You are 30 weeks and 4 days

In the uterus and in his first months, your baby relies on your immunity to various infections.

66 days until your due date

If your immune system saw your baby as foreign, it would attack him, but you're both designed so this doesn't happen. Your baby can't make antibodies in the uterus (which would attack you); he relies entirely on you to protect him from infection, both before and after birth.

This protection after birth works because antibodies from your immune system cross the placenta into your baby's blood during pregnancy. If you're immune to diseases such as measles, mumps, polio, and many other serious infections, your baby carries your antibodies too. This "passive immunity" fades over time, which is why from two months your baby will need a program of immunizations against these and other illnesses.

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Your body: Exercise myths

Many studies of pregnant women exercising agree: safe, effective, moderate exercise in healthy women is beneficial. As well as boosting your health and energy, it gets you in great shape for labor, which is effectively a workout!

The myths:

"Exercising will harm my baby if I move too much." Your baby is protected by amniotic fluid and nourished by the placenta. If you follow safe exercise guidelines and avoid high-impact sports and activities with a risk of falls or injury, you're not putting your baby at risk.
"Exercise will use up nutrients my baby needs." Your baby's growth is monitored at appointments, so you'll know whether to eat more. If you're worried, eat more on days you exercise.
"Abdominal exercises will harm the baby." You can do them, just not lying on your back in the second and third trimesters, when the baby can press on the vena cava (the large vein returning blood to your heart), lowering your blood pressure and reducing oxygen to the baby. The first sign is dizziness; roll onto your left side and it should pass. Talk to your doctor if you're worried, and choose safe abdominal exercises that don't involve lying on your back.

This is general information based on NHS guidance, not medical advice, and every pregnancy is different. Talk to your midwife or GP about anything that worries you. If your baby's movements slow down or change, or you have bleeding, severe pain or leaking fluid, call your maternity unit straight away. In an emergency, call 999.

Your body: Exercise myths

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