When Alix Mellor fell ill with COVID, she cycled through the full gambit of symptoms: coughing throughout the night, soaring temperatures and unforgiving physical fatigue.
But it was the thing she couldn't feel that really made her worry. Days into the infection and 34 weeks pregnant, she noticed her baby was uncharacteristically still.
"I called the midwives and they said to come into the hospital and they did some fetal monitoring to make sure the baby is OK," the Melbourne mother says. "It was in my mind that it's not just about me, it's about the baby."
It was the second time in three weeks the Melbourne mother had found herself at the hospital with a respiratory illness. The first was with a nasty bout of influenza which saw her hospitalised for four days with a "really high pulse rate".
Women who test positive for COVID while pregnant have a higher risk of hospitalisation and ventilation than those who aren't pregnant and are also at greater risk of premature birth and stillbirth. It's a similar situation for the flu, which can be deadly for expectant mothers.
And now, as COVID cases once again trend upwards with the arrival of new Omicron subvariants BA.4 and BA.5, and Australia braces for a bumper flu season, pregnant women have been left to decide whether to attempt to limit their contact with the outside world or risk contracting the virus.
Alix was well aware of her increased vulnerability and had been trying to take precautions to limit her exposure to the disease. She has also received three COVID vaccine doses — she tested positive just before she became eligible for her fourth — which research shows significantly reduces the risk of severe disease and pregnancy complications.
"I managed to avoid COVID and the flu for the last few years, then, of course, at the very end of the pregnancy, I got it," she says. "Congestion and coughing all through the night, when I'm already uncomfortable, it's not fun."
Alix's unborn baby thankfully appears to be healthy — but two weeks since testing positive for COVID, the 38-year-old still hasn't fully recovered.
And with a four-week countdown to the birth, she's desperately hoping her symptoms subside sooner rather than later.
What we know about pregnancy and COVID
The link between COVID, pregnancy and an increased risk of complications has been apparent since early in the pandemic. This includes higher rates of premature births and stillbirths in women who test positive while pregnant, as well as higher rates of hospitalisation and ventilation.
"All the sorts of bad things that you don't want to happen when you're pregnant can happen if you layer COVID on pregnancy in an unvaccinated population," says Professor Caroline Homer, a co-program director of maternal, child and adolescent health at the Burnet Institute.
There are a number of reasons why this is the case. During pregnancy, the cardiovascular and respiratory systems are already working overtime to provide for the fetus. Then, as the baby grows, the mother's lung capacity is further reduced as the fetus takes up more space in the body.
"You lose some of that lung expansion and you can't breathe in as much as you usually could," Professor Homer says. "So when you get COVID, and you get pneumonia or a lung infection, you're unable to clear it as easily when you're pregnant — particularly in that last third of pregnancy."
When there's an inflammatory response in the body, say from COVID or other illnesses, the body can also respond by going into early labour. High temperatures in the mother, particularly in early pregnancy, have also been linked to abnormalities later on.
"If the mother's sick, the baby is sick as well, the baby's oxygen levels are completely dependent on that of the mothers," says Lisa Hui, an Associate Professor in obstetrics and gynaecology at the University of Melbourne.
"That's part of the reason why babies might need to be born prematurely; because they're being compromised due to maternal illness but also the mother might not be able to cope with her own illness and support the baby at the same time."
Vaccination benefits the mother — and the unborn baby
The good news, according to Professor Homer, is vaccination goes a long way to reducing severe COVID symptoms in the mother — which then reduces the likelihood of harm to the unborn baby.
"Vaccination reduces all the risks hugely, it probably doesn't take everything away, but it makes an enormous difference," she says. "And it doesn't seem to have any adverse effects on the baby or the mother."
A recent Victorian study, led by Associate Professor Hui, looked at data from 12 Melbourne maternity hospitals between July 2021 and March this year and found no increase in birth defects or fetal growth restrictions in vaccinated pregnant women.
The study, which is yet to be peer-reviewed, also found vaccinated women had significantly lower stillbirth and pre-term birth rates and a lower rate of catching COVID during pregnancy compared to their unvaccinated peers.
Of women who caught COVID while pregnant, 2.3 per cent of vaccinated women had a preterm baby compared to 7 per cent of unvaccinated women, according to the report.
Associate Professor Hui attributes some of the findings to the biological effects of the vaccine — that it reduces the risk of severe COVID disease which is associated with pre-term birth and stillbirth — but says "it's probably not the complete story".
"We know that one of the biggest influences on whether a pregnant woman decides to have a vaccination during pregnancy or not is the quality of the relationship she has with her maternity care provider … so the women who didn't get vaccinated may actually be in a group that is less engaged with antenatal care or is maybe feeling marginalised," she says.
"The results of our study have two important messages: one is that it gives us, as health professionals in the community, confidence that vaccination during pregnancy is safe but it is also a message to the healthcare system that we need to try harder to look after women that haven't been vaccinated."
A study published in the New England Journal of Medicine last week has also shown that the antibodies generated after vaccination during pregnancy can pass through the placenta to the baby, which results in a reduction of COVID hospitalisation in infants under six months old.
"That's a similar mechanism to what happens with influenza vaccination during pregnancy, it leads to a boost in the mother's own production of these antibodies, they cross the placenta, and the baby is born with protection," Associate Professor Hui says.
"We have the data now and it's all very reassuring; by getting vaccinated during pregnancy you protect the mother, you protect the unborn baby and you protect your newborn."
The 'flurona' double threat
At the moment, Professor Homer says it's "pretty uncommon" for pregnant women to be hospitalised for COVID. But there's another viral disease going around that poses an equal danger — influenza.
Alix was unlucky enough to catch both in short succession.
"It's been six weeks of being really unwell," she says. "I can't really do much at all, it's sort of ruining the last part of the pregnancy."
The combination of the COVID pandemic and a bigger-than-usual flu season has experts worried about simultaneous infections of influenza and COVID — dubbed "flurona".
A dose of this Frankenstein illness would be particularly dangerous for pregnant women, who are more at risk of death and severe illness from the flu.
The annual influenza vaccine has been recommended for pregnant women for the last decade, and Professor Homer says it's particularly important this year as "we're seeing influenza in the community at very high levels".
With people over 30 now able to access a fourth COVID vaccine dose, she also urges all pregnant people to take it up as soon as possible. "Pregnancy is not a reason to delay getting those booster doses," she says, "because we know that having boosters on board makes your symptoms a whole lot less".
Vaccinated or not, pregnant women who catch COVID should seek advice from their midwife or doctor. In many hospitals, this will trigger a check-in system where the mother receives extra monitoring during their illness.
With the increase in COVID and flu cases, Associate Professor Hui also recommends employing additional social distancing strategies and wearing a mask when this isn't possible.
For Alix, the advice from her obstetrician has been to rest, drink lots of fluid, take Panadol for fevers and "just be patient". "My immune system is already suppressed being pregnant, then having flu and COVID on top of that, it's normal to be exhausted and for it to take time," she says.
But, if at any point the baby stops moving, her heart rate goes up, or she starts to feel really unwell, it's back to the hospital.
"I feel like I've done what I can, there's not much more I can do other than rest," she says. "But preparing for the birth is a marathon in itself, and I've got a daughter already, I need to rest but it's not easy."
