Normal Pregnancy

Chapter 104 TintinalliPresented by Dr. KelleyDecember 6, 2005

Normal Pregnancy

THE POSSIBILITY OF PREGNANCY MUST BE CONSIDERED IN EVERY WOMAN OF REPRODUCTIVE AGE REGARDLESS OF CHIEF COMPLAINT!!!!

Normal Pregnancy

A study showed that 7% of women who stated there was no chance of pregnancy and had normal on-time last menstrual periods were pregnant.Barrier method use, contraceptives, and tubal sterilization does not guarantee pregnancy prevention!!

Terminology

Gravidity Total # of

pregnancies regardless of duration or outcome.

Parity # of pregnancies

completed to delivery during viable period.

G#P# (Full term-Preterm-Aborted-Living)G3P2 (2-0-1-2)

Terminology

Duration= 40 weeks (calculated from first day of last menstrual period)3 Trimesters of Equal Length- 1st- Conception to 14 weeks 2nd- 14-28 weeks 3rd- 28-42 weeks

Term pregnancy requires completion of at least 37 weeks.

Physiology

Cardiovascular 40-45% circulating blood volume 43% in CO 17% in resting HR 20% in SVR BP of diaphragm displaces heart and to the

leftlarger cardiac silhouette on CXRleft axis deviation on EKG (Also, small benign pericardial effusioncardiac silhouette)

Physiology Cont.

Respiratory Dyspnea common complaint Hormone-induced 40% in tidal

volume pCO (nl. Pregnancy value 30mmHg) Functional residual capacity b/c of

of diaphragm

Physiology Cont.

GI Gastric reflux 2º to delayed gastric

emptying, intestinal motility, and lower esophageal sphincter tone.

Gallbladder emptying delayed and less efficient risk of cholesterol stone formation.

Physiology Cont.

GU renal blood flow kidney size GFR (up to 50% by 2nd trimester)

results in BUN/Creat.

Physiology Cont.

Hematopoietic 40-45% circulating

blood volume 2º to plasma volume and # of erythrocytes

HgB conc. 2º to dilutional intravascular volume but should not below 11g/dL

High Fe requirements Reticulocyte count 2nd

half of preg. Leukocyte counts

range 5000-12000 cells/µL

Leukocyte function 2nd trimester so susceptibility to infection.

coagulation factors ESR Slight platelets

Physiology Cont.

Endocrine Hyperinsulinemia and fasting

hypoglycemia 2º to changes in carbohydrate metabolism

Postprandial hyperglycemia 2º to altered response to glucose ingestion.

Thyroid with vascularity and mild hyperplasia but clinically detectable goiter is not normal. (Free thyroxine and TSH to assess thyroid function during pregnancy)

Physiology Cont.

Uterus uterine weight (701100g) intrauterine volume (105000mL) 12 weeks uterus expands into

abdominal cavity

Physiology Cont.

Breasts Breast tenderness and tingling

starting in 1st trimester Breasts enlarge Nipple size pigmentation

History and Physical

HistoryOb/gyn history including menstrual status and contraceptive use on every women of reproductive ageHints of pregnancy-nausea, vomiting, fatigue, cessation of menses, urinary frequencyLMP datePrenatal care and course of current and past pregnancies

History and Physical Cont.

Quickening (1st maternal perception of fetal movement)- 18-20 weeks primigravida- 2 weeks earlier in subsequent pregnancies.

Physical ExaminationRoutine assessment of motherFetal Heart Tones- auscultated by fetal stethoscope by 16-19 weeks (nl. 120-160 beats/minute)

History and Physical Cont.

A pelvic exam must be performed whenever pregnancy part of differential diagnosis. Key components: Appearance of cervix Presence of discharge or blood Wet prep. & culture for Neisseria

gonorrhoeae & Chlamydia trachomatis Bimanual exam to determine size &

tenderness of uterus and adnexa.

History and Physical Cont.

