PRENATAL ASSESSMENT:

GUIDELINES FOR ASSESSMENT AND CARE OF THE PREGNANT WOMAN

 

 

LESSON #14

 

John Dorsch, MD

Director of Rural Health Programs

University of Kansas School of Medicine – Wichita

Family and Community Medicine

 

And Family Practice Preceptor for

 

Via Christi Regional Medical Center

Wesley Medical Center

 

These lecture notes are based on the CR-ROM by Dr. Dorsch and selected references from the course textbook  (Swartz, Textbook of Physical Diagnosis, chapter 20)

 

A Generally good Web Site for Women’s Health Issues:

                http://www.medscape.com

 

 

SIGNIFICANCE OF MATERNAL MORTALITY IN THE UNITED STATES

(FROM 1990-1995)

 

·         Embolism                                       17%

·         Hypertension                                               12%

·         Ectopic pregnancy                       10%

·         Hemorrhage                                  9%

·         Stroke                                             8%

·         Anesthesia complications          7%

·         Abortion related                           5%

·         Cardiomyopathy                          4%

·         Infection                                        3.5%

 

 

GENERAL APPROACHES AND KEY ADJECTIVES FOR

APPROACH TO THE PREGNANT PATIENT

 

·         Use a gentle, steady approach

·         Be thorough

·         Be efficient

·         Be systematic

 

 

INITIAL PRENATAL VISIT:  Key Points

 

·         Provide time for a longer office visit, for example, 45 minutes

·         Have patient come in early & complete paper work

·         Help patient feel comfortable

·          Begin interview with patient fully clothed

·         Sit down & make eye contact

·         First visit is preferred at 6 weeks gestation  (6-8 weeks)

 

THOROUGH MEDICAL HISTORY:  Key points

 

·         Important, as with any initial health care visit

·         Attitudes can indicate future parent-child relationship risk factors:

·         How does the patient feel about the pregnancy?

·         Was the pregnancy planned

·         Underlying medical problems need to be identified, especially:

·         Diabetes

·         Hypertension

·         Renal disease

·         Hemoglobinopathy

·         Isoimmunization

·         STDs

·         Significant other infections

·         All components of PMH are important, especially

·         Age

·         Last pelvic exam and pap smear

·         Menstrual history

·         Previous pregnancies, abortions, miscarriages, deliveries

·         Birth control  (methods used)

·         Fertility – infertility issues

·         Anesthesia issues or reactions

·         Pelvic injury

·         Medications:  prescription, OTC & complimentary therapies

·         Allergies reactions

·         Emphasize need to communicate all

medications considered during pregnancy

·         Social & home environment influences

·         Life-style issues:  diet, exercise, sleep, drugs, alcohol, smoking…

·         ROS: pre-pregnancy weights & baselines

 

 

COMMON SYMPTOMS OF PREGNANCY TO CONSIDER:  Key points

 

·         Amennorrhea:

·         Results from high levels of  hormones:

estrogen, progesterone & hCG (human chorionic gonadotropin)

·         Currently used pregnancy tests are based on amount of hCG in

blood or urine, with hCG present as early as 8 days after fertilization

·         Depending on the specific test used, concentrated urine improves

pregnancy detection rate of urine to equal that of serum testing

·         Test may be positive as early as 3-4 days after implantation

·         98% of test results are positive within 7 days after implantation

 

 

·         Nausea or “morning sickness of pregnancy”:

·         Most common between 8-14 weeks gestation

·         Hypersensitivity to odors may develop

·         Severe vomiting may result in dehydration or ketosis

 

 

 

 

·         Breast Changes:

·         Increased tenderness

·         Increased vascularity & sense of heaviness

·         Nipples more erectile, with increased  pigmentation

·         Raised Montgomery’s tubercles on areola

·         Colostrum secreted by 16th week

 

 

 

 

·         Heartburn:

·         Relaxation of gastroesophageal sphincter

·         Upward  displacement of stomach due to  uterine enlargement

·         Digestions delays, due to decreases in gastric mobility & gastric acid

 

