Of pregnancy is believed that they provided regular menstrual periods (every 28 days) lasts from the day of conception to 266 days or the first day of the last menstrual period of 280 days. The due date is calculated based on the last menstrual period. A birth 2 weeks before or after the predicted date is normal.
The earliest signs of pregnancy and the reason that leads most women to the doctor for the first time, is the absence of a menstrual period. For sexually active women of reproductive age with regular menstrual cycles, the lack of a menstrual period ? 1 week a circumstantial evidence of a pregnancy. Of pregnancy is believed that they provided regular menstrual periods (every 28 days) lasts from the day of conception to 266 days or the first day of the last menstrual period of 280 days. The due date is calculated based on the last menstrual period. A birth 2 weeks before or after the predicted date is normal. Clinical Calculator: Pregnancy progress based Naegele’s rule and ultrasound biometry Physiology Pregnancy causes in all maternal organ systems physiological changes; most return to their normal state after birth. Generally, these changes are more dramatic in a multiple pregnancy than in singleton pregnancies. Cardiovascular Starting from the 6th SSW the cardiac output (CO) rises by 30-50%, with a peak between the 16th-28th SSW (usually 24 weeks of gestation). It remains to be increased up to 30 weeks, is then dependent on the body position. Layers, by virtue of the increasing uterine the vena vava most hinder (for. Example, the lying position), the CO reducing strongest. The cardiac output increases on average usually slightly from 30 weeks until labor begins. During labor cardiac output increases by 30%. After the birth of the uterus to contract, and the cardiac output falls to a level 15-25% above the normal level quickly. Then it decreases more gradually (often over the next 3-4 weeks) until 6 weeks post partum to baseline before pregnancy. The cause of the increase in cardiac output during pregnancy are the demands of the uteroplacental circulation. The volume of the uteroplacental circulation increases considerably, and the circulation within the intervillous space behaves like an arteriovenous shunt. As the placenta and the fetus to develop, the blood flow to the uterus to about 1 l / min (20% of normal cardiac output) must increase until the deadline. The increased demand of the skin (for temperature control) and the kidneys (fetal to excrete metabolic products) account for a portion of the rise in cardiac output. In order to increase the cardiac output, the pulse increases from normally 70 to 90 beats / minute (beats / min, bpm) is added, and the stroke volume increases. During the second trimester, blood pressure normally falls (and the pulse pressure is on), although the cardiac output and renin and Angiotensinspiegel rise because the uteroplacental circulation expands (the intervillous spaces of the placenta develop) and systemic vascular pressure decreases. The resistance decreases because blood viscosity and sensitivity decrease to angiotensin. During the third trimester, the blood pressure is normal. For twins, the cardiac output increases more, and the diastolic blood pressure is in the 20th week lower than a Einlingsgravidität. Physical exercise increases cardiac output, heart rate, O2 -Consumption and minute ventilation during pregnancy more than usual. Hypercirculation pregnancy increases the frequency of functional murmurs and accentuates the heart sounds. X-ray or ECG, the heart is rotated to the left shifted with enlarged cross-section in a horizontal position. Atrial and ventricular premature beats are common during pregnancy. All these changes are normal and should not be diagnosed as heart disease by mistake; they can be well controlled solely by empathetic Explaining most. However, paroxysmal atrial tachycardia occur more frequently in pregnant women and in some cases require prophylactic digitalization or other antiarrhythmic drugs. Pregnancy does not affect the indications for or the safety of Kardioversion.Hämatologisch The total blood volume increases in proportion to the cardiac output, but it is the increase of the plasma volume is larger (up to close to 50%, usually at about 1600 ml in a total volume of 5200 ml) as the mass of erythrocytes (about 25%) so that the Hb is lowered by dilution of about 13.3 to 12.1 g / dl. This dilution anemia reduces blood viscosity. For twins, the maternal whole blood volume increases more closely to (closer to 60%). The number of white blood cells increased slightly from 9000 to 12,000 / ul. A significant leukocytosis (? 20,000 / ul) occurs after birth during childbirth and the first few days. The iron requirement grows throughout pregnancy by a total of 1 g and is in the second half of pregnancy higher (6-7 mg / day). Fetus and placenta need about 300 mg of iron, and the increased maternal red cell mass requires additional 500 mg. 200 mg are attributable to excretion. To a decrease in Hb values ??to prevent additional iron preparations are required, since the amount of absorbed from the diet and from the iron stores recruited iron (average total 300-500 mg) is usually not sufficient to decken.Urologisch the needs of Pregnancy changes in renal function are roughly comparable to those of cardiac function. Glomerular filtration rate (GFR) is growing by 30-50%, culminates 16 to 24 SSW and keeps at this level until close to the deadline, then easily drop because the pressure of the uterus on the vena cava often a venous congestion caused in the lower extremities. The renal blood flow (RBF) increases proportionally to the GFR. As a result, the blood urea takes up to about <10 mg / dl from (<3.6 mmol urea / l), and creatinine levels drop accordingly at 0.5-0.7 mg / dl (44-62 .mu.mol / l). A marked widening of the ureters (Hydroureter) is due to hormonal influences (predominantly progesterone) and caused by a backflow which is triggered by the pressure of the enlarged uterus to the ureters and, in some cases also leads to a hydronephrosis. After the birth, it sometimes takes up to 12 weeks before the urinary tract are back in their normal state. Positional changes affect pregnancy more on