Nucleotides and the double helix. DNA, or deoxyribonucleic acid, is the heritable material found in all cells. DNA provides the instructions to build, maintain, and regulate cells and organisms and is passed on when cells divide and when organisms reproduce.
Calculating Conception. Gestational age, or the age of the baby, is calculated from the first day of the motherâs last menstrual period.Since the exact date of conception is almost never known, the first day of the last menstrual period is used to measure how old the baby is. Use our Pregnancy Calculator to calculate these dates for you.he baby can be measured as early as 5 or 6 weeks after the motherâs last menstrual period. Measuring the baby using ultrasound is most accurate in early pregnancy. It becomes less accurate later in pregnancy. The best time to estimate gestational age using ultrasound is between the 8th and 18th weeks of pregnancy.
Fetal Development. Calculating the day your baby begins to develop and keeping track of your pregnancy dates can be a challenge. The development of pregnancy is counted from the first day of your last normal period, even though the development of the fetus does not begin until conception.Pregnancy is calculated from this day because each time a woman has a period, her body is preparing for pregnancy.he following information is used as a general guide for healthy pregnancy development, although development may vary due to the motherâs health or a miscalculation of ovulation. Gestational age is the age of the pregnancy from the last normal menstrual period (LMP), and fetal age is the actual age of the growing baby.