Week 8
Your baby is the size of a raspberry
What's happening this week
Your baby is the size of a raspberry — about 15 to 17mm from crown to rump — and this week marks a massive milestone: every major organ system has now begun to form. Not completed, but started. The heart, brain, lungs, liver, kidneys, intestines — the blueprints are all in place and construction is accelerating.
The most visible change this week is that your baby is starting to look more human. The facial features are becoming more defined — upper lip and nose have formed, eyelids are developing (though they'll stay fused shut for months), and the outer ears are taking shape. The head is still disproportionately large compared to the body, making up nearly half the embryo's total length, because the brain is growing so rapidly.
Those paddle-like arm and leg buds? They're now clearly arms and legs, with elbows beginning to form. At the tips, fingers and toes are emerging — still webbed, but distinctly present. Your baby can make tiny, spontaneous movements now, though you won't feel them for many more weeks.
The tail-like structure that was visible in earlier weeks is almost completely gone. Inside the tiny body, the intestines are still too long for the abdominal cavity and loop into the umbilical cord — they'll retract into the abdomen later. Bone marrow is starting to form within the developing bones. By the end of this week, the embryonic period is nearing its close — next week, your baby will officially graduate from 'embryo' to 'fetus.'
Your body this week
Week 8 is often when morning sickness is at its most relentless. If you're struggling with constant nausea, know that you're at or near the peak — for most people, symptoms begin to improve around weeks 10-12 as hCG levels plateau. That doesn't make right now easier, but there is a light at the end of this particular tunnel.
You might notice your clothes fitting differently, even though you probably don't have a visible bump yet. Bloating and water retention are common, and your uterus — normally the size of a fist — is expanding to accommodate the growing embryo and its support systems. Some people feel a heaviness or fullness in their lower abdomen.
Other symptoms that may appear or intensify this week: heartburn (progesterone relaxes the valve between your stomach and esophagus), constipation (progesterone also slows digestion), and heightened emotional sensitivity. You might cry at a commercial or feel irrationally angry about something small — welcome to the first trimester hormonal rollercoaster.
If your first prenatal appointment is this week, here's what to expect: a full medical history review, blood work (checking blood type, Rh factor, iron levels, and immunity to infections like rubella), a urine test, and possibly your first ultrasound. If they do an ultrasound, you may see or hear cardiac activity — a moment most parents describe as overwhelming in the best possible way.
Remember: if something doesn't feel right, call your provider. That's not overreacting — that's good prenatal care.
For dads
If the first prenatal appointment is this week, be there. Seriously — rearrange your schedule if you need to. This visit is where the pregnancy becomes tangible for most partners. You may see an ultrasound showing cardiac activity. You'll hear the provider talk about due dates and screening tests. And your partner will have a lot of information thrown at her in a short time. Having a second set of ears is genuinely helpful. Take notes on your phone, ask questions, and don't be afraid to speak up. Providers expect and welcome partners who are engaged — it's a sign that this child will have two invested parents.
Your partner is probably at peak misery with first trimester symptoms right now. The nausea, the fatigue, the emotional swings — this is the hardest stretch physically, and it's made worse by the fact that most people haven't shared the news yet, so she's suffering in silence at work and in social settings. You might be one of the only people who knows what she's going through. Honor that by being her safe space. Don't minimize what she's feeling. A simple 'you're doing an incredible job growing a person, and I see how hard this is' goes further than you might think.
Common concerns
Is it normal to feel worse at week 8 than earlier weeks?+
Yes — for many people, morning sickness peaks between weeks 8 and 10. This corresponds to the highest levels of hCG in your system. While it's unpleasant, worsening nausea at this stage is a typical pattern. Most people experience significant improvement by weeks 12-14. If nausea is severely impacting your ability to eat, drink, or function, talk to your provider about safe treatment options.
What will my first ultrasound show?+
At around 8 weeks, a transvaginal ultrasound can typically show the gestational sac, yolk sac, and embryo with visible cardiac activity. Your provider may measure the embryo's crown-to-rump length to confirm your due date. You may also see the tiny arm and leg buds. The image will be small and may not look like much — but that flickering heartbeat is unmistakable.
Is it true my baby has a tail right now?+
Earlier in development, the embryo does have a small tail-like projection — it's a normal part of vertebrate development, not a cause for concern. By week 8, this structure has almost completely receded. It's one of those fascinating developmental remnants that shows how much building and reshaping happens during the embryonic period. By the end of the first trimester, it will be completely gone.
When should I go to the ER instead of calling my doctor?+
Head to the emergency room if you experience heavy bleeding (soaking through a pad in an hour or less), severe or sharp abdominal pain — especially if it's on one side, fever above 101°F (38.3°C) combined with pain or bleeding, or dizziness and fainting. For less urgent concerns — mild cramping, light spotting, persistent nausea — call your provider's office during business hours or their after-hours line. Trust your instincts: if something feels seriously wrong, don't wait.
Product picks for week 8
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Maternity leggings (early fit)
Your regular pants may feel uncomfortable already — soft, stretchy leggings with a low waistband work perfectly for the bloating stage.
Heartburn relief chews
Calcium-based antacid chews that are safe during pregnancy — keep them on your nightstand for middle-of-the-night heartburn.
Pregnancy announcement cards
If you're planning to share the news soon, a set of announcement cards or a fun reveal prop lets you do it in your own way.
A quick note: This content is for informational purposes only and is not a substitute for professional medical advice. Always talk to your healthcare provider about any questions or concerns. Learn how we create our content.
Content based on guidance from the American College of Obstetricians and Gynecologists (ACOG), the American Academy of Pediatrics (AAP), Mayo Clinic, and peer-reviewed medical literature. Learn more about how we create our content.