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Obstetrics Simplified - Diaa M. EI-Mowafi

Radiology in Obstetrics

Uses

  • Diagnosis of pregnancy after 16 weeks (formation of the skeleton).
  • Multiple pregnancy.
  • Presentation and position.
  • Vesicular mole (no foetal shadow).
  • Gross congenital anomalies as hydrocephalus and anencephaly.
  • Localisation of placental site (the old methods of head displacement from the symphysis pubis or placentography).
  • Intrauterine foetal death.
  • Pelvimetry and cephalometry.
  • Diagnosis of maturity:
    • Distal femoral epiphysis appears at 36 weeks.
    • Upper tibial epiphysis appears at 38 weeks.
    • Measurement of foetal lumbar vertebrae.

All these indications are now covered by ultrasound and radiodiagnosis is nearly out of modern obstetrics due to its hazards.

Hazards

  • Death of the embryo or teratogenicity particularly if used in the first trimester.
  • Gene mutation of the foetus or mother.
  • Leukaemia of the newborn.

Obstetric Diagnosis

The diagnosis in medicine depends upon the triad of history, examination and investigations.

HISTORY

Personal History

  • Name:
    • Essential for hospital and clinic records.
    • To be familiar to the patient.
  • Age:      
    • Elderly primigravida has her own risk.
    • Detection of future fertile years approximately.
  • Occupation:
    • Certain occupations are carrying the risk of teratogenicity as radiation technicians.
  • Residence:
    • Some diseases are common or endemic in certain areas as rheumatic heart in dark humid areas.
  • Marital state.
  • Special habits: as smoking, alcohol, heroin....etc.

Complaint

  • In patient’s own words.
  • Arranged according to its importance and order of events.
  • Amenorrhoea is the main complaint in a pregnant patient and may be the only one when she is coming for routine antenatal care.

Present History

It is the analysis of each complaint arranged according to events and includes:

  • Onset: sudden or gradual.
  • Duration.
  • Course: progressive, stationary or regressive.
  • Relation of each complaint to the others.
  • Medical or surgical intervention.
  • Factors improving or worsen the condition.
  • The already done investigations are mentioned.
  • Any urinary symptoms.
  • Any gastrointestinal symptoms.

Menstrual History

  • The first day of last normal menstrual period (LNMP).
  • The regularity of menses before LNMP.

Obstetric History

  • Gravidity.
  • Parity.
  • In each pregnancy ask about:
    • duration of pregnancy,                
    • any complication during it,
    • mode of termination,               
    • the offspring (male or female, alive or dead),
    • the puerperium or postabortive period,
    • the time of last delivery or abortion.

Past History

  • Medical diseases as hypertension, diabetes, cardiac, syphilis or T.B.
  • Operations especially the uterine as myomectomy.
  • Trauma to the pelvis, spines or lower limbs.
  • Induction of ovulation (in twin pregnancy).
  • Exposure to radiation.

Family History

Diabetes, hypertension or T.B.

EXAMINATION

The physician is standing on the right side of the patient.

General Examination

  • General condition.       
  • Gait.   
  • Body built.
  • Weight.
  • Length
  • Level of consciousness.
  • Hair distribution.
  • Vital sings: pulse, temperature, blood pressure.
  • Face:
    • eyes:
      • anaemia (pallor of the conjuctiva),
      • jaundice (yellowish conjuctiva),
      • oedema of the eye lids.
    • Nose:
      • depressed nose (congenital syphilis),
      • epistaxis (hypertension).
    • Lips:
      • anaemia,
      • cyanosis.
    • Teeth:      
      • septic focus.
  • Neck:      
    • thyroid,
    • lymph nodes,       
    • congested neck veins.
  • Chest and heart.
  • Breasts:
    • signs of pregnancy,
    • retracted nipple.
  • Lower limbs:
    • oedema,
    • dilated veins,   
    • tender calf muscles (deep vein thrombosis),
    • deformities.
    • manifestations of rickets.
  • Back: for deformities.

