Poster Presentation Society of Obstetric Medicine of Australia and New Zealand and Australasian Diabetes in Pregnancy Society Joint Scientific Meeting 2017

Birth trauma in babies born to women with and without type 1 diabetes in Sweden 1998-2012: relationship with maternal and baby weight (#138)

Paulina Arntyr Hellgren 1 , David Simmons 2 , Ulf Hanson 3 , Anders Magnuson 4 , Helena Fadl 5
  1. Department of Obstetrics and Gynaecology, Örebro University Hospital, Örebro, Sweden
  2. University of Western Sydney, Campbelltown, NSW, Australia
  3. Department of Women’s and Children’s Health, Uppsala University, Sweden
  4. Clinical Epidemiology and Biostatistics, Örebro university Hospital, School of Health and medical Sciences,, Örebro University, Örebro, Sweden
  5. Department of Obstetrics and Gynaecology, School of Health and Medical Sciences, Örebro University, Örebro, Sweden

Introduction: We compared birth trauma rates in pregnancies among women with and without type 1 diabetes (T1DM) and tested the relationship with maternal body mass index (BMI) and large for gestational age (LGA) as risk factors.

Methods: This is a population-based cohort study 1998-2012 using the Swedish Medical Birth Registry which includes 99% of Swedish pregnancies. All pregnancies up until gestational week 41 were included. We excluded mothers with other types of diabetes, duplex pregnancies and all pregnancies ending with a caesarean section (51.1%/16.5% in women with/without T1DM respectively). The incidence of birth trauma was adjusted for BMI, maternal age, parity, Nordic/non-Nordic origin, smoking, chronic hypertensive disease, LGA and baby gender using logistic regression.

Results: There were 2,758 and 783,412 births with complete data among T1DM and control mothers respectively. The mean BMI, maternal age and gestational age at birth in full weeks were 25.6 (SD 4.5), 30.0 (SD 5.1) and 37.9 (SD 1.9) respectively among women with T1DM and 24.2 (SD 4.3), 29.7 (SD 5.1) and 38.9 (SD 1.5) respectively among controls. Birth trauma did not vary significantly with increasing BMI compared with the reference (18.50-24.9 kg/m2) among women with T1DM (odds ratios (OR) with increasing BMI (<18.49, 25.0-29.9, 30.0-34.9, >35.0 kg/m2) were 1.9 (95%CI 0.2-15.7), 1.0 (95%CI 0.7-1.5), 0.5 (95%CI 0.2-1.0), 1.1 (95%CI 0.5-2.4) respectively). Conversely, among controls, the OR for birth trauma increased with increasing BMI: 0.7 (95%CI 0.6-0.9), 1.4 (95%CI 1.3-1.5), 1.8 (95%CI 1.6-2.0), and 2.2 (95%CI 1.9-2.4) respectively. However, birth trauma was 3.9 (95%CI 2.7-5.7) and 7.0 (95%CI 6.5-7.5) fold more common after adjustment with LGA among women with and without T1DM respectively.  

Conclusions: Birth trauma rates are associated with LGA with comparatively greater impact among women without, than with, T1DM, possibly due to greater monitoring and earlier planned delivery.