DIAGNOSIS OF PREGNANCY AND PRENATAL CARE potx

RIA, RRA, or ELISA can be used for the diagnosis of preg-nancy as early as 8–12 days after ovulation.. ULTRASONOGRAPHY Typically, early first trimester ultrasound has four objectives: ●

The correct early diagnosis of pregnancy is often urgent For

ex-ample, a diagnosis is essential to institute studies or treatment ofproblems that may jeopardize the life or health of mother or off-

spring Today this is usually accomplished by early beta-subunit hCG testing or ultrasonic scanning because a definite clinical di-

agnosis of pregnancy before the second missed period is possible

in only about two thirds of patients However, the practitioner must

be familiar with the signs and symptoms of pregnancy to properlytest for and treat the early pregnancy

CLINICAL DIAGNOSIS

OF PREGNANCY

Traditionally, the clinical criteria for the diagnosis of pregnancyhave been categorized into presumptive, probable, and positive(Table 5-1)

The differential diagnosis of the common signs and symptoms

of pregnancy involves other conditions associated with similar plaints or alteration (Table 5-2)

com-PELVIC FINDINGS OF

EARLY PREGNANCYCritical to the diagnosis of pregnancy by physical examination arethe pelvic findings The presumptive indications of pregnancyinclude the following

Cyanosis of the vagina (Chadwick’s sign, Jacquemier’s sign) is

present by about 6 weeks

5

DIAGNOSIS OF PREGNANCY AND PRENATAL CARE

Nausea, vomiting Changes in color

Breast tingling, mastalgia consistency, size, orUrinary frequency, urgency shape of cervix or

Temperature elevation (usually by BBT)Enlargement of abdomenBreasts enlarged, engorged,nipple dischargePelvic souffle (bruit)Uterine contractions (withenlarged corpus)

* Although these may be suggestive, even 2 are not diagnostic of pregnancy.

Softening of the tip of the cervix (Fig 5-1) occasionally is noted

by the 4th–5th week of pregnancy However, infection or ring may prevent softening until late pregnancy

scar-Softening of the cervicouterine junction often occurs by 5–6

weeks A soft spot may be noted anteriorly in the middle ofthe uterus near its junction with the cervix (Ladin’s sign) (Fig.5-2) A wider zone of softness and compressibility in the loweruterine segment (Hegar’s sign) is the most valuable sign of earlypregnancy and can usually be noted at ⬃6 weeks (Fig 5-3).Ease in flexing the fundus on the cervix (McDonald’s sign) gen-erally appears by 7–8 weeks

Irregular softening and slight enlargement of the fundus at

the site of or on the side of implantation (Von Fernwald’ssign) occur by ⬃5 weeks Similarly, if implantation is in the re-gion of a uterine cornu, a more pronounced softening and sug-gestive tumor like enlargement may occur (Piskacek’s sign)(Fig 5-4)

Generalized enlargement and diffuse softening of the uterine corpus usually occur 8 weeks of pregnancy (Fig 5-5)

TABLE 5-2

COMPARATIVE DIFFERENTIAL DIAGNOSIS

OF PRESUMPTIVE SYMPTOMS AND SIGNS

pseudocyesis,anorexianervosa), GI disorders(gastroenteritis,peptic ulcer, hiatal hernia, appendicitis,intestinalobstruction, foodpoisoning),acute infections (e.g., influenza, encephalitis)

(Continued )

TABLE 5-2

(Continued )

Cause(s) if Differential DiagnosisPregnant (Not Pregnant)

breast tingling (duct anovulation,

stimulation), fibrocystic progesterone breast disease(alveolar

stimulation)Urinary urgency, Estrogen Urinary tract frequency (cystourethral infection (UTI),

turgescence) cystourethritis or

cystocele,anxiety,diabetes,pelvic tumors,emotionaltensionQuickening Fetal movements Increased

14 weeks peristalsis, free (approx.) adnexal cyst,

pseudocyesis,gas, contractionsConstipation Altered diet; Low fluid, low

hypoperistalsis fiber diet

effectWeight gain Gestational Overeating

anabolism

Signs

Leukorrhea Estrogen Vaginitis,

cervicitis,genital foreign body, tumorPelvic organ

Softening of Hormones Chronic cervicitis

softening,

enlargement

(
8 weeks)

