Pregnancy5 min read

34 weeks pregnant: preeclampsia warning signs

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Quick answer: Week 34: BP numbers to watch, headache & vision changes, protein in urine, when to go in.

Week 34 — you’re in the third trimester, the final stretch. Your baby is gaining weight rapidly, your body is working harder than ever, and the finish line is in sight. It’s completely normal to feel a mix of excitement, anxiety, and ‘let’s just get this done.’

Baby Development This Week

At week 34, your baby is approximately the size of a cantaloupe — measuring around 17.7 in / 45cm. Lung development nearly complete. Survival outside womb is over 99%. Growth and final organ maturation are the priorities now. Your baby gains approximately half a pound per week from week 28 onward, laying down the fat deposits that will regulate body temperature after birth.

Symptoms You May Feel

Third trimester week 34 commonly brings: shortness of breath as the uterus presses against the diaphragm (improves when baby drops lower, usually weeks 36–38 for first pregnancies), heartburn at its peak as the stomach is compressed, frequent urination returning with a vengeance, swollen ankles and feet from fluid retention and venous compression, pelvic pressure and occasional ‘lightning crotch’ (sharp nerve pain), Braxton Hicks becoming more frequent and sometimes intense, carpal tunnel syndrome from fluid pressing on wrist nerves, and sleep disruption from physical discomfort and frequent waking.

BP numbers to watch, headache & vision changes, protein in urine, when to go in

Preeclampsia affects approximately 5–8% of pregnancies and most commonly develops after 34 weeks. Warning signs requiring immediate OB contact: severe headache unresponsive to acetaminophen, visual disturbances (spots, blurring, flashing lights), sudden significant swelling especially of the face and hands, upper abdominal pain (right side, below the ribs), and reduced fetal movement. Blood pressure above 140/90 on two readings 4 hours apart, combined with protein in urine, confirms the diagnosis. Severe preeclampsia (BP ≥160/110 or organ involvement) requires hospitalization and often delivery regardless of gestational age. Regular blood pressure monitoring at each OB visit is the primary screening tool.

How do I know if I’m in labor at week 34?

At 34 weeks, labor is still considered preterm and your OB will likely attempt to delay it for at least 48 hours (to allow steroid injections to mature the baby’s lungs if there’s time). Signs: regular contractions, pelvic pressure increasing, fluid loss, loss of mucus plug (can look bloody — ‘bloody show’). Babies born at 34 weeks typically need 2–3 weeks of NICU care for feeding and breathing support; long-term outcomes are generally excellent. If you haven’t started the hospital bag, do it this week.

Practical Tips for Week 34

  • Sleep on your left side — it optimizes blood flow to the placenta and reduces vena cava compression.
  • Start kick counts from week 28 — 10 movements in 2 hours is the standard guideline; call your provider if concerned.
  • Pack your hospital bag by week 35 — babies don’t always wait until their due date.
  • Practice perineal massage from week 34 to reduce tearing risk at birth.
  • Attend all prenatal appointments — monitoring frequency increases in the third trimester for good reason.
  • Discuss your birth preferences with your provider before week 36.

When to Call Your Midwife or OB

In the third trimester, call your provider immediately for: fewer than 10 fetal movements in 2 hours, regular painful contractions before 37 weeks, severe persistent headache with visual changes or facial swelling (preeclampsia warning signs), any bleeding, signs of water breaking, or any gut feeling that something isn’t right. From week 34, always err on the side of calling — your team would always rather you check in unnecessarily than miss something important.

Frequently Asked Questions

How do I know if I’m in labor?

True labor contractions are regular, progressively stronger, longer, and closer together — and they don’t stop with rest, hydration, or position changes (unlike Braxton Hicks). They typically start every 10–15 minutes and intensify over hours. Other labor signs include: bloody show (pink-tinged mucus from the cervical plug), your water breaking, and lower back pain that radiates to the front. The 5-1-1 rule for hospital: contractions every 5 minutes, lasting 1 minute, for 1 hour.

Is extreme fatigue normal at week 34?

Absolutely. Third trimester fatigue combines extra physical weight, disrupted sleep, frequent urination, and the enormous metabolic cost of a baby gaining half a pound weekly. Your cardiac output is 30–50% above baseline, your kidneys filter 50% more blood, and your body produces extra blood, hormones, and nutrients continuously. Rest is not laziness at this stage — it is medically appropriate preparation.

What is the mucus plug and when does it come out?

The mucus plug is a thick collection of cervical mucus that seals the cervix throughout pregnancy to protect against infection. It can come out days or even weeks before labor, or during early labor itself. It may be clear, white, yellow, or tinged with pink or brown blood. Losing it doesn’t mean labor is imminent, but it does mean your cervix is beginning to prepare. Any bright red bleeding should always be reported to your provider.

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Medical context only

This content supports decision-making but does not replace advice from your GP, midwife, health visitor or paediatric clinician.