There is generalized physical fatigue immediately after delivery. The pulse rate may be elevated a few hours after childbirth due to excitement or pain and usually normalizes on the second day. The blood pressure could be elevated due to pain or excitement but is generally in the normal range.[3] A significant decrease (> 20% below baseline) in blood pressure could be a sign of postpartum hemorrhage or septic shock.[4] Conversely, high blood pressure could be a sign of pain or pre-eclampsia.[5]
The temperature is slightly elevated up to 37.2C (99F) along with increased shivering, sweating, or diaphoresis in the first 24 hours and normalizes within 12 hours.[3][6] The temperature rise is attributable to the systemic absorption of metabolites accumulated due to muscle contractions. There could be a transient temperature rise (by 0.5C) on the third or fourth day due to breast engorgement. The respiratory rate also begins to fall back to the pre-pregnancy level within 2 to 3 days. A rise of temperature beyond the third day or over the upper limit is usually a sign of infection.[7][8][9][7] There is a weight loss of 5 to 6 kg due to the expulsion of products of gestation and accompanying blood loss. Further weight loss of 2 to 3 kg can be attributed to the brisk diuresis. The weight loss due to diuresis may continue up to 6 months after delivery.
Physiology Of Normal Puerperium Pdf 14
Involution, a part of postpartum physiology, is the term given to the process of reproductive organs returning to their prepregnant state. Immediately following the delivery, the uterus, and the placental site contracts rapidly to prevent further blood loss. This rapid uterine contraction can lead to abdominal pain or cramps after childbirth. At this point, the uterus has an increased tone, feels firm, and weighs 1000 gms, and at the end of the first week, it weighs 500 gms, and by six weeks, it weighs approximately 50 gms. The female may complain. Initially, the contraction of the uterus is due to a substantial reduction in myometrial cell size; it constricts the blood vessels and limits the bleeding. The subsequent decrease in size is due to autolysis and infarction of uterine blood vessels.[10][11][12] The withdrawal of estrogen and progesterone leads to an increase in the activity of uterine collagenase and other proteolytic enzymes, accelerating the process of autolysis.[13] The intima and elastic tissues in the uterine blood vessels also undergo fibrosis and hyaline degeneration, leading to infarction and shedding of more uterine cells, which are removed by macrophages. The superficial and basal layers of the endometrium become necrotic and sloughed.[14] The endometrium is usually fully restored within 2 to 3 weeks.[15]
The lochia is the vaginal discharge that originates from the uterus, cervix, and vagina. The lochia is initially red and comprised of blood and fragments of decidua, endometrial tissues, and mucus and lasts 1 to 4 days. The lochia then changes color to yellowish or pale brown, lasting 5 to 9 days, and is comprised mainly of blood, mucus, and leucocytes. Finally, the lochia is white and contains mostly mucus, lasting up to 10 to 14 days. The lochia can persist up to 5 weeks postpartum. The persistence of red lochia beyond one week might be an indicator of uterine subinvolution. The presence of an offensive odor or large pieces of tissue or blood clots in lochia or the absence of lochia might be a sign of infection.[16][17][18] The cervix and vagina may be edematous and bruised in the early postpartum period and gradually heal back to normal.[19]
The onset of the first menstrual period following delivery is variable and depends if the mother is lactating or not. If the mother is not breastfeeding, then the menstrual function returns by the sixth to eighth week postpartum in most of the cases. The duration of anovulation depends on the frequency and intensity of breastfeeding and is attributed to high serum prolactin levels associated with suckling.[24] Elevated serum prolactin levels inhibit the ovarian response to the follicular stimulating hormone, suppress the release of luteinizing hormone, suppressing the secretion of gonadotropins even further. This approach offers a natural method of contraception to the lactating female. In lactating females, menstruation usually reappears in 4 to 5 months, and in some cases, can be as late as 24 months. However, ovulation can commence in the absence of menstruation, and pregnancy can occur.[25][26][27] Non-lactating mothers should use contraceptive measures after three weeks, and lactating mothers after three months of delivery.[28] The level of human chorionic gonadotropin that mimics stimulating thyroid hormone falls dramatically after delivery. Consequently, the thyroid gland volume regresses to the pre-pregnant state by 12 weeks, and the thyroid function returns to normal by four weeks postpartum.[29][30] The diabetogenic effects of pregnancy are due to the production of placental insulinase, corticotropin-releasing hormone, and human placental lactogen.[31] The insulin sensitivity begins to increase after delivery and becomes restored within 2 to 3 days following delivery.[32] However, in obese females, postpartum normalization of insulin sensitivity may take 15 to 16 weeks.[33]