Temperature Progesterone Infection, corpus

therapy, faulty thermometerAbdominal Uterine size Obesity, pelvic or

tumor, ascites, obesity, relaxation of abdominalmuscles,pelvic and abdominaltumors, ascites,

or ventral hernia

Breast changes

Enlargement, Estrogen and Mastitis,

engorgement, progesterone malignancy,

secondary PMS, areola pseudocyesis

(
6–8 weeks)

Colostrum Prolactin, Hypothalamic

(
16 weeks) progesterone galactorrhea

excessPelvic souffle Increased pelvic Pelvic tumor or

anomaly(aneurysm)

contractions contractions tightening–

musclesSkin Pituitary

pigmentation melanotropin Ultraviolet

Active movements usually are palpable 18 weeks By the 16th–

18th week, passive movements of the fetus may be elucidated by

abdominal and vaginal palpation A firm tap on the uterine wall or

vaginal fornix displaces the fetus as a floating body An impulse

then can be felt as a thrust as the fetus moves back to its former

position (ballottement) Ascites and tumors must be excluded After

the 24th week, the fetal outline may be palpated in many pregnant

women

FIGURE 5-1. Softening of the cervix.

FIGURE 5-4. Piskacek’s sign.

110

No subjective evidence of pregnancy is totally diagnostic,

how-ever, and laboratory diagnosis is essential

LABORATORY EVIDENCE OF PREGNANCYBETA-SUBUNIT hCG

Assays for beta-subunit hCG, commonly used to diagnose nancy, have an admitted failure rate (⬃1%) Moreover, they may

preg-be positive in nongestational ovarian choriocarcinoma or in common gastrointestinal or testicular tumors Nevertheless, a pos-itive beta-subunit hCG test may be considered reasonable proof ofpregnancy A true positive followed by a true negative pregnancytest may indicate abortion The major methods for determining thebeta-subunit hCG are as follows

un-FIGURE 5-5. Bimanual pelvic examination.

IMMUNOLOGIC TESTS

Immunologic tests for pregnancy (Table 5-3) are based on hCG’santigenic potential (direct or indirect agglutination of sensitizedRBC or latex particles) These tests require slides or test tubes forreagents and take from a few minutes to over an hour to complete.Test sensitivities vary widely (250–1400 mIU/mL)

Radioimmunoassay (RIA)

The hCG radioimmunoassay (RIA) requires a gamma counter forthe highest sensitivity The test, reportable in 90 min is extremely accurate ( ⬃20 mIU/mL.) Thus, it usually is used when sensitivity

is crucial.

Radioreceptor Assay (RRA)

The RRA measures the biologic activity by in vitro binding of hCG

to bovine corpus luteum membrane Unfortunately, hCG and hLHcannot be separated by RRA A commercially available RRA, Bio-cept G, has set its negative endpoint high to avoid false positive re-

ports The accuracy does not approach that of RIA or ELISA.

Enzyme-Linked Immunoabsorbent Assay (ELISA)

A specified monoclonal antibody produced by hybrid cell ogy is used for the ELISA assay With ELISA, the enzyme induces

technol-a color chtechnol-ange indictechnol-ating the hCG level ELISA is simple technol-and rtechnol-apid

TABLE 5-3

IMMUNOLOGIC TESTS FOR PREGNANCY

Direct Latex particles Coagulation if coagulation coated with anti- hCG is present

hCG serum or (pregnant)urine

Inhibition of Anti-hCG  serum Coagulation if

Sensitized red cells inhibition if

Latex particles (pregnant)coated with hCG

(5 min), no isotopes are used, and it can be an office (serum) test

(e.g., Prognosis slide test, which measures to 1.5–2.5 mIU/mL) Thetube, office or home test (e.g., Preco Rapid Care) measures only to1.0 mIU/mL Nevertheless, even ELISA home kits are at least 90%accurate within the range mentioned

RIA, RRA, or ELISA can be used for the diagnosis of

preg-nancy as early as 8–12 days after ovulation hCH has a doubling time of 1.2–2.5 days during the first 10 weeks of pregnancy, with a slow decline to about 5000 mIU/mL thereafter.

