ANTENATAL ASSESSMENT

CHAPTER 20

Antenatal Assessment

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Careful history taking and examination of the pregnant woman is an essential component of antenatal care.

TIMING OF THE FIRST VISIT/REGISTRATION

• The first visit or registration of a pregnant woman for ANC should take place as soon as the pregnancy is suspected.
• Every woman in the reproductive age group should be encouraged to visit her health provider if she believes she is pregnant.
• Ideally, the first visit should take place within 12 weeks.

Early detection of pregnancy is important for the following reasons:

• It facilitates proper planning and allows for adequate care to be provided during pregnancy for both the mother and the fetus.
• Record the date of the Last Menstrual Period (LMP), and calculate the Expected Date of Delivery (EDD).
• The health status of the mother can be assessed and any medical illness that she might be suffering from can be detected and also to obtain/record baseline information (on blood pressure, weight, haemoglobin, etc.).

NUMBER OF ANTENATAL VISITS

Ideal recommendations for Antenatal visits = (13-14)

WHO (2016) Recommendations

ANTENATAL ASSESSMENT

History Taking

The obstetric history and clinical examination are best done using a set pattern so that important points are not missed. The mother should be comfortable so that she can speak in privacy.

Vital Data

Name ______________ Husband’s name ____________

Age ________________ Age _______________________

Religion ____________ Religion ___________________

Occupation _________ Occupation ________________

Education __________ Education _________________

Address __________________________________________

Date of first examination ___________________________

Duration of marriage ______________________________

• Age more than 35 years and less than 18 years is considered as a high-risk pregnancy.
• Occupation is also relevant in some cases as it may involve exposure to ionizing radiation, which should be avoided.
• The level of education is also relevant in relation to the women’s adherence to subsequent visits and compliance to taking medicines.
• A low socioeconomic class may be associated with complications like anemia and preterm labor.

1st method: GxPa (x = number of times of conception; a = number of pregnancies crossed the period of viability).

Example: A pregnant female at 24 weeks has a history of 1 full-term live birth at 37 weeks.

Answer = G2P1

2nd method: GxPa+b(x = number of times of conception, a= number of pregnancies crossed the period of viability; b= no. of abortions.

3rd method: GxPa+b+c+d (also called GTPAL system) [x = number of times of conception, a = no. of term deliveries; b= no. of preterm deliveries; c = no. of abortions; d = no. of live births].

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Obstetric Formula

G = Gravidity, the number of pregnancies, including the present one.

T = Term births, the number born at term i.e., 37 weeks or more.

P = Preterm births, the number born before 37 weeks.

A = Abortions, the number of abortions or miscarriages

L = Current living children

Acronym GTPAL

Example: A fourth-time pregnant woman had a history of 1 abortion, a daughter born at 40 weeks, a boy born at 34 weeks

Answer = G4T1P1A1L2

Twins/Triplets are considered as one pregnancy only. (Woman had who delivered a twin in her last pregnancy is still a gravid one and para one.

Basic Terminologies

Period of Gestation

The duration of pregnancy is expressed in terms of completed weeks. First-trimester ultrasound is a very good predictors of the date.

Gestational age can be calculated by:

• A crown-rump length in the first trimester is the best predictor of gestational age with an error of only ± 5 days.
• The gestational age in weeks can be calculated by adding 6.5 to the CRL in cm.
• If a first-trimester scan is not available, a second trimester scan and biometry between 14-20 weeks will give an idea of gestational age with an error of ± 7 days.
• Date of quickening Fetal movements are a reliable sign of fetal well-being. Fetal movements, also called ‘quickening’, begins at around 18–22 weeks of pregnancy.

The expected date of delivery (EDD) can be calculated by:

Naegeles’ formula i.e., by adding 280 days or 9 months and 7 days to the first day of the LMP.

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Example Mrs. R; LMP is 12.9.2022

EDD = 19.6.2023 (By adding 7 in date and 9 in months)

Presenting Complaints

• If the mother has any presenting symptoms then it should not be ignored. Such complaints can be a pain, bleeding or leaking.
• If bleeding is present then ask when it started, its amount and is she still bleeding. Any precipitating factors for it such as coitus or trauma need to be asked.
• The presence of associated pain and whether she had similar pain in the past need to be checked.
• History may have to be modified depending upon presenting complaints.
• Nausea, vomiting, backache, swelling of legs and other minor complaints should be elicited in the history

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History of Present Pregnancy

• It should be asked whether the pregnancy was planned and whether folate was taken in the preconception period and in the first trimester.
• Date of the first urine pregnancy test, first-trimester scan and date of quickening help to ascertain the delivery date.
• Any bleeding in the first trimester as it may lead to IUGR.