Abdominal Examination

Inspection

  • Contour: vertical in longitudinal lie and transverse in transverse lie.
  • Pendulous abdomen: detected in the standing position.
  • Size: oversized in multiple pregnancy and polyhydramnios.
  • Foetal movement: may be seen.
  • Localised bulges or grooves.
  • Scars.
  • Site of the umbilicus.
  • Pigmentations.        
  • Dilated veins.
  • Hernial orifices.
  • Pubic hair distribution.

Palpation

Palpation of the nine areas of the abdomen (Rt. and Lt. hypochondrium, Rt. and Lt. lumber, Rt. and Lt. iliac fossae, epigastrium, umbilical and suprapubic).

  • Superficial:
    • to get patient’s confidence,
    • to detect rigidity or tenderness,
    • to detect superficial masses.
  • Deep for the:
    • liver and spleen (starting from the right iliac fossa),
    • kidneys (in the renal angle between the last rib posteriorly and vertebral column),
    • other masses.

Obstetric palpation

  • Fundal level: is detected by the ulnar border of the left hand starting from the xiphisternum downwards after centralising the uterus.
    • In primigravida, the fundal level at 40 weeks is felt at the level of about 32 weeks due to engagement of the head.
    • Differentiation between 32 and 40 weeks may be known by:
      • LNMP,
      • date of quickening,
      • manifestations of lightening and pelvic pressure,
      • engagement of the head detected abdominally or vaginally,
      • shelfing of the fundus in standing position,
      • the clinical assessment of the baby size,
      • ultrasound assessment of the gestational age.
  • Fundal grip: by the palms of both hands one of the following may be detected:
    • Breech (96% of cases): large, soft, irregular, does not ballot and continuous with the back.
    • Head (3.5% of cases): small, hard, globular, ballots with a groove between it and the back.
    • Empty fundus (0.5% of cases): in transverse lie.
  • Umbilical (lateral) grip: by the palms of both hands placed on both sides of the umbilicus.
    • The back of the foetus is identified being smooth, firm and convex while the limbs are knobby and mobile.
    • In case of transverse lie, the head is felt on one side and the breech on the opposite side of the middle line.
    • External ballottement can be done to assess the amount of liquor.
  • First pelvic grip: the right hand is used to grasp the presenting part while the left hand is applying gentle downward pressure at the fundus to steady the foetus. The presenting part cannot be well grasped if it is engaged.
  • Second pelvic grip: The physician faces the patient’s feet and the 2 hands are placed in the iliac fossae and approximated to:
    • feel the engaged head.
    • assess the degree of head flexion by identifying the relation of the occiput to the sinciput.
  • The consistency of the uterus is detected which may be:
    • Cystic: in polyhydramnios.
    • Doughy: in vesicular mole.
    • Hard or woody: in abruptio placentae and during contractions.

Auscultation

The FHS is heard as a tic-tac rhythm over the anterior shoulder.

  • In cephalic presentation: it is heard below the level of the umbilicus.
  • In breech presentation: it is heard above the level of the umbilicus.
  • In transverse lie: it is heard on one side of the umbilicus.
  • In occipito-anterior position. it is heard over the mid point of a line joining the anterior superior iliac spine with the umbilicus.
  • In occipito-posterior position: it is heard away from the middle line near the flanks.
  • In mento-anterior position. it is heard at the middle line through the foetal chest wall.

Differential diagnosis:

  • Uterine souffle: caused by rush of blood in the uterine vessels . It is soft, blowing and synchronous with maternal pulse.
  • Umbilical souffle: caused by rush of blood in the umbilical arteries. It is sharp, whistling and synchronous with FHS.
  • Aortic pulsation: synchronous with maternal pulse.
  • Intestinal movements.