The latest beta-specific latex tube or slide tests that are based

on agglutination or agglutination-inhibition are still adequate for thediagnosis of normal pregnancy
1–2 months The ELISA test usu-ally picks up earlier gestations and is more accurate, although af-ter pregnancy, an ELISA test may require weeks to become nega-

tive Therefore, RIA will continue to be the method employed for serial quantitative studies in problem pregnancies, particularly trophoblastic disease.

ULTRASONOGRAPHY

Typically, early first trimester ultrasound has four objectives:

● Locate, measure, and observe the configuration of the tational sac (mean sac diameter, MSD length  width height/3),

ges-● Identify embryo(s), document fetal number, and record ence or absence of life (usually determined by heartbeat),

pres-● Determine the extent of fetal development and measure the crown-rump length (CRL),

● Evaluate the uterus, cervix and adnexa.

Currently, endovaginal ultrasonic detection of the implanted products of conception is possible when the MSD is 2–3 mm This

occurs at ⬃4 wk 3 d menstrual age (MA) and the hCG is istically 500–1500 IU/mL Generally, transabdominal ultrasound will

character-detect the gestational sac at 5 mm MSD (⬃5 wk MA) At this time,the endometrium is markedly echogenic with prominent arcuate ves-sels The sonolucent gestational sac is surrounded by trophoblastic

decidual reaction that sonographically appears as a hyperechoic rim (or rind) In a normal early pregnancy, the mean gestational sac di- ameter increases by ⬃1.2 mm/day To determine the gestational age

(in days), add 30 to the mean gestational sac diameter: a mean sacdiameter of 20 mm corresponds to a gestational age of 50 days

The yolk sac is often the first sonographic structure visualized within the gestational sac (from MSD 10–15 mm, 40–45 d MA) The

yolk sac is frequently visualized as a “double bleb” with the niotic sac The dorsal yolk sac incorporates into the primitive gutand the secondary yolk sac detaches from the midgut loop by the

am-end of the 8th week MA The yolk sac increases to a maximum of

⬃5 mm at 11 weeks MA and disappears by 14–15 weeks MA The embryo may be ultrasonically visualized at a CRL of 2–3.9

mm (34–40 d MA) There is generally cardiac activity by 22–36 d when the embryo is 1.5–3 mm An important correlation is that fetuses destined to progress will have cardiac activity by CRL of

5 mm At this time, the MSD is 15–18 mm and the MA is 6.5 wk.

Generally, the early fetal heartbeat is more rapid (160 bpm) andslows with gestation Near term, the rate is 120–140 bpm

By CRL of 12 mm the head should be discernable from the rax Limb buds develop by 8 weeks MA During the interval of 8–10 week, MA there is rapid embryonic development At 11 week

tho-MA (9 wk from conception), the embryo is 20–35 mm CRL and is termed a fetus.

Early pregnancy ultrasonography may reveal findings that dicate fetal compromise or impending fetal loss Examples of suchfindings include the following

in-● Fetal developmental disorganization (or dissolution) andlack of a heartbeat is associated with virtually 100% fetalloss, particularly if previous development and heart activityhad been sonographically determined

● Decreased amniotic fluid (evidenced by small gestationalsac size) is associated with a 94% spontaneous abortion rate

● A MSD (mm) minus CRL (mm) of 5 is associated with

an 80% spontaneous loss

● Absence of an embryo in a gestational sac with MSD

25 mm is associated with 45% abortion rate

● An intrauterine hematoma is associated with ⬃25% tion incidence

abor-Ultrasonic examination is often utilized to evaluate a firsttrimester pregnancy complicated by vaginal bleeding Given anembryo with satisfactory development and a heart beat, there is

roughly double the risk of spontaneous abortion when vaginal bleeding complicates a first trimester pregnancy [e.g.,6 wk there

is a 33% abortion risk with bleeding (vs 16% without bleeding), at7–9 wk there is a 10% abortion risk with bleeding (vs 5%), and

at 9–11 wk there is a 4% chance of bleeding (vs 1%–2% withoutbleeding)]

