Maternal Adaptations During Pregnancy Fa22 Student

Maternal Adaptation During Pregnancy

• Presenter: Lauren Milam, MSN, RN, NUR 403

Learning Objectives

• Determine gravidity and parity using the 2 vs 5 digit system

• Describe various types of pregnancy tests, including timing and interpretation of results

• Explain expected maternal anatomic and physiologic adaptations to pregnancy

• Differentiate among presumptive, probable, and positive signs of pregnancy

• Identify maternal hormones produced during pregnancy, their target organs, and major effects

• Calculate EDC (Estimated Date of Confinement) per Naegle's Rule

The Language of Gestation

• Trimesters: Pregnancy is divided into three trimesters of 13 weeks each.

• Key Terms:

  • EDC: Estimated Date of Confinement

  • EDD: Estimated Due Date

  • Term Gestation: 37-42 weeks

  • Postdates/term: > 42 weeks

  • Preterm: 20-37 weeks (late preterm: 34-36.6 weeks)

  • Gravid: The state of being pregnant

  • Gravida: Total number of pregnancies regardless of outcome

  • Para: Number of births (fetus of at least 20 weeks)

  • Nulligravida: Never experienced pregnancy

  • Primigravida: Pregnant for the first time

  • Multigravida: Pregnant for at least the 3rd time

2-Digit vs. 5-Digit System

• 2-Digit:

  • G, P

    • G: Gravida (total pregnancies)

    • P: Para (births > 20 weeks)

• 5-Digit:

  • TPAL

    • T: Term gestation (37 weeks)

    • P: Preterm

    • A: Abortus (miscarriages)

    • L: Living children

Examples

• Scenario 1: Has been pregnant 3 times, has 1 baby at home, had a miscarriage at 14 weeks

  • G? P?

• Scenario 2: Currently pregnant, has one child born at 27 weeks, had an abortion at age 15

  • G TPAL?

Answers to Examples

• Scenario 1: G3 P1

• Scenario 2: G3 T0 P1 A1 L1

Naegle’s Rule = EDC Formula

• Formula: -3m + 7d + 1y

• Example: LMP: July 10, 2021

  • Convert to numbers: m7, d10, y21

  • EDC Calculation:

    • Months: 7-3=4

    • Days: 10+7=17

    • Years: 21+1=22

  • EDC is 4-17-2022

Signs and Symptoms of Pregnancy (Box 11.1)

Presumptive Signs (Time of Occurrence)

• Fatigue (12 weeks)

• Breast tenderness (3-4 weeks)

• Nausea and vomiting (4-14 weeks)

• Amenorrhea (4 weeks)

• Urinary frequency (6-12 weeks)

• Hyperpigmentation of skin (16 weeks)

• Fetal movements (16-20 weeks)

• Uterine enlargement (7-12 weeks)

• Breast enlargement (6 weeks)

Probable Signs (Time of Occurrence)

• Braxton Hicks contractions (16-28 weeks)

• Positive pregnancy test (4-12 weeks)

• Abdominal enlargement (14 weeks)

• Ballottement (16-28 weeks)

• Goodell sign (5 weeks)

• Chadwick sign (6-8 weeks)

• Hegar sign (6-12 weeks)

Positive Signs (Time of Occurrence)

• Ultrasound verification (4-6 weeks)

• Fetal movement felt by experienced clinician (20 weeks)

• Auscultation of fetal heart tones (10-12 weeks)

Probable Signs Explained

• Hegar sign: Softening of the lower uterine segment

• Goodell sign: Softening of the cervix

• Chadwick sign: Bluish-purple coloration of vaginal mucosa and cervix

• Ballottement: Rebound from the floating fetus during examination

Screening Tool of Pregnancy

• hCG (Human chorionic gonadotropin):

  • Earliest chemical marker of pregnancy, detectable 1 week before period

  • Levels double every 2 days for 4 weeks; peaks at 60-70 days post-fertilization

  • Levels too high may indicate molar pregnancy or multiple gestation; too low may suggest ectopic pregnancy

Adaptation: Reproductive System

• Ovaries: Ovulation ceases due to estrogen and progesterone

• Uterus:

  • Fundal height increases predictably

  • Braxton Hicks contractions (irregular contractions)

  • Lightening: dropping of the fetus (engaging)

• Cervix: Hegar’s and Goodell’s signs, mucous plug protects the uterus

• Vagina: Increased vascularity and normal discharge (Leukorrhea)

Breasts During Pregnancy

• Increased size, vascularity, Montgomery tubercles, and striae gravidarum

• Colostrum: Creamy yellowish fluid produced

Cardiovascular Adaptations

• Blood volume increases by 40-50%

• Physiology of anemia normal in pregnancy; iron supplementation needed

• BP slightly declines, CO increases by 30-50%

• Heart rate may increase by 10-15 beats/min

Coagulation Changes

• Increased fibrinogen, clotting factors, slow circulation = hypercoagulable state

• Increased risk of DVT due to venous stasis

Respiratory Adaptations

• Common issues: nosebleeds, stuffy nose, increased O2 consumption by 40%

Renal/Urinary Changes

• Structural changes to bladder, ureters, kidneys

• Increased risk of UTIs, GFR increases by 40-60%

Integumentary Changes

• Melasma and Linea Nigra: pigmentation changes during pregnancy

• PUPPP: Pruritic Urticarial Papules of Pregnancy, severe pruritus

Musculoskeletal Adaptations

• Diastasis recti and lordosis due to growing abdomen

• Relaxin softens ligaments for easier delivery

Neurologic/Immunologic Changes

• Symptoms: carpal tunnel, headaches, ocular changes, sleep alterations

• Enhanced innate immunity; suppression of adaptive immunity to prevent fetal rejection

Gastrointestinal Changes

• Nausea & vomiting (hyperemesis gravidarum)

• Changes in tone leading to constipation and heartburn

Endocrine Changes

• Hormonal shifts: include hCG, progesterone, estrogen, and other placental hormones impacting metabolism and fetal development

Table of Placental Hormones (Table 11.3)

• Human chorionic gonadotropin (hCG): Maintains corpus luteum, basis for pregnancy tests

• hPL (human chorionic somatomammotropin): Prepares mammary glands, affects maternal metabolism

• Relaxin: Inhibits uterine contractions, softens joints for birth

• Progesterone: Maintains endometrium, prevents contractions, supports breast development

• Estrogen: Supports uterine growth, regulates other hormones, aids breast tissue development

Hormonal Levels During Pregnancy**

• Chart showing levels of key hormones: hCG, progesterone, estrogen, and their roles in pregnancy

• Visual Aid: Graphic representation of hormone levels throughout pregnancy

• Understanding: Importance of hormonal balance for successful pregnancy and fetal development