Notes from NEET topper

GESTATION

Gestation is the period during which an embryo or fetus develops inside a female’s uterus until birth. In human reproduction, this period is crucial as it encompasses the entire process of embryonic and fetal development, leading to childbirth. Here’s an overview of human gestation:

Duration of Gestation

The average duration of human gestation is approximately 40 weeks, counted from the first day of the last menstrual period (LMP). This is typically divided into three trimesters, each with distinct developmental stages and physiological changes in the mother.

First Trimester (Weeks 1-12)

Embryonic Development: The first eight weeks involve critical development where all major organs and body systems start to form.

Placenta Formation: The placenta develops and takes over the role of nourishing the embryo.

Hormonal Changes: Significant hormonal changes can cause symptoms like morning sickness.

End of First Trimester: By the end of 12 weeks, the embryo is now a fetus, and the risk of miscarriage decreases significantly.

Second Trimester (Weeks 13-26)

Growth and Development: The fetus grows rapidly, and its movements can be felt.

Structural Development: Bones harden, and vital organs like the brain continue to develop.

Maternal Changes: The mother’s abdomen becomes noticeably larger, and the pregnancy becomes more apparent.

Medical Assessments: Routine screenings and ultrasounds are conducted to monitor fetal health and development.

Third Trimester (Weeks 27-40)

Final Development: The fetus gains weight, and its lungs mature.

Preparation for Birth: The fetus moves into a head-down position in preparation for birth.

Braxton Hicks Contractions: The mother may experience these “practice” contractions.

Birth Preparedness: Final preparations for childbirth, including childbirth education classes and preparing a birth plan.