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नेपाली विकिपीडियाबाट
यसमा जानुहोस्: परिचालन, खोज्नुहोस्
1513

Obstetrics (from the Latin obstare, "to stand by") is the surgical specialty dealing with the care of a woman र उनको offspring during pregnancy, childbirth र the puerperium (the period shortly after birth). Many obstetricians are also gynaecologists; see Obstetrics र gynaecology.

Antenatal care[सम्पादन गर्ने]

In obstetric practice, the obstetrician will see a pregnant woman on a regular basis to check the progress of उनको pregnancy. The exact schedule varies depending on resources र risk factors, such as diabetes.

The main rationale for these visits is surveillance for diseases of pregnancy which are detectable. Some examples are:

  1. pre-eclampsia. The blood-pressure र urine of a pregnant woman is checked at every opportunity to check for this.
  2. placenta praevia. On ultrasound, the placenta is visible obstructing the birth canal
  3. abnormal presentation (late pregnancy only). The fetus may be feet-first or buttocks-first(breech), side-on (transverse), or at an angle (oblique presentation)
  4. IUGR (Intrauterine Growth Restriction), this is a general designation, where the fetus is too small for its gestational age. Causes can be intrinsic (in the fetus) or extrinsic (usually placental problems). IUGR refers to fetal growth that is less than 10% of what is expected at that gestational age.

Signs[सम्पादन गर्ने]

चित्र:PregnancyAnatomicalModel.jpg
Anatomical model of a human pregnancy

Trimesters[सम्पादन गर्ने]

First trimester: elevated β-hCG (up to 100,000 mIU/mL by 10 weeks GA) can cause morning sickness, fatigue, mood swings र food cravings. The symptoms can last through 12 to 16 weeks of gestation.

Second trimester: The abdomen shows an obvious swelling arising from the pelvis, starting the "obvious phase" of pregnancy. Hyperpigmentation, including linea nigra, may appear.

Third trimester: The mother may experience backaches due to increased strain. Typically, the curvature of the spine is changed as pregnancy evolves in order to counteract the change in weight distribution. The mother may also suffer mild urinary incontinence due to pressure on the bladder by the pregnant uterus, as well as heartburn (due to compression of the stomach).

Overall[सम्पादन गर्ने]

Maternal physiology[सम्पादन गर्ने]

During pregnancy, the woman undergoes many physiological changes, which are entirely normal, including cardiovascular, renal, hematologic, metabolic or respiratory changes that become very important in the event of complications.

Metabolism[सम्पादन गर्ने]

During pregnancy, both protein metabolismcarbohydrate metabolism are affected. One kilogram of extra protein is deposited, with half going to the fetusplacenta, र another half going to uterine contractile proteins, breast glandular tissue, plasma protein, र hemoglobin.

Nutrition[सम्पादन गर्ने]

  • Increased caloric requirement by 300 kcal/day
  • Gain of 20 to 30 lb (10 to 15 kg)
  • Increased protein requirement to 70 or 75 g/day
  • Increased folate requirement from 0.4 to 0.8 mg/day (important in preventing neural tube defects)

All patients are advised to take prenatal vitamins to compensate for the increased nutritional requirements.

Cardiovascular[सम्पादन गर्ने]

The woman is the sole provider of nourishment for the embryo र later, the fetus, र so उनको plasma र blood volume slowly increase by 40-50% over the course of the pregnancy to accommodate the changes. This results in overall vasodilation, an increase in heart rate (15 beats/min more than usual), stroke volume, र cardiac output. Cardiac output increases by about 50%, mostly during the first trimester. The systemic vascular resistance also drops due to the smooth muscle relaxation caused by elevated progesterone, leading to a fall in blood pressure. Diastolic blood pressure consequently decreases between 12–26 weeks, र increases again to prepregnancy levels by 36 weeks. If the blood pressure remains abnormal beyond 36 weeks, the woman should be investigated for pre-eclampsia, a condition that precedes eclampsia.

Pulmonary[सम्पादन गर्ने]

All of these changes can contribute to the dyspnea (shortness of breath) that a pregnant woman may experience.

Hematology[सम्पादन गर्ने]

  • The plasma volume increases by 50% र the red blood cell volume increases only by 20-30%.
  • Consequently, the hematocrit decreases.
  • White blood cell count increases र may peak at over 20 mil/mL in stressful conditions.
  • Decrease in platelet concentration to a minimal normal values of 100-150 mil/mL
  • The pregnant woman also becomes hypercoagulable due to increased liver production of coagulation factors, mainly fibrinogenfactor VIII.

