OBGYN Puerperium - Female reproductive tract changes

PUERPERIUM

1. Reproductive Tract Changes Uterus The increased blood flow during pregnancy is reduced back to its pre-pregnancy state via reduction of the caliber of the pelvic vessels After a week: Opening narrows Cervix thickens Endocervical canal re-forms

2. Uterine Changes After delivery, the fundus of the uterus lies approximately below the umbilicus. During the next few weeks, the lower uterine segment contracts from being able to accommodate a fetal head to a barely discernable uterine isthmus between the corpus and the internal cervical os Postpartum – 1000g 1 week – 500g 2 weeks – 300g 4 weeks – 100g (complete involution) Uterus and the endometrium return to pregravid size by 8 weeks (sonogram)

3. Endometrial lining Decidua basale remains after the separation of the placenta ~2 – 3 days, the decidua basale divides into two layers The upper layer becomes necrotic and is sloughed off The lower layer forms the new myometrium Site of placental implantation exhibits slower endometrial regeneration compared to other parts of the uterus. Localized endometritis is a normal reparative process after separation of the placenta

4. Clinical aspects

5. Afterpain Present usually in multiparas Primipara uterus usually remain tonically contracted after delivery Multipara uterus often vigorously contract at intervals, resulting to afterpains They are similar but of lesser intensity to labor contractions More pronounced with parity Intensifies during breastfeeding Usually regress after 3 days Afterpains are more severe and persistent in postpartum uterine infections

6. Lochia Vaginal discharge from sloughed off decidual tissue Erythrocytes Shredded decidua Epithelial cells Bacteria Lochia rubra – red lochia due to presence of blood; present in the first few days Lochia serosa – paler lochia which appears after 3 – 4 days Lochia alba – reduced fluid and the increased amount of leukocytes results into a yellowish or white lochia after after 10 days Lochia persists for 24 – 36 days

7. SUbinvolution Hindrance of uterine involution due to infection, retained placental fragments, or other causes Associated with prolonged lochia, or excessive or irregular uterine bleeding On bimanual examination, uterus is larger and softer than expected If bleeding is present, pelvic sonography may be useful in excluding causes such as retained placenta or vascular malformations. Methylergonovine 0.2mg orally q3-4 for 24 – 48 hours If infection is present, antimicrobial treatment is recommended Azithromycin or Doxycycline for mild cases of infection

8. Late postpartum hemorrhage Defined as bleeding 24 hours to 12 weeks after delivery Clinically worrisome bleeding is seen within 1 – 2 weeks, usually caused by abnormal involution of placental site Retention of placental fragment Uterine artery pseudoaneurysm The retained placental fragment may undergo necrosis with deposition of fibrin This eventually forms into a placental polyp If the necrotic polyp detaches, hemorrhage occurs

9. Late postpartum Hemorrhage Curettage is not routinely done because retained placental fragments is rare. It may also worsen bleeding because it may avulse the placental implantation site. It is only employed if sonography demonstrates large clots within the cavity Gentle suction curettage is recommended In a stable patient, medical management is recommended: Oxytocin, methylergonovine, or a prostaglandin analogue is given If with infection, antimicrobials are given

10. The urinary Tract Pregnancy – induced hyperfiltration returns to pre-pregnancy levels by 2 weeks Ureters and Renal pelves (which are dilated during pregnancy) return to their previous caliber by 2 – 8 weeks. The dilated collecting system, residual urine, and the bacteriuria in a traumatized bladder predispose the new mother to symptomatic urinary tract infection. Postpartum, the bladder has increased capacity and is less sensitive to intravesical pressure. Overdistention Incomplete emptying Excessive residual urine

11. Peritoneum and abdominal wall The abdominal wall is usually soft and flaccid after pregnancy Abdominal girdles may be necessary It may take several weeks before the abdominal walls to regain their suppleness along with exercise. May be started anytime after vaginal delivery May start after 6 weeks following C/S Striae Gravidarum may develop Diastasis Recti occurs when abdominal muscles remain atonic, resulting to marked separation of the rectus abdominis muscles

