Understanding how the medical world dates a pregnancy can be confusing. When a woman says she’s five weeks pregnant, what does that mean? When a doctor says she’s in the second trimester, what does that mean? Here are some definitions to help you understand the medical terms accurately:
While many men and women think of pregnancy as beginning at conception (when the sperm meets the egg), the medical world identifies the beginning of a pregnancy (referred to as the gestation by doctors) as the first day of the woman’s last menstrual period. Huh? Does that make sense?
It does when you realize that a woman’s cycle is her body preparing for the possibility of a pregnancy every month. Her body prepares the lining of the uterus to be ready if conception occurs. When a woman ovulates but doesn’t conceive, her body discards what it had prepared for the baby’s development. So her menstrual cycle is counted toward the 40-week gestational cycle. A pregnancy is divided into thirds, called trimesters. The second trimester begins at 14 weeks of gestation, and the third trimester begins at 28 weeks of gestation.
So saying that a woman is five weeks from conception is different than what a doctor means when he or she says that a woman is at five weeks in her pregnancy. If a medical professional confirms a pregnancy diagnosis and tells you that you’re five weeks along, that is (on average, for the typical woman) about three weeks from conception. Five weeks from conception is actually (about) seven weeks in the gestational cycle of the pregnancy. So if you’re thinking that you know exactly how long you’ve been pregnant because you know exactly when you had sex and possibly became pregnant, you may have your dates wrong. The actual date of the pregnancy is most accurately determined by an obstetrical ultrasound.
Some medical procedures are only recommended during certain times of a woman’s pregnancy. It’s important to understand the dates and the terms that your care providers are using. If you still have questions, send us a message or give us a call. We always have time to answer your questions.
Here’s another explanation from American Pregnancy: gestational age
(Selah’s nurse manager always uses the gestational age when confirming a pregnancy diagnosis with a limited obstetrical ultrasound, as most medical professionals do.)