Growth - Fetal Growth Chart
Even though babies grow at different rates, there's a fetal development standard in the medical community that all doctors and midwives use to determine how well your developing child is doing. Although there is this standard guideline, it doesn't necessarily mean there's a problem if your baby is significantly smaller or larger than what this guideline suggests the norm is.
How Are Babies Measured?
All babies are measured from head to toe, otherwise known as crown to rump. According to the fetal growth chart, the average size of a healthy developing baby during the 14th week of pregnancy - right around the time you might be starting to show - is 3.42 inches or 8.7 centimeters. The average weight of a 14-week fetus is 1.52 ounces or 43 grams. But it's not necessary to be alarmed if your baby measures smaller or larger than this.
Because so many women get ultrasounds so early in pregnancy, what looks like slow fetal growth can be detected much earlier. This can be concerning for a mother-to-be especially if this is her first child. Technicians who interpret the ultrasounds measure the size of the baby and determine the age of the fetus in weeks and days. It's important to keep in mind that while all technicians are trained equally on how to measure and read an ultrasound, each eventually develops his or her own way of doing it that can be different from another technician. These different measurement styles can sometimes give the appearance of a lower or higher than average growth rate.
If your physician is especially concerned about any ultrasound results, he or she may order another ultrasound and get another analysis done of the fetal growth pictures. This can done during any trimester of the pregnancy whether it's in the early weeks or well into the third trimester.
What Is Normal Fetal Growth?
Normal fetal weight is a sign that your pregnancy is progressing as it should and that your unborn child is developing properly. It's a sign that your body is properly passing nutrition to your baby. There is a fetal development standard that all health practitioners follow and, as mentioned earlier, your child can still be healthy even though he or she may not be precisely meeting all the growth milestones.
In the first trimester, the average weight of your fetus should be between ½ ounce and one ounce. This jumps drastically in the second trimester when your baby begins to gain weight much faster. By the end of the fourth month your child should be approximately four times heavier than the first trimester. Four ounces by the end of the fourth month is common. By the end of the fifth month, the fetus generally has grown to ¾ pounds and by the end of the sixth month the weight should have grown to between 1 1/4 pounds and 1 ½ pounds.
Fetal growth in the third trimester further increases as your child develops the necessary fat to survive outside the womb and as his or her internal organs get bigger. Around 28 weeks, the seventh month and 26 weeks after conception, your baby should be around two to 2 ½ pounds and is approximately 10 inches long. Survival rate with fewer complications if born at this stage is high at about 90 percent. A full term healthy baby at 40 weeks gestation should typically be at least 14 inches long and weigh about 7 ½ pounds.
Possible Reasons for Fetal Growth Restriction
If your doctor or midwife decides that your baby isn't growing as quickly as she should, the practitioner may check into possible causes. Fetal growth retardation can be caused when something is wrong with the placenta, if the mother is experiencing preeclamsia or hypertension, fetal chromosomal abnormalities, atmosphere influences like air pollution or smoking, or a chronic health condition of the mother like diabetes or sickle cell anemia. All these factors can reduce the amount of oxygen reaching the baby and slow growth.