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A 35-year-old primigravid woman had a dichorionic diamniotic twin pregnancy with Glanzmann thrombasthenia (GT). She underwent elective caesarean section (CS) under general anaesthesia at 36 + 5 weeks of gestation.

Recombinant factor VIIa and tranexamic acid were administered preoperatively. Pre-emptive uterotonic agents were administered intraoperatively to minimise haemorrhage. Postpartum management included a 7-week course of tranexamic acid.

The case report by Vicky X. Xu, a clinical research fellow at the Pregnancy Research Centre, Department of Maternal-Fetal Medicine, Royal Women’s Hospital, Melbourne, Australia, and colleagues highlights the importance of multidisciplinary care planned to optimise pregnancy outcomes in women with GT, with a focus on minimising the risk for severe haemorrhage.

The Patient and His History

The patient had GT in a dichorionic, diamniotic twin pregnancy. She was referred to a tertiary-level maternity service for pregnancy management.

She had been diagnosed with GT prior to pregnancy, had a history of menorrhagia, and was managed with iron infusions, high-dose progestogens, and continuous use of the combined oral contraceptive pill.

Previously, the patient had received platelet transfusions before minor surgical procedures and tranexamic acid postoperatively. Her only reported relevant family history was that her father bruised easily.

During pregnancy, the patient experienced epistaxis requiring minimal management; otherwise, she experienced no bleeding episodes.

She was Rhesus positive, her routine antenatal test results were unremarkable, and her mid-trimester ultrasound scan revealed normal morphology in both twins.

Serial ultrasound scans at 25, 30, and 35 weeks of gestation demonstrated well-grown and biophysically healthy babies with normal interval growth.

At 35 weeks, twin A had an estimated foetal weight (EFW) of 2382 g (60th percentile), and twin B had an EFW of 2431 g (65th percentile). Both were cephalic, with normal amniotic fluid volumes and umbilical cord Doppler blood flow readings.

Findings and Diagnosis

The patient received multidisciplinary antenatal care involving maternal-foetal medicine, haematology, and anaesthetic services. A mutually agreed delivery plan was developed in consultation with the patient and her care team. An anaesthetic review determined that spinal neuraxial analgesia was not appropriate because of her bleeding risk, so CS under general anaesthesia was planned.

Her CS was scheduled at 36 + 5 weeks to reduce the risk for spontaneous labour and the need for an emergency CS. She was placed first on the operating list with senior clinicians who were rostered to perform and attend her surgery.

Postoperatively, she was admitted to the complex care unit (CCU) for increased monitoring during the first 3 postpartum days.

Perioperative management for her GT included recombinant factor VIIa before and after surgery: 7 g intravenously every 4 hours for 48 hours post-CS, followed by 7 mg intravenously every 6 hours for 24 hours, after which it was stopped.

Tranexamic acid was administered preoperatively and continued at 1 g three times a day for 7 weeks postoperatively. Pneumatic compression stockings were used both intraoperatively and postoperatively.

Enoxaparin, aspirin, and other nonsteroidal anti-inflammatory drugs were contraindicated and not prescribed.

Her CS was uncomplicated, with an estimated blood loss of 400 mL.

Twin A had Appearance, Pulse, Grimace, Activity, and Respiration (APGAR) scores of 6 and 6 and weighed 2.9 kg. Twin B had APGAR scores of 1 and 4 and weighed 2.7 kg.

Both twins required brief intermittent positive pressure ventilation followed by continuous positive airway pressure. They were admitted to the special care nursery for prematurity and hypoglycaemia, with twin B having additional concerns of hypothermia and risk for sepsis.

Twin B had a platelet count of 99 (with platelet clumps) on day 2 of life, which improved to 196 on day 5. Twin A did not require a complete blood cell count. Postpartum, the patient had mild epistaxis, petechiae, and bruising at her wound site, all of which resolved spontaneously.

She was followed up in the outpatient haematology clinic 4 weeks postpartum and recovered without complications.

Discussion

“This case report describes a coordinated, multidisciplinary approach to mitigate risks of peripartum haemorrhage in particular in a woman with GT (a bleeding disorder) and a twin pregnancy (risk for uterine atony). A CS under general anaesthesia with a senior and experienced surgical team, predelivery haemorrhage prophylaxis, uterotonics intraoperatively, as well as postoperative recombinant factor VIIa and tranexamic treatment in association with CCU monitoring, optimised conditions for the patient to minimise her risk of severe haemorrhage,” the authors concluded.

This article was translated from Univadis Germany.

Researchers at the University of British Columbia have shown that our gut bacteria can feed on these large molecules — something thought to not be possible — thanks to enzymes that normally help us break down dietary fiber.

“Researchers assumed that these thickening agents, which are artificial derivatives of natural cellulose, just pass right through the digestive system unaltered,” says Dr. Deepesh Panwar, a postdoctoral fellow at the Michael Smith Laboratories and lead author of the study published in the Journal of Bacteriology. “But our study provides a first glimpse at how these food additives are actually digested by our gut bacteria thanks to natural polysaccharides in our diets.”

The complex structure of these cellulose derivatives is what makes them valuable as thickening agents in popular products like ketchup, salad dressing and even toothpaste. This structure is also why gut bacteria have a harder time breaking them down — and why in higher concentrations, they’re even used as laxatives.

This new in vitro study, however, shows that if our gut bacteria are ‘primed’ with natural polysaccharides — long chains of sugars found in fruits, vegetables and cereals — the cellulose derivatives can be digested. This is because the natural polysaccharides activate enzymes that are produced on bacteria cell surfaces that can also break down artificial cellulose molecules.

The findings don’t challenge the fact that these compounds are safe to consume, proven by years of testing and history of use. However, the new research suggests that more work should be done to explore the physical, chemical and biological effects of the digestion of cellulose derivatives by gut bacteria.

One reason researchers may not have seen this before is because bacteria in the lab are often exposed to polysaccharides, including cellulose derivatives, in isolation, instead of in combinations that mimic our diet. On their own, these cellulose derivatives can’t activate the same enzymes, preventing their digestion.

“It was really unexpected for us to see that these cellulose derivatives are in fact used as a source of sugar for bacterial growth,” says Dr. Harry Brumer, a professor in the Michael Smith Laboratories and Department of Chemistry. “It is always a surprise when a new finding goes against the conventional wisdom, in this case showing that these common additives are not just inactive thickeners.”

Dr. Brumer also notes that the next steps in this research will be to look for this ability in a wider range of human gut bacteria, and eventually explore potential effects on nutrition in people.

So, next time you pair a green salad with a sweet dressing, know that your gut bacteria are hard at work helping to break down all parts of your meal.