There is a shift of fluid from extravascular to intravascular space, corresponding to 6 to 8 liters of total body water. Furthermore, the persistent activity of the renin-angiotensin-aldosterone system (RAAS) during pregnancy leads to an excess of 950 mEq of sodium.[40] In the postpartum period, there is increased serum levels of the atrial natriuretic peptide (1.5 times normal) that inhibits aldosterone, angiotensin II and vasopressin and promotes urinary sodium excretion. There is brisk diuresis in the first two weeks after childbirth, and it is not uncommon to have a urinary output of 3000 cc/day. The amount of loss is usually in line with the amount of fluid retained during pregnancy. The glomerular filtration rate returns to baseline at eight weeks postpartum.[39] Lactosuria is not uncommon on the third or fourth day of the start of lactation.[41]
The hematocrit may initially drop due to blood loss associated with delivery but starts to rise again plasma volume decreases due to diuresis and hemoconcentration.[42] The hematocrit values return to normal in 3-5 days postpartum as plasma volume starts to increase. The discrepancy in hemoglobin values in the postpartum phase is due to the variability in the plasma volume due to fluid shifts. Studies evaluating the longitudinal values of hemoglobin in the postpartum phase indicate that it takes at least 4-6 months to restore the pregnancy-induced dip in hemoglobin to non-pregnant states.[43] The patient may develop leucocytosis (approximately 25,000/mm^3) due to the stress associated with labor. The white blood cell count returns to pre-pregnant values within four weeks.[44] The gestational thrombocytopenia resolves in 4 to 10 days after delivery as platelet count increases in response to platelet consumption during delivery.[44][45] During pregnancy, the fibrinogen, factor VII, VIII, X, XII, von Willebrand's factor, and ristocetin activity increase significantly as gestation progresses to prepare for delivery and prevent excess blood loss.[46] In the early postpartum period, the fibrinogen levels are still high, and platelets begin to rise to normal values. The tissue plasminogen, an enzyme responsible for clot lysis, doesn't rise or normalize in the early postpartum period. During pregnancy, the hypercoagulable state resolves gradually after birth, as clotting factor levels normalize in 8 to 12 weeks postpartum.[47][48] The changes in the coagulation system confer an increased risk for thromboembolic phenomena that are approximately ten-fold during pregnancy and twenty-fold during the early postpartum period.[49][50] Furthermore, the in vitro tests to assess or predict the possibility of thromboembolism, such as d-dimer tests, fibrin degradation products assay, are less reliable in the immediate postpartum period.[51]
Hyperpigmentation is the most commonly reported skin change during pregnancy, affecting 85% to 90% of females.[64] The hypothesis is that melanocytes are sensitive to elevated levels of estrogen, progesterone, and endorphins during pregnancy. Humoral factors produced by the placenta lead to the upregulation of tyrosine kinase, promoting further melanin synthesis.[65][66] The pigment changes accompanying pregnancy (melasma and linea nigra) usually disappear by 6 to 8 weeks.[67] Elevated estrogen during pregnancy can lead to telangiectasis and spider angiomata.[68] Venous dilation and increased hydrostatic pressure due to the gravid uterus can lead to nonpitting edema and varicosities in lower extremities, which returns to baseline in the postpartum period.[69] The nails undergo symmetrical, uniform hyperpigmentation during pregnancy that fades away in the postpartum period.[70] The abdominal muscles are overstretched during pregnancy and strained during labor and are slow to regain their normal tone and elasticity, returning to pre-pregnancy levels by 6 to 8 weeks. The patient may have divarication of recti, and the striae or stretch marks over the abdomen and legs might not disappear.[66]
Human physiology is significantly altered during pregnancy and in the postpartum period. The physician should be aware of the physiological changes associated with the postpartum period. The clinician should be able to tell the difference between healthy and abnormal to effectuate a diagnostic and therapeutic algorithm, especially in cases of acute emergencies such as postpartum hemorrhage, sepsis, amniotic fluid embolism, or uterine inversion. Furthermore, one should be aware of the hormonal changes related to the puerperium and lactation to formulate an effective contraception plan in the postpartum period. Thromboprophylaxis in the postpartum period is a constant topic of debate due to the high incidence of venous thromboembolism in the postpartum period, and females are risk-stratified into low-risk, medium-risk and, high-risk. Females with a history of no coagulation anomalies or low-risk don't require any thromboprophylaxis. Intermediate-risk females should be instituted thromboprophylaxis after delivery up to 7 days of puerperium. The females that are high risk receive thromboprophylaxis throughout pregnancy and up to 7 days of postpartum. The conduct of anesthesia for surgery also varies according to the timeline post-delivery. Patients undergoing surgery under general anesthesia within 48 hours of delivery should be treated as full stomach and should receive anti-aspiration measures, including non-particulate antacid and rapid sequence induction of anesthesia. 2ff7e9595c
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