Table 19 Research gaps

   • Alternative imaging or diagnostic technologies (alternatives to X-ray pelvimetry) to predict cephalopelvic disproportion in the antepartum period

   • Pathophysiology of impaired placentation and identification of clinical markers of poor placentation/perfusion to develop tests of stillbirth risk

   • Development of optimal methodologies for vibroacoustic stimulation (frequency, placement, amplitude, etc), and studies of efficacy and predictive reliability

   • Safety of vibroacoustic stimulation (auditory function, cognitive development) and pulse oximetry (cognitive development)

   • Interventions to prevent and treat oligohydramnios, particularly in cases of intact membranes

   • Non-interventional sensitivity, specificity, and predictive value testing of untested screening techniques in unselected populations (low- and high-risk pregnant women)

   • Development of predictive variables for stillbirth at term

   • Low-tech strategies, such as the partograph, for identifying high-risk pregnancies in low-resource settings

   • New adjunctive techniques to improve the positive predictive value of fetal distress and hypoxia of cardiotocography

Well-designed RCTs of interventions powered to detect stillbirth rates

   • Community-based pregnancy risk screening schemes

   • Formal fetal movement monitoring in high-risk pregnancies

◦ Comparisons of different methods

◦ Impact of timing from monitoring-to-intervention on perinatal mortality

   • Optimal combinations of tests to screen for fetal growth restriction

   • Optimal management of fetal growth restriction and timing of delivery

   • Ultrasound assessment of placental appearance (lesions and calcifications) in high-risk pregnancy

   • Ability of uterine artery Doppler ultrasound in combination with other testing for pre-eclampsia prediction and subsequent development of prevention measures for women at highest risk

   • Optimising glycaemic control in managing diabetes mellitus in pregnancy

   • Assessment of stillbirth risk in instances of gestational diabetes and impaired glucose tolerance (little data compared to pre-existing diabetes mellitus)

   • Usefulness of BPP in identifying fetal compromise

   • Vibroacoustic stimulation studies in labour

   • Impact of in-hospital fetal surveillance units on stillbirth outcomes

   • Partograph versus no partograph use

Effectiveness and cost-effectiveness trials in large populations/at scale

   • Cost-benefit analyses of routine ultrasound for gestational age dating and multiple pregnancy detection in resource-poor settings

   • Cost-effectiveness studies of fetal surveillance units in hospitals

   • Safety of out-of-hospital bed rest and outpatient fetal surveillance in high-risk pregnancies in resource-poor settings (including economic analyses)