pregnancy

Overview of Antepartum Care

  • Introduction to antepartum care discussing the concept of pregnancy in detail. Emphasis on the importance of understanding pregnancy physiology and timeline.

Menstrual Cycle and Ovulation

  • Follicle Development:

    • Follicle-stimulating hormone (FSH) signals the ovary to prepare several follicles.

    • Eventually, a dominant follicle is selected for ovulation.

    • Families with twins often have a genetic predisposition for double ovulation.

  • Ovulation Process:

    • Luteinizing hormone (LH) induces ovulation, releasing the egg while estrogen aids its journey through the fallopian tube.

    • Progesterone supports the uterine lining development.

  • Fertilization Timing:

    • An egg remains viable for approximately 24 hours post-ovulation, whereas sperm can last 48 to 72 hours.

    • Importance of timing when discussing infertility or contraceptive methods, such as the calendar method.

Genetics and Chromosomes

  • Fertilization:

    • Occurs in the fallopian tube, forming a zygote with 23 chromosomes from the egg and 23 chromosomes from the sperm.

    • Irregular chromosome numbers may lead to non-viability of the pregnancy.

  • Trisomies: Presence of an extra chromosome; examples include trisomy 13, 18, and 21.

    • Trisomy 21 classified as Down syndrome, noted for its physical and mental challenges.

Pregnancy Testing

  • Beta hCG:

    • The hormone detected in urine pregnancy tests indicating a positive result.

    • Common misconception regarding the necessity of testing methods, with urine tests being sufficient for initial confirmation.

    • Blood tests may be utilized for confirming viability if doubt exists regarding pregnancy continuation.

Signs and Symptoms of Pregnancy

  • Distinction:

    • Symptoms: Presumptive signs reported by the patient (e.g., missed period).

    • Signs: Objective findings confirmed through physical examination.

  • Classification of Signs:

    • Presumptive: Patient-reported (e.g., amenorrhea).

    • Probable: Observed signs (positive pregnancy test).

    • Positive: Direct evidence of a fetus (e.g., fetal heartbeat).

  • Goodell's, Chadwick's, and Hager signs: Indicate physical changes in the uterus observable by healthcare providers.

Estimated Due Date (EDD)

  • Terminology:

    • EDB: Estimated Date of Birth.

    • EDC: Originally stood for Estimated Date of Confinement.

  • Calculating EDD using Naegele's Rule:

    • First day of the last menstrual period (LMP) is used:

    • Subtract three months, add seven days, adjust year as necessary.

    • Example: LMP of April 1 leads to estimated due date around January 8 of the following year.

Pregnancy Gestation Period

  • Full term pregnancy is considered 40 weeks:

    • First trimester: Up to 12 weeks 6 days.

    • Second trimester: From 13 weeks to 27 weeks 6 days.

    • Third trimester: From 28 weeks to delivery.

  • Acknowledgment of the first two weeks before conception due to uterine preparation.

Prenatal Visits Schedule

  • First and second trimesters: Visits approximately every four weeks.

  • From 28 weeks: Visits shift to every two weeks until 36 weeks.

  • Post 36 weeks: Weekly visits, ramping up to twice a week if continuing past EDD.

Health and Risk Assessment

  • Importance of identifying risk factors and medical histories early in pregnancy to address potential issues.

  • Considerations include:

    • Substance use (drugs/alcohol).

    • Dietary restrictions (veganism, religious beliefs impacting care).

    • Need for adjusting medications during preconception counseling to maintain health without harming the fetus.

Major Physiological Changes During Pregnancy

Cardiovascular System

  • Approximately 50% increase in circulating blood volume.

    • Blood pressure remains stable due to hormonal protective measures (cortisol and possibly progesterone).

    • Dilutional anemia occurs as a result of increased volume.

Respiratory System

  • Diaphragm displacement leading to potential shortness of breath; physiological adaptations support oxygen transfer to fetus.

Renal System

  • Increased frequency of urination due to fetal movement and pressure on the bladder, not due to increased urine production.

  • Protein and glucose testing regularly to monitor renal efficiency.

Skin Changes and Hormonal Effects

  • Common skin changes during pregnancy include the mask of pregnancy, stretch marks, and linea nigra.

Laboratory Testing During Pregnancy

  • Initial labs performed during first prenatal visit include:

    • STI screenings,

    • Hemoglobin and hematocrit (H&H) measurements.

    • Checking for antibodies against rubella and varicella with vaccinations to be administered postpartum if not immune.

  • Follow-up tests at 24-28 weeks for glucose testing and again at 35-37 weeks for Group B Streptococcus screening.

Products of Conception

  • Components include placenta, amniotic sac, and amniotic fluid:

    • The placenta acts as an endocrine organ, facilitating nutrient exchange and waste management.

    • The amniotic fluid cushions and protects the fetus, maintaining an optimal environment for development.

Fetal Circulation

  • Highlighting alterations in fetal circulation involving:

    • Ductus venosus: Bypasses liver, delivering blood to systemic circulation.

    • Ductus arteriosus: Connects pulmonary artery to aorta, allowing blood to bypass non-functional fetal lungs.

    • Foramen ovale: Connects right and left atrium of the heart for optimal blood flow.

Potential Complications and Monitoring

  • Understanding the implications of not closing fetal circulation pathways post-delivery, potentially resulting in murmurs detected in infant examinations.

Conclusion

  • Wrap-up of main points, encouraging students to review slides prior to future lectures, enhancing understanding of antepartum care and related physiological changes.

    • Reinforcement of testing schedules, newborn care, and considerations when discussing high-risk pregnancies or concerns.