The sonographic differential diagnosis of early pregnancy cludes: bleeding, endometritis, endometrial cysts, cervical stenosis,

in-and the pseudogestational sacs associated with ectopic pregnancy Additionally, sonographic pitfalls to be avoided in the first trimester include: incorrect assessment of fetal number (somewhat obviated

by fetal, not sac, visualization), the inability to accurately mine eventual placental placement, and difficulty in assessment

deter-of morphologic abnormalities Examples deter-of the latter requiring

accommodation include: the early integument simulating edema,the natural extraabdominal intestinal phase, and difficulty in deter-mining ultimate fetal cranial development that can lead to a falsediagnosis of anencephaly Although initially thought to be most ac-curate, caution must be exercised in sonographic gestational dating

accomplished in the first trimester, for it is now apparent that ough second trimester assessment, when more parameters can be measured, may be more exact.

thor-DURATION OF PREGNANCY AND EXPECTED DATE

OF CONFINEMENT

ESTIMATED DATE OF CONFINEMENTAfter a positive diagnosis, the duration of pregnancy and the esti-

mated date of confinement (EDC) must be determined Because it

is uncommon to know the exact onset of pregnancy, these

calcula-tions start from the first day of the last menstrual period (LMP).

Pregnancy in women lasts about 10 lunar months (9 calendar

months) The average length of pregnancy is 266 days The median duration of pregnancy is 269 days However, only ⬃6% of patients will deliver spontaneously on their EDC Most (60%) will deliver

within 2 weeks of the EDC Thus, as in most physiologic events,term should be regarded as a season or period of maturity, not aparticular day

A major variable in the calculated duration of pregnancy is ognized because not all women have a 28-day cycle Hence, the

rec-physician also must consider the length of her cycle A patient with

a regular 40-day cycle obviously will not ovulate on day 14 butcloser to or on day 26 Therefore, her EDC cannot be estimatedaccurately by Nagele’s rule alone Moreover, some women tend tohave long or short gestations as a familial predisposition Primi-paras tend to have slightly longer gestations than multiparas Thus,the EDC cannot be calculated precisely, although the following clin-ical approximations have proven useful

be March 11 of the following year.

Nagele’s rule is based on a 28-day menstrual cycle with tion occurring on the 14th day In calculating the EDC, an adjust-ment should be made if the patient’s cycle is shorter of longer than

ovula-28 days The discrepancies caused by 31-day months and the 29-dayvariation in February of leap year are not correctable by Nagele’srule Nevertheless, it provides an acceptable estimate of the EDC.HEIGHT OF FUNDUS AS

MEASURED ABDOMINALLY

The uterus increases from a nonpregnant length ⬃7 cm to 35 cm

at term; it increases 20 times in weight and grows in volume from

500–1000 times Thus, the size of the uterus should be evaluated

at each prenatal visit to determine the normality of progress Most

examinations involve an estimate of the height of the fundus uteri

on the abdomen, not the length of the uterus The superior ramus

of the pubis, the umbilicus, and the xiphoid are the fixed referencepoints from which the height of the fundus is measured A roughrule is provided by Table 5-4, and a more precise estimation can bemade by the modified McDonald’s rule

TABLE 5-4

UTERINE HEIGHT AND STAGE OF GESTATIONWeek of Pregnancy Approximate Height of Fundus

12 Just palpable above symphysis

15 Midpoint between umbilicus and

symphysis

28 6 cm above the umbilicus

Unusually large measurements suggest an incorrect date of ception, multiple pregnancy, fetal macrosomia, fetal defect, or poly- hydramnios Unexpectedly small measurements imply fetal death, fetal undergrowth, developmental abnormality, or oligohydramnios.

con-MODIFIED MCDONALD’S RULE

Measure the height of the fundus (over the curve) above the

symphysis with a centimeter tape measure The distance in timeters will approximate the gestational age from 16–38 weeks

cen-3 weeks

The same examiner should measure the fundus whenever sible because variations by personnel may inaccurately suggestpregnancy complications

pos-Additionally, a rough guide to fetal weight may be calculatedfrom the modified McDonald’s uterine measurement (Johnson’srule) However, recall that wide variations in the weights of fetuses

in the third trimester may be due to the following

● The age-weight patterns of previous infants

● An expected increase in weight of each successive infant

● Hereditary traits or acquired disorders affecting infant size,for example, race, nutrition, diabetes mellitus, preeclampsia-eclampsia

JOHNSON’S ESTIMATE

OF FETAL WEIGHT

Fetal weight (in grams) is equal to the fundal measurements (in centimeters) minus n, which is 12 if the vertex is at or above the ischial spines or 11 if the vertex is below the spines, multiplied

by 155.

