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Results of the BUMPES Trial: Sitting Up or Lying Down to Promote Vaginal Delivery with an Epidural in the 2nd Stage of Labor?


  • Recent Cochrane Review did not demonstrate a difference between upright or recumbent when assessing the chance of a spontaneous vaginal birth in women with epidural anesthesia
  • Brockehurst et al. (BMJ, 2017) sought to determine whether the  upright position  during the second stage of labor increases the chance of spontaneous vaginal birth in women with a low-dose epidural


  • Birth in the Upright Maternal Position with Epidural in Second stage (BUMPES) Trial
  • Multicenter randomized controlled trial (RCT)
  • Inclusion Criteria
    • ≥ 16 years, ≥ 37 weeks gestation, nulliparous, singleton cephalic presentation, and intended to have a spontaneous vaginal birth
    • 2nd stage with low dose epidual in situ
  • Subjects were assigned to the following groups:
    • Upright position
      • Maintain pelvis in as vertical a plane as possible
      • Walking, kneeling, sitting etc. all acceptable
    • Lying down position
      • Up to 30 degrees inclination
    • Groups were stratified by center
      • Blinding of participants or clinicians not possible
    • Primary outcome was spontaneous vaginal birth
    • Secondary outcomes were
      • mode of birth, perineal trauma, infant Apgar score <4 at 5 minutes, admission to a neonatal unit
      • longer term outcomes included maternal physical and psychological health, incontinence, and infant gross developmental delay


  • 1,556 participants were in the upright group and 1,537 in the lying down group
  • Primary Outcome
    • There were significantly fewer spontaneous vaginal births in the upright group (35.2%) vs the lying down group (41.1%) with adjusted risk ratio (RR) 0.86 (95% CI 0.78 to 0.94)
  • Secondary Outcomes
    • No evidence of difference for most of the secondary maternal, neonatal, or longer term outcomes including
      • Vaginal delivery, obstetric anal sphincter injury, infant Apgar score <4 at five minutes and maternal fecal incontinence at one year


  • There is a 5.9% absolute increase in the chance of spontaneous vaginal birth in the lying down group
  • Authors recognize limitations of the study
    • Inability to mask
    • Unless there is an indication to do otherwise, guidance and practice promote women using any position they find more comfortable and may have resulted in superior adherence in the upright group
  • No obvious mechanism to explain findings
  • When adding this current cohort of approximately 3,000 well randomized women to previous data, sum of evidence strengthens findings in this paper
    • Combining present results with previous data, odds ratio of upright vs lying down is 0.80 (95% CI 0.70 to 0.92)

Learn More – Primary Sources:

Upright versus lying down position in second stage of labour in nulliparous women with low dose epidural: BUMPES randomized controlled trial

Does Maternal Depression or Stress Affect Fetal Growth?


  • Intrauterine fetal growth restriction (FGR or IUGR), defined as weight below the 10th percentile, has been associated with excessive maternal stress 
  • Most studies are based on birth weight, and therefore cannot fully assess timing of various exposures in addition to confounders  
  • Grobman et al. (Journal of Ultrasound in Medicine, 2017) sought to determine whether women reporting greater perceived stress or depression symptoms at start of or during pregnancy would demonstrate altered longitudinal fetal growth 


  • NICHD Fetal Growth Study multicenter prospective (2009 – 2013) 
  • Women screened at 8 weeks and 13 weeks 6 days gestation for stress/depression status and underwent serial sonographic examinations
  • Definition of high risk 
    • Cohen Perceived Stress Scale (PSS):  Score ≥ 15
    • Edinburgh Postpartum Depression Survey (EPDS): Score of ≥ 10 (13 used for sensitivity analysis)
  • Fetal weight growth curves and individual biometric parameters were created using serial sonographic data  
  • Interaction between race/ethnicity and stress/depression scores were assessed 


  • Multicenter longitudinal study of 2334 women 
  • 89% and 90% of women completed PSS and EPDS, respectively, at least once in all trimesters 
  • Despite participant’s reported PSS or EPDS score, longitudinal growth curves and fetal weight were similar 
  • Race/ethnicity did not modify biometric parameters 


