Prenatal care

ROBAB DAVAR M.D.Obstetrician and Gynecologist, Fellowship of

Infertility

Shahid sadoughi university of medical sciences

• In the United States, the first organized prenatal care programs began in 1901 with home nurse visits. The first prenatal clinic was established in 1911.

Content of the Preconception Visit

• Unalterable Factors

• are preexisting factors that cannot be altered in any medical way by clinical intervention. These include the patient's height, age, reproductive history, ethnicity, educational level, socioeconomic status, genetic composition, and to some extent her body mass index (BMI).

• Factors Benefiting from Early Intervention

poor nutrition; an underweight or obese BMI; and poorly controlled medical diseases such as diabetes mellitus, asthma, epilepsy, phenylketonuria, hypertension, and thyroid disease.

• Some prescription medications that are known teratogens should be discontinued . These include medications such as isotretinoin (Accutane), warfarin sodium (Coumadin), certain anticonvulsants, and angiotensin-converting enzyme inhibitors. However, many medications are safe, such as medications for asthma and most antihistamines. Some medications such as antidepressants need to be evaluated for the risk:benefit ratio.

• Alcohol is a known teratogen. There is no correlation between the quantity of alcohol consumed and the manifestation of adverse fetal effects. Therefore, the best advice to women who wish to become pregnant is to stop drinking.

• Smoking cigarettes is associated with adverse pregnancy outcomes, including low birth weight, premature birth, and perinatal death.

• status of a patient's immunity to rubella, varicella, and hepatitis is appropriate during the preconception visit. If needed, the influenza vaccine is safe. In high-risk populations or endemic geographic areas, patients should be assessed for active tuberculosis with skin testing and chest x-ray.

• evaluation of the thyroid and breasts is important.

• If a Pap smear has not been done within a year, this test should be repeated at this time.

• assessment of dental hygiene is important.

• Folic acid can reduce the occurrence and recurrence of neural tube defects and may reduce the risk of other birth defects as well.

• Women who have had a previous pregnancy affected by neural tube defects should take 4 mg of folic acid per day, starting 4 weeks prior to conception through the first trimester.

• For all other women , 1 mg of folic acid should be prescribed.

Initial Prenatal Visit

• The optimal timing of this visit may vary. For women who have not undergone the preconception visit, prenatal visits should begin as soon as pregnancy is recognized.

• All other women should be seen by about 8 menstrual weeks (6 weeks after conception) gestation.

• Gestational Age• The NÃgele rule is commonly applied in calculating an

estimated date of confinement (EDC). • Using the date of the patient's last menstrual period

minus 3 months plus 1 week and 1 year, for convention, 280 days is the currently accepted average gestation.

• The majority of pregnancies deliver within 2 weeks before or after this estimated date.

• When the last menstrual period is unknown or the cycle is irregular, ultrasound measurements between the 14 and 20 weeks for determination of gestational age .

Physical Examination•includes BMI, blood pressure, thyroid, skin, breasts, and pelvis. •On pelvic examination, the cervix is inspected for anomalies and for the presence of condylomata, neoplasia, or infection. A Pap smear is performed, and cultures for gonorrhea and chlamydia are taken, if indicated. On bimanual examination, the cervix is palpated to assess consistency and length as well as to detect the presence of cervical motion tenderness. Size, position, and contour of the uterus are noted. The adnexa are palpated to assess for masses. •The pelvic examination may include evaluation of the bony pelvis specifically, the diagonal conjugate, the ischial spines, the sacral hollow, and the arch of the symphysis pubis.

Laboratory Evaluation

•Blood Tests

•white blood cell count, hemoglobin, hematocrit, and platelet count. Full red cell indices are advised for women of Asian descent to evaluate for thalassemia, a serologic test for syphilis (RPR, rapid plasma reagin or VDRL), a rubella titer, a hepatitis B surface antigen, a blood group (ABO), and Rh type and antibody screen. HIV testing.

• Urine Tests

• All women should have a clean-catch urine sent for culture. Asymptotic bacteriuria occurs in 5% to 8% of pregnant women.

• The use of routine genital tract cultures in pregnancy is controversial.

• The ACOG recommends assessment for chlamydiosis and gonorrhea at the first prenatal visit for high-risk patients.

• Physical Examination• The patient's weight is measured, and total weight

gain are evaluated . • The blood pressure is taken and trends are

assessed for possible pregnancy-induced hypertension. As blood pressure tends to decrease during the second trimester, increases of 30 mm Hg systolic or 15 mm Hg diastolic over first-trimester are considered abnormal .

• The fundal height is measured.

• Gestational age is approximately equal to fundal height in centimeters from 16 to 36 weeks gestation.

• Measurements that are more than 2 cm smaller than expected for week of gestation are suspicious for oligohydramnios, IUGR, fetal anomaly, abnormal fetal lie, or premature fetal descent into the pelvis.

• larger than expected measurements may indicate multiple gestation, polyhydramnios, fetal macrosomia, or leiomyomata.