Palpation of fundus of uterus- 12 weeks- Symphysis pubis 16 weeks- Midway between

symphysis pubis and umbilicus 20 weeks- Umbilicus 20-32 weeks- 1 cm above umbilicus

for every 1 week

Making the Diagnosis

Serum and/or Urine HCG HCG is a glycoprotein produced by

trophoblast after implantation. Composed of alpha and beta subunits with

beta subunit unique to HCG. ELISAs detect beta-HCG in urine as low as

10-20mIU/mL approx. 1 week after conception

<1% false negative rate on nondilute urine.

Making the Diagnosis Cont.

+ pregnancy test does not confirm a normal intrauterine pregnancy!!!!+ beta-HCG can be found in ectopic, recent spontaneous or induced abortion, and HCG secreting tumors (molar pregnancies).Pelvic ultrasonography after 4-5 weeks gestation for definitive diagnosisSerial beta-HCG levels useful- level doubles every 1.4-2.0 days following implantation in early pregnancy if not ectopic or nonviable pregnancy.

Making the Diagnosis Cont.

Pelvic UltrasonographyGestational Sac- 5.5-6 weeks gestation-

transabdominal 4-5 weeks gestation- transvaginal

Cardiac Activity- 6 weeks gestation

Abdominal Discomfort-Differential Diagnosis

Must include all possiblities for nonpregnant and pregnant women!!!1st trimester-

Ectopic and threat. Abortion

Late 2nd/3rd trimester- Premature labor,

abruption, uterine rupture

Early pregnancy- Vascular cong. Of pelvic

tissue, round ligament tension

Late pregnancy- Braxton-Hicks (irregular,

palpable contractions)

Appendicitis- location of pain upward and rightwardCholelithiasis- may cause cholecystits or pancreatitis

Syncope-Differential Diagnosis

Anemia Electrolyte imbalanceDehydrationPulmonary embolismCardiac arrythmias Sometimes unclear etiology but pregnant

women with PVCs and PACs May occur in patients with and without

heart disease.

Medication Use in Pregnancy

Gestational age and stage of development, dose, duration of exposure and individual susceptibility influence the potential effects of drug exposure during pregnancy.

Fetus is most vulnerable to teratogenic effects at 4-12 weeks gest. (period of organogenesis)Table 104-1- FDA Categorization of Drug Risk in Pregnancy.

Medication Use in Pregnancy-Antimicrobial Agents

All enter fetal circulation to some extent.Info on safety of newer extended-spectrum or late-generation agents limited.Table 105-1PCN and Cephalosporins generally are regarded as safe for use in any trimester!!!!

Medication Use in Pregnancy-Analgesic Agents

Acetaminophen is the analgesic agent of choice!ASA- 1st trimester- congenital defects. Later- Coagulation abnormalities with hemorrhagic

complications in neonate and mother and premature patent ductus arteriosus closure

ASA and NSAIDs- May prolong gestation and labor thru inhibition of

cylooxygenase. Also assoc. with oligohydramnios, intestinal perforation, hydrops fetalis, and renal failure (especially Indomethacin).

Medication Use in Pregnancy-GI Agents

Nausea and Vomiting- Antiemetics safety has not been studied in

prospective human trials, but benefit of improved metabolic conditions and maternal well being should be considered.

Promethazine (category C), prochlorperazine (C), metoclopramide (B) (5-10mg PO, IV,IM q 8 º), ondansetron (B) (8mg PO q 8 º)

Dyspepsia- Most OTC antacid preps, cimetidine, and

ranitidine are regarded as safe.

Medication Use in Pregnancy-Cold Preparations

OTC cold preps are usually combinations with sympathomimetic agents vasoconstrictive properties vascular-mediated congenital defects.When absolutely necessary consider each agent of combined prep.1st trimester exposure to dextromethorphan or guaifenesin has not been assoc. with adverse fetal effects.

