A New Name for a New Stage
Something significant happened this week, even though you can't feel it yet. Your baby has transitioned from an embryo to a fetus [1]. In medical terms, this means the period of major organ formation (organogenesis) is essentially complete. From here forward, the focus shifts to growth, maturation, and fine-tuning all the systems that were laid down in those intense early weeks.
It sounds clinical, but it carries real meaning: the most vulnerable window of development has passed. The architecture is built. Now it's about making everything bigger, stronger, and more functional.
Your Baby This Week
At ten weeks, your fetus is about the size of a prune, measuring roughly 1.2 inches (3 cm) from crown to rump and weighing around 4 grams [4]. Those webbed fingers and toes from week 8 have now separated into distinct digits, and tiny fingernails are beginning to form. The outer ears are taking their familiar shape. Eyelids have formed and are fused shut, where they'll stay until around week 27.
The bones are still soft cartilage but will gradually harden (ossify) over the coming weeks. Your baby can make small, jerky movements, though you won't feel them for another two months or so. The liver, kidneys, and brain are all functioning at a basic level, each system building complexity day by day [1].
The NIPT Decision
Week 10 marks the opening of the window for Non-Invasive Prenatal Testing (NIPT), also called cell-free DNA screening. ACOG recommends that all pregnant patients, regardless of age or risk factors, be offered prenatal genetic screening and counseled about their options [2].
Here's what you should know:
- What it is. A simple blood draw from your arm. The lab analyzes tiny fragments of your baby's DNA that circulate in your bloodstream.
- What it screens for. Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome), Trisomy 13 (Patau syndrome), and, if you choose, sex chromosome differences. Many labs also report the baby's sex.
- How accurate it is. NIPT is the most sensitive screening test available for the common aneuploidies, with detection rates above 99% for Trisomy 21 [3].
- What it is not. A screening, not a diagnosis. A positive result means increased risk, not certainty. Diagnostic testing (amniocentesis or CVS) would be the next step if a screen comes back high-risk.
- It's optional. You are not required to have this test, and your provider will support whatever you decide.
The Anxiety of Waiting for Results
If you decide to get the NIPT, there's a part nobody fully prepares you for: the waiting. Results typically take 7 to 14 days, and that window can feel like an eternity. You may find yourself refreshing your patient portal obsessively, reading forums of other women's result timelines, and mentally rehearsing what you'd do if the news isn't what you hoped.
Some couples describe this as the longest two weeks of their lives. Others manage to distract themselves enough to be surprised when results arrive. Neither response is right or wrong. What helps: remembering that the vast majority of NIPT results come back low-risk, and that even a high-risk result is not a diagnosis. It's a flag that prompts further conversation and, if desired, definitive testing.
If you choose not to get the NIPT, that is equally valid. Prenatal screening is deeply personal, and opting out does not make you less prepared or less caring.
"What if the NIPT results show something, and I don't know what I would do?" The anxiety before genetic screening results is often less about the test itself and more about the decisions it might require. You do not need to have your response mapped out in advance. Many women take the test and then decide how they feel about the results when they arrive. Your MomDoc provider can connect you with a genetic counselor before or after testing, someone trained to help you process information without pushing you toward any particular choice.
What's Happening in Your Body
- Blood volume is increasing. Your body is producing up to 50% more blood than before pregnancy, which is why veins may be more visible on your breasts, abdomen, and legs.
- Round ligament stretching. As your uterus grows, the ligaments supporting it stretch, which can cause sharp, brief pains in your lower abdomen, especially when you change position quickly.
- Nausea may (or may not) be easing. For some women, the worst of morning sickness starts to lift around week 10. For others, it persists through week 14 or beyond. Both patterns are normal [1].
- Skin changes. Increased blood flow can give you a flushed "glow," but it can also bring breakouts, thanks to hormonal shifts in oil production.
Looking Ahead
You're now past the halfway mark of the first trimester. The next big milestones are the nuchal translucency scan (typically weeks 11 to 13) and the end of the first trimester itself, which for many women brings the emotional relief of the "safe to tell" threshold. Your baby, meanwhile, is busy growing, moving, and becoming more distinctly human every day.
You've carried a secret, weathered nausea, and made it through the most delicate developmental window. The prune stage is brief, but the courage it took to get here is not.