• Screening for Gestational Diabetes• The 1-hour, 50-g oral glucose screen is used to

detect glucose intolerance in pregnancy. Following an abnormal screen, a 3-hour glucose tolerance test, commencing with a fasting blood sugar, followed by a 100-g glucola, is currently recommended.

• Two or more abnormal values on this test are considered diagnostic of GDM.

• All Rh-negative women who are unsensitized should be retested at approximately 26 to 28 weeks gestation. If the antibody screen remains negative, the mother should receive Rh0(D) immune globulin 300 mcg at 28 weeks to prevent isoimmunization in the third trimester.

• Approximately 1% of Rh-negative women will become sensitized if not given Rh immune globulins.

• Routine Ultrasound

• ultrasound should be performed before 20 weeks so that appropriate referrals and consultation can be obtained if abnormalities are discovered.

The list of warning signs includes the following:•Vaginal bleeding•Leaking of fluid from the vagina•Rhythmic cramping pains of more than six per hour•Abdominal pain of a prolonged or increasing nature•Fever or chills•Burning with urination•Prolonged vomiting more than 24 hours•Severe continuous headache, visual changes, or generalized edema•A pronounced decrease in the frequency or intensity of fetal movements.

Maternal Weight Gain• Women with a BMI <19.8 should gain between 30 and 40 lb.• Women with a normal BMI of 19.8 to 26 should gain between 25 and 35 lb.• Women with a high BMI, between 26.1 and 29, should gain 15 to 25 lb. •Women who are obese should aim for a 15 lb weight gain . •The optimal weight gain for women with twins with a normal BMI is approximately 40 lb or 10 to 15 lb more than for a singleton.

• A diet should be balanced by containing foods from all of the basic food groups.

Maternal Diet

Vitamin and Mineral Supplementation

• Multivitamin supplements are not routinely necessary in a woman eating a well-balanced diet. However, 800 to 1,000 mg of supplemental folic acid daily is necessary .

• Mineral supplementation is also not needed in healthy women. The exception is iron. The iron requirements of pregnancy total about 1 g.

• supplementation with 30 mg of elemental iron is recommended in the second and third trimesters.

• Calcium supplementation is not necessary in women with a diet that includes adequate dairy foods.

• recommended dietary allowance (RDA) of 1,200 to 1,500 mg per day during pregnancy and 2,000 mg per day with lactation.

• Women with twins may be given 2,000 mg daily. Women in their mid thirties should also receive increased dosing. Calcium is best absorbed in an acidic pH, similar to iron. To absorb calcium, adequate vitamin D is needed.

Pica

• Pica is the compulsive ingestion of nonfood substances with little or no nutrient value.

• Megadose Vitamins• There is an association between high doses of

supplemental vitamin A and birth defects similar to those seen with isotretinoin.

• minimum teratogenic dose in humans has not been identified, it may be 10,000 IU per day. Beta-carotene is a provitamin of vitamin A, but it does not produce similar toxicity.

• Most prenatal vitamins contain less than 5,000 IU of vitamin A and, this should be considered the maximum safe supplemental dose.

Nausea and Vomiting•Recurrent nausea and vomiting during the first trimester occurs in over one half of pregnancies. •Symptoms usually begin in weeks 6 to 8, peak during weeks 12 to 14, and are significantly resolved by week 22.• Hormonal as well as emotional factors have been investigated. Symptoms can be mild or so severe that the patient becomes dehydrated and risks of electrolyte imbalance and caloric malnutrition.• Nonpharmacologic measures include avoidance of fatty or spicy foods; eating small, more frequent meals, and inhaling peppermint oil vapors.•vitamin B6, 25 mg two to three times a day.

• antihistamines, doxylamine, promethazine, metoclopramide, trimethobenzamide, methylprednisolone, and serotonin 5-Ht3 antagonists such as ordansetron.

• Because supplemental vitamin and mineral preparations may exacerbate symptoms of nausea, they should be stopped until the symptoms have resolved.

• Hyperthyroid disease will exacerbate nausea and vomiting, and if signs of thyroid disease, free T4 levels and treatment initiated.

• Some studies have found Helicobacter pylori infection.

• Ptyalism

• Ptyalism is the increased production of saliva

Heartburn

• is usually caused by reflux esophagitis from both mechanical factors (the enlarging uterus displacing the stomach above the esophageal sphincter) and hormonal factors (progesterone causing a relative relaxation of the esophageal sphincter).

• Treatment consists of eliminating acidic and spicy foods, decreasing the amount of food and liquid at each meal, limiting food and liquid intake before bedtime, sleeping in a semi-Fowler position or propped up on pillows, and use of antacids. Liquid forms of antacids and H2-receptor inhibitors.

• Proton pump inhibitors are sometimes necessary in severe cases.

Constipation

• Progesterone-induced relaxation of the intestinal smooth muscle slows peristalsis and increases bowel transit time.

• Dietary management includes increased fluids and liberal intake of high-fiber foods.

