25 weeks pregnant: baby is the size of a zucchini

Your baby this week

Your baby is gaining fat, so the skin looks less wrinkled and is beginning to fill out. The nostrils are opening, and your baby is practising breathing movements. Hair on the head has colour and texture that may change later.

Your baby is also responding to touch and to sounds. You may feel a definite reaction if you press gently on your belly, or if there is a sudden loud noise. Movements have a pattern now, with quiet spells and busy spells.

How it happens. Your baby's nervous system is connecting more and more pathways, and the lungs continue to prepare for air. The brain is developing the structures that will handle memory and thinking, and this process will continue for years after birth.

Your body this week

Your body now holds much more fluid than before pregnancy. Blood volume has risen by almost half, and hormones cause your body to retain water. Your uterus presses on the large veins that return blood from your legs, so fluid can pool in your feet and ankles.

At the same time, your blood pressure is checked at every visit. This is because a condition called pre-eclampsia can start from about 20 weeks, and it is easier to catch early when your blood pressure and urine are monitored.

Normal swelling and how to ease it

Swelling that is mild, affects both feet and ankles equally, is worse at the end of the day and is better after a night's rest is common.

To ease it:

• Put your feet up. Raise your legs above hip level when you can.
• Avoid standing or sitting for a long time. Change position and walk.
• Wear comfortable shoes. Avoid tight socks or straps.
• Drink water. It sounds odd, but drinking more can reduce fluid retention.
• Try swimming or water exercise. The pressure of water helps push fluid out of the tissues.
• Consider support tights if your provider agrees.
• Lie on your left or right side to improve blood return.

For tingling hands, wrist splints worn at night can help, and the symptoms usually settle after birth.

Pre-eclampsia: what it is

Pre-eclampsia is a condition that affects some pregnancies, usually after 20 weeks, and can also occur soon after birth. It involves high blood pressure and can affect the kidneys, liver and brain. Most cases are mild and picked up at routine checks, but it can become serious for both parent and baby if it is not treated.

Your provider checks your blood pressure and tests your urine for protein at each visit to catch it early. Some people are at higher risk, for example if it is a first pregnancy, if you had pre-eclampsia before, if you have high blood pressure, kidney disease or diabetes, if you are expecting twins, or if there is a family history. If any of these apply, ask your provider whether you should take low-dose aspirin, or have extra monitoring, or whether a calcium supplement suits you. Do not start any of these without advice.

The warning signs

Pre-eclampsia may cause no symptoms at first. These signs need urgent action, on the same day, or straight away if severe:

• A severe headache that does not go away with usual painkillers.
• Vision changes, such as blurring, flashing lights or spots.
• Pain under the ribs, usually on the right side.
• Sudden swelling of the face, hands or feet, especially if it is new or fast.
• Vomiting that is new, particularly in the second half of pregnancy.
• Feeling generally and severely unwell.

Call your maternity unit or go to hospital right away if you have any of these. Do not wait for your next appointment. If the diagnosis is made, your team will monitor you closely, and the only cure is the birth of the baby. Timing depends on how severe it is and how far along you are.