 

·         Backache:

·         Increased hormone secretions (estrogen & progesterone)

·         Increased pelvic relaxation

·         Loss of abdominal muscle tone

·         Increased uterine weight

 

 

Abdominal Enlargement:

·         Uterus rises out of pelvis into abdomen by 12th week of gestation

 

 

·         Quickening:

·         Usually felt at 20 weeks in primigravida, but earlier in multipara

 

 

·         Skin Changes:

·         Hyperpigmentation

·         Linea alba darkens to linea nigra

·         Chloasma pigmentation of face

·         “Stretch Marks” or striae gravidarum

·         Nail changes  increased grooving, brittleness or softening

·         Increased sweating

·         Hirsutism

 

 

·         Urinary Changes:

·         Increased frequency due to uterine pressure in early & late pregnancy

 

 

·         Vaginal Discharge:

·         Increased asymptomatic, white, milky cervical mucous & vaginal discharge

 

·         Fatigue:

·         Common in early pregnancy

 

·         Headaches:

·         Common, especially  around 16 – 20 weeks gestation

 

·         Other symptoms:

·         Varicose veins

·         Leg cramps

·         Edema of legs & hands

·         Constipation

·         Bleeding gums

·         Insomnia

·         Dizziness

 

 

 

THOROUGH PHYSICAL EXAMINATION

 

·         Objectives:

·         Evaluate health of mother & fetus

·         Determine gestational age of fetus

·         Initial plan of care

 

·         Measurements & Vital Signs:

·         Height & Weight

·         Baseline vital signs & BP

 

·         Skin changes:              choasma of face

 

·         Teeth & Gums:  check for hypertrophy of gums (increased vascularity)

 

·         Thyroid:  symmetrical enlargement (R/O goiter)

 

·         Heart & Lungs:  (In later stages of pregnancy):

·         PMI elevated & lateral in 3rd trimester

·         Non-pathological systolic flow murmurs develop

Diastolic murmur is always pathological

 

 

·         Breasts & Nipples:  Note expected changes

·         Everted nipples indicate possible interference with breast feeding

·         Discrete masses are considered pathological

 

·         Abdomen:

·         Contour

·         Skin changes:  linea nigra, striae gravidarum

·         Fetal movement  (felt by 24 weeks)

·         Uterine size & fundal height

·         Fetal Heart Rate (FHR):  (120-160 per minute)

Fetal Heart Tones audible with Doppler, from 11-13 weeks gestation

 

 

 

 

 

 

 

 

 

·         Genitalia

·         External genitalia & anus:  lesions & varicosities

·         Vaginal leukorrhea

·         Adenexal areas:  corpus luteum cyst-like enlargment

·         Bimanual & pelvic measurements

 

COMMON SIGNS OF EARLY PREGNANCY                                                             

 

Sign                                       Finding                                                  Gestational Age

                               

                                Goodell                                  softening of cervix                               4-6 weeks

                                Hegar                                     softening of uterine isthmus              6-8 weeks

                                McDonald                             fundus flexes easily on cervix            7-8 weeks

                                Chadwick                               bluish color or cervix,

Vagina & vulva                                    8-12 weeks

 

·         Extremities:

·         Varicosities

·         Edema

 

 

 

INITIAL DISCUSSIONS WITH PATIENT

 

 

·         Expected weight gain

·         Ideal:              25-30 pounds total

·         2 pounds per month:   1st & 2nd trimester

·         1 pound per week average:  last trimester

 

·         Exercise and activity levels

·         Varies with physical conditioning of patient

·         Contact sports not recommended

·         Core temperature elevations about 101.5  may be  harmful to fetus

 

·         Diet

 

·         Prenatal appointment schedule:

·         Monthly:  up to 32 weeks gestation

·         Every 2 weeks from 32 to 36 weeks

·         Every week from 36 to 40  weeks

 

·         Expected changes of pregnancy & selected important things to know

 

·         Prenatal Vitamins: 

