1. Maternal Physiologic Changes
Chapter 20
Maternal Physiologic Changes

2. Maternal Physiologic Changes
Postpartum period is interval between birth and return of reproductive organs to their nonpregnant state
Referred to as puerperium or fourth stage of pregnancy
Traditionally lasts 6 weeks, although this varies among women

3. Reproductive System and Associated Structures
Uterus
Involution: return of uterus to nonpregnant state following birth
Progresses rapidly
Fundus descends 1 to 2 cm every 24 hours
2 weeks after childbirth uterus lies in true pelvis
Subinvolution: failure of uterus to return to nonpregnant state
Common causes are retained placental fragments and infection

4. Reproductive System and Associated Structures—cont’d
Uterus
Contractions
Hemostasis achieved by compression of intramyometrial blood vessels as uterine muscle contracts
Hormone oxytocin, released from pituitary gland, strengthens and coordinates uterine contractions

5. Reproductive System and Associated Structures—cont’d
Uterus
Afterpains
Placental site
Lochia: postbirth uterine discharge
Lochia rubra
Blood and decidual and trophoblastic debris
Duration of 3 to 4 days

6. Reproductive System and Associated Structures—cont’d
Uterus
Lochia: postbirth uterine discharge
Lochia serosa
Old blood, serum, leukocytes, and debris
Duration of 22 to 27 days
Lochia alba
Leukocytes, decidua, epithelial cells, mucus, serum, and bacteria
Continues 2 to 6 weeks after birth

7. Reproductive System and Associated Structures—cont’d
Cervix
Soft immediately after birth
Within 2 to 3 postpartum days it has shortened, become firm, and regained form
Ectocervix appears bruised and has small lacerations—optimal conditions to develop infections
Cervical os, dilated to 10 cm during labor, closes gradually

8. Reproductive System and Associated Structures—cont’d
Vagina and perineum
Estrogen deprivation responsible for thinness of vaginal mucosa and absence of rugae
Vagina gradually returns to prepregnancy size by 6 to 10 weeks after childbirth
Thickening of vaginal mucosa occurs with return of ovarian function
Dryness and coital discomfort, dyspareunia, may persist until return of ovarian function

9. Reproductive System and Associated Structures—cont’d
Vagina and perineum
Introitus is erythematous and edematous
Episiotomies heal within 2 to 3 weeks
Hemorrhoids and anal varicosities are common and decrease within 6 weeks of childbirth

10. Reproductive System and Associated Structures—cont’d
Vagina and perineum
Pelvic muscular support
Supportive tissues of pelvic floor torn or stretched during childbirth
Require up to 6 months to regain tone
Kegel exercises encourage healing

11. Abdomen Abdomen During first 2 weeks abdominal wall remains relaxed
Woman has still-pregnant appearance
Return to prepregnancy state takes 6 weeks
Depends on previous tone, proper exercise, and amount of adipose tissue

12. Endocrine System Placental hormones
Expulsion of placenta results in dramatic decreases of placental-produced hormones
Decreases in chorionic somatomammotropin (hCS), estrogens, cortisol, and placental enzyme insulinase reverse effects of pregnancy
Estrogen and progesterone levels drop markedly

13. Endocrine System—cont’d
Pituitary hormones and ovarian function
Lactating and nonlactating women differ in timing of first ovulation and menstruation
70% of nonbreastfeeding mothers menstruate within first 12 weeks
In breastfeeding women return of ovulation depends on breastfeeding patterns
May ovulate before first menstrual cycle

14. Urinary System Urine components Postpartal diuresis
Within 12 hours women begin to diurese
Profuse diaphoresis often occurs at night for first 2 to 3 days
Urethra and bladder
Excessive bleeding can occur because of displacement of the uterus if bladder is full

15. Breasts Breastfeeding mothers Nonbreastfeeding mothers
Before lactation a yellowish fluid, colostrum, can be expressed from nipples
Tenderness may persist for 48 hours after start of lactation
Nonbreastfeeding mothers
Engorgement resolves spontaneously, and discomfort decreases within 24 to 36 hours
Breast binder or tight bra, ice packs, or mild analgesics may be used to relieve discomfort

16. Cardiovascular System
Blood volume
Blood volume increase eliminated within first 2 weeks after birth, with return to nonpregnancy values by 6 months after delivery
Readjustments in maternal vasculature after childbirth dramatic and rapid

17. Integumentary System
Chloasma of pregnancy usually disappears at end of pregnancy
Hyperpigmentation of areolae and linea nigra may not regress completely after childbirth
Some women will have permanent darker pigmentation of those areas
Stretch marks on breasts, abdomen, and thighs may fade but not disappear

18. Immune System
No significant changes in maternal immune system occur during postpartum period
Mother’s need for rubella vaccination or for Rho (D) immune globulin for prevention of Rh isoimmunization is determined

19. Key Points
Uterus involutes rapidly after birth, returning to true pelvis within 2 weeks
Rapid decrease in estrogen and progesterone levels after expulsion of placenta responsible for triggering many anatomic and physiologic changes in puerperium

20. Key Points—cont’d
Assessment of lochia and fundal height is essential to monitor progress of normal involution and identify potential problems
Return of ovulation and menses is determined in part by whether woman breastfeeds infant
Few alterations in vital signs are seen after birth under normal circumstances

21. Key Points—cont’d
Hypercoagulability, vessel damage, and immobility predispose the woman to thromboembolism
Marked diuresis, decreased bladder sensitivity, and overdistention of the bladder can lead to problems with urinary elimination
Pregnancy-induced hypervolemia allows women to tolerate considerable blood loss at birth