Subjective symtoms of 3RD TRIMESTER OF PREGNANCY

  1. Amenorrhea persist
  2. Enlargement of the abdomen is progressive which produces some mechanical discomfort to the patient such as palpitation or dyspnea following exertion.
  3. Lightening –at about 38thweek is especially in primigravida ,a sence of relief of pressure symtoms is obtained due to engagement of the presenting part.
  4. Frequenency of micturition – reappears
  5. Fetal movement are more pronounced.

Objective science

  1. Cutaneous changes
    • These are more prominent with increased pigmentation and striae.
  2. Uterine shape
    • It is changed from cylindrical to spherical beyond 36th week.

Fundal height

The distance between the umbilical and the ensiform cartilage is divided into 3 equal parts.
The fundal height corresponds to the junction of the upper and middle third at 32 weeks,upto the level of enciform cartilage at 36th week and it comes dowm to 32 weeks level at 40th week because of engagement of the presenting part.
To determine whether the height of the uterus corresponds to 32 weeks or 40 weeks,engagement of the head should be tested.
If the head is floating, it is of 32 week pregnancy and if the head is engaged,it is of 40 weeks pregnancy.

Symphysis of fundal height (SFH)

The upper border of the fundus is located by the ulnar border of the left hand and this point is marked.The distance between the upper border of symphysis pubis upto the marked point is measured by a tape in cms.
After 24 weeks the sfh measured in cms. Corresponds to the number of weeks upto the 36 weeks.
A variation of +2 cms. Is accepted as normal.
Variation beyond the normal range needs further evolution.

Braxton hicks contraction

It is also known as practice contraction and they are more evident.

Fetal movements

It is easily felt.
Palpation of the fetal part and their identification become much easier,lie,presentation and position of the fetus are determined.

FHS(Fetal heart sound)

It is heard distinctly in areas corresponding to the presentation and position of fetus.
FHS may not be audible in cases of maternal obesity,polyhedrammias,occpituposterior position and certainly in IUD.


Gestational age estimation by BPD,HC,AC and FL is less accurate (variation + 3weeks).
Fetal growth assessment can be made provided accurate dating scan has been done in first or second trimester.
Fetal AC at the level of the umbilica vein is used to assess gestational age and fetal growth profile (IUGR or macrosomia), fetal weight estimation can be done.
Amniotic fluid volume assessment is done to detect oligohydramnios (AFI<5) or polyhydramnios (AFI>25)

Placemental anatomy

Location (fundus of previa)
Thickness placentomegaly in diabeter

Clinical signs

Progressive enlargement of abdomen.
Perception of fetal movements by the mother.


face – chloasma
A temporary condition, typically caused by hormonal changes, in which large brown patches form on the skin (melasmer gravidarum) or Mask of pregnancy
Mostly seen on cheek, forhead, bridge of the nose, chin.


Increased vascularity, Montgomery tubecler Pigmented primary areola and nipple, 2nd areola.


Linea nigra
Striae gravidarum
Proturuded umbilicus
Pigmented previous surgical scars


•Accentuation of pigments


• Breast – specific consistency and colostrum expressed from nipples
• Abdomen

Superficial palpation

Pregnant uterus( a globalous, softcontactile, painless mass, Braxton hicks contraction)
Mesurement of height of uterine fundus
Abdomen palpation.

Deep palpation

• Identification of presenting art (if the head, firm, rounded, large and regulated).
• Lateral palpation- on the sides of uterus (the back is an alongated firm mass, the limbs are small, irregular parts).


• FHS (110 – 160 b/min) in vertex presentation below the umbilicus.

