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.
- १ Antenatal care
- २ Signs
- ३ Maternal physiology
- ४ Prenatal Care
- ५ Complications
- ६ Induction
- ७ Labour
- ८ Emergencies in obstetrics
- ९ Imaging, monitoring र care
- १० Terms र definitions
- ११ External links
- १२ See also
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:
- pre-eclampsia. The blood-pressure र urine of a pregnant woman is checked at every opportunity to check for this.
- placenta praevia. On ultrasound, the placenta is visible obstructing the birth canal
- abnormal presentation (late pregnancy only). The fetus may be feet-first or buttocks-first(breech), side-on (transverse), or at an angle (oblique presentation)
- 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 १०% of what is expected at that gestational age.
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).
- Bluish discoloration of vagina र cervix (Chadwick's sign)
- Softening र cyanosis of cervix after ४ weeks (Goodell's sign)
- Softening of uterus after ६ weeks (Ladin's sign)
- Breast swelling र tenderness
- Linea nigra from umbilicus to pubis
- Palmar erythema
- Nausea र vomiting
- Breast pain
- Fetal movement
- Sciatica (Pain caused by compression of the sciatic nerve)
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.
During pregnancy, both protein metabolism र carbohydrate metabolism are affected. One kilogram of extra protein is deposited, with half going to the fetus र placenta, र another half going to uterine contractile proteins, breast glandular tissue, plasma protein, र hemoglobin.
- Increased caloric requirement by ३०० kcal/day
- Gain of २० to ३० lb (१० to १५ kg)
- Increased protein requirement to ७० or ७५ g/day
- Increased folate requirement from ०.४ to ०.८ mg/day (important in preventing neural tube defects)
All patients are advised to take prenatal vitamins to compensate for the increased nutritional requirements.
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 ४०-५०% over the course of the pregnancy to accommodate the changes. This results in overall vasodilation, an increase in heart rate (१५ beats/min more than usual), stroke volume, र cardiac output. Cardiac output increases by about ५०%, 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 १२–२६ weeks, र increases again to prepregnancy levels by ३६ weeks. If the blood pressure remains abnormal beyond ३६ weeks, the woman should be investigated for pre-eclampsia, a condition that precedes eclampsia.
- Increased tidal volume (३०-४०%)
- Decreased total lung capacity (TLC) by ५% due to elevation of diaphragm from uteral compression
- Decreased expiratory reserve volume
- Increased minute ventilation (३०-४०%) which causes a decrease in PaCO२ र a compensated respiratory alkalosis
All of these changes can contribute to the dyspnea (shortness of breath) that a pregnant woman may experience.
- The plasma volume increases by ५०% र the red blood cell volume increases only by २०-३०%.
- Consequently, the hematocrit decreases.
- White blood cell count increases र may peak at over २० mil/mL in stressful conditions.
- Decrease in platelet concentration to a minimal normal values of १००-१५० mil/mL
- The pregnant woman also becomes hypercoagulable due to increased liver production of coagulation factors, mainly fibrinogen र factor VIII.
- nausea र vomiting ("morning sickness") due to elevated B-hCG, which should resolve by १४ to १६ 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
- Increase in kidney र ureter size
- Increased glomerular filtration rate (GFR) by ५०%, which subsides around २० weeks postpartum
- Increased renin-angiotensin system, causing increased aldosterone levels
- Plasma sodium does not change because this is offset by the increase in GFR
- Increased estrogen, which is mainly produced in the placenta
- Fetal well being is associated with maternal estrogen levels
- Causes an increase in thyroxine-binding globulin (TBG)
- Increased human chorionic gonadotropin (β-hCG), which is produced by the placenta. This maintains progesterone production by the corpus luteum
- Human placental lactogen (hPL) is produced by the placenta र ensures nutrient supply to the fetus. It also causes lipolysis र is an insulin antagonist, which is a diabetogenic effect.
- Increased progesterone production, first by corpus luteum र later by the placenta. Its main course of action is to relax smooth muscle.
