Thread: Clinical obstetrics viva

FAQ in Clinical obstetrics

Answer of all/ any question and mention question no. while answering.

Continue adding such frequently asked and basic as well as typical questions asked in exams and important for knowledge purpose.

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1. Various methods to calculate gestational age.

2. Why at 32 & 36weeks, fundal height is same? how can you differentiate the two?

3. Signs of onset of labour.

4. Signs of seperation of placenta.

5. What are Braxton-Hicks contrations and their purpose?

6. Why head is ballotable?

7. How to differentiate between true and false labour pains?

8. How can you say form distance that patient has entered into 2nd stage of labour?

9. What is crowing and Why crowing occurs?

10. Why LOA position is most common? Why cephalic presentation is most common?

11. What is deep transverse arrest?

12. What do you mean by contracted pelvis? Difference between contracted pelvis and CPD?

13. How to locate ant. shoulder and importance of it? Why FHS heard best at ant. shoulder or back only?

14. Why head engaged at 37week? Causes of non-engaged in primigravida at term.

15. Different methods to confirm FHS.

16. What is non-stress test?

17. What do you mean by antepartum fetal surveillance?How it is done?

18. Differentiate between ant. fontanelle fomr post. fontanelle.

19. Define asynclitism, mouling and it's importance.

20. Diff. between Caput succedaneum and cephal Hematoma.

Here I have tried to answer of all the questions( 1-20 ) in the "FAQ in OBSTETRIC" asked by Vitrag..

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1. Various methods to calculate gestational age

IMPORTANCE TO KNOW LMP and EDD :
-In Diagnosis of IUGR/IUGD
-In Management of High risk Pregnancy
Gestational Age is about 280 days from last menstrual period ( LMP ).
To calculate, Add a year in First day of LMP, Deduct 3 months, Add 7 days..( This is perhaps EASIEST METHOD )
OR
Add 9 months and 7 days to first date of LMP..( NAEGELE's FORMULA )
CLINICALLY..
-According to SFH
-By the Sign - LIGHTENING
-By Vaginal Examination ( Rough Idea just Prior to labour )
USG
-Gestational Sac : 5 weeks
-As per CRL : Crown Rump Length ..7 wk -10 mm
10 wk - 34 mm ( CRL in cm + 6.5 = Weeks Of Pregnancy )
-FL measurement ( Femur Length )
X-Rays
Ossification Center at upper end of TIBIA at 38-40 wks
At lower and of Femur at 36-37 wks



2. fundal height at 32 and 40 weeks..

( I think that SFH is same at 32 and 40 weeks ...not at 32 and 36 weeks..)

The fundal height should be measured as the distance over the abdominal wall from the top of the symphysis pubis to the top of the fundus. The bladder must be emptied before making the measurement..It is 3 cm more with full bladder.
Between 18 and 30 weeks, the uterine fundal height in centimeters coincides with weeks of gestation.

It reaches maximum at 36 weeks and comes down to 32 weeks level at 40 weeks because of engagement of the fetal parts..

To differentiate in between 32 anf 40 weeks...CHECK THE ENGAGEMENT OF FETAL HEAD..If its engaged then its 40 weeks..If it is still floting, then its 32 weeks of pregnancy...


3. Signs of onset of labour.
Possible Signs Labor May Begin Soon.
· Backache: Not the type of backache you have in late pregnancy that changes when you shift position, but a persistent dull ache that makes you restless and irritable.
· Cramps. Abdominal cramping that is mild to moderate in discomfort.
· PMS symptoms: crabby, irritable.
· Nesting Urge.
· Frequent, soft bowel movements.

Preliminary Signs :
· Bloody show
· Water breaks
· Contractions

Positive Signs of Labor
· Gush of amniotic fluid from vagina.
· Progressing contractions: Get longer, stronger, and/or closer together with time. Are usually described as ‘very strong’ or ‘painful’, felt in the abdomen, back, or both. May start in the back, and radiate around to front. Usually increase if you walk.
· Dilation of cervix seen in vaginal exam.



4. Signs of separation of placenta.

The Four signs of placental separation are:
1.Apparent lengthening of the visible portion of the umbilical cord.
2.Increased bleeding from the vagina.
3.Change in shape of the uterus from flat (discoid) to round (globular).
4.The placenta being expelled from the vagina.



5. Braxton-Hicks contrations.
They are intermittent, painless contraction that may occur every 10 to 20 minutes after the first trimester of pregnancy. These contractions were first described in 1872 by British gynecologist John Braxton Hicks. Sometimes these contractions are also called prelabor contractions or Hicks sign. Not everyone will notice or experience these contractions, and some will have them frequently. Some mothers say that they notice them more in subsequent pregnancies than in their first pregnancy.

