Pregnant mums less likely to show Covid symptoms, but more go to ICU

Pregnant women seen in hospital with Covid-19 are less likely to show symptoms and may be at an increased risk of being admitted to intensive care, a study has suggested.

Researchers also found that they are more likely to give birth early, with their newborns more likely to be admitted to a neonatal unit.

An international team of researchers, including experts from the World Health Organisation (WHO), reviewed evidence from 77 studies involving more than 11,000 pregnant and recently pregnant women admitted to hospital and diagnosed with suspected or confirmed Covid-19.

Their study found these women were less likely to report symptoms of fever and myalgia (muscle pain), but were more likely to need admission to an intensive care unit and need ventilation, when compared with non-pregnant women of reproductive age.

Being older, overweight, and having pre-existing medical conditions such as hypertension and diabetes also appear to increase the risk of having severe Covid-19 in these women, the findings published in the British Medical Journal (BMJ) show.

The odds of giving birth prematurely were also higher in pregnant and recently pregnant women with Covid-19 compared to those without the disease.

A quarter of all babies born to mothers with Covid-19 were admitted to a neonatal unit and were at increased risk of admission than those born to mothers without the illness.

Professor Shakila Thangaratinam, from the WHO Collaborating Centre for Global Women’s Health, Institute of Metabolism and Systems Research, University of Birmingham, leads the ongoing review.

She explained that for every 100 pregnant women seen in hospital with Covid-19, four get admitted to intensive care, and three need invasive ventilation.

She said 17% had given birth pre-term, or before 37 weeks.

Prof Thangaratinam said early births could be due to a medically dictated reason, but more research was needed to understand why.

But researchers found that “spontaneous pre-term birth”, where mothers just went into labour and delivered without a decision being made, only happened in 6% of cases, similar to among those without Covid-19.

“We also have to remember that these studies are international studies, so it could be policy in a unit for example, if somebody’s got Covid at 36 weeks, they might just go ahead and deliver them,” Prof Thangaratinam said.

The research highlighted that stillbirth and newborn death rates were low.

Addressing potential concerns from mothers, Prof Thangaratinam said: “I think they need to be reassured that the risk of a really bad outcome in terms of death either to themselves or the babies (is) extremely, extremely low.”

She added: “We haven’t seen any major adverse outcome to the baby, we know that a quarter of the babies get admitted to the… neo-natal unit… but it could be just a policy in many hospitals where they separate the baby from the mother.”

“So just an admission to the unit (does) not necessarily mean that baby was affected, it’s just a reflection of the policy,” she said.

Pregnant women are already considered to be a high risk group for severe Covid-19 infection, with concerns over the potential affects of the virus on mothers and children.

Scientists said their “living systematic review” of research in this area will be regularly updated as new evidence emerges.

Researchers acknowledged that some study limitations, such as differences in size, design and symptom definition may have affected their results, but argued the review was strengthened by the large sample size and robust methods.

Prof Thangaratinam said clinicians should be aware that a large proportion of pregnant women might not display Covid-19 symptoms as might be expected in the general population.

She said suitable facilities should also be available to take into account the possible slight higher risk of pregnant women with Covid-19 who may need admission to intensive care.

Researchers also recommended that “mothers with pre-existing comorbidities will need to be considered as a high risk group for Covid-19, along with those who are obese and of greater maternal age”.

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