Week 9: No Longer an Embryo
Your baby officially graduates from embryo to fetus! All essential organs have begun forming. Tiny earlobes, toes, and even tooth buds are developing.
Medically reviewed by Samantha L. Fox, RN, BSN, MSN
Nursing Informaticist · United States Navy Nurse Corps · Last reviewed
Your baby is the size of a...
🍒 Cherry!
👶 Baby Development
- ✓Baby is now officially a fetus
- ✓All essential organs have begun developing
- ✓Tiny earlobes are visible
- ✓Toes are formed and the tail disappears
- ✓Muscles begin to develop
- ✓Tooth buds appear under the gums
💊 Common Symptoms
- •Mood swings and emotional sensitivity
- •Waist may start thickening
- •Increased heart rate
- •Nasal congestion (pregnancy rhinitis)
- •Occasional dizziness or lightheadedness
- •Continued fatigue
🩺Clinical Context — From a Nurse's View
Week 9 is the embryo-to-fetus transition. Major organogenesis is now largely complete — the heart has four chambers, the brain has hemispheres, and limbs are properly differentiated. This is biologically why first-trimester teratogen exposure (medications, infections) matters most before this point and tapers afterward. If you're worried about something you took before you knew you were pregnant, bring the specific drug and dates to your next visit — most common medications are not actually teratogenic, and the worry usually outweighs the actual risk. Your blood volume is starting its 40-50% pregnancy expansion, which is why you may feel lightheaded standing up quickly and your heart rate may be 10-15 BPM faster than your baseline. That's adaptive, not concerning. Nausea is still peaking for many. If you've had heart palpitations that aren't tied to standing up — episodes of racing or skipped beats lasting more than a few seconds — flag that. Most are benign in pregnancy, but they earn an EKG.
Written by Samantha L. Fox, RN, BSN, MSN — Emergency Department nurse, US Navy Nurse Corps officer.
🚨 When to Call (or Go to the ER)
- !Palpitations lasting more than a few seconds, especially with chest pain or fainting — ER
- !Heavy bleeding or one-sided pain — ER
- !Severe headache that doesn't respond to acetaminophen — call
- !Inability to keep fluids down for 12+ hours — call
✅ Normal — Even If It Feels Worrying
- ✓Faster resting heart rate (up 10-15 BPM from baseline)
- ✓Lightheadedness when standing up too fast
- ✓Nasal congestion (pregnancy rhinitis) — totally normal, often lasts the whole pregnancy
- ✓Increased vaginal discharge
✅ To-Do This Week
- Look into parental leave policies at your workplace
- Start thinking about a birth plan
- Increase your calcium intake (dairy, leafy greens)
- Consider a pregnancy pillow for better sleep
- Stay active with gentle exercises like walking or swimming
- Take breaks throughout the day to rest
🩺 Questions for Your Doctor
- ?Is occasional dizziness something to worry about?
- ?How much water should I be drinking daily?
- ?When will I need another ultrasound?
- ?Are my headaches related to pregnancy hormones?
- ?What supplements should I add beyond prenatals?
- ?Is my heart rate increase normal?
📚 References
- [1]ACOG Committee Opinion No. 762: Prepregnancy Counseling. Obstet Gynecol. 2019;133(1):e78-e89.
- [2]ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy. Obstet Gynecol. 2018;131(1):e15-e30.
Editorial review: Samantha L. Fox, RN, BSN, MSN. Last reviewed: see footer.
Your baby is the size of a...