PURPOSE : Braxton Hicks contractions seem to be a part of the stages of pregnancy development. It is thought that Braxton Hicks contractions help your body to prepare for actual labor. They are commonly called "practice contractions" as they help your uterus prepare for the contractions it will experience during labor. Without Braxton Hicks contractions, your labor contractions would be longer, more painful, and less effective at pushing your baby out. Braxton Hicks contractions felt later in pregnancy also help to soften the cervix.



6. Why head is ballotable..??

Any Structure with PEDICLE ballots normally..For example - Our Kidneys..In case of Baby, Neck acts as PEDICLE..And so in Ballots in Amniotic Cavity...

7. True and false labour pains



8. How can you say patient has entered into 2nd stage of labour?
Pushing and what to expect:

The entire process of the second stage lasts anywhere from 20 minutes to 2 hours.
Intensity of hte PAIN Increases..Contractions will last about 45-90 seconds with a 3-5 minute rest in between.

Pt will have a strong natural urge to push
Pt will feel strong pressure at your rectum
Pt will likely have a slight bowel or urination accident
Baby's head will eventually crown (become visible) and Due to decent, SFH even gradually decreases...

9. Crowing
Crowning describes when the baby's head is pushing though the fully dilated cervix and ready to pass into the birth canal.

After Internal Rotation of head, Further decent occurs until the subocciput lies underneath the pubic arch....At this stage, the Maximum diameter of the head ( BPD-Bi Parital Diameter )stretches the vulval outlet without any recession of the head even after the contraction is over....
Crowning occurs to maintain flexion of the headThe purpose of incresing flesion of the hear is to ensure that the small suboccipito-frontal diameter 10 cm distends the vulval outlet instead of larger occipito-frontal diameter..



10. LOA position & cephalic presentation

CEPHALIC PRESENTATION : Baby can Float freely in WOMB..But at the end of the pregnance.Fetus has reached enough size which restricts its movements..So fetus takes Flexion attitude to accomodate easily..
1.Head comes down to accomodate larger breech portion in roomy part of uterus..
2. CENTER OF GRAVITY may play role as head is more heavier..( but its my personal thinking..yet not verified about it)....Its towards head, So it settles first Giving CEPHALIC PRESENTATION..
3. With Head Down Position, Baby can guide its own delivery through cervix...( To see the way through cervix--_As EYES ARE IN THE HEAD..!!--What You SAY..!!..??)

LOA POSITION : Because Right Oblique Diameter of maternal Pelvis is occupied by SIGMOID COLON...So there is no place for baby's head there...Which makes LOA more common...


11. Deep transverse arrest

This is the technical term that describes a delay in the second stage of labour because the baby's head, having failed to turn sufficiently to travel down the birth canal, gets 'caught' on the bones of the mother's pelvis. In order to deliver vaginally, the head needs to be turned using Keilland's forceps. This is sometimes referred to as a high forceps delivery and requires delivery by an obstetrically trained doctor. Anaesthetic is also needed, either a pudendal block or an epidural.

Although the forceps are designed to encase, rather than squeeze the baby's head, there is often some swelling and bruising after birth if delivery has been assisted in this way, which will subside quite quickly.



12. Difference between contracted pelvis and CPD

Contracted Pelvis is a one with less than normal measurements in any diameter.

Whereas CPD is when a babies head or body is too large to fit through the mother’s pelvis. It is believed that true CPD is rare, but many cases of “failure to progress” during labor is given a diagnosis of CPD. When an accurate diagnosis of CPD has been made, the safest type of delivery for mother and baby is a cesarean delivery.
Thus All CPD dont have Contracted Pelvis, But Contracted Pelvis is one of cause of CPD...Other factors also play the role...I think you got it...

The possible causes of cephalopelvic disproportion (CPD) include:

1.Large baby due to:
-Hereditary factors
-Diabetes
-Postmaturity (still pregnant after due date has passed)
-Multiparity (not the first pregnancy)
2.Abnormal fetal positions
3.Small Pelvis
4.Abnormally shaped pelvis





13.Why FHS heard best at anterior shoulder..??

The faint sounds seem to be amplified by the proximity of the bone and therefore are frequently more easily heard in this area. Even at this place, the baby is well cushioned by fluid and you will cause no harm.
Also It is near to the heart of the baby..


14. Why head engaged at 37week? Causes of non-engaged in primigravida at term.

When Greatest horizontal plane ( Biparital Diameter ) passes Pelvic Brim , The head is said to be engaged...
In Multigravida It occurs late in First stage of labour..
But in Primigravida, It is earlier at around 37 weeks BECAUSE...-Abdominal wall is tight compared to Multigravida, so fetus finds no place to move freely..

CAUSES OF NON-ENGAGED HEAD IN PRIMIGRAVIDA AT TERM..
-It is sign of CPD-Cephalo Pelvic Disproportion
-Deflexed Head placing larger diameter