  • Quantified depressive symptoms and greater perceived stress are not associated with alterations in fetal growth throughout all three trimesters 
  • Authors recommend further research to determine whether combination of stress and/or depression with environmental factors may alter fetal growth 
  • This paper complements the Wing et al. study that likewise did not find an association between perceived maternal stress and neonatal growth measurements (summarized in ‘Related ObG Topics’ below) 

Learn More – Primary Sources:  

Maternal Depressive Symptoms, Perceived Stress, and Fetal Growth

Practical obstetrics info for your women's healthcare practice

Exposure to Ionizing Radiation During Pregnancy – What Now?


When considering the effects of ionizing radiation during pregnancy:

  • Do not recommend termination solely on the basis of exposure to ionizing radiation
  • Patients should be counseled and prenatal imaging performed for structural anomalies and growth restriction for exposure >50mGy
    • Radiation exposure through radiography, CT scan or nuclear imaging is usually at a dose that is lower than the threshold exposure associated with risk to the fetus and should not be withheld if necessary
  • Ultrasound and MRI are not associated with fetal risk and are first line imaging modalities
    • Use ‘prudently’ and when the results will provide medical benefit
  • Consult radiation physicist to calculate total dose, if multiple imaging studies were performed
    • The Health Physics Society (HPS) maintains an open access website with information for professionals and patients (see ‘Learn More – Primary Sources’ below)
  • A 10-20 mGy fetal exposure may increase the background risk of leukemia by a factor of 1.5-2.0
  • There is no risk to lactation from external sources of ionizing radiation

Interim ACOG Update (October 2017) Regarding Exposure to MRI and Gadolinium in Pregnancy

  • Limit the use of gadolinium contrast with MRI
  • Only use gadolinium contrast if it ‘significantly improves diagnostic performance’ and will improve maternal and/or fetal outcomes
  • Breastfeeding should not be interrupted after use of gadolinium, consistent with ACR guidance
  • A recent retrospective cohort study by Ray et al. (JAMA, 2016) comparing gadolinium MRI (n = 397) at any time during pregnancy with no MRI (n = 1,418,451), demonstrated
    • The risk of any rheumatological, inflammatory, or infiltrative skin condition in offspring was increased (adjusted hazard ratio (HR) 1.36; 95% CI, 1.09 to 1.69)
    • Stillbirths and neonatal deaths (within 28 days of birth) were increased (adjusted relative risk 3.70; 95% CI, 1.55 to 8.85) for an adjusted risk difference of 47.5 per 1000 pregnancies (95% CI, 9.7 to 138.2)


X-ray procedures may be indicated during pregnancy or may occur inadvertently before the pregnancy is diagnosed. The risk to a fetus from ionizing radiation is dependent on the gestational age at the time of the exposure and the dose of radiation. Growth restriction, microcephaly and intellectual disability are the most common adverse effects from high dose radiation exposure. They have not been reported with radiation exposure less than 50 mGy.  Actual fetal doses are dependent on gestational age, maternal body habitus and acquisition parameters.


Fetal Dose for common radiologic exams

  • Chest X-ray, two views generally: 0.0005-0.01 mGy
  • Abdominal radiography: 0.1-3 mGy
  • IVP: 5-10 mGy
  • Double contrast barium enema: 1.0-20 mGy
  • Head or neck CT: 1.0-10 mGy
  • Chest CT or CT pulmonary angiography: 0.01-0.66 mGy
  • Abdominal CT: 1.3-35 mGy

‘All or None’ Effect

  • Before implantation (0 to 2 weeks after fertilization)
    • Death of embryo or no consequence
    • Estimated threshold: 50-100 mGy

Learn More – Primary Sources:

ACOG Committee Opinion 723: Guidelines for Diagnostic Imaging During Pregnancy and Lactation

JAMA: Association Between MRI Exposure During Pregnancy and Fetal and Childhood Outcomes

HPS: Radiation & Reproduction

HPS: Pregnancy and Radiation Exposure – Patient FAQs

ACR Manual on Contrast Media