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• Details of drug intake, smoking and alcohol, febrile illnesses and exposure to teratogens should be noted.
• Details of immunization and supplements such as iron or calcium should be ascertained.
• Weight gain in pregnancy should also be noted.
• Details of blood investigations should be enquired into.

Previous Obstetric History

This is only related to multigravidae. The previous obstetric history needs to be recorded chronologically

• Medical History
• Surgical History
• Menstrual History
• Social History
• Personal History

Previous Medical and Surgical History

PHYSICAL EXAMINATION

Physical examination comprises :

General Examination

• Height : A height less than 140 cm is considered to be regarded with caution as such woman is more likely to have small pelvis.
• Weight : The average Indian woman’s weight gain during pregnancy is 11 kg.
• BMI : It can be calculated if the prepregnancy weight or weight in the first trimester is available.
• Build: Obese/average/thin
• Gait: Stable/Shuffling

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General Examiantion

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• Pallor: The presence of pallor indicates anaemia. The woman should be examined for pallor at each visit. For this, one needs to examine the woman’s conjunctiva, nails, tongue, oral mucosa and palms.
• Jaundice: Look for yellowish discolouration of the skin and sclera. The colour of the skin and sclera varies depending on the level of bilirubin. When the bilirubin level is mildly elevated, they are yellowish. When the bilirubin level is high, they tend to be brown. Approximately 3–5% of the pregnant women have abnormal liver function tests. However, jaundice in pregnancy is relatively rare but has potentially serious consequences for maternal and fetal health.
• Cyanosis: Mother with cyanosis will show bluish discolration of lips, tongue, oral mucosa, nose tip, ear lobules, hands and feet.
• Neck (Thyroid enlargement): Neck vein, thyroid gland and lymph gland should be noted for any abnormality.
• Varicosities of legs: Check the legs for presence of varicosity.

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• Spine for deformities: Examine the mother for Kyphosis, Lordosis, Scoliosis.
• Oedema: Oedema (swelling), which appears in the evening and disappears in the morning after a full night’s sleep, could be a normal manifestation of pregnancy. Any oedema of the face, hands, abdominal wall and vulva is abnormal. Oedema can be suspected if a woman complains of abnormal tightening of any rings on her fingers. She must be referred immediately for further investigations
• Vital signs

Systemic Examination

• Cardiovascular system
• Respiratory system
• Neurological system
• Abdominal examination for an enlarged liver, spleen or kidney.

Obstetric Examination/�Abdominal Examination

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• Inspection of scars/any other relevant abdominal findings.
• Measurement of fundal height.
• Determination of fetal lie and presentation by fundal palpation, lateral palpation and pelvic grips.
• Auscultation of the FHS

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Preparation for Abdominal Examination (Role of a Nurse)

• Ask the woman to empty her bladder (give her a clean bottle to collect a sample of urine for testing) immediately before proceeding with the abdominal examination. This is important as even a half-full bladder might result in an increase in the fundal height.
• Ask the woman to lie on her back with the upper part of her body supported by cushions. Never make a pregnant woman lie flat on her back, as the heavy uterus may compress the main blood vessels returning to the heart and cause fainting (supine hypotension).

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• Ask her to partially flex her hips and knees. Stand on the woman’s right side to examine her in a systematic manner. Divert the woman’s attention with conversation. The hand must be warm and should be placed on the abdomen till the uterus is relaxed before palpation.
• Poking the abdomen with the fingertips should be avoided at all costs.
• Maintain privacy throughout the examination

INSPECTION

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• Whether the uterine ovoid is longitudinal, transverse or oblique.
• Contour of the uterus: Fundal notching, convex, cylindrical or spherical shape.
• Undue enlargement of the uterus.
• Skin condition of the abdomen.
• Any incisional scar or mark on the abdomen.

