Obstetrics

Obstetrics Overview

  • Learning Objectives

    • Identify common processes in obstetrics

    • Describe the specialty of obstetrics

    • Spell medical terms and use correct abbreviations

    • Identify medical specialties associated with obstetrics

    • Explore common complications and procedures related to obstetrics

Introduction to Obstetrics

  • Definition: Obstetrics is focused on the mother and fetus during pregnancy, childbirth, and immediate postpartum.

  • Specialty: Obstetricians study both obstetrics and gynecology, commonly referred to as OB/GYN.

Fertilization

  • Process: Occurs when a sperm and an oocyte (egg) combine, resulting in a diploid cell known as a zygote.

  • Egg Release: Typically, a woman releases one egg during ovulation; in rare cases (1%), two eggs may be released and fertilized, resulting in dizygotic (fraternal) twins.

  • Monozygotic Twins: Occur when one zygote divides into two, leading to identical twins.

  • Pregnancy Duration: Full-term lasts about 270 days (38.5 weeks) from conception; obstetricians typically estimate due dates at 284 days from the last menstrual period (LMP).

  • Trimesters: The average pregnancy is divided into three trimesters, each roughly 13 weeks long.

Stages of Childbirth

  • Three Stages:

    1. Dilation

      • Full dilation of the cervix to 10 cm is necessary for vaginal birth; typically lasts 6-12 hours, varying with previous births.

    2. Birth

      • Involves multiple steps: presentation of the head, delivery of the anterior and posterior shoulders, and then the lower body and umbilical cord.

    3. Afterbirth

      • Delivery of the placenta and fetal membranes.

Apgar Score

  • Purpose: Assesses the newborn's transition to life outside the womb.

  • Established by: Dr. Virginia Apgar in 1952 to evaluate newborn health, particularly after anesthesia use in laboring mothers.

  • Criteria:

    • Appearance: Skin color

    • Pulse: Heart rate

    • Grimace: Reflex response

    • Activity: Muscle tone

    • Respiration: Breathing effort

  • Scoring:

    • Scores range from 0 to 2 for each criterion, totaling up to a maximum of 10.

    • Scores of 7-10 are considered normal, while 0-3 requires immediate resuscitation.

Procedures Related to Obstetrics

  • In Vitro Fertilization (IVF):

    • Definition: Assisted reproductive technology where eggs and sperm are combined in a laboratory.

    • Indications: Used for various fertility issues, including blocked fallopian tubes and low sperm quality.

    • Process Steps:

      1. Ovarian hyperstimulation

      2. Transvaginal oocyte retrieval

      3. Sperm preparation

      4. Fertilization and embryo culture

      5. Embryo transfer into the uterus.

References

  • CrashCourse video on pregnancy and development

  • Adaptations from Anatomy and Physiology by Betts et al.

  • CC BY 4.0 international license.