Methods of Obstetrical Examination

Ans. is a i.e. Femur length

Best parameters for estimation of fetal age

• 1st trimester        Crown Rump length (CRL).
• 2nd trimester       Corrected biparietal diameter (cBPD) or head circumference (HC).
• 3rd trimester        Femur length (most important), Head circumference, corrected biparietal diameter.
• Overall                 Crown rump length.

Friends, if Head circumference is given in options – I would go for it ‑

“Head circumference is one of the most reliable individual parameters for estimation of menstrual age. This is due to its shape independence and the fact that it represents a balance between ease of measurement (and therefore, measurement accuracy) and predictive validity for age.”

Also know :

• Best time to assess gestational age by USG is 9 – 12 weeks (by crown rump length).°
• Best indicator of fetal growth – Abdominal circumference.°
• The diameter which in mm when measured between 14 and 24 weeks corresponds to the gestational age in weeks – Inter cerebellar diameter.°
• CRL in cms + 6.5 gives a rough estimate of gestational age in weeks.°

Radio – immunoassay

Beta HCG

Ans. is a i.e. 12-14

Schedule for antenatal visits in India :

• Monthly visits upto 28 weeks.
• Two weekly visit between 28 and 36 weeks.
• Weekly visit from 36 weeks onwards

This means a total of 12-15 visits.

WHO recommends atleast 4 visits :

1st at       – 16 weeks

2nd at      – 24-28 weeks

3rd at       – 32 weeks

4th at       – 36 weeks

As per Indian scenario – minimum 3 visits are essential;

1st at – 20 weeks (or as soon as pregnancy is known)

2nd – 32 weeks 3rd – 36 weeks

• The first visit that a woman makes to a health care facility is called the booking visit.

A booked case is one that has atleast 3 visits with at least two in the last trimester.

3

20

266 days or 38 weeks

At approximately the midpoint of the menstrual cycle, the ovum is expelled. Once this occurs, the surrounding granulosa and theca cells undergo luteinization and begin to secrete a large amount of estrogen and progesterone.

This mass of hormone secreting cells is known as the corpus luteum (because of its yellow color).

If pregnancy does not occur, the corpus luteum will persist for 14 days, after which point it degenerates. With the degeneration of the corpus luteum, hormone levels drop, the endometrium sloughs, and menstruation occurs.

If a pregnancy does occur, the trophoblastic cells of the pregnancy will secrete human chorionic gonadotropin (hCG).

This hormone goes to the corpus luteum and prevents its degradation, signaling it to continue its excretion of estrogen and progesterone to maintain an environment that is favorable for pregnancy.

The presence of human chorionic gonadotropin forms the basis for the urine and serum pregnancy test.

hCG steadily increases over the first several weeks of the pregnancy, reaching a peak at approximately 10 weeks.

After that, hCG levels decrease gradually during the remainder of the pregnancy.

During early pregnancy, most women experience some nausea.

One of the leading theories for the cause of this nausea is the hormone hCG, because the nausea of early pregnancy appears to mirror the rise and fall of the hCG levels–peaking at roughly 10 weeks and improving after that.

Leopold’s Maneuvers are a common and systematic way to determine the position of a fetus inside the woman’s uterus; they are named after the gynecologist Christian Gerhard Leopold. The maneuvers consist of four distinct actions, each helping to determine the position of the fetus. The maneuvers are important because they help determine the position and presentation of the fetus.

• Fundal grip- First Leopold
• Lateral grip -Second Leopold
• Pawlik’s grip – Third Leopold
• Pelvic grip – Fourth Leopold

Urine pregnancy test can detect hCG in serum upto 1-2 mIU/ml and as early as 5 days before the first missed period.

It is based on one monoclonal antibody that binds the hCG and a second antibody that is linked with enzyme alkaline phosphatase to ‘sandwich’ the hCG.

This is more specific and sensitive.

Therefore the most appropriate answer given here is 5mIU/ml.

Answer is D (Decidua) :

Decidua has not been mentioned to play any role in antenatal diagnosis

Maternal Blood

• Can be used as in estimation of AFP (MSAFP) :
• MSAFP level is elevated in a number of conditions.

– wrong gestational age

– open neural tube defects Q

– multiple pregnancy ^Q

– Intra uterine fetal death Q

– Renal anomalies Q

Amniotic fluid

• Forms on important tool for antenatal diagnosis.
• Following tests may be performed on amniotic fluid :

– estimation of Alpha feto-protein (AFP).

– culture and chromosomal study of desquamated fetal cells in the amniotic fluid.

Fetal Blood

• May be used for

– fetal anemia

– Bleeding disorders

– Rheusus disease

– Non-Immune Hydrops Fetalis

Ans. B i.e. Crown Rump Length

CRL is most accurate with an error of 2.1 days in the first trimester BPD, FL, HC (head circumference) & AC is commonly used for dating thereafter.

Ans. B: 2 days

• With a sensitive test, the hormone hCG can be detected in maternal serum or urine by 8 to 9 days after ovulation.
• The doubling time of serum hCG concentration is 1.4 to 2.0 days.
• Serum hCG levels increase from the day of implantation and reach peak levels at 60 to 70 days.
• Thereafter, the concentration declines slowly until a plateau is reached at approximately 16 weeks.

Ans. C: Syncytiotrophoblast

Ans. C: HCG can be detected as early as 8-9 days after conception

Ans. A i.e. First day of last menstruation

Ans. C: 40 weeks

The World Health Organization defines normal term for delivery as between 37 weeks and 42 weeks

• EDD is calculated by Naegele’s rule
• Add 7 days to the first day of the last period and subtract 3 months
• Naegele’s rule is based on 28 days regular cycle.
• If the cycle is shorter or longer than 28 days, EDD will be corrected and written as corrected EDD.
• Examples:

40 days cycle regularly, to get corrected EDD, add 12 days (40-28) with the EDD calculated from LMP.

21 days cycle regularly, to get corrected EDD, subtract 7 days (28-21) with the EDD calculated from LMP.