Third Trimester


The third trimester is an amazing time for you and your baby.  A whole slew of changes are occurring in your body as well as your emotional state and also in your babies development.  I decided the best way to cover some of the most important changes was to list them week by week.  Just imagine by the end of this trimester you will be getting ready to greet your new little miracle and venture into the world of being a parent.  Good luck and enjoy the list of happenings you have to look forward to during the third trimester!

At week 27 the fetus weighs a little over 2 pounds and it is the start of the third trimester.

At 28 weeks the fetus has nails in the toes and opens and closes his eyes. The most outer layer of fat begins to accumulate which smooths out wrinkles.

At 29 weeks the average weight of the fetus is 3 lb. It is now beginning to appear very much like a newborn baby.

At 30 weeks the vital organs are almost completely formed such as the bone marrow as well as the red blood cells.

At 31 weeks breathing movements are more harmonious. Movements in the abdomen are becoming more constrained due to the lack of space.

At 32 weeks, the average fetus weighs almost 4 lbs. In male fetuses the testicles and scrotum are nearly formed. The upper and lower limbs begin to look like those of a newborn.

At 33 weeks, you may notice fetal hiccups, a normal and frequent occurrence for most pregnant women.

At 34 weeks, his weight is nearing 5 lbs. The movements are very slight now due to the reduction of space in the uterus but can still be felt.

At 35 weeks the lungs have completely matured. If the fetus is born at this stage, it should not need an incubator. The fetus is now preparing to be delivered.

At 36 weeks weighs the fetus weights just under 6 lbs. He continues to mature neurologically and if born now would still be considered a premature fetus. The fetus will often turn it’s head inside of your uterus in search of light. Body fat increases. Fingernails reach the tips of the fingers.

At 37 weeks he has become a full term fetus. The tiny hairs on the fetus body have disappeared on the whole body except the upper arms and shoulders. Nails now extend beyond the toes. The grip of the hand is firm.

At 38 weeks the fetus weighs a little over 6 lbs. The baby is likely now in it’s final birth position which for most is head first.

At 39 weeks the fetus is fully matured in the uterus. 32% of their time is spent in deep sleep, 13% in active sleep, 53% in active waking and 2% in wakefulness at rest.

At week 40, the fetus weighs on average of about 7 lbs and is about 50 cm long. This is typically the final week of gestation and you will be meeting your baby boy or gril any day now!

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