Example: A gravida with a fundal height of 30 cm whose vertex

is at 2 station can be represented as (30  12)  155 2790 g Ifthe patient weighs
200 pounds, subtract 1 cm from the fundal meas-urement By this calculation, an estimate within 375 g can be ex-pected for about 70% of neonates

EARLY hCG TESTING

Determinations of beta-subunit hCG in maternal serum comparedwith a scale of predetermined quantitative values provide the mostaccurate estimate of gestational age during the first 8–10 weeks.After this, hCG levels slowly decrease, and the method becomesinaccurate

BIRTH DEFECT SCREENING

The age screening, prior reproductive screening, and historical screening are generally done on the patient’s first antenatal visit Commonly, those gravidas 32 years of age at the time of their EDC are considered to be of advanced maternal age (AMA) Every pa- tient’s previous reproductive history is reviewed for any recidive event (including multiple spontaneous abortions) or potentially in- heritable disorder (mendelian or multifactorial) A three-generation family history for mental retardation in males, previous congenital

anomalies, and previous chromosomal abnormalities is performed.Many providers utilize a self-administered genetic screening ques-tionnaire for this purpose

Patients of African-American ancestry are customarily offered screening for sickle cell trait or disease If the mother is positive

for trait or disease, the father is also screened If both have sicklecell disease or sickle cell trait, an amniocentesis is commonly of-fered to detect the sickle cell status of the child

Maternal serum analyte screening for Down syndrome as well

as open neural tube defects has been described as “an integral

com-ponent of contemporary antenatal care.” In the United States, tiple marker screening has commonly included maternal serumalpha fetoprotein (MSAFP), total human chorionic gonadotropin(hCG), and unconjugated estriol (UE3) They are usually accom-plished at 15–20 weeks gestation Significant risk of Down syn-drome is customarily those at
1:295 risk, whereas risk of openneural tube defect (NTD) generally are those that exceeded 2 mul-tiples of the mean value (MOM) When abnormal multiple markertest results are obtained, reverification of gestational age (usually

mul-by ultrasound) is necessary, for a very common problem is rect gestational age Multiple marker screening has proven usefulfor the purposes it was intended (detection of Down syndrome,detection of open NTD, and detection of trisomy 18) as well asassisting in detection of certain cases of intrauterine fetal demise,multiple gestation, and erroneous gestational dates

incor-Other markers are available; for example, in the United

Kingdom maternal serum free beta-hCG and pregnancy-associatedplasma protein-A (PAPP-A) are utilized, and allow more rapidanalysis In one study, this added an additional 16% to the detec-tion rate accomplished by nuchal thickness and maternal age screen-ing Combining the four tests in screening for Down syndrome, thedetection rate is reported to be 75.8%–89% with false-positive rates

of⬃5%

Many authorities recommend that every gravida receive at least

one ultrasound, commonly at 16–20 weeks gestation, geared to

screen for fetal defects, ascertain multiple gestation, and determineplacental location The latter two objectives are easily met; how-ever, there is a sizable discrepancy in reported detection of fetalmalformations This may be due to widely different levels of ex-perience among sonographers as well as the difficulty to detectcertain defects

NUCHAL TRANSLUCENCY

THICKNESS SCREENING FOR

CHROMOSOMAL ANOMALIES

An important series of recent observations indicate the desirability

of sonographic screening earlier than the second trimester, that is

to say, at 10–14 weeks These studies indicate that measuring nuchaltranslucency thickness is a method of screening for chromosomalanomalies (notably trisomy 21 and trisomy 18) and other disorders