12. Blood and Blood Volume Leukocytosis and Thrombocytosis may be present during and after labor With WBC counts reaching 30,000/µL Relative Lymphopenia Absolute eosinopenia Hemoglobin and Hematocrit fluctuate moderately in the first few days postpartum If they become markedly reduced, blood loss may be significant Fibrinogen level remains increased for the first week. Hypercoagulability is also present increasing the risk of deep-vein thrombosis and pulmonary embolism within 12 weeks after delivery

13. Pregnancy-induced hypervolemia If there is little blood lost during delivery, the mother’s elevated blood volume returns to its pre-pregnancy state about a week after delivery Cardiac output remains elevated 24 – 48 hours after delivery and returns to pre-pregnancy state after 10 days Systemic vascular resistance is lowered up until 2 days postpartum, after which it would increase to nonpregnant status. There is structural remodeling seen within the blood vessels which may explain the reduced risk of preeclampsia upon subsequent pregnancies.

14. Diuresis Postpartum Diuresis is the reversal of the increased extracellular sodium and water retention during pregnancy. There is approximately 2L decrease of sodium space during the first week after delivery Corresponds with the loss of pregnancy hypervolemia In pre-eclampsia, there may be pathological retention of fluid during labor and the post partum diuresis may be increased. Results to 2 – 3kg weight loss Weight loss is maximal after 2 weeks (7 – 9kg; with a surplus from prepregancy of 1.4kg)

15. Breastfeeding and lactation

16. Normal anatomy of the breast Each breast consists of 15 – 25 lobes arranged radially and separated from each other by fat Each lobe consists of lobules Each lobule consists of multiple alveoli Each alveolus has its own duct that joins other ducts to form a larger ducts that eventually lead to the nipple called lactiferous ducts

17. Secretory products Colostrum is a deep lemon – yellow liquid released after the second day postpartum. It is rich in immunological components ( IgA ) and is richer in amino acids and minerals, more protein, but less fat and sugar Persists for 5 days to 2 weeks and gradually transitions to plain old breastmilk (Mature Milk) by 4 – 6 weeks Mature milk concentrations and contents change even during a single feeding and are influenced heavily by a mother’s diet and they newborn’s age, health, and needs. 600mL daily Maternal gestational weight gain has little impact on quality or quantity Vitamin K is absent in breastmilk and thus a dose should be given to a newborn 22IU/mL intramuscularly

18. Breastmilk contents Whey is a milk serum with large amounts of Interleukin – 6 Human milk has a whey-to-casein ratio of 60:40 which is optimal for absorption. Other critical components Prolactin Epidermal growth factor Lactoferrin Melatonin Oligosaccharides Essential fatty acids

19. Endocrinology of lactation Hormones involved in the growth and development of the breast lobules and milk secreting cells Progesterone, estrogen, placental lactogen, prolactin, cortisol, and insulin With delivery, maternal serum levels of progesterone and estrogen decline abruptly and profoundly Progesterone and estrogen inhibits alpha-lactalbumin and lactose synthase Alpha – lactalbumin and lactose synthase are involved in the production of milk lactose Progesterone also inhibits Prolactin Prolactin stimulates alpha – lactalbumin production Calcium sensing receptors ( CaSR ) in mammary epithelial cells downregulates parathyroid hormone related protein Serotonin is also produced in the mammary epithelial cells and is needed in milk production

20. Endocrinology of lactation Lactation intensity and duration is heavily influenced by the repetitive nursing and emptying of milk from the breast and is mediated by the hormone prolactin Mothers with extensive pituitary necrosis or disruption in the secretion of prolactin do not lactate Serum levels fall to pre-pregnancy levels but quickly rise by the act of suckling. Breast stimulation inhibits dopamine release Dopamine inhibits prolactin release Prolactin release is pulsatile and causes contraction in the myoepithelial cells in the breasts Milk letdown reflex is initiated by suckling, an infant’s cry and is inhibited by maternal fright or stress