A randomized controlled trial studying the effect of maternal hyperoxygenation on fetal heart rate in suspected fetal distress

OBJECTIVE

To investigate the effect of maternal hyperoxygenation on fetal heart rate (FHR) when applied for suspected fetal distress during the second stage of term labor.

APPROACH

A single-center randomized controlled trial was conducted in a tertiary care hospital in The Netherlands. Participants were included during the second stage of labor in case of an intermediary or abnormal FHR pattern. Patients were randomized to receive either 100% oxygen at 10 l/min until delivery, or conventional care without additional oxygen. The primary outcome was the change in FHR pattern before and after the onset of the study, measured as the change in depth and duration of FHR decelerations. Secondary outcome measures were features based on phase-rectified signal averaging (PRSA), baseline assignability, and deceleration characteristics of the FHR pattern.

MAIN RESULTS

Between March 2016 and April 2018, 117 women were included. The FHR pattern could be analyzed for 71 participants, the other 46 women delivered before the end of the post time-frame. A 2.3% reduction in depth and duration of FHR decelerations was found after maternal hyperoxygenation, compared to a 10% increase in the control group (p = 0.24). Maternal hyperoxygenation had a significantly positive effect on PRSA metrics, with a decrease in PRSA-acceleration capacity (p = 0.03) and PRSA-deceleration capacity (p = 0.02) in the intervention group compared to the control group.

SIGNIFICANCE

The difference in depth and duration of decelerations after the start of the study was not significantly different between both study groups. A statistically significant positive effect on PRSA-deceleration capacity and PRSA-acceleration capacity was found after maternal hyperoxygenation, which might be associated with a positive effect on neonatal outcome.

What is the best drug treatment for premenopausal women with bleeding irregularities using the levonorgestrel-releasing intrauterine system? A systematic review

OBJECTIVE

Up to 60% of women discontinue using the levonorgestrel-releasing intrauterine system (LNG-IUS) within 5 years because of bleeding irregularities, pain and/or systemic progestogenic adverse effects. The aim of the study was to assess treatment options for bleeding irregularities in women using the 52 mg LNG-IUS.

METHODS

Database searches of Medline, Embase/Ovid and the Cochrane Library were carried out, and journals were searched by hand, for relevant studies published from database inception to March 2020. Inclusion criteria were randomised controlled trials (RCTs), prospective cohort studies and case-control studies of premenopausal women using the LNG-IUS and receiving medical treatment for bleeding irregularities. Screening, data extraction and quality assessment of retrieved articles were carried out independently by two pairs of reviewers. The primary outcome was the reduction of bleeding/spotting days.

RESULTS

Of the 3061 studies identified, eight met our inclusion criteria: six RCTs and two prospective cohort studies. The eight studies enrolled a total of 677 women who were treated with tamoxifen, mifepristone, ulipristal acetate, naproxen, oestradiol, mefenamic acid, tranexamic acid or the progesterone receptor modulator CDB 2914. The results of our analysis indicated that naproxen may be effective for the prophylactic treatment of bleeding immediately (<12 weeks) after LNG-IUS insertion (high level of evidence). Oestradiol may be effective in treating ongoing bleeding irregularities >6 months after insertion (low level of evidence).

CONCLUSION

Evidence for the medical treatment of (ongoing) bleeding irregularities during use of the LNG-IUS is lacking and more research is needed on the topic.