·         Maternal ingestion of 0.4 – 0.8 mg of Folic Acid per day reduces the

occurrence of fetal neuronal tube defect

·         Most prenatal vitamins contain 1 mg of folic acid

·         Prenatal vitamins with folic acid are often recommended

for non-pregnant women of child-bearing age who are planning pregnancy

 

 

 

 

·         Calculating the Due Date or Expected Date of Confinement (EDC)

Last menstrual period (LMP) 

 

LMP less 3 months

Add 1 year +  7 days = EDC

 

Or

 

Nagele’s Rule:

LMP

Add 9 months + 7 days = EDC

 

 

·         A Prenatal Flow Sheet for recording visits is through & efficient

 

 

 

               

 

 

 

 

MILESTONE  LABORATORY TESTS

 

·         Routine, mandatory:  completed at first visit

 

CBC:                                       detects anemia, hemoglobinopathies,  infections

UA:                                         baseline for protein, glucose:  r/o

diabetes, renal disease, hypertensive disease of

pregnancy

                ABO & Rh typing                checks compatibility of maternal-fetal blood types

                                                                & need for Rhogam

                Rubella titer                           determine presence or absence of maternal

Antibodies  (Rubella causes blindness, heart &

hearing abnormalities in fetus)

                Pap smear                              Screens for cervical intraepithelial dysplasia or neoplasia

                HBsAg                                   Hepatitis B surface antigen.  Virus infects fetus,

                                                                may cause fetal anomalies

                VDRL                                     or RPR: screens for syphilis, which infects fetus, causing

                                                                congenital anomalies

 

·         Highly recommended lab screening (not mandatory) at first visit:

 

STD smears/cultures           Gonorrhea, Chlamydia, Herpes

                                                Generally cause eye infections & blindness,

 repiratory infections & other infections of

newborns.  Active  herpes near due date

indicates need for C-section birth

                HIV                                         requires permission, and signed informed

                                                                consent by patient

               

 

 

 

 

 

MILESTONE LAB TESTS & PROCEDURES SCHEDULED LATER IN PREGNANCY

 

·         16-18 Weeks:

               

Ultrasound:   most accurate for dating pregnancy

Not mandatory, but most commonly done

 

·         17-21 Weeks:  (when standardized values for this test are most accurate)

Alpha Fetal Protein (AFP)

Medical-legal point:    Important to offer this test, and document that it was offered

It is not mandatory in the sense that the patient can refuse

High levels may indicate neuronal tube defects in the fetus

Low values (not as predictive) may be indicative of trisomy 21 &other trisomy defects

Triple Screen:             may be used, and combines the following:

                                        AFP

                                        SerumEstriol

                                        HCG

 

·         24-28 Weeks:

 

50 Gram Glucose Tolerance Test (glucose challenge)

 

 H & H:  may repeat  at 28 weeks (especially with anemia)

 

 

·         28-36 Weeks

 

Beta Hemolytic Streptococcus Screen

Collect culture swabs from vaginal introitus (not cervix)

If positive, mother must be treated before delivery to prevent fetal sepsis

 

 

 

 

EVERY OB VISIT

Monitor:               

·         weight, BP temp,

·         UA for protein & glucose (dip stick UA),

Lower renal threshold in pregnancy

2+ or greater UA protein could signal pregnancy induced hypertension (PIH)

·         Serum glucose screen

·         Fundal height:  measured from top of pubic bone to top of uterine fundus

Measurement is most accurate from 20-36 weeks gestation

Each 1 cm increase indicates one additional week of gestation

·         Edema:  dependent edema from pressure on inferior vena cava & iliac veins

·         Nausea & vomiting:  most prominent from 8-14 weeks gestation

·         Pain & contractions

·         Fetal movements

Discuss this at 16 weeks & ask patient to record when fetal movements are felt

(usually between 17-18 weeks)

·         Bleeding or  discharge

·         Recent illness & concerns

 

 

 

MEASURING UTERINE SIZE

 

·         Nulliparous uterus:                                      golf ball size

·         8 weeks gestation (or if second baby):     hand ball size

·         10 weeks:                                                       baseball size

