Baby is the size of a grapefruit
👶 Baby's development
The lungs start producing surfactant — what will allow breathing after birth.
💛 How mom feels
Leg swelling in the evening is possible. Stay hydrated and do pregnancy exercises.
📖 Tip of the week
The lungs are developing rapidly, but aren't ready for independent breathing yet. The vestibular system is working — the baby feels when you move or rock. The glucose tolerance test is usually scheduled for weeks 24–28 — don't miss it.
🔬 Detailed baby development
- The fetus's skin is wrinkled and translucent, appearing red due to visible blood vessels
- Rapid eye movements (REM) can be detected, suggesting the fetus may be dreaming
- The fetus responds to light — a bright light shone on the belly may cause it to move away
- The lungs continue to develop branches and air sacs (alveoli) though they are not yet mature
- Fat deposition continues, gradually making the skin less transparent
- The fetus is about 28.9 cm long and weighs approximately 500 grams, roughly the size of a large mango
🤱 What mom may feel
- Swollen and puffy ankles and fingers, especially in warm weather
- Dark patches on the face (melasma) may be more noticeable
- Difficulty sleeping due to the growing belly and frequent need to urinate
- Feeling of heaviness or pressure in the pelvic area
- Visible fetal movements — kicks and rolls may be seen through the belly
🏥 Tests and check-ups
No major scheduled tests for week 23. Continue regular prenatal visits. Your provider will monitor weight gain, blood pressure, and fundal height. If you are at risk for preterm labor, cervical length measurement may be performed via transvaginal ultrasound.
💡 Tips for this week
- Remove rings if your fingers are swelling to avoid them getting stuck
- Sleep with your feet elevated on a pillow to reduce morning ankle swelling
- Continue regular moderate exercise — it helps with sleep, swelling, and overall well-being
- Moisturize your belly, breasts, and hips to soothe itchy, stretching skin
❓ Frequently asked questions
Why are my fingers swelling?
Mild swelling (edema) is caused by your body retaining more fluid during pregnancy and increased blood volume. Reduce salt intake, elevate your hands, and stay hydrated. Sudden severe swelling, especially with headache or visual changes, requires immediate medical attention.
Can the baby see light?
Yes, by 23 weeks the eyes are developed enough to detect changes in light through the uterine wall. The fetus may turn away from a bright light source. Full vision development continues after birth.
Is it normal to have trouble sleeping?
Insomnia affects up to 78% of pregnant women. The growing belly, frequent urination, heartburn, and anxiety all contribute. Use pregnancy pillows, maintain a sleep routine, avoid screens before bed, and practice relaxation techniques.
📝 Week 23 of pregnancy: what's happening
Your baby is now around 28.9 cm long and weighs approximately 501 g — just over half a kilogram, similar in size to a large grapefruit. The lungs are developing rapidly but are not yet mature enough to function outside the womb — the production of surfactant, a substance that helps the air sacs inflate after birth, is a critical step that continues over the coming weeks. Your baby can now hear sounds quite clearly, including external voices and music. A regular heartbeat of around 120–160 beats per minute should be audible to your midwife using a handheld Doppler at your appointments.
You may notice that your baby is most active at certain times of day, often in the evenings or when you are sitting still. Movement counts are not formally recommended until later in pregnancy, but becoming familiar with your baby’s individual pattern is important. Skin changes may continue — some women experience cholestasis of pregnancy (intense itching, particularly on the palms and soles), which requires medical attention; always mention new or unusual itching to your midwife. Increased pigmentation, such as darkening of moles or freckles, is also common.
At this stage, no routine NHS antenatal appointment is scheduled unless there are specific concerns — your next routine check is typically at week 25 (for first pregnancies). However, if you have any worries about reduced movements, pain, bleeding, or any other concerns, you should contact your maternity unit without hesitation. Your MATB1 certificate (a form used to claim Statutory Maternity Pay) will be issued by your midwife at around 20 weeks or later — check that you have received this and submit it to your employer as required.
Think about practical preparations for your baby’s arrival, such as researching and purchasing a car seat, cot, or Moses basket. Some items, such as car seats, should ideally be new to ensure safety standards are met. If you are planning a home birth, speak to your midwife about what equipment the NHS will provide and what you need to arrange yourself. Eating iron-rich foods such as lean red meat, legumes, dark leafy greens, and fortified cereals is particularly important now as your blood volume continues to expand. Pair plant-based iron sources with vitamin C for optimal absorption.
⚠️ When to see a doctor
- Vaginal bleeding of any amount
- Severe headache or vision changes
- Severe abdominal or lower back pain
- Swelling of face and hands (possible preeclampsia)
- Decreased or absent fetal movement after 20 weeks
- Blood pressure above 140/90
Sources
- WHO recommendations on antenatal care (2016)
- ACOG Practice Bulletins
- Williams Obstetrics, 26th Edition
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