It started with sniffles in early May.

A week later, she was on a ventilator at Virtua Voorhees Hospital, fighting for her life – and the life of her unborn child.

She shared the harrowing details of her COVID-19 ordeal in hopes of helping other pregnant people avoid what happened to her. The airlift to the Hospital of the University of Pennsylvania. The emergency cesarean section to deliver her son, 10 weeks early. The hemorrhage. The lung embolism. The six weeks on life support. The separation from loved ones. And now, the ongoing struggle to recover from the debilitating physical, cognitive, and mental health after-effects of intensive care.

She knows well that vaccination during pregnancy is an anguishing decision. But she now believes pregnant people should do what she did not do – get vaccinated. As she grapples with COVID’s many effects, she asked that her name not be used.

“I don’t think I am mentally ready for any type of negative feedback from anyone,” she said.

The highly contagious delta variant is fueling a small but noticeable increase in unvaccinated, severely ill pregnant COVID-19 patients across the country. And that trend, not seen in previous pandemic surges, is changing the difficult balancing act faced by expectant parents, eager to do whatever is best for both mother and unborn child.

Pregnancy involves physiologic changes, particularly in the immune system, that can increase vulnerability to severe illness. What’s more, the mother’s immune system protects her newborn with antibodies shared through the placenta. That’s why some immunizations, such as flu and whooping cough, are highly recommended before delivery.

Initially, though, the coronavirus defied expectations. The chance of severe COVID-19 in pregnancy was low – albeit higher than in nonpregnant young people – even though a surprisingly high percentage of patients tested positive when they arrived to deliver at a hospital.

A Mount Sinai study of 130 women, conducted last fall at a public hospital in Queens, N.Y., found more than a third tested positive for COVID-19, yet 72% had no symptoms. A U.S. Centers for Disease Control and Prevention analysis found more than half of 548 hospitalized pregnant women who tested positive were asymptomatic.

That CDC analysis also found COVID-19 was rare in newborns of infected mothers, suggesting perinatal transmission was uncommon. And infants who did test positive usually “had mild or no symptoms and recovered.”

No wonder that when the Pfizer and Moderna vaccines became available in December, pregnant people and many of their obstetricians thought the risks outweighed the benefits. Why get a novel immunization that wasn’t tested on pregnant people to ward off a virus that seemed relatively inconsequential for mother and child?

These days, the calculus is different.

With the delta variant dominant across the country, hospitals are reporting that young, healthy, unvaccinated pregnant people are winding up on ventilators, delivering prematurely, even dying of COVID-19.

Meanwhile, compelling new data show the shots are safe and protect against severe disease in pregnancy. The CDC, the American College of Obstetricians and Gynecologists, and the Society for Maternal and Fetal Medicine now recommend pregnant people get inoculated.

Yet less than a quarter of them do so. That much has not changed, 20 months into the pandemic.

At Virtua Health, the South Jersey network with maternity services at three hospitals, three unvaccinated, severely ill pregnant COVID-19 patients were in intensive care in the past four months, compared to five in the prior 18 months.

Between 15% and 20% of Virtua’s maternity patients are vaccinated – and that’s an increase since vaccines first became available, said ob-gyn Nicole Lamborne, Virtua’s vice president of clinical operations for women’s services.

Even though the Pfizer and Moderna vaccines have stellar safety profiles in pregnancy — and any problems would likely have emerged by now — history offers cautionary tales about unforeseen side effects of other drugs. A notorious example is thalidomide, prescribed to relieve morning sickness in the late 1950s and 1960s. It caused horrific birth defects in thousands of babies, although very few in this country, thanks to vigilant U.S. regulators who saw the unfolding disaster in Europe.

“The scary part is that there are medicines we treated women with in the past that turned out to be harmful and cause birth defects,” Lamborne said. “I think the reason patients as well as ob-gyns have been reluctant about COVID-19 vaccination is that we don’t know what’s going to happen 10 years down the line.”

On the other hand, she said, prenatal research and drug development have come a long way. Elaborate lab studies in cells and animals are designed to detect potential problems.

“We know how to study and monitor effects,” Lamborne said. “We have better data and we know early on.”

Now that medical authorities unanimously recommend vaccination in pregnancy, Lamborne and her colleagues counsel their patients differently than earlier in the pandemic, when the only sure safeguard was living like a hermit for nine months.

“Now,” she said, “we know pregnancy is a risk factor for severe COVID-19, and the safety profile of the vaccines” is clear.

The Virtua patient who was airlifted to Penn got pregnant in November, before the Pfizer and Moderna vaccines received emergency authorization.

By May, her husband and many relatives were fully vaccinated. Although she worried that there could be unknown effects, she, too, intended to get the shots. She figured she was in her final trimester and all indicators were that the baby was healthy.

“I thought about getting vaccinated. I researched it,” she said. “Truly, as bad an excuse as it is, life just got busy. We had just moved into our house, I had a toddler, and I was also watching my niece. It was like, when can I get to Walgreens?”

She has no memory of her weeks on a ventilator. On June 17, when she was breathing on her own and her sedation was reduced, she regained consciousness, thinking she was still pregnant.

She couldn’t talk because a tube, or tracheostomy, had been implanted in her neck so she could be connected to the ventilator. But she quickly learned she had a son, weighing less than 3 pounds, in the neonatal intensive care unit. Like her, he was tethered to a myriad of tubes and wires.

“It’s still very raw,” she said of that traumatic reawakening. “The sedation was living hell for my family. For me, it was just black. The hell started for me when I woke up.”

She spent three weeks in a rehabilitation center, doing three hours a day of physical and occupational therapy, plus speech therapy and tests to evaluate her thinking and memory. She was put on medications to relieve her anxiety attacks, depression, and insomnia.

“Every day, I struggled and thought: I will never be the parent I want to be again,” she recalled.

At this point, she knows that isn’t true. And her “miracle” baby, now nine pounds, is at home, thriving, with no apparent problems.

Still, she is profoundly changed in ways that she could never have imagined, and that people who can’t relate don’t understand.

“Physically, every day is an improvement,” she said. “But mentally, I’ll never be ‘recovered’ from this.”

She has begun to use social media again, because it no longer tortures her to see posts about happy pregnancies and births. But it still upsets her to read judgmental, insensitive opinions about getting, or not getting, vaccinated. That influenced her decision to remain anonymous in this story.

“Posts like, ‘COVID-19 patients don’t deserve hospital beds.’ Or ‘If parents don’t get the vaccine, it’s child abuse,’ ” she said, adding that she got her first shot two weeks ago. “I know it’s not directed at me, but that’s the PTSD [post traumatic stress disorder] of being a survivor” of life-threatening COVID-19.