Placenta Previa
Placenta Previa Dos & Don’ts, & What To Expect When You Give Birth
It’s going to be OK.
Expecting parents who are diagnosed with placenta previa, during what was supposed to be just a routine ultrasound, can naturally feel taken aback. Ask your doctor all the questions you want, and get familiar with the placenta previa dos and don’ts to prevent bleeding (like how getting intimate is a no-no until after the baby arrives). It can be nerve-wracking to hear you have any high-risk condition during pregnancy. With placenta previa, having a healthy pregnancy and delivery is all about taking precautions and finding the right place to give birth.
What is placenta previa?
During pregnancy, the placenta grows inside and attaches to the wall of the uterus, where it provides oxygen and nutrients to the fetus. Placenta previa happens when the placenta attaches lower than usual in the uterus, and is partially or completely covering the cervix , according to the American College of Obstetrics and Gynecology (ACOG).
“Placenta previa in general happens in about 0.5% of all pregnancies,” says Dr. Victor Feldbaum, M.D., board-certified OB-GYN and department chair of obstetrics and gynecology at Bayfront Health. “Placenta previa is something where the placenta covers a portion of the cervix, and there are different definitions in terms of where that can be.”
It’s not known why the placenta attaches lower than it should, Feldbaum says, but there are some factors that can make it more likely. These include:
- Being pregnant at 35 or older.
- Carrying twins or multiples.
- Having a history of surgery involving the uterus, like C-sections.
- Having five or more pregnancies.
- Previously having placenta previa.
- Short interval pregnancy.
Placenta previa can cause bleeding during the pregnancy, and increases the risk of hemorrhaging during birth.
“Rarely, you can have heavy bleeding during pregnancy to the point that it could require emergency surgery and blood transfusions,” says Dr. Daniela Carusi, M.D., MSc, board-certified OB-GYN, director of surgical obstetrics and placental abnormalities at Brigham and Women’s Hospital, and associate professor of obstetrics and gynecology at Harvard Medical School. “At delivery, patients who have placenta previa — they usually always have C-sections — are at high risk for a postpartum hemorrhage. The chance of having a blood transfusion at delivery is much higher than it is for the general population. For the baby, placenta previa doesn’t tend to directly harm them. The biggest issue for the baby is prematurity if the mom is bleeding enough that she has to have an early C-section. In these rare events where the mother hemorrhages during pregnancy and loses a lot of blood, the baby can have distress.”
Placenta previa types
If you’re reading up on placenta previa online, you might see a few different terms used to describe the types of placenta previa: marginal, partial, or complete placenta previa. They’re actually not different conditions, but a way to describe how much of the cervix is covered by your placenta.
“You can have a complete placenta previa, where the placenta completely goes over the cervix and covers it, and then there used to be a term called partial placenta previa where it might just be partially covered, and marginal placenta previa where the cervix is not covered with the placenta, but it's within 2 centimeters of that area. Basically, all three of those terms tell you that there is something wrong with where the placenta is located, and so if it's covering the cervix in any shape or form or it's close to that cervix, it creates a risk for the patient.”
Many OB-GYNs, Feldbaum included, are moving away from these three terms you’ll see often online and now use different terminology.
“They used to say, complete, marginal, or partial placenta previa, and now they’ve gotten rid of those words and they’ll say you have placenta previa or low lying placenta. Low lying placenta means the placenta is within 2 centimeters of the cervix, and with previa, it’s covered,” says Carusi.
Placenta previa can cause bleeding during the pregnancy, and may require some changes to your lifestyle and birth plan , experts say.
Placenta previa symptoms
For most parents-to-be, the only symptom of placenta previa is bright red vaginal bleeding that is totally painless. There are also people with placenta previa who never experience bleeding at all, these experts say.
“I would say that is the symptom,” says Carusi. “Other than that, patients usually don't feel anything. I do have patients — usually patients who've had babies before, and especially those who've had C-sections before who have a complete previa — who tell me they feel a lot of pressure in their low pelvis. Sometimes it can be aching, sometimes it's a little bit painful. I think it's just all that stretching of their lower uterus from the placenta being down there. And when they've had surgery there before, they can feel it more than other people would.”
Usually, placenta previa is diagnosed before you ever experience bleeding (or, in those rare cases, pelvic pressure).
“Most patients will have an ultrasound around 16 to 20 weeks to look for the baby anyway, and it’s the standard of care now that everybody should have their placenta location checked [during this ultrasound],” says Carusi. “If we do see it at 16 weeks, then we usually repeat an ultrasound to check it sometime between 28 and 32 weeks.”
