Jesy Nelson has announced that her previously revealed pregnancy "complications" have "gotten worse," as she now must undergo a procedure for the "best chance" of survival for her unborn twins. On Saturday, March 8, the 33-year-old Little Mix alum was joined by boyfriend Zion Foster for an Instagram video in which she provided an emotional "update on our situation" for fans. The pair first announced in a Jan. 12 post that they were expecting together, alluding to twins in their caption. Then on Wednesday, March 5, Nelson revealed that the unborn babies are monochorionic, diamniotic (MCDA) — meaning each has its own amniotic sac but they share a single placenta, per Columbia University. At the time, Nelson shared in a vulnerable video that "one baby might take all the nutrients" from the single placenta, or "the other might, which — really awful to say — could lead to both babies dying." Now, Nelson is detailing how she's been "feeling a bit poorly the past few days" and noticed "a few of the symptoms I need to watch out for," including her stomach tightening and trouble breathing. "Today, we came into the hospital to have a checkup basically just in case, and unfortunately the symptoms have got worse," Nelson said in her latest update. "They have to perform the procedure, which is obviously not what we wanted to happen. But it’s necessary because it’s going to give our babies the best chance of surviving." "So yeah, we’re just waiting to go in and we’re just hoping and praying for the best, really," she added. The "Boyz" singer added that she was "hoping that we wouldn’t even be in this position," with Foster reiterating that the surgery would give the unborn children the "best chance" of survival. "That’s why they do this procedure, because it literally gives you the best chance of your babies surviving," Nelson added. "But it’s obviously just really scary because there’s so many things that can happen.” Both Nelson and Foster then asked fans to "please" keep them in their prayers. Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories. Earlier this week, in her Wednesday pregnancy update, Nelson informed her followers that she was "pre-stage TTTS," or twin-to-twin transfusion. She was getting "scanned" twice a week and had been "monitored very closely," the musician added. "We feel so blessed that we've been given twins," she said, tearing up. "I'm just really sad that unfortunately, it [can] come with these complications, which we had no idea about. We honestly had no clue that this kind of thing [can happen] when you have twins." In sharing candid updates about Nelson's condition, the parents-to-be said that they ultimately wished to "raise awareness about this because there's so many people that don't know about this." "So we feel it's really important to share our journey with you guys and let [you] know what's happening," Nelson explained. "But like I said, we are just hoping for the best, and we're really fortunate that I am lucky enough to be scanned twice a week and we get to check on the babies." Nelson, who was a member of Little Mix from its 2011 inception until her departure in 2020, has been linked to Foster since January 2022 and the couple has been dating on and off since then, per the Daily Mail. The pair released their collaborative single "Mine" in August 2024.