Indeed, in both high risk and low risk groups, the positive tive value of enhanced nuchal translucency is sufficient to warrantsuggesting further prenatal diagnostic testing Because most casesare discovered after the most appropriate time for chorionic villussampling (CVS), the majority of cases are further evaluated byamniocentesis.

predica-The screening is recommended at 10–14 weeks and most

au-thors use a nuchal thickness of
2.5–3 mm (depending on stage ofgestation) as abnormal Cumulate studies indicate a sensitivity of

⬃77% and a false positive rate of ⬃10% for aneuploidy Selection

of patients for invasive testing by this method alone allows the tection of about 80% of affected pregnancies However, using thismethod for selection of patients requires about 30 invasive tests foridentification of one affected fetus Observation of a thickening thatsubsequently resolves is not reassuring Fetuses with normalkarotype and enhanced nuchal thickness have greater rates of spon-taneous abortion related to the amount of thickness (3-fold increasewith 3.0–3 9 mm thickening and nearly seven fold increase for

de-
4 mm)

The mechanism(s) creating enhanced nuchal thickness are notcompletely defined It appears, however, that impairment of atrialcontractility is involved This has been implicated in cases of chro-mosomal aneuploidy as well as in cases of cardiac failure (e.g., theanemia associated with beta-thalassemia), heart, and/or great vesseldefects In the case of major congenital cardiac defects, the posi-tive and negative predictive values have been stated to be 1.5% and99.9% respectively Another suggested mechanism for increasednuchal thickness is intrathoracic compression-related pulmonaryhypoplasia, as seen with diaphragmatic hernia

A potential confounder to the measurement of nuchal cency thickness is the ⬃8% of fetuses having a nuchal cord at 10–14weeks gestation This potential bias may be reduced by use of colorDoppler to confirm nuchal cord and the average 0.8 mm cord thick-ness subtracted

translu-Currently, nuchal translucency thickness sonographic screening

is not a substitute for the more standard care of multiple-markerserum screening It has not been recommended as an alternative

to genetic counseling and CVS or amniocentesis in women ofadvanced maternal age or those with significant risk of aneuploidy.Additionally, data concerning the false negative rate (i.e., a normalnuchal translucency with aneuploidy or significant structural defect)

in a risk population is not sufficient to warrant replacement ofinvasive testing Indeed, it may be that combining the variousmodalities will prove most efficient in screening for chromosomalabnormalities

SECOND AND THIRD

TRIMESTER SONOGRAPHY

Although it is not the purpose of this text to comprehensively review

ultrasonography, certain basics may assist the reader The objectives

of later pregnancy ultrasound include the following:

● Determine fetal life, number, and presentations

● Estimate the amount of amniotic fluid

● Determine the placental location, appearance (grade), andrelation to the internal cervical os

● Assess the gestational age using a variety of fetal ments

measure-● Perform a fetal anatomic survey

● Evaluate the uterus and adnexa (including documentation ofsize, type, and location of uterine or adnexal abnormalities)

The examination should note abnormal heart rate and/or rhythm

as well as a four-chamber view of the heart, including the heart’s

position within the thorax Additionally, from 16–18 weeks on,

eval-uation of the cardiac outflow tracts may be useful.

Estimation of gestational age requires several measurements Both the biparietal diameter (BPD) and the head circumference (HC) are measured at a level including the cavum septi pellucidi

and the thalamus In cases of cephalic configuration abnormality

(brachycephaly or dolichocephaly), the cephalic index (BPD to

fronto-occipital diameter ratio) may be useful The abdominal

cir-cumference (AC) is determined at the level of the umbilical vein and portal sinus junction The HC/AC ratio is useful in determina-

tion of fetal growth pattern After the 14th week of gestation, and

despite considerable variation, both femur and humerus lengths are

useful in estimation of gestational size and dates

In addition to the previous measurements, the fetal anatomic survey usually includes: cerebral ventricles, spine, stomach, urinary bladder, renal region, and the umbilical cord insertion site on the anterior abdominal wall Ultrasonic examination of Multiple preg- nancies should note the placental number, sac number, presence or absence of an interposed membrane, and comparison of fetal sizes.