·         12 weeks:                                                       soft ball size

Palpable just above symphysis pubis

·         12-14 weeks:                                                  uterus rises up into abdominal cavity

·         16 weeks:                                                       fundus palpable halfway between

symphysis & umbilicus

·         20 weeks:                                                       fundus at umbilicus (lower border)

·         28 weeks:                                                       fundus halfway between umbilicus & xiphoid

·         34 weeks:                                                       fundus just below xiphoid

·         38-40 weeks                                   :               fundus drops (“lightening”)

 

 

 

MILESTONES TO MONITOR ON SUBSEQUENT OB VISITS

 

·         Fetus:

·         FHT with Doppler:   12 weeks

·         Quickening:  16-19 weeks

(ask patient to keep track of movements)

·         Primipara                        (later, about 18-19 weeks)

·         Multipara                       (sooner, about 16 weeks)

 

16-18 Weeks:

·         Ultrasound

·         Offer AFP or Triple Screen:  17-21 weeks

 

·         24-28 Weeks:

·         50 Gm Glucose Tolerance Test (glucose challenge)

·         May repeat H&H at 28 weeks (anemia vs hemodilution)

·         Rhogam given if Rh negative

 

·         32 Weeks:

·         Encourage to enroll in Lamaze classes

 

·         36 Weeks:

·         Talk about when to go to the hospital

·         What to do if water breaks

·         Mucous plug

·         Analgesia, anesthesia, epidural

·         Conduct of labor

·         Need to IV access

·         Episiotomy

·         Post natal contraception

·         Tour of birth center

·         Practitioner for infant medical care

·         Circumcision

·         Feeding:  breast – bottle

 

 

 

PELVIMETRY:  Key Points

 

·         Initial considerations

·         Pelvic shape

·         Diagonal conjugate

·         Obstetrical conjugate

·         Angle of subpubic arch

·         Coccyx

 

·         Pelvic shapes

 

·         Gynecoid (50% of women):        

Pelvic outlet is round & pubic arch is wide

Ancticipated delivery is vaginal, spontaneous

·         Android (25% of women):          

Pelvis outlet is heart shaped & pubic arch is narrow

Anticipated delivery could be vaginal with forceps or cesarean

·         Anthropoid (24% of women):    

Pelvic outlet is vertically oval & pubic arch is narrow

Anticipated delivery is vaginal, possible forceps

·         Platypelloid (3% of women):     

Pelvic outlet is transversely oval & pubic arch is wide

Anticipated delivery is vaginal, sponanteous

 

·         Diagonal conjugate

 

·         One of the most import measurements of AP diameter of pelvic inlet

·         12.5 – 13 cm measurement from the inferior border of the symphysis

pubis to sacral promontory

 

·         Obstetric conjugate

 

·         Also measured the AP diameter of the pelvic inlet, more accurately

obtained by x-ray

·         Diagonal conjugate minus 1.5 – 2 cms from the posterior board of

The symphysis pubis to the sacral promontory

 

·         Angle of pubic arch or subpubic arch

 

·         Estimation of angle of subpubic arch is done by using both

thumbs, & examiner externally traces descending rami down to

ischia tuberosities

·         A wide pubic arch (105 degrees or more) accommodates spontaneous

vaginal delivery

·         A narrow pubic arch (less than 90 degrees) indicates a more difficult

Delivery, with use of forceps or suction, or a cesarean section

 

·         Coccyx

 

·         When palpated during bimanual examination, a prominent

inward pointing coccyx could indicate possible problems with

vaginal delivery

 

 

COMMON CLINICAL URGENT PATHOLOGICAL CONDITIONS

 

·         First trimester bleeding:           consider normal implantation of ovum,

cervicitis, vaginal varicosities, threatened

abortion (ectopic pregnancy, especially with

abdominal pain)

·         Second semester bleeding:        abruptio placenta or placenta previa

 

·         Postpartum hemmorage:           blood loss over 500 ml during first

24 hours after delivery

 

·         Pseudocesis:                                                false pregnancy (psychiatric considerations)