ANY unusual spike in infant deaths is emotive, and potentially alarming. During a global pandemic, though, it is fodder for antivaxxers.

When the Herald revealed on November 19 that an investigation had been launched into an abnormally high level of neonatal deaths in September, the story went viral with anonymous social media users claiming to know of dozens of cases where seemingly healthy newborns had died suddenly in hospital. Their mothers "were all vaccinated against Covid”.

There is absolutely nothing to substantiate these stories.

However, preliminary investigations appear to have ruled out the likeliest culprit: Covid.

HeraldScotland: Confirmed Covid infections surged in Scotland in August after pandemic restrictions ended and schools returned, peaking at an average of 6,400 per day on September 6Confirmed Covid infections surged in Scotland in August after pandemic restrictions ended and schools returned, peaking at an average of 6,400 per day on September 6

Given a spike in cases during late August, low vaccine uptake in mothers-to-be, and evidence linking the infection to premature births, it seemed like a probable explanation.

READ MORE: Spike in neonatal deaths 'not linked to Covid' in mothers or babies

So what else?

Unhelpfully, the vaccination status of the mothers has not been disclosed.

The Herald requested the information from Public Health Scotland, but was told the agency is "never going to comment on" it due to patient confidentiality.

To vaccine sceptics this lack of transparency will be seized on as evidence of cover up: perhaps the vaccines themselves triggered premature labours?

HeraldScotland: Source: Covid-19 vaccine surveillance report, UK Health Security Agency (England only)Source: Covid-19 vaccine surveillance report, UK Health Security Agency (England only)

An England-wide study published last week found that rates of premature births were indeed around 9% higher in vaccinated than unvaccinated women, but - crucially - the vaccinated women were also more likely to be older and have underlying conditions (both factors which increase the probability of pre-term birth).

The same study also found similar stillbirth rates for vaccinated and unvaccinated women (3.35 and 3.6 per 1,000 births respectively).

A study published in the New England Journal of Medicine (NEJM) in April tracked 827 women given the Pfizer or Moderna vaccines in pregnancy.

There were no neonatal deaths, one stillbirth, 104 miscarriages - of which 96 occurred before 13 weeks gestation - and 10 other baby losses, such as ectopic pregnancy.

These “were similar to incidences reported in studies involving pregnant women that were conducted before the Covid-19 pandemic" and “did not show any obvious safety signals”, said the researchers.

HeraldScotland: Source: Covid-19 Vaccine Surveillance Report, UK Health Security Agency (England only)Source: Covid-19 Vaccine Surveillance Report, UK Health Security Agency (England only)

Dr Sarah Stock, an expert in maternal and foetal medicine at Edinburgh University, said she would feel "extremely confident" to rule out any link between the neonatal mortality spike in September and Covid vaccines.

She said: "We've got very good data coming out from around the world on the safety of the Covid-19 vaccination and there is no evidence of any increase in baby deaths from the Covid vaccines."

READ MORE: Mixed messaged left pregnant women exposed to Delta wave

Dr Stock added that even if Covid infections were not directly responsible, the wider impacts of the pandemic could be.

"We recognise that there are wider impacts in healthcare provision with maternity and neonatal services being extremely stretched at the moment, so I guess that's something that further investigation might look at."

HeraldScotland: The neonatal mortality rate had significantly exceeded expected thresholds in September, triggering an investigation which is still ongoingThe neonatal mortality rate had significantly exceeded expected thresholds in September, triggering an investigation which is still ongoing

Surveillance is ongoing across Scotland's population as a whole into the impact of vaccination or Covid infection on pregnant women and their babies through the 'Covid in Pregnancy in Scotland' study.

Rachel Wood, a public health consultant in maternal and child health for PHS who co-leads the study is clear that the safety data is good.

She said: "We look every month at both the numbers of stillbirths and neonatal deaths following infection and vaccination, and - as we would expect - we are not seeing any concern following vaccination whereas, in line with what we know from the international evidence, there are concerns that stillbirths are increased following Covid infection."

READ MORE: One in four intensive care Covid patients were under-40 during Delta wave

Dr Wood stressed that PHS does not yet have a "definitive answer" as to whether pre-term births really did increase substantially during September.

"Some of the information relies on the definitive hospital discharge records, which take some time to come through," she said.

HeraldScotland: Dr Sarah StockDr Sarah Stock

Further work is also been done to ensure that Covid infections really can be ruled out in the mothers.

It is still possible "but not likely" that the spike in September was an anomaly, added Dr Wood.

"That's really what the point of the warning threshold is: to say 'it's now so unlikely that this is just random chance that we feel it warrants some further investigation.

"There could be all sorts of reasons underlying that, both directly through infection and indirectly through wider impacts [of the pandemic] on wellbeing, stress, resilience of services and so on."