Whereas limited examinations may be useful in clinical

emer-gencies or as a follow-up to a complete examination, the more detailed sonography is generally more useful In some circum-

stances (e.g., potential intrauterine growth retardation, potential

macrosomia) serial interval examinations are helpful in diagnosis and management More specialized (targeted) sonography is use-

ful in evaluation of potential fetal defects

Early (20 weeks) ultrasonographic measurements of the fetalBPD, AC, CRL, FL, or total uterine volume have been correlatedaccurately with gestational age Fetal growth between 20 and 30weeks is rapid and linear, and there is marked third trimester vari-ability in fetal size (as noted previously) Hence, initial measure-ments should be taken and recorded as early as possible with sub-sequent later determinations A comparison of these diameters withstandard curves can estimate the gestational age 11 days with 95%confidence When only one measurement is possible or when ini-tial measurements are obtained after the 30th week, accuracy isreduced.

● To identify and institute care for any risk state

● To individualize the level of care necessary

● To assist the gravida in her preparation for labor, delivery,and childrearing

● To screen for common diseases that may affect the gravida’s

or child’s life or health

● To reinforce good health habits for the gravida and herfamily

To achieve these, admittedly, ideal goals require an organized and thoughtful approach Indeed, to be maximally effective, pre- natal care begins before conception Although not the only way to

provide prenatal care, the following is intended as a guide or tional method that has assisted in fulfilling the stated purposes

func-Standard record forms are commercially available These,

com-pleted with explanations when indicated, will amass most of thenecessary information Thus, it is important to identify those datathat should be recorded

GENERAL INFORMATION

Record the patient’s correct name, address, birth date, telephonenumber(s), choice of whom to call in an emergency, and specialpersonal preferences

Fertilization Crown-

(Weeks) Length* Length* Weight* Gross Appearance Internal Development

3 3 mm 3 mm — Early dorsal concavity Optic vesicles appear, double heart

changes to convexity; recognized, fourteen mesodermalhead, tail folds form; somites present

neural grooves close partially

(Continued)

Fertilization Crown-

(Weeks) Length* Length* Weight* Gross Appearance Internal Development

4 4 mm 4 mm 0.4 g Head is at right angle Vitelline duct only communication

to body; limb rudiments between umbilical vesicle and obvious, tail intestines, initial stage of most

8 1.7 cm 3.5 cm 2 g Eyes, ears, nose, mouth Sensory organ development well

recognizable, digits along, ossification beginning in formed, tail almost occiput, mandible, humerus gone (diaphysis), and clavicles, small

intestines coil within umbilical cord,pleural, pericardial cavities forming,gonadal development advanced without differentiationFetal stage

12 5.8 cm 11.5 cm 19 g Skin pink, delicate, Brain configuration roughly

resembles a human complete, internal sex organs now

bodies ossify

16 13.5 cm 19 cm 100 g Scalp hair appears, fetus Sex organs grossly formed,

active, arm–leg ratio myelinization, heart muscle well now proportionate, developed, lobulated kidneys ingender determination final situation, meconium in possible bowel, vagina and anus open,

ischium ossified

appreciably, distance from umbilicus to pubis increases

24 23 cm 32 cm 600 g Skin reddish and Os pubis (horizontal ramus) ossifies,

wrinkled, slight viability possiblesubcuticular fat,

vernix, primitive respiratory-likemovements

Fertilization Crown-

(Weeks) Length* Length* Weight* Gross Appearance Internal Development

28 27 cm 36 cm 1100 g Skin less wrinkled; more Testes at internal inguinal ring

fat, nails appear, if or below, astragalus ossifiesdelivered, may survive

with optimal care

32 31 cm 41 cm 1800 g Fetal weight increased Middle fourth phalanges ossify

proportionately morethan length

36 35 cm 46 cm 2500 g Skin pale, body rounded, Distal femoral ossification

(for lanugo disappearing, hair centers presentCaucasian) fuzzy or wooly, earlobes

soft with little cartilage, umbilicus in center ofbody, scrotum small with few rugae, few sole creases

lanugo hair on shouldersand upper back, earlobesstiffened by thick cartilage, nasal and alar cartilages,nails extend over tips of digits, testes in full,pendulous, rugous scrotum,

or labia majora welldeveloped, creases coversole

* Approximate.