Gastrointestinal[सम्पादन गर्ने]

  • nausea र vomiting ("morning sickness") due to elevated B-hCG, which should resolve by 14 to 16 weeks
  • prolonged gastric empty time
  • decreased gastroesophageal sphincter tone, which can lead to acid reflux
  • decreased colonic motility, which leads to increased water absorption र constipation

Renal[सम्पादन गर्ने]

Endocrine[सम्पादन गर्ने]

Musculoskeleton र dermatology[सम्पादन गर्ने]

  • Lower back pain due to a shift in gravity
  • Increased estrogen can cause spider angiomatapalmar erythema
  • Increase melanocyte-stimulating hormone (MSH) can cause hyperpigmentation of nipples, umbilicus, abdominal midline (linea nigra), perineum, र face (melasma or chloasma)

Others[सम्पादन गर्ने]

Edema, or swelling, of the feet is common during pregnancy, partly because the enlarging uterus compresses veins र lymphatic drainage from the legs. For the sake of comfort, many pregnant women wear larger shoes or go without. This may have something to do with the origin of the phrase "barefoot र pregnant".

Prenatal Care[सम्पादन गर्ने]

Prenatal care is important in screening for various complications of pregnancy. This includes routine office visits with physical exams र routine lab tests:

First trimester[सम्पादन गर्ने]

Second trimester[सम्पादन गर्ने]

  • MSAFP/triple screen (maternal serum alpha-fetoprotein) - elevation correlated with neural tube defects र decrease correlated with Down's syndrome
  • ultrasound
  • amniocentesis in older patients

Third trimester[सम्पादन गर्ने]

  • hematocrit (if low, mother will receive iron supplementation)
  • glucose loading test (GLT) - screens for gestational diabetes; if > 140 mg/dL, a glucose tolerance test (GTT) is administered; if fasting glucose > 105 mg/dL, gestational diabetes is suggestive.

Complications[सम्पादन गर्ने]

See Complications of Pregnancy

Fetal assessments[सम्पादन गर्ने]

Common
  • ultrasound is used for many functions:
    • Dating the gestational age of a pregnancy, most accurate in first trimester
    • Detecting fetal anomalies in the second trimester
    • biophysical profiles (BPP)
    • Blood flow velocity in umbilical cord -- decrease/absence/reversal or diastolic blood flow in the umbilical artery is worrisome.
    • Congenital anomalies can be diagnosed with second trimester ultrasound
  • Fetal karyotype for the screening of genetic diseases can be obtained via amniocentesis or chorionic villus sampling (CVS)
Uncommon

Induction[सम्पादन गर्ने]

An obstetrician may recommend a woman have उनको labour induced if it is felt that continuation would be more dangerous to her, the fetus, or both. Reasons to induce include:

  1. pre-eclampsia
  2. IUGR
  3. diabetes
  4. other general medical condition, such as renal disease

Induction may occur any time after 24 weeks of gestation if the risk to the fetus or mother is greater than the risk of delivering a premature fetus regardless of lung maturity. Prior to 32 weeks gestation steroids are given to the mother to help mature the fetus's lungs.

If a woman does not eventually labour by 41–42 weeks, induction may be performed, as the placenta may become unstable after this date.

Induction may be achieved viaa several methods:

  1. pessary of Prostin cream, prostaglandin E2
  2. vaginal or oral administration of misoprostol
  3. cervical insertion of a 30-mL Foley catheter
  4. surgical induction, by piercing the amnion
  5. infusion of oxytocin

Labour[सम्पादन गर्ने]

During labour itself, the obstetrician may be called on to do a number of things:

  1. monitor the progress of labour, by reviewing the nursing chart, performing vaginal examination, र assessing the trace produced by a foetal monitoring device (the cardiotocograph)
  2. accelerate the progress of labour by infusion of the hormone oxytocin
  3. provide pain relief, either by nitrous oxide (nowadays uncommon, at least in the U.S.), opiates, or by epidural anesthesia done by anaethestists or an anesthesiologist
  4. surgically assisting labour, by forceps or the Ventouse (a suction cap applied to the fetus' head)
  5. Caesarean section, if vaginal delivery is decided against or appears too difficult. Caesarean section can either be elective, that is, arranged before labour, or decided during labour as an alternative to hours of waiting. True "emergency" Cesarean sections (where minutes count) are a rarity.

Emergencies in obstetrics[सम्पादन गर्ने]

Two main emergencies are ectopic pregnancy र (pre)eclampsia.

