The Quick Brief
Your baby is now the size of a strawberry, and something remarkable has happened: fingers and toes are fully formed, and fingernails are starting to develop. The bones are beginning to harden from soft cartilage. But this week's main task for you isn't developmental—it's decisional. Genetic testing options are now available, and understanding what they can (and can't) tell you requires some homework.
What's Happening with Baby
At week 10, your baby measures about 1.2 inches—roughly the size of a strawberry. The embryo officially became a fetus at week 9, marking the transition from organ formation to organ maturation.
Key developments this week: arms, hands, fingers, feet, and toes are fully formed—no more webbing. Fingernails and toenails are beginning to develop. Bones are hardening from soft cartilage, though the skeleton won't fully ossify until after birth. The external ears are taking shape, moving from the neck toward their final position. External genitals are beginning to form, though it's too early to determine sex via ultrasound.
The fetus can now move its arms and legs, opening and closing its fists, though these movements are too small to feel. The brain is producing neurons at an astounding rate—approximately 250,000 per minute. All major organs are present and beginning to function. The liver is producing bile. The kidneys are starting to produce urine.
What's Happening with Mom
The good news: for many women, nausea begins to decrease somewhere between weeks 10-14. The challenging news: it's not a switch that flips overnight. HCG levels peak around weeks 10-11 and then begin a gradual decline for the remainder of pregnancy. As hormone levels stabilize, symptoms often improve.
Round ligament pain may begin around this time. The round ligaments support the uterus; as the uterus expands, these ligaments stretch, causing sharp or aching pain in the lower abdomen or groin. It's usually harmless but can be startling. Sudden movements, sneezing, or laughing can trigger it.
Blood volume continues to increase, which can cause visible veins, especially on the breasts and abdomen. Some women notice their waistbands getting tighter—the uterus is now about the size of an orange. Visible baby bump typically comes later, but clothes may fit differently.