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Let's be honest, the third trimester is a wild ride. You're huge, you can't see your feet, sleeping is a distant memory, and every little twinge makes you wonder if this is it. Is that a contraction or just gas? Is the baby moving less or just running out of room? It's enough to make anyone a bit of a nervous wreck.
I remember with my first, I spent half the time on the phone with the nurse's line, apologizing for bothering them. Looking back, some of my calls were probably overkill. But others? They were spot on. There's a line between normal third trimester discomfort and genuine danger signs of pregnancy in the third trimester, and knowing where that line is can be the difference between peace of mind and a serious complication.
This isn't meant to scare you. Knowledge is power, right? The goal here is to give you a clear, no-nonsense map of the symptoms that mean "call your doctor now" and the ones that mean "head to the hospital, don't even call first." We're going to break it down, talk about the "why" behind each sign, and hopefully, help you feel more prepared and less anxious.
Stop Reading and Go to the Hospital NOW: The Non-Negotiables
These are the big ones. If you experience any of the following danger signs in your third trimester, do not wait, do not call your doctor first (unless they're in the building), just get to the nearest labor and delivery unit or emergency room. Time is critical.
Heavy Vaginal Bleeding
We're not talking about light spotting or a pinkish tinge on toilet paper (which you should still mention to your doctor, by the way). This is bleeding that's as heavy as a period or heavier, with or without pain. It could be bright red or dark red.
Why it's a major red flag: This could indicate a problem with the placenta, like placenta previa (where the placenta covers the cervix) or placental abruption (where the placenta starts to separate from the uterine wall before birth). Both are serious emergencies for you and the baby. The American College of Obstetricians and Gynecologists (ACOG) is very clear that heavy bleeding requires immediate evaluation.
A Sudden Gush or Constant Leaking of Fluid
If you feel a huge, uncontrollable gush of fluid or a constant trickle that soaks through a pad, your water has likely broken. Sometimes it's obvious, sometimes it's subtle. The fluid is usually clear and odorless, but it can be tinged with white flecks (vernix) or have a slightly sweet smell.
The concern here isn't just that labor is starting. Once your water breaks, the protective barrier between your baby and the outside world is gone, increasing the risk of infection. You need to be assessed to confirm it's amniotic fluid and to check on the baby. They'll also want to know the color—green or brownish fluid can mean the baby has passed meconium (their first stool), which requires extra monitoring.
Severe, Unrelenting Abdominal Pain or Tenderness
Not the dull, achy, "my ligaments are stretching" pain. Not the intermittent cramping of early labor. This is a constant, severe pain in your abdomen or back that doesn't go away. Your belly might feel hard as a rock and stay that way, and it could be tender to the touch.
This is the classic sign of a placental abruption. It's like your body is sounding a five-alarm fire siren. The pain is caused by bleeding behind the placenta. It's rare, but it's one of the most serious danger signs of pregnancy in third trimester.
Trust your gut. If the pain feels wrong, it probably is.Call Your Doctor *Today*: The "Don't Wait Until Tomorrow" Signs
These symptoms might not require a lights-and-siren ambulance ride, but they absolutely warrant a same-day call to your healthcare provider. Don't put it off until your next appointment.
A Significant Decrease in Fetal Movement
This one causes so much anxiety, and for good reason. Your baby's movements are their way of sending you a wellness report. A change is often the first sign they might be under some stress.
What does "significant decrease" mean? It's not just a quiet hour. If your normally active baby becomes unusually still, try the "kick count." Lie on your left side, focus, and count movements. You should feel at least 10 distinct movements (kicks, rolls, swishes) in two hours. If you don't, call. Don't wait the full two hours if you feel nothing at all for a long while.
Some babies do run out of room and their movements change from big kicks to more rolls and stretches. But a drastic drop-off is a key danger sign. The Mayo Clinic advises never to ignore a concerning change in movement patterns.
Visual Disturbances and Severe Headaches
Not every headache is a crisis. Third trimester headaches are common from hormones, dehydration, and sheer exhaustion. But a headache that won't quit with Tylenol, rest, or water? One that's severe, throbbing, and feels "different"? That's a problem.
Pair that headache with vision changes, and the alarm bells should be deafening. We're talking about:
- Seeing spots, flashes of light, or floaters.
- Blurred vision or temporary loss of vision.