Obstetrical examination

• Speculum examination(cervix, vagina, perineum)

Ultra sound imaging

• Transabdominal sonography(TAS)
• Transvagina sonography(TVS)


➢Fetal morphology and biometry(BPD,FI,AC)
➢Fetal heart movements
➢Breathing movements
➢Evolution of amniotic fluids
➢Placental insertion and maturation degree

Presumptive evidence of pregnancy

Subjective symtoms

Disturbance in urination
The perception of fetal movement

Presumptive symptoms of pregnancy:

Cessation of menses
Nausea with or without vomiting
Frequent urination
Breast tenderness, fullness, tingling
Maternal perception of fetal movement (“Quickening”)
Breast changes – enlargement, hyperpigmentation, montgomery’s tubercles
Bluish or purplish coloration of the vaginal mucosa and cervix (chadwick’s sign)
Increased skin pigmentation – chloasma, linea nigra
Appearance of striae on abdomen and breasts

Probable signs of pregnancy:

Enlargement of the abdomen
Changes in the size, shape, and consistency of the uterus
Changes in the cervix
Palpation of Braxton-Hicks contractions
Outlining the fetus manually
Endocrine tests of pregnancy

Positive signs of pregnancy:

Identification of the fetal heart beat separately and distinctly from that of the mother
Perception of fetal movements by the examiner
Visualization of pregnancy on ultrasound
Fetal recognition on X-ray

Assessment of Gestational Age

By LMP (last menstrual period) – the mean length of a normal pregnancy is 280 days from the first day of the last normal menstrual period
With the help of physical exam
By ultrasound

Naegele’s Rule

Add 7 days to the first day of the LMP, then subtract 3 months
EXAMPLE: LMP = October 15+7 days = October 22-3 months = July 22 = EDD

Fetal growth velocity

It is maximum over the 32-36 week of pregnancy.
It declineds gradually to 24 gms./day over the 36-40 weeks of gestation.
Individual fetal growth varies considerable.

Changes in pregnant women body

Increased skin temperature as the fetus radiates body heat, causing the mother to feel hot.
The increased urinary frequency returns due to increased pressure being placed on the bladder.
Blood pressure may decrease as the fetus presses on the main vein that returns blood to the heart.
Swelling of the ankles, hands and face may occur (called edema), as the mother continues to retain fluids.
Hair may begin to grow on a woman’s arms, legs, and face due to increased hormone stimulation of hair follicles. Hair may also feel coarser.

Leg cramps may become more frequent.
Braxton-hicks contractions (false labor) may begin to occur at irregular intervals in preparation for childbirth.
Stretch marks may appear on the abdomen, breast, thighs and buttocks
Colostrum (a fluid in the breasts that nourishes the baby until the breast milk becomes available) may begin to leak from the nipples.

Dry, itchy skin may persist, particularly on the abdomen, as the skin continues to grow and stretch.
A woman’s libido (sexual drive) may decrease.
Skin pigmentation may become more apparent, especially dark patches of skin on the face.
Constipation, heartburn and indigestion may continue.
Increased white-colored vaginal discharge (leukorrhea) which may contain more mucus.
Backaches may persist and increase in intensity.
Hemorrhoids may persist and increase in severity.
Varicose veins in the legs may persist and increase in severity.

discomforts of third trimester of pregnancy

Third Trimester Tests During Pregnancy

Group B streptococcus screening

• Vaginal and rectal swabs are taken at 35 to 37 weeks of pregnancy to detect group B strep bacteria. Although group B strep can be present in up to 30% of all healthy women, it’s the leading cause of life-threatening infections in newborns and can also cause intellectual disability, impaired vision, and hearing loss. Women who test positive are treated with antibiotics during delivery to protect the baby from contracting the infection at birth.

Electronic fetal heart monitoring

• Electronic fetal heart monitoring is done during pregnancy, labor, and delivery to monitor the heart rate of the fetus. The fetal heart rate can indicate whether the fetus is doing well or is in trouble and can be done any time after 20 weeks.

Nonstress test

• Done weekly in many high-risk pregnancies, such as in cases where a women is carrying more than one fetus, or has diabetes or high blood pressure
• This test involves using a fetal monitor strapped across the mother’s abdomen to measure the baby’s heart rate as it moves. It’s also used for monitoring overdue babies.

Contraction stress test

• Also done in high-risk pregnancies, a fetal monitor measures the baby’s heart rate in response to contractions stimulated either by oxytocin (Pitocin) or nipple stimulation. Doctors use the measurements to predict how well the baby will cope with the stress of labor.

Biophysical profile

• Can be done with just an ultrasound or with a combination of a nonstress test and an ultrasound.

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