Medication Use in Pregnancy-Anesthetics

Lidocaine- Not associated

with detrimental fetal effects.

Combination Tetracaine, Adrenaline-Epinephrine, & Cocaine (TAC) and Lidocaine, Adrenaline, & Tetracaine (LAT) should not be used b/c risks of absorbed cocaine and adrenaline-epinephrine.

Medication Use in Pregnancy-Contraceptives

Should be d/c’d ASAP!!!!However, no demonstrated risk of fetal malformation in early pregnancy.

Immunizations During Pregnancy

YESInactivated (killed-virus) vaccines including: Influenza Tetanus toxoid with

or without diptheria toxid

Immunoglobins including tetanus, hepatitis, rabies, & varicella

NOLive-virus vaccines including: Measles Mumps Rubella Poliomyelitis Varicella

Preventive Medicine & Counseling

Nutrition & Nutritional Supplements Average total weight gain- 12.5 kg (28 lbs.) Folic Acid before and during pregnancy to

prevent neural tube defects (1mg/day-no history of neural tube defects, 4mg/day- + h/o previous pregnancy with neural tube defects)

Vitamins A, D, C, and B6 in excess may lead to congenial defects.

Fe supplementation recommended Zinc deficiencyneural tube

defects15mg/day recommended

Preventive Medicine & Counseling Cont.

Caffeine Studies show an increased risk of

miscarriage in 1st and 2nd trimesters with consumption of >150mg/day.

Aspartame Metabolized to phenylalanine crosses into

fetal circulation high concentration can lead to mental retard. (Fetal toxicity unlikely unless excessive maternal intake or maternal heterozygous carrier of PKU)

Preventive Medicine & Counseling Cont.

Substance AbuseCocaine- risk of abruptio placenta, growth-restricted infants, preterm labor, developmental delayOpiates- no known teratogenic effects. danger with withdrawal.Amphetamines- congenital abnorm.

Hallucinogens & “Designer Drugs”- inconclusiveNicotine- rates of spontaneous Ab., abruption, preterm labor, low birth weight, risk of SIDS (effects if cessation by 16 weeks)—Nicotine gum (Category C), Nicotine patch (D)

Preventive Medicine & Counseling Cont.

Substance Abuse Cont.Alcohol-

Fetal Alcohol Syndrome- microcephaly, mental retardation, & behavioral d/o

Greatest risk 1st trimester

No established safe quantity of consumption.

Travel No restraints in

normal pregnancy.

Frequent ambulation during long duration.

Protective restraint devices at all times!

Preventive Medicine & Counseling Cont.

Exercise-OK for moderate physical exerciseACOG recommends: Non-weight bearing (minimize chance

of abdominal trauma) No scuba diving No exercise in supine position Individual based programs

Disposition

Normal Uncomplicated Pregnancy Recommend f/u for prenatal care &

Obstetrics evaluation by 6-8 weeks gestation. F/u for specific signs & symptoms- Table 104-

3 Recommendations on activities, lifestyle, and

appropriate use of prescription and OTC meds given.

Ob consult when needed for management options.

Questions

1. If a 35 yoa female tells you that she has had a tubal ligation, you should not be concerned about the possibility of pregnancy. A. True B. False

2. Pregnancy causes a decrease in cardiac output. A. True B. False

3. During pregnancy, which of the following is false? A. Increased renal blood flow B. Increased kidney size C. Increased GFR D. Increased BUN/Creat.

4. At 20 weeks gestation the uterine fundus should be palpated where? A. Umbilicus B. Pubic symphysis C. Between umbilicus and nipple line D. Is not able to be palpated at this

time

5. The differential diagnosis for syncope in pregnancy includes all of the following except: A. Anemia B. Electrolyte imbalance C. Dehydration D. Pulmonary Embolus E. Cardiac Arrythmia F. All of the above are true

Answers

1. False2. False (increase in CO)3. D4. A5. F