first trimester

Thân thiện

A woman holds a calendar marking the first trimester of her pregnancy.

Definition

1. Noun:
   • The initial three-month period of a pregnancy: The "first trimester" is a specific medical and developmental timeframe in human pregnancy. It is calculated as extending from the first day of the woman's last menstrual period (LMP) through the completion of 12 weeks of gestation. This period encompasses the early stages of embryonic and fetal development.

Usage Examples

• Noun:
  • Morning sickness is most common during the first trimester.
  • Many important developmental milestones occur in the first trimester, including the formation of major organs.
  • Her prenatal appointments were scheduled every four weeks during the first trimester.

Advanced Usage

• Medical Context: In obstetrics, the pregnancy is divided into three trimesters. The "first trimester" is a critical period for organogenesis (the formation of the body's organs).
  • Screening tests for certain genetic conditions are typically performed at the end of the first trimester.

Variants and Related Words

• Trimester (noun): Any one of the three approximately three-month periods into which a pregnancy is divided.
  • The second and third trimesters involve significant fetal growth.
• Gestation (noun): The process of carrying or being carried in the womb between conception and birth.
• Prenatal (adjective): Relating to the period before birth.

Synonyms

• Early pregnancy: A less precise, non-medical term for the initial phase of pregnancy.

Related Phrases

• First-trimester screening: A specific set of tests (blood tests and ultrasound) offered during this period to assess the risk of certain chromosomal conditions.
  • They opted to undergo first-trimester screening.

Học thuật

Noun

1. time period extending from the first day of the last menstrual period through 12 weeks of gestation