bewshea"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "Nicholas Kennedy"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom"
      ],
      "name": "Jennifer Blackman"
    },
    {
      "affiliations": [
        "Monash Health, Melbourne, Australia"
      ],
      "name": "Sally Bell"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "Tariq Ahmad"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "James Goodhand"
    },
    {
      "affiliations": [
        "Royal Devon University Healthcare, Exeter, United Kingdom",
        "Exeter IBD and Pharmacogenetics Research Group, Exeter, United Kingdom"
      ],
      "name": "Jennie Clough"
    }
  ],
  "title": "P242 The impact of obesity on pregnancy in women with inflammatory bowel disease (IBD)",
  "uid": "a9c33f11-5035-5496-8983-68b91ece734d"
}