- Seeing halos around lights.
These are hallmark symptoms of preeclampsia, a dangerous pregnancy condition characterized by high blood pressure and protein in the urine. It can damage your organs and threaten the baby's supply of oxygen and nutrients. It's one of the top things doctors screen for in the third trimester.
Upper Abdominal Pain, Particularly Under the Ribs
This specific pain, especially on the right side, can be a sign of a related condition called HELLP syndrome (a severe form of preeclampsia) or simply indicate that preeclampsia is affecting your liver. It often feels like a bad stitch or a sharp ache under your ribs. It might be worse when you take a deep breath.
People often confuse it with heartburn or the baby kicking up high, but the key is its persistence and location. Combined with a headache or swelling, it's a triple warning sign.
| Symptom | Possible Cause | Action Required |
|---|---|---|
| Severe headache with vision changes | Preeclampsia | Call doctor immediately, likely need to go to hospital for BP check & urine test. |
| Pain in upper right abdomen | HELLP Syndrome, Liver involvement | Call doctor immediately, requires urgent blood work. |
| Sudden, severe swelling in face/hands | Preeclampsia | Call doctor same day. Distinguish from normal ankle swelling. |
| Fever over 100.4°F (38°C) with no other illness | Intra-amniotic infection (Chorioamnionitis) | Call doctor/go to hospital. Risk to both mother and baby. |
The Gray Area: Symptoms You Should Monitor and Mention
Not everything is a five-alarm fire. Some things are just the uncomfortable reality of the third trimester. But even these "gray area" symptoms can sometimes tip over into being a danger sign of pregnancy in the third trimester, depending on their severity.
Swelling (Edema)
Swollen ankles and feet? Welcome to the club. Increased blood volume and pressure from your uterus on your veins cause this. It's usually worse at the end of the day and better after elevating your feet.
When does it become a danger sign? When the swelling is sudden and severe. If your face (especially around your eyes) becomes puffy, or if your hands swell so much your rings won't come off—and this happens over a day or two, not gradually over weeks—it can be a sign of preeclampsia. Normal swelling tends to be in the lower body and improves with rest.
Contractions Before 37 Weeks
Braxton Hicks contractions are your uterus's practice runs. They're usually irregular, don't get stronger, and go away if you change position or drink water.
Real labor contractions are different. They get longer, stronger, and closer together. If you're having regular, painful contractions (try timing them) and you're less than 37 weeks pregnant, you need to call. This could be preterm labor. Even if they stop, it's worth a check to see if your cervix is changing.
Quick Tip: To time contractions, note when one starts and when the next one starts. That's the frequency. Time how long each contraction lasts. If they're coming every 10 minutes or less, consistently, for an hour, call your provider, especially if preterm.
Itching All Over
Stretching skin itches. Dry skin itches. But intense, unrelenting itching, especially on the palms of your hands and soles of your feet, that gets worse at night is no joke. It could be a sign of Intrahepatic Cholestasis of Pregnancy (ICP).
ICP is a liver condition where bile acids build up in your bloodstream. The main symptom is that maddening itch, often with no rash. It's more than an annoyance; it's associated with a higher risk of stillbirth, so it requires diagnosis via a blood test and close monitoring. If over-the-counter creams do nothing for a total-body itch, mention it to your doctor.
Your Third Trimester Danger Signs Questions, Answered
Putting It All Together: Your Action Plan
So, what do you do with all this information? First, don't let it paralyze you. Most third trimesters progress with a mix of discomfort and excitement, not drama.
Here’s a simple mental checklist:
- Know your baseline: What is your baby's normal movement pattern? What does your normal swelling look like?
- Listen to your body: You know it better than anyone. If something feels "off," pay attention. That internal voice is powerful.
- Have your numbers handy: Keep your OB/GYN's after-hours number and the number for Labor & Delivery triage saved in your phone and posted on the fridge.
- Err on the side of caution: This is the golden rule. It's always the right choice. A trip to triage for monitoring that turns out to be nothing is a win, not a failure.
The last few weeks are about vigilance, not fear. Understanding the real danger signs of pregnancy in third trimester empowers you to advocate for yourself and your baby. It turns vague anxiety into specific awareness. You've got this. Pay attention, trust yourself, and never, ever hesitate to ask for help. That's what your care team is there for.