  • Ectopic pregnancy is when an embryo implants in the Fallopian tube or (rarely) on the ovary or inside the peritoneal cavity. This may cause massive internal bleeding.
  • Pre-eclampsia is a disease caused by mysterious toxins secreted by the placenta. These toxins act on the vascular endothelium, causing hypertensionproteinuria. If severe, it progresses to fulminant pre-eclampsia, with headaches र visual disturbances. This is a prelude to eclampsia, where a convulsion occurs, which is often fatal.

Imaging, monitoring र care[सम्पादन गर्ने]

In present society, medical science has developed a number of procedures to monitor pregnancy.

Antenatal record[सम्पादन गर्ने]

On the first visit to उनको obstetrician or midwife, the pregnant woman is asked to carry out the antenatal record, which constitutes a medical historyphysical examination.

On subsequent visits, the gestational age (GA) is rechecked with each visit. Symphysis-fundal height (SFH; in cm) should equal gestational age after 20 weeks of gestation, र the fetal growth should be plotted on a curve during the antenatal visits. The fetus is palpated by the midwife or obstetrician using Leopold maneuver to determine the position of the baby. Blood pressure should also be monitored, र may be up to 140/90 in normal pregnancies. High blood pressure indicates hypertension र possibly pre-eclampsia, if severe swelling (edema) र spilled protein in the urine are also present.

Fetal screening is also used to help assess the viability of the fetus, as well as congenital problems. Genetic counseling is often offered for families who may be at an increased risk to have a child with a genetic condition. Amniocentesis at around the 20th week is sometimes done for women 35 or older to check for Down's Syndrome र other chromosome abnormalities in the fetus. Even earlier than amniocentesis is performed, the mother may undergo the triple test, nuchal screening, nasal bone, alpha-fetoprotein screening र Chorionic villus sampling, also to check for disorders such as Down Syndrome. Amniocentesis is a prenatal genetic screening of the fetus, which involves inserting a needle through the mother's abdominal wall र uterine wall, to extract fetal DNA from the amniotic fluid. There is a risk of miscarriage र fetal injury with amniocentesis since it involves penetrating the uterus with the baby still in utero.

Imaging[सम्पादन गर्ने]

A dating scan at 12 weeks

Imaging is another important way to monitor a pregnancy. The mother र fetus are also usually imaged in the first trimester of pregnancy. This is done to predict problems with the mother; confirm that a pregnancy is present inside the uterus; guess the gestational age; determine the number of fetuses र placentae; evaluate for an ectopic pregnancy र first trimester bleeding; र assess for early signs of anomalies.

X-rayscomputerized tomography (CT) are not used, especially in the first trimester, due to the ionizing radiation, which has teratogenic effects on the fetus. Instead, ultrasound is the imaging method of choice in the first trimester र throughout the pregnancy, since it emits no radiation, is portable, र allows for realtime imaging. Ultrasound imaging may be done at any time throughout the pregnancy, but usually happens at the 12th week (dating scan) र the 20th week (detailed scan).

A normal gestation would reveal a gestational sac, yolk sac, र fetal pole. The gestational age can be assessed by evaluating the mean gestation sac diameter (MGD) before week 6, र the crown-rump length after week 6. Multiple gestation is evaluated by the number of placentaeamniotic sacs present.

Pregnancy has different cultural aspects related to the perception of the body, the relationship with partner र to the meaning of the event.

Terms र definitions[सम्पादन गर्ने]

  • embryo - conceptus between time of fertilization to 10 weeks of gestation
  • fetus - from 10 weeks of gestation to time of birth
  • infant - time of birth to 1 year of age
  • gestational age - time from last menstrual period (LMP) up to present
  • first trimester - up to 14 weeks of gestation
  • second trimester - 14 to 28 weeks of gestation
  • third trimester - 28 weeks to delivery
  • viability - minimum age for fetus survival, ca. third trimester
  • previable infant - delivered prior to 24 weeks
  • preterm infant - delivered between 24–37 weeks
  • term infant - delivered between 37–42 weeks
  • gravidity (G) - number of times a woman has been pregnant
  • parity (P) - number of pregnancies with a birth beyond 20 weeks GA or an infant weighing more than 500 g
  • Ga Pw-x-y-z - a = number of pregnancies, w = number of term births, x = number of preterm births, y = number of miscarriages, z = number of living children; for example, G4P1-2-1-3 means the woman had a total of 4 pregnancies, of which 1 is of term, 2 are preterm, 1 miscarriage, र 3 total living children (1 term + 2 preterm).

External links[सम्पादन गर्ने]

See also[सम्पादन गर्ने]


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