CHAPTER 18
DIAGNOSIS OF PREGNANCY–SIGNS, DIFFERENTIAL DIAGNOSIS, CONFIRMATORY TESTS
INTRODUCTION
Maternal ability to reproduce begins at menarche and ends at menopause. The reproductive age is from 13 years to 45 years.
EXPECTED DATE OF DELIVERY
The expected date of delivery can be calculated by the following methods alone or in combination with two or more.
Patient’s Statement or Subjective Data
Date of Fruitful Coitus
EDD can be calculated by adding 266 days to the date of coitus.
Naegele’s Rule
The EDD is calculated by adding 280 days to the first day of LMP. This is the most commonly used formula in which 9 months and 7 days are added to the last LMP. Extra days are to be added in longer cycles whereas lesser days are to be subtracted to get the EDD.
Date of Quickening
Quickening is the first fluttering movement of the fetus usually felt at 16-20 weeks in primigravidae and 2 weeks earlier in multigravidae. For the EDD, add 22 weeks to the date of quickening.
EDD = date of quickening + 22 weeks
Example :Calculate the EDD of a woman with LMP 26 October 2022 using Naegele’s rule.
Answer: Add 7 days and 9 months to the LMP. In this example, the LMP date is 26. Now by adding 7 days to it, the next upcoming date will be 2nd of November. In this type of LMP, 9 months are counted from the month next to the month in which the date of EDD falls, i.e., skip the month having the date (November) and start counting from December.
Previous Records
Clinical
Investigation Records
Investigations
PERIOD OF GESTATION
Example: Calculate the POG of the fetus till 14 April 2023 of a mother with LMP 26 October 2022.
Answer: LMP = 26 October 2022
date till POG is to be calculated = 14 April 2023
Month Days
Total = 170 days
POG = total days/7
= 170/7
= 24 weeks 2 days
FIRST TRIMESTER (FIRST 12 WEEKS)
Subjective Symptoms
Subjective symptoms are those noticed by the woman herself. Following are the presumptive symptoms of early months of pregnancy.
Morning Sickness
This is the first sign observed after fertilization and may last beyond the first trimester. It varies from nausea on rising from bed to loss of appetite or even vomiting.
Amenorrhea
After conception, there is a cessation of the menstrual cycle and no menstrual bleeds is observed, but there could be cyclic bleed that may occur up to 12 weeks of pregnancy. This type of bleeding is usually scanty, lasting for a shorter period of time with respect to the normal menstrual bleeding. This is termed a placental sign.
Frequency of Micturition
Breast Discomfort
A pregnant woman may feel breast fullness and pricking sensation at 6-8 weeks. It is especially experienced by the primigravidae.
Fatigue
It is the most common symptom that may be present in all the trimesters of pregnancy.
Objective Signs
Objective signs are the signs noticed by the medical professional. Following are the objective signs of pregnancy in the first trimester
Breast Changes
There is an enlargement of the breast, well observed in primigravidae between 6-8 weeks.
Breast changes during pregnancy (A) pigmentation of the primary areola and nipple
(B) appearance of secondary areola, development of Montgomery tubercles and increased vascularity
Pelvic Changes
Vulvar Changes
Jacquemier’s or Chadwick’s sign: It is the dark purplish discoloration and congestion of the vulva and vaginal mucosa membranes (Fig. 2). It is well observed between 4-8 weeks and will be at peak around the 16th week and may continue throughout pregnancy.
Different signs of pregnancy
Vaginal Sign
Osiander’s sign: It is the stronger and harder vaginal pulsations caused by the greatly increased blood supply and the enlarged uterine artery. It is palpable at around 8th week.
Cervical Sign
Goodell’s sign: It is a non-specific indication of pregnancy that is characterized by the compressibility and softening of the cervical isthmus at about 6-8 weeks
Uterine Signs
The size, shape and consistency of the uterus change. The uterus enlarges to the size of the egg of the hen at around 6th week, the size of a cricket ball by 8th week and the size of the fetal head by the 12th week.
Immunological Test for Pregnancy (Confirmatory Test)
Principle: Pregnancy test is based on the presence of the antigen such as hCG in the maternal serum or urine along with the monoclonal or polyclonal antibodies.
Classification of immunological tests for pregnancy
Summary of pregnancy test (beta hCG)
Ultrasonography
Various ultrasonographic findings mentioned:
SECOND TRIMESTER (13-28 WEEKS)
Symptoms
General Examinations
Chloasma: It is the extreme form of patchy or diffuse pigmentation around the cheeks, forehead, and around the eyes.
Breast changes: Enlarged and heavy breast with a prominent and darker areola and nipple. These changes are markedly present in primigravidae.
Abdominal Examination
The level of the uterus at different weeks
Auscultation
Fetal Heart Sound
It is the most accurate clinical sign of pregnancy. It can be heard between 18-20 weeks using a stethoscope. The rate is 110-160 beats per minute and varies with the position of the fetus.
There are two other sounds that get confused with the fetal heart sound.
Vaginal Examination
Imaging Studies
Ultrasonography
THIRD TRIMESTER (29-40 WEEKS)
Symptoms
Signs
Location of fundus at different weeks of gestation
How to measure the symphysis fundal height
DIFFERENTIAL DIAGNOSIS OF PREGNANCY
(pseudophantom, spurious– false pregnancy) It is one of the psychological disorder where the woman has a false but firm belief that she is pregnant though she is not.
A slowly growing tumor, in the absence of amenorrhea. It feels soft to hard.
History of Koch’s infection with longer duration of amenorrhea.
In chronic urinary retention of urine due to the retroverted gravid uterus, the distended bladder may be mistaken as ovarian cyst or acute hydramnios.
SIGNS OF PREVIOUS CHILD BIRTH