kidney function than at any other time; d. H. the prone position increases renal function more and the upright position it reduces more than usual Renal function intensifies also clearly on its side, particularly on the left side. when pregnant women are, this position takes the pressure that the enlarged uterus exerts on the large vessels. This position-dependent increase in kidney function is one reason why pregnant women need to urinate more frequently if they fall asleep versuchen.Respiratorisch The lung function changes, partly because progesterone increases and partly because of the growing uterus affects the expansion of the lungs. Progesterone signals the brain to reduce CO2 levels. In order to reduce CO2 levels, tidal and minute volume to be increased, which increases the serum pH. The O2 consumption increases by about 20% in order to meet the increased metabolic needs of the fetus, placenta and several maternal organs. Inspiratory and expiratory reserve volume, residual volume and capacity and the Pco2 in serum decrease. Vital capacity and Po 2 do not change. The chest circumference increases by about 10 cm. A significant hyperemia and edema of the respiratory tract occur. Occasionally there is a symptomatic nasopharyngeal obstruction and nasal congestion. The Eustachian tubes are temporarily blocked, and tone and character of the voice change. A slight exertion is normal, and the frequency of deep breaths takes zu.Gastrointestinal (GI) and hepatobiliary With pregnancy progresses, the pressure of the growing uterus to the rectum and the lower portion of the colon can cause constipation. Gastrointestinal movements are sparse because the elevated progesterone levels relax smooth muscle. Heartburn and belching are common, possibly as a result of delayed gastric emptying and of gastroesophageal reflux, due to the relaxation of the lower esophageal sphincter and the hiatus diaphragmaticus. The HCl production decreases, so that stomach ulcers are uncommon during pregnancy, and preexisting ulcers are often less agonizing. The incidence of gallbladder disease is increasing more. Pregnancy affects subtly on liver function, especially the transport of bile. The values ??of routine liver function tests are normal, may be out of the levels of alkaline phosphatase, which continuously increase during the third trimester and increased to the 2- or 3-fold at term. The increase in the production of this enzyme in the placenta and less of a malfunction of the liver zurückzuführen.endokrines system Pregnancy alters the function of almost all endocrine glands, in part because the placenta produces hormones and partly because most hormones in protein-bound circulate shape and the protein binding increases during pregnancy. as follicle-stimulating and luteinizing hormones - - the corpus luteum maintains, thereby preventing ovulation in the placenta, the beta subunit of human chorionic gonadotropin (beta-hCG), a trophic hormone that is produced. Estrogen and progesterone levels rise early during pregnancy because beta-hCG stimulates the ovaries to produce them continuously. After 9 to 10 weeks of pregnancy, the placenta itself produces large amounts of estrogen and progesterone to maintain the pregnancy. The placenta produces a hormone (similar to thyroid stimulating hormone, TSH), which stimulates the thyroid gland and thus causes hyperplasia, increased vascularization and a moderate magnification. Östrogenstimuliert the hepatocytes and thus leads to increased levels of thyroxine-binding globulin. Therefore, the level of total thyroxine can increase, the level of free thyroid hormones within normal limits remain. The effects of thyroid hormones are increasing more and may resemble with tachycardia, palpitations, excessive sweating and mood swings of hyperthyroidism. A true hyperthyroidism occurs only in 0.08% of all pregnancies. The placenta produces corticotropin-releasing hormone (CRH), which stimulates maternal ACTH production. Elevated ACTH levels let the levels of adrenal hormones, especially aldosterone and cortisol, increase and thereby contribute to edema formation. The increased production of corticosteroids and the increased placental production of progesterone lead to insulin resistance and an increased need for insulin as cause him stress of pregnancy and possibly also increased levels of human placental Laktogens. Insulinase, emerged in the placenta, may increase also requires insulin, so many women with Gestationsdiabetesklinisch develop more obvious forms of diabetes. In the placenta melanocyte-stimulating hormone (MSH), which causes late in pregnancy an increased skin pigmentation is formed. The pituitary gland enlarges during pregnancy by about 135%. The maternal serum prolactin levels increases by 10 times. The increased prolactin is associated with an estrogen stimulated increased production of thyroid stimulating hormone -Releasing. The primary function of prolactin is to ensure increased lactation. Post partum reverse the mirror - even among women who breastfeed - to the normal values ??zurück.Dermatologisch Elevated levels of estrogen, progesterone and MSH contribute to pigmentation changes, although the exact pathogenesis is unknown. These changes include melasma (mask of pregnancy) which is a patchy brownish pigment in the area of ??forehead and cheek bones is darkening of mamillären areolae, axilla and genitals Linea nigra, a dark line which appears below the middle abdomen melasma by pregnancy form in usually back within a year. The incidence of Spinnennävi, usually just above the waist, and thin-walled, far asked capillaries, especially in the calves is increasing. Melasma DR P. MARAZZI / SCIENCE PHOTO LIBRARY var model = {thumbnailUrl: '/-/media/manual/professional/images/m1301021-melasma-science-photo-library-high_de.jpg?la=de&thn=0&mw=350' imageUrl: '/-/media/manual/professional/images/m1301021-melasma-science-photo-library-high_de.jpg?la=de&thn=0', title: 'melasma' description: ' u003Ca id = " v38397083 "class = " anchor "" u003e u003c / a u003e u003cdiv class = "" para "" u003e u003cp u003eDieses photo shows brown spots on the cheeks of a patient with melasma. u003c / p u003e u003c / div u003e 'credits' DR P. MARAZZI / SCIENCE PHOTO LIBRARY'