As you approach the end of the third trimester, hence the end of your pregnancy, being pregnant is becoming less and less appealing. The babies continue to grow and there is just no space in there. Your belly is now big enough to balance your dinner plate on it and you no longer fit in most "booths". Your body is swollen and stretched. I remember those days and most of them weren't much fun.

Though you are now ready to move on and see your new blessings, there are still questions that you probably have that pertain to this phase of your pregnancy. Since you are expecting twins, the babies' current weight may be your primary concern during the third trimester.

You may be also asking questions such as: "If they were born today, would they survive?" Another constant question you'll be asking yourself is, "How much do they weigh today?" Or, "what length are they now?" I remember being constantly concerned about my twins' lung development during the third trimester.

Let's solve some of the mystery of the third trimester for you now.

Third Trimester

The final laps of the Pregnancy Marathon can be used to describe the third trimester. Usually looked upon as less eventful than the second trimester, the third trimester tests expectant parent's patience, especially parents who are having twins. Mom may be experiencing symptoms such as heartburn because one or both of the babies has lots of hair or she may feel discomfort because of the placement of the babies in her abdomen. There is a chance a mom pregnant with multiples has been placed on bed rest, whether complete where she has some freedoms, like short walks or total bed rest where she is confined to bed until delivery. I was prescribed total bed rest for the final 12 days of my pregnancy.

The third trimester begins at 27-28 weeks gestation. On average, the babies' growth will begin to slow around 30-32 weeks, where a singleton baby's growth continues until delivery. They will begin the third trimester around 2-2 1/2 pounds and 11-14 inches in length, each. At full-term delivery, which is 38 weeks for a twin delivery, the babies will weigh, again, on average, about 6 pounds apiece and measure anywhere from 18- 21 inches. My twins weighed 5lb, 11oz and 5 lb (twin b weighing more), respectively, and they both measured 19 inches. They were full-term, so their weight was below average but their lengths were in the range.

Other significant milestones the babies will reach during the third trimester include:

* The babies have begun crying tears at approximately 29 weeks
* Their brains continue to develop, but will not reach its' full size until the twins are school age
* Try to control the environment around as much as possible, as sudden movements loud noises and can frighten them
* If born at 35 weeks or later, the babies have a better than 90% chance of survival
* Between the weeks of 36 and 37, the babies have placed themselves in the position they will remain in until birth. If you find that one or both babies are in the breech position (butt down), speak with your doctor about your options at delivery.
* Movements at 38 weeks become less intense as there is simply not enough room for two babies to move freely
* At week 38 in a twin pregnancy, the babies' organs are fully formed and ready to function outside of the womb, (including the lungs, which are the last to develop during pregnancy) and the babies are ready to be born.

Keep in mind that all weights, measurements and time-lines given in this article are averages for a twin gestation. Every pregnancy is unique, even within the same mother.