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Measurement of Fundal Height�

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• This indicates the progress of the pregnancy and fetal growth. The uterus becomes an abdominal organ after 12 weeks of gestation.

Nursing Tip

The gestational age (in weeks) corresponds to the fundal height (in cm) after 24 weeks of gestation in a singleton pregnancy with longitudinal lie.

• Remember that while measuring the fundal height, the woman’s legs should be kept straight and not flexed.
• The normal fundal height is different at different weeks of pregnancy.

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Measurement of Fundal Height

Marking of fundal height

Reasons for less or more height of uterus in relation to amnenorrhea

Palpation to Determine Fetal Lie and Presentation

• The pelvic grips (four in number) are performed to determine the lie and the presenting part of the fetus.
• Palpate for the fetal lie and assess whether it is longitudinal, transverse or oblique. Remember that even if a malpresentation is diagnosed before 36 weeks, no active management or intervention is recommended at that point of time. Advise the woman to go in for an institutional delivery.

Leopolds’ Maneuvers and their Application

Auscultation of FHS

• Fetal heart sounds gives us information regarding the presentation and position of fetus and its wellbeing.
• They are heard best through the back in vertex and breech and through the chest in face presentation.
• In cephalic presentations the FHS are heard below umbilicus and in breech above the umbilicus.
• In occipito anterior positions they are best heard close to the midline on the side, in occiput transverse more laterally and in occipitoposterior well out in the flanks.

Fundal Grips/Leopold Maneuvers

Location of FHS in different presentations of the position of the fetus

Auscultating FHS

Multiple pregnancy:

This must be suspected if the following are detected on abdominal examination:

• An unexpectedly large uterus for the estimated gestational age.
• Multiple fetal parts discernable on abdominal palpation.

PROCEDURE: ANTENATAL EXAMINATION

Preprocedural Preparations

Articles Required

Procedure

• Ask the mother to sit comfortably and explain the procedure to her.
• Arrange the articles at the patient’s bedside and maintain the privacy of the patient.
• Provide a comfortable position for the mother and wash hands.
• Collect the personal information of the mother.
• Ask for complete obstetric history.

• Perform the general assessment
• Perform head-to-foot assessment.
• Prior to any obstetrical examination ask the mother to empty the bladder and ask for some of the urine to be stored in a container to test for sugar and proteins.
• Maintain privacy and take verbal consent.
• Inspect the abdomen for linea nigra, striae gravidarum, shape, contour, and scars.
• Perform abdominal palpation, ask the mother to lie in a comfortable position.
• Measuring fundal height (in cm) using measuring tape

• Measure fetal lie and presentation, ask the mother to flex her knees.
• Perform fundal palpation/first maneuver (Done facing the patients’ face).
• Perform lateral palpation or grip/ second maneuver (Done facing the patients’ face).
• Perform the superficial pelvic grip/ third maneuver (Done facing the patients’ face).
• Perform deep pelvic grip/fourth maneuver (Done facing patients’ feet).
• Place the fetoscope or stethoscope after 20 weeks of pregnancy over the convex portion of the fetus closest to the anterior uterine wall.

Postprocedural Responsibilities

BREAST EXAMINATION

Examination of the breasts is mandatory not only to note the presence of pregnancy changes but also to note the nipples (cracked or depressed) and skin condition of areola.

• Observe the size and shape of the nipples for the presence of inverted or flat nipples.
• Try and pull out the nipples to see if they can be pulled out easily.
• Flat nipples that can be pulled out do not interfere with breastfeeding.
• Truly inverted nipples might create a problem in breastfeeding.
• If the nipples are inverted, the woman must be advised to pull on them and roll them between the thumb and index finger.
• A 10 cc or 20 cc disposable plastic syringes can also be used for correcting inverted nipples.

Examination Steps

• Cut the barrel of the syringe from the end where the needle is attached. Take out the plunger and put it in from the opposite end, which is the cut end of the syringe. Push the piston forward fully, and gently place the open end of the barrel in such a way that it encircles the nipple and areola. Pull back the plunger, thus creating negative pressure. The nipple will be sucked into the barrel and pulled out in the process.
• Look for crusting and soreness of the nipples. If these are present, the woman must be advised on breast hygiene and the use of emollients such as milk cream.
• The breasts must be palpated for any lumps or tenderness.

LABORATORY INVESTIGATIONS

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Standard Panel of Tests

• Hemoglobin, Hematocrit estimation and a CBC to identify anemia.
• Hb should be checked in each trimester.
• Urine should be tested for protein and deposits (Helps to detect eclampsia and preeclampsia).
• Rapid malaria test.
• If pus cells are present, urine culture and sensitivity testing are needed.
• Screening for asymptomatic bacteriuria is recommended for all women if possible.
• Blood grouping and Rh typing are to be done and if a woman is Rh negative then the partner’s blood group should also be assessed and if he is Rh positive; then perform an indirect coombs test.
• Testing for Syphilis and Hepatitis B to be done.

Routine investigations in pregnancy �(WHO and NICE)

Assessment of fetal wellbeing

Daily Fetal Movement Count

• The test is valid after 30 weeks of pregnancy.
• The mother counts the fetal movement she feels in 3 hours during the period of 12 hrs, e.g., 9 am–9 pm. 1 hour at the beginning, one hour at the middle and one hour at the end of this period.
• The count is multiplied by 4 to get the fetal movements in 12 hours. If it is less than 10 movements, this indicates that the fetus may be at risk and non-stress test (NST) is indicated.

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BIOPHYSICAL ASSESSMENT

Non-stress Test

Vibroacoustic Stimulation

Procedure and Interpretation

The test takes approximately 15 minutes to complete, with the fetus monitored for 5–10 minutes before stimulation to obtain a baseline FHR.

If the fetal baseline pattern is nonreactive, the sound source (usually a laryngeal stimulator) is then activated for 3 seconds on the maternal abdomen over the fetal head. Monitoring continues for another 5 minutes, after which the monitor tracing is assessed.

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Interpretation

The desired result is a reactive NST (accelerations present are normal).

The test may be repeated at 1 min. interval up to three times when there is no response.

Further evaluation with CST and biophysical profile if the pattern is still nonreactive.

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Contraction Stress Test/Oxytocin Challenge Test

Procedure:

1. Nipple-stimulated Contraction Test
2. Oxytocin-stimulated Contraction Test

Biophysical Profile

Management Biophysical Profile

Ultrasonography

• Ultrasonography is the use of high-frequency sound waves to detect different tissue densities and visualize outline within the body.
• Diagnostic ultrasonography is an important, safe technique in antepartum fetal surveillance.
• It provides critical information to the health care providers regarding fetal activity and gestational age, normal versus abnormal organ, visual assistance with which invasive tests may be performed more safely, fetal and placental anomaly, and fetal well-being.

Cardiotocography (CTG)

• This is a common method of external fetal heart rate monitoring. The fetal heart rate is detected through the maternal abdominal wall utilizing an ultrasound Doppler principle.
• The unit has a transducer that emits ultrasound waves and a sensor to detect a shift in the frequency of the reflected sound.
• The transducer is placed on the maternal abdomen at a site where FHR is best heard.
• A coupling gel should be used, as air does not conduct ultrasound waves. The device is held in a position with a belt.

BIOCHEMICAL TEST

Biochemical assessment involves biological examination (e.g., as chromosomes in exfoliated cells) and chemical determinations (e.g., lecithin/sphingomyelin {L/S} ratio, bilirubin level, surfactant/albumin {S/A} 223

ratio).

Amniocentesis

Chorionic Villus Sampling

Percutaneous Umbilical Sampling/ Cordocentesis

Alpha Fetoprotein/Maternal Serum Alpha–Feto Protein (MSAFP)

• MSAFP screening can be done with reasonable reliability anytime between 15 and 20 weeks of gestation (16 to 18 weeks is ideal).
• A blood sample is drawn and sent for analysis.
• Once the MSAFP is determined, it is compared with normal values for each week of gestation. Values also should be correlated with maternal age, weight, race, presence of a multifetal pregnancy and whether the woman has insulin-dependent diabetes.
• Higher than normal levels are associated with NTDs.

Multiple Marker Screens

• Triple and quad-screen results Low MSAFP and unconjugated estriol levels and high hCG levels are associated with trisomy 21.
• Low values in all three markers are associated with trisomy 18.
• Low inhibin A levels indicate the possibility of trisomy 21.