Placenta previa treatment
There’s no “cure” to make placenta previa go away, but Feldbaum and Carusi agree that it can sometimes improve on its own. “As you progress in pregnancy, the uterus grows, and as the uterus grows, the placenta kind of grows with it and it can sometimes basically get pulled upward away from the cervix,” says Feldbaum. “So, with that you see marginal placenta previa sometimes going away. You can have partial and complete placenta previa sometimes improving or going away.”
If you’re not bleeding, placenta previa can be managed at home. If you are bleeding, you’ll need to be monitored more closely. “If someone's bleeding after 24 weeks, we'll often put them in the hospital,” says Carusi. “It might just be for a couple days because we bring them in, realize the bleeding has completely stopped and they look great, and we'll send them back home. There are patients who are in and out of the hospital multiple times because their bleeding keeps stopping and starting. There are patients who have to almost live in the hospital because their bleeding is there almost every day or they live far away. And if the patient lives an hour or more away and she's bleeding from a previa, it's probably safer to be in the hospital than far away from the hospital.”
When it comes to delivering your baby (and the placenta), Carusi says some OB-GYNs are OK with letting patients with low lying placentas attempt a vaginal birth. But for patients with placenta previa, a C-section is the most common way to deliver.
“The placenta is covering the cervix, so if you try pushing the baby into that, you're going to get more bleeding and eventually the baby's not going to get nutrients or blood supply, so not a good idea,” says Feldbaum.
Placenta previa dos and don’ts
Since waiting it out or delivering your baby are the only ways to get rid of placenta previa, doctors want parents to focus on managing the condition. Here are their guidelines:
Don’t: Have sex, use tampons, or put anything in your vagina.
Carusi and Feldbaum agree that people with placenta previa need to go on what they call “pelvic rest,” meaning nothing should enter your vagina (yep, that means no intercourse ). There’s no rule about when pelvic rest should begin; some doctors prescribe it as soon as they discover you have placenta previa, and others wait a little longer. Carusi adds that anyone with placenta previa who is experiencing bleeding before that 28-week mark should also be on pelvic rest.
“The concern is that if the patient has intercourse or puts anything in their vagina, that it could put pressure on the placenta or disrupt it and make it start bleeding,” Carusi says. “That risk goes up as the pregnancy gets further along. So, I think most people across the board agree that if the patient reaches the third trimester — so they get past 28 weeks and still have a previa — that they should be on pelvic rest. That's what I usually tell my patients.”
Do: Find a hospital that can handle high-risk deliveries.
Both doctors also recommend giving birth at a hospital that specializes in high-risk deliveries — these would be hospitals designated a level three or four maternal care hospital by ACOG and the Society for Maternal-Fetal Medicine (SMFM). Carusi says these facilities are best equipped to handle potential complications from placenta previa, like hemorrhaging. You can ask your OB-GYN for recommendations about where to give birth, or talk to hospital staff about their maternal care level if you tour their labor and delivery unit.
Don’t: Think you have to go on bed rest.
If you like to be active or have a job that keeps you moving all day, you might wonder if it’s safe to continue with your usual routine.
“We don't really have any evidence that bed rest is helpful for previa patients,” Carusi says. “I think people just put themselves on bed rest or their doctors tell them, ‘You can't exercise. You can't do heavy housework. You can't commute to work if you have a previa.’ And there's really no medical evidence for that. Other than the pelvic rest part, I let my patients do all their usual activities. If they start having bleeding during their pregnancy, then we might have to restrict some activity, especially if they bleed every time they're active. But for the general patient, it's not something they need to do.”
Do: Talk to friends, family, and employers about your placenta previa.
Carusi tells her patients with placenta previa that, especially if they're bleeding during pregnancy, they may need to make special arrangements with work, or organize care for older children should they need to be hospitalized.
Both doctors emphasize that if you have any bleeding during pregnancy, you should call your OB-GYN and head to your nearest emergency room. “The most important thing is if you have any kind of bleeding, come in to triage and get that evaluated,” Feldbaum says. “It can be a sign of labor or early labor, or a sign of something like abruption or placenta previa.”
Dr. Daniela Carusi, M.D., MSc, board-certified OB-GYN, director of surgical obstetrics and placental abnormalities at Brigham and Women’s Hospital, and associate professor of obstetrics and gynecology at Harvard Medical School
Dr. Victor Feldbaum, M.D., board-certified OB-GYN and department chair of obstetrics and gynecology at Bayfront Health
This article was originally published on March 1, 2023