- Increased prolactin
- Increased alkaline phosphatase
Musculoskeleton र dermatology[सम्पादन गर्ने]
- Lower back pain due to a shift in gravity
- Increased estrogen can cause spider angiomata र palmar erythema
- Increase melanocyte-stimulating hormone (MSH) can cause hyperpigmentation of nipples, umbilicus, abdominal midline (linea nigra), perineum, र face (melasma or chloasma)
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]
- complete blood count (CBC)
- blood type (blood transfusion may be needed in an emergency)
- general antibody screen (indirect Coombs test) for HDN
- Rh D negative antenatal patients should receive RhoGam at २८ weeks to prevent Rh disease.
- Rapid plasma reagent (RPR) which screens for syphilis
- Rubella antibody screen
- Hepatitis B surface antigen
- Gonorrhea र Chlamydia culture
- PPD for tuberculosis
- Pap smear
- Urinalysis र culture
- HIV screen
- Group B Streptococcus screen—will receive IV penicillin if positive (if mother is allergic, alternate therapies include IV clindamycin or IV vancomycin)
Second trimester[सम्पादन गर्ने]
- MSAFP/triple screen (maternal serum alpha-fetoprotein) - elevation correlated with neural tube defects र decrease correlated with Down's syndrome
- 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 > १४० mg/dL, a glucose tolerance test (GTT) is administered; if fasting glucose > १०५ mg/dL, gestational diabetes is suggestive.
Fetal assessments[सम्पादन गर्ने]
- 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)
- Fetal hematocrit for the assessment of fetal anemia, Rh isoimmunization, or hydrops can be determined by percutaneous umbilical blood sampling (PUBS) which is done by placing a needle through the abdomen into the uterus र taking a portion of the umbilical cord.
- Fetal lung maturity is associated with how much surfactant the fetus is producing. Reduced production of surfactant indicates decreased lung maturity र is a high risk factor for neonatal respiratory distress syndrome (NRDS). Typically a lecithin:sphingomyelin ratio greater than १.५ is associated with increased lung maturity.
- Nonstress test (NST) for fetal heart rate
- Oxytocin challenge test
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:
Induction may occur any time after २४ 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 ३२ weeks gestation steroids are given to the mother to help mature the fetus's lungs.
If a woman does not eventually labour by ४१–४२ weeks, induction may be performed, as the placenta may become unstable after this date.
Induction may be achieved viaa several methods:
- pessary of Prostin cream, prostaglandin E२
- vaginal or oral administration of misoprostol
- cervical insertion of a ३०-mL Foley catheter
- surgical induction, by piercing the amnion
- infusion of oxytocin
During labour itself, the obstetrician may be called on to do a number of things:
- 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)
- accelerate the progress of labour by infusion of the hormone oxytocin
- 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
- surgically assisting labour, by forceps or the Ventouse (a suction cap applied to the fetus' head)
- 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 hypertension र proteinuria. 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 subsequent visits, the gestational age (GA) is rechecked with each visit. Symphysis-fundal height (SFH; in cm) should equal gestational age after २० 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 १४०/९० 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 २०th week is sometimes done for women ३५ 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 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-rays र computerized 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 १२th week (dating scan) र the २०th 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 ६, र the crown-rump length after week ६. Multiple gestation is evaluated by the number of placentae र amniotic 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 १० weeks of gestation
- fetus - from १० weeks of gestation to time of birth
- infant - time of birth to १ year of age
- gestational age - time from last menstrual period (LMP) up to present
- first trimester - up to १४ weeks of gestation
- second trimester - १४ to २८ weeks of gestation
- third trimester - २८ weeks to delivery
- viability - minimum age for fetus survival, ca. third trimester
- previable infant - delivered prior to २४ weeks
- preterm infant - delivered between २४–३७ weeks
- term infant - delivered between ३७–४२ weeks
- gravidity (G) - number of times a woman has been pregnant
- parity (P) - number of pregnancies with a birth beyond २० weeks GA or an infant weighing more than ५०० 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, G४P१-२-१-३ means the woman had a total of ४ pregnancies, of which १ is of term, २ are preterm, १ miscarriage, र ३ total living children (१ term + २ preterm).
|विकिमिडिया कमन्समा अरु धेरै सामग्रीहरू छन्: Obstetrics|
- Childbirth from Embryo to Fetus video clip २ min.
- Childbirth- Final Stage of Labor video clip २ min.
- Obstetrics Forums
- Ingenious: archive of historical images related to obstetrics, gynaecology, र contraception.