Pregnancy Week 5: Your Baby's Heart Begins — What to Expect

▶ Watch the week-by-week video series on YouTube: https://www.youtube.com/@HelloBumpAndBloom

A sesame seed with a heartbeat — that's your baby this week. Week 5 is small on the outside and monumental on the inside. Here's your calm, complete guide.

Your baby this week. Your baby is about the size of a sesame seed. The headline event: the heart tube forms and begins its very first beats — not yet the steady rhythm you'll hear at an ultrasound, but the beginning of it. At the same time, the neural tube is forming along your baby's back; over the coming weeks it becomes the brain and spinal cord. The basic body plan — head end, tail end, the curve of a tiny body — is taking shape.

Your body & symptoms: the first wave arrives. This is often the week symptoms check in: tender breasts, a tiredness that naps don't fix, more trips to the bathroom, heightened smell, and for many moms the first queasiness. Some moms still feel nothing at all — both experiences are completely normal at week 5.

The neural tube & why folic acid matters now. The neural tube closes in these very early weeks — often before women even know they're pregnant — which is why folic acid is recommended before conception and through the first trimester. It significantly reduces the risk of neural tube defects. If you haven't started, start today; you're still in the window where it matters most.

Choosing your provider & booking your first visit. Decide who will care for you — an OB-GYN, a midwife, or your family doctor, depending on your health and where you plan to give birth — and book the first prenatal visit, usually scheduled for around weeks 8–10. Write down your questions as they occur to you; no question is too small.

Warning signs. Heavy bleeding, severe or worsening pain, pain on one side, fainting, or vomiting so much you can't keep fluids down — call your provider the same day.

Next up: Week 6, and the first heartbeat flicker.

Key takeaways:

• Your baby's heart tube is beginning its first beats; the neural tube is forming
• Folic acid matters most right now, while the neural tube is closing
• The first wave of symptoms is normal — and so is feeling nothing yet
• Choose your provider and book your first prenatal visit (usually weeks 8–10)

Watch the full week-by-week series on Bump & Bloom: https://www.youtube.com/@HelloBumpAndBloom — and for your older little one while you rest, see our activity books: https://www.amazon.com/author/tanvirahmed

General information only, not medical advice. Always follow your own doctor or midwife for personal care.