A typical pregnancy consists of three trimesters. Each trimester lasts between 12 and 14 weeks or about 3 months.
The first trimester
The first trimester is the first 13 weeks of pregnancy and is the most crucial stage of Your Child’s development. Your little one’s organs, brain, and body parts start to develop as the embryo cells divide and grow. You may experience morning sickness, nausea, and hormonal changes. These symptoms usually subside after the first trimester, while the risk of a miscarriage drop close to zero.
The second trimester
The second trimester lasts from week 14-27. During this period, your baby bump begins to form. It is considered the easiest trimester of pregnancy for most women. You will get to know Your Child’s gender and feel your little one move for the first time. The chances of a miscarriage are significantly less, and at 23 weeks, babies born preterm can survive inside an incubator with intensive care.
The third trimester
During the third trimester, which lasts from week 28 to week 42, Your Child is continuing to grow in weight and size. The little one will start to practice breathing motions to prepare for life outside of the womb. You may feel more of Your Child’s kicks and feel increasingly uncomfortable now as you continue to gain weight and begin to experience early contractions. The trimester usually ends in a very tiring yet beautiful rendezvous with someone you’ll likely love more than anything.
Calculating the correct due date
A child’s due date is usually estimated using Naegle’s rule, which is determined by subtracting three months from the first day of your last menstrual period (LMP) and adding 1 year and 7 days to that date. The due date based on Naegele’s rule is just an estimate and not usually the exact date. An ultrasound done in the first trimester of pregnancy is the most accurate way to date a pregnancy. So if you want to be sure about Your Child natural due date, speak to your doctor to confirm it with an ultrasound scan in the first trimester.
Dr. Piyawut Kreetapirom, MD. (17 May 2021)