By Weeks 11 and 12, the body is moving toward the end of the first trimester, a milestone many people find both reassuring and significant. While physical symptoms may shift, important developmental progress is continuing inside the womb.

Understanding what is happening during this stage can help you feel more informed, prepared, and supported as you navigate early pregnancy.

Week 11: Continued Growth and Early Function

By Week 11, the embryo is transitioning into what is medically referred to as a fetus, a term used once major organ systems have formed and begin further growth and maturation. At this stage, the fetus measures approximately 1.6–2 inches long and weighs about 0.25 ounces – roughly the size of a fig.¹

Many foundational systems are already in place:

• Theheart is fully formed and continues to beat rhythmically, pumping blood throughout the developing body.²
• Bonesare beginning to harden, replacing cartilage in many areas.³
• Hands and feetare more clearly defined, and fingers and toes are separated.
• Facial features, including eyelids and ears, are developing more detail, though they remain closed for now.¹

Inside the body, organs such as the liver, kidneys, and intestines are beginning to function at a basic level. The intestines, which initially developed outside the abdomen, are now moving into their permanent position.³

For many women, early pregnancy symptoms like nausea and fatigue may still be present during Week 11, though some begin to notice improvement as hormone levels stabilize.⁴

Week 12: Approaching the End of the First Trimester

By Week 12, the fetus measures approximately 2–2.5 inches long and is about the size of a lime.¹ This week marks the final stretch of the first trimester, a period when the risk of miscarriage significantly decreases.⁵

Developmental highlights during Week 12 include:

• Reflexesare beginning to emerge. The fetus may make small movements, such as opening and closing fingers, though these movements are not yet felt.²
• External genitaliacontinue developing, though sex determination via ultrasound may still be difficult at this stage.¹
• Digestive and urinary systemsare functioning, with the kidneys producing urine.³
• Nerve cellsare rapidly increasing, supporting early brain development.²

From a physical standpoint, some women notice reduced nausea, improved energy, or changes in appetite during Week 12. Others may still experience symptoms such as bloating, heartburn, or mild discomfort as the uterus continues to grow.⁴

Why Early Prenatal Care Matters

Weeks 11 and 12 are a critical time for assessing development and establishing ongoing prenatal care. An ultrasound during this stage can help:

• Confirm pregnancy viability
• Estimate gestational age
• Identify the number of pregnancies
• Provide reassurance during a time that can feel uncertain

At Amnion Pregnancy Care Medical Center, we offer free pregnancy testing, limited ultrasounds, and confidential support, helping clients better understand their pregnancy and available options in a safe, compassionate environment.

If you’d like to schedule an appointment or talk with someone who cares, reach out anytime.
We’re here for you!