• Iron salts may exacerbate the problem.• OTC products containing psyllium draw fluid into

the intestine and promote a more rapid transit time.

• Enemas should be avoided.

Exercise

• For a normal pregnancy, a low-impact exercise regimen may be continued throughout pregnancy.

• There are no data to indicate that pregnant women must decrease the intensity of their exercise or lower their target heart rates.

• motionless standing or the supine position can result in decreased venous return and cardiac output. This will result in hypotension or syncope.

• women who exercise regularly have shorter labors.• women with GDM, regular exercise has been shown

to be helpful for glucose control.

Varicosities and Hemorrhoids

• Varicosities most often occur in the lower extremities and may be seen in the vulva as well. Treatment includes avoidance of garments that constrict at the knee and upper leg, support stockings, and increased periods of rest with the legs elevated.

• Hemorrhoids, which are varicosities of the rectal veins, are due to mechanical compression by the enlarging uterus as well as from constipation and straining at stool.

• Treatment includes OTC preparations, topical preparations, cool sitz baths, and stool softeners.

Fatigue

• Pregnant women will usually have an increased sense of fatigue during pregnancy.

Syncope

• Venous pooling in the lower extremities increases as the pregnancy progresses. This can lead to dizziness or lightheadedness, especially after standing upright abruptly or for long periods of time.

• Other causes of syncope include dehydration, hypoglycemia, and the shunting of blood flow to the stomach after eating a large meal.

Sleep Disturbances, and Leg Cramps•Most women will develop alterations from their normal sleep patterns during pregnancy.• More frequent urination, more common gastric reflux, and physical discomfort with the growing pregnancy all contribute to poorer sleep. • Antihistamines are usually recommended. •Almost half of all pregnant women suffer from recurrent painful spasms of the muscles of the lower extremities, especially the calves.• Leg cramps are more frequent at night and usually occur during the third trimester. therapeutic options have been suggested , calcium lactate and high-potassium foods such as banana, kiwi . Massage, heat, and stretching the affected muscle(s) relieves the cramps .

Backache

• Most pregnant women experience lower backaches as pregnancy progresses.

• These are usually alleviated by minimizing the amount of time spent standing, increasing rest, wearing a specially designed support belt over the lower abdomen, and taking an analgesic such as acetaminophen.

Round Ligament Pain

• most frequently occurs during the second trimester when women report sharp, bilateral, or unilateral groin pain. it is not known if round ligament stretch is the true etiology. The pain may be increased with sudden movement or change in position.

Headache

• Generalized headaches are not uncommon during the first trimester.

• The frequency and intensity of migraine headaches may increase or decrease during pregnancy.

• Headaches during the second and third trimesters are not an expected symptom of pregnancy.

Emotional Changes

• Pregnancy is a time of significant psychological stress.

• Changes in hormonal levels; changes in relationships to partners, family, and friends; and changes in body image all lead to increased psychological stress.

• Increased levels of placental corticotropin-releasing hormone also affect the maternal hypothalamic pituitary axis and other brain loci involved in stress responses.

Sexual Relations

• Coital activity during normal pregnancy need not be restricted.• libido often decreases in the first and third trimesters.• Nipple stimulation, vaginal penetration, and orgasm can cause

uterine contractions secondary to the release of prostaglandins and oxytocin.

• The question of the effect of coitus in women at risk for preterm labor or early spontaneous pregnancy loss remains unanswered.

• There are two concrete interdictions to coitus during pregnancy. The first is that intercourse should not occur after membrane rupture or in the presence of known placenta previa. The second is that forceful introduction of air into the vagina should be avoided because of the risk of fatal air embolism.

Employment

• Strenuous physical activity, including repetitive lifting and prolonged standing for more than 5 hours, has been associated with a greater rate of adverse outcomes.

Urinary Frequency

• Patients often experience urinary frequency during the first 3 months of pregnancy, as the enlarging uterus compresses the bladder, and again during the last weeks, as the fetal head descends into the pelvis.

Skin Changes

• many women experience increased hair growth during pregnancy and hair loss postpartum.

Leukorrhea

• An increase in the amount of vaginal discharge is physiologic during pregnancy.

• Discharge accompanied by itching or burning or a malodorous discharge should be treated.

• Douching has no place in the treatment or management of leukorrhea in pregnancy.

X-rays/Ionizing Radiation

• Patients may undergo dental x-rays as needed, provided that the abdomen is fully covered by a lead apron. Exposure to video display terminals is safe in pregnancy.

Travel

• the patient should try to stretch her legs and walk for 10 minutes every 2 hours.

Immunizations

• Four immunizations using vaccines containing live viruses are relatively contraindicated during pregnancy. These are measles, mumps, rubella, and yellow fever.

• Tetanus toxoid, if needed, is acceptable in pregnancy.

• Flu vaccine is recommended for pregnant women.

• Women who are receiving hepatitis B vaccine may continue receiving it during pregnancy.