19 weeks pregnant: baby is the size of a mango

Your baby this week

A white, waxy coating called vernix caseosa is beginning to cover your baby's skin. It protects the skin from the amniotic fluid, since without it the skin would wrinkle and chap. It also helps the baby slip through the birth canal. Timing varies by source, and the coating becomes thicker later in pregnancy.

The senses are developing. Areas of the brain that will handle smell, taste, vision, hearing and touch are growing. Your baby's kidneys are working, and the bladder empties into the amniotic fluid. The legs are in proportion with the arms, and your baby stretches and kicks a lot.

How it happens. Special glands in the skin make oils that mix with shed skin cells to form the vernix. If you are having a girl, her ovaries hold a lifetime supply of eggs by mid-pregnancy.

Your body this week

Your uterus is at or near your belly button. The weight of the baby, the placenta and the amniotic fluid is increasing, and relaxin, a hormone that loosens joints and ligaments, is at work. Relaxin prepares your pelvis for birth, but it also affects the joints in your hips, back and feet.

Your blood volume is much higher than before pregnancy, and your heart is working hard. It is common to feel warmer than usual at night.

Sleeping comfortably

Sleep gets harder as pregnancy goes on. These changes help many people.

• Sleep on your side. The NHS and many other guidelines recommend side-lying, either side, as your bump grows. Lying on your side keeps the weight of the uterus off major blood vessels.
• Use pillows. Place one between your knees, another under your bump and one behind your back. A long body pillow works well for many people.
• Raise your head and chest. Extra pillows help with heartburn and breathlessness.
• Avoid lying flat on your back for long periods. The weight of the uterus can compress a large vein and make you dizzy or short of breath. If you wake on your back, roll to your side.
• Keep the room cool. A slightly cooler bedroom helps with night sweats.
• Follow a wind-down routine. A warm shower, a light snack and a regular bedtime help.
• Limit fluids in the evening, but do not restrict them during the day.

If you cannot sleep for hours night after night, or you snore loudly and wake gasping, tell your provider. Sleep problems in pregnancy are common, and some need assessment.

Leg cramps

Cramps in the calf muscle, usually at night, are common in the second and third trimester. The cause is not fully understood. Weight, circulation changes and tired muscles may all play a role.

What may help:

• Stretch before bed. Stand about an arm's length from a wall, place your hands on it, and step one foot back with the heel down. Hold for 20 to 30 seconds.
• Walk during the day. Regular gentle activity can reduce cramps.
• Stay hydrated.
• When a cramp hits, flex your foot toward your shin, stand on the leg and walk around, or massage the muscle.
• Warm the muscle with a warm bath or heat pack before bed.

Some people take magnesium for cramps. Research is mixed, and the benefit is uncertain, so ask your provider before taking any supplement.

Cramp is usually harmless. But if you have pain, redness, warmth or swelling in one calf that does not go away when you stretch, this could be a blood clot (deep vein thrombosis). Seek urgent medical help.

Hip and pelvic pain

The pelvis is made of joints that are meant to be stable. Under the influence of relaxin, they become more flexible. Some people develop pelvic girdle pain, with pain at the front of the pelvis, in the lower back or in the buttocks. It is often worse when climbing stairs, turning in bed, getting out of a car or standing on one leg.

What helps:

• Keep your knees together when you turn in bed or get in and out of a car.
• Take smaller steps, and avoid crossing your legs or standing on one leg.
• Use a support belt. Many people find a maternity belt helpful.
• Ask for a referral. A physiotherapist who specializes in pregnancy can give exercises and advice.

Tell your provider if pain is severe, makes it hard to walk, or comes with fever or bleeding.