Vaginal Examination

Indications:

  • To diagnose early pregnancy.
  • Complications as bleeding, pain or discharge.
  • At 37-38 weeks to:
    • assess the pelvic capacity (see clinical pelvimetry),
    • detect engagement of the presenting part,
    • do cephalopelvic disproportion tests if the head is not engaged.
  • During labour.

DIAGNOSIS

It should include:

  • Gravidity: total number of pregnancies including the current one e.g. primigravida, and 2nd gravida...etc.
  • Parity: Number of previous deliveries e.g. nullipara, unipara, 2nd para...etc.
  • Number of abortions.
  • So G3 P1 +1 means 3 pregnancies, one delivery and one abortion
  • Duration of present pregnancy: in weeks.
  • Lie, presentation and position.
  • Associated complications as:
    • Previous caesarean section.
    • Hypertension.  
    • Diabetes.
    • Cardiac disease.
    • Antepartum haemorrhage.   
    • IUGR.
    • IUFD....etc.

Full diagnosis may be like: 4th gravida, 2nd para + 1, pregnant ± 38 weeks, cephalic, L.O.A, previous C.S.

The four-digit code: e.g. para 4024 means 4 full term deliveries, no abortions, 2 preterm labours and 4 living children.

CALCULATION OF THE GESTATIONAL AGE AND EXPECTED DATE OF DELIVERY

Menstruation - Labour Interval (Naegele’s rule)

Expected date of delivery (EDD)=

  • 1st day of the last menstrual period (LNMP + 7 days + 9 calendar months)or
  • 1st day of LNMP + 7 days - 3 calendar months + one year or
  • 1st day of LNMP + 15 days + 9 Arabic months or
  • 1st day of LNMP + 280 days (40 weeks).

Labour may occur one week before or after the calculated EDD.

Fallacies:

  • Pregnancy may occur during a period of amenorrhoea e.g. lactational amenorrhoea.
  • Bleeding at expected time of menstruation may occur in the first trimester but not after that due to obliteration of the decidual space.
  • Bleeding in early pregnancy e.g. threatened abortion may be mistaken with a menstruation.
  • This method is not so accurate if menses were irregular before pregnancy.
  • Patient may forget her LNMP.

Date of Single Coitus

EDD is calculated by adding 266 days to it.

This is easier to be applied in case of rape.

Date of Quickening

EDD= date of quickening + 20 -22 weeks in primigravida and + 22 -24 weeks in multipara.

Size of the Uterus (fundal level)

  • During the first month, no clinically appreciable changes.
  • At the end of 8th week, uterus is 5 cm in diameter.
  • At the end of 12th week, uterus is 10 cm in diameter, globular in shape, felt at symphysis pubis in primigravida and a little higher in multigravida.
  • From the 16th week upwards it is pyriform in shape and felt at the levels shown in the figure.
  • Causes of over-sized and under-sized uterus: (see before).

Symphysis - Fundal Length (Mc Donald Formula)

After 24 th weeks, the distance from the symphysis to the fundus in cms. multiplied by 8/7 gives the duration of pregnancy in weeks e.g. at full term distance = 35x8/7 = 40 weeks.

Abdominal Girth

Measured at the lower border of the umbilicus:

  • at 36 weeks it is about 36 inches,
  • at 40 weeks it is about 40 inches.

This gives a high false results due to interfering factors as maternal obesity, ascitis, polyhydramnios, multiple pregnancy...etc.

Radiology

  • Cephalometry: BPD is 7.5 cm at 32 weeks, 8.5 cm at 36 weeks and 9.5 cm at 40 weeks.
  • Ossification centres: Talus at 26 weeks, distal femoral epiphyses at 36-37 weeks proximal tibial epiphyses and fermoral head at 38-40 weeks.

Ultrasound

Detection of gestational age and hence EDD by measuring of gestational sac diameter, CRL, BPD, FL.

Practically speaking, the most useful, safe and accurate methods used nowadays are LNMP (menstruation- labour interval) and ultrasound.

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