Third trimester of pregnancy

Final weight gain takes place, which is the most weight gain throughout the pregnancy. Babies weigh about 2 1/4 pounds by the start of the third trimester. They can blink their eyes, which now sport lashes. And their wrinkled skin is starting to smooth out as they put on baby fat. They’re also developing fingernails, toenails, and real hair (or at least some peach fuzz), and adding billions of neurons to their brain. Your blossoming baby will spend his or her final weeks in utero putting on weight. At full term, the average baby is more than 19 inches long and weighs nearly 7 pounds. The woman’s abdomen will transform in shape as it drops due to the fetus turning in a downward position ready for birth. During the second trimester, the woman’s abdomen would have been upright, whereas in the third trimester it will drop down low. The fetus moves regularly, and is felt by the woman. Fetal movement can become strong and be disruptive to the woman. The woman’s navel will sometimes become convex, “popping” out, due to the expanding abdomen.

Head engagement, where the fetal head descends into cephalic presentation, relieves pressure on the upper abdomen with renewed ease in breathing. It also severely reduces bladder capacity, and increases pressure on the pelvic floor and the rectum.

It is also during the third trimester that maternal activity and sleep positions may affect fetal development due to restricted blood flow. For instance, the enlarged uterus may impede blood flow by compressing the vena cava when lying flat, which is relieved by lying on the left side.

You’re on the home stretch! This is the first week of the last part of your pregnancy. In some ways, these final three months are a bit like the first three. You may be more tired and more emotional. Aches and discomforts in your belly and back are more common. Try to rest as much as you can. Read about your baby’s development and your pregnancy week by week.

29 to 32 weeks


Your baby continues to be very active at this stage, and you’ll probably be aware of lots of movements. There is no set number of movements you should feel each day – every pregnancy is different. You should be aware of your baby’s own pattern of movements, and if this pattern changes contact your doctor.

The sucking reflex is developing by now and your baby can suck its thumb or fingers. The baby is growing plumper and the skin begins to look less wrinkled and much smoother.

The white, greasy vernix and the soft, furry lanugo (fine hair) which have covered your baby’s skin for some time begin to disappear. Your baby’s eyes can focus now. The lungs are developing rapidly, but your baby wouldn’t be fully able to breathe on its own until about 36 weeks.

By about 32 weeks the baby is usually lying with their head pointing downwards ready for birth. This is known as ‘cephalic presentation’. If your baby isn’t lying head down at this stage, it’s not a cause for concern – there is still time for them to turn.

The amount of amniotic fluid in your uterus is increasing, and your baby is still swallowing fluid and passing it out as urine.

As your bump pushes up against your lungs and you have extra weight to carry around, you may feel breathless.

Leg cramps at night are common around 29 to 32 weeks pregnant. You may find it hard to sleep because you can’t get comfortable. Try lying curled up on your side with a pillow between your legs and a cushion under your bump to see if it feels more comfortable. You might find you need to pass urine a lot as well.

Your doctor will measure the size of your womb and check which way up the baby is at every antenatal visit. They will also measure your blood pressure, test your urine for protein and discuss the results of any screening tests from your last appointment.

33 to 36 weeks


By 33 weeks of pregnancy the baby’s brain and nervous system are fully developed. Your baby’s bones are also continuing to harden, apart from the skull bones. These will stay soft and separated until after the birth to make the journey through the birth canal easier – the bones can move gently and slide over each other so that the head can be born safely while still protecting the brain.

Your baby is curled up in the uterus now, with legs bent up towards the chest. There is little room to move about, but they will still change position, so you’ll still feel movements and be able to see them on the surface of your bump.

If your baby is a boy, his testicles are beginning to descend from his abdomen into his scrotum.

By 36 weeks your baby’s lungs are fully formed and ready to take their first breath when they’re born. They will also be able to suckle for feeds now, and the digestive system is fully prepared to deal with breast milk.

You need to slow down because the extra weight will make you tired, and you may get backache. From about 34 weeks pregnant, you may be aware of your womb tightening from time to time. These are practice contractions known as ‘Braxton Hicks’ contractions, and are a normal part of pregnancy. It’s only when they become painful or frequent that you need to contact your doctor.

37 to 40 weeks


At 37 weeks, your pregnancy is considered full-term.

The baby’s gut (digestive system) now contains meconium – the sticky, green substance that will form your baby’s first poo after birth. It may include bits of the lanugo (fine hair) that covered your baby earlier in pregnancy. If your baby does a poo during labour, which can sometimes happen, the amniotic fluid will contain meconium. If this is the case, your doctor will want to monitor your baby closely as it could mean they are stressed.

In the last weeks, sometime before birth, the baby’s head should move down into your pelvis. When your baby’s head moves down like this, it is said to be ‘engaged’. When this happens, you may notice that your bump seems to move down a little. Sometimes the head doesn’t engage until labour starts.

The average baby weighs around 3-4kg by now.

The lanugo that covered your baby’s body is now almost all gone, although some babies may have small patches of it when they’re born. Due to the hormones in your body, the baby’s genitals may look swollen when they’re born, but they will soon settle down to their normal size.

Your baby is ready to be born, and you’ll be meeting them some time in the next couple of weeks.Top-Early-Signs-Of-Pregnancy

When you are around 37 weeks pregnant, if it’s your first pregnancy you may feel more comfortable as your baby moves down ready to be born, although you will probably feel increased pressure in your lower abdomen. If it’s not your first pregnancy, the baby may not move down until labour.

Most women will go into labour between 38 and 42 weeks of pregnancy. Your doctor should give you information about your options if you go beyond 41 weeks pregnant.

Call your doctor at any time if you have any worries about your baby or about labour and birth.



Changes in Your Body-Third Trimester of pregnancy


First trimester 

Second trimester 



Pregnancy Symptoms Alarming Symptoms




Related Topics


 Overdue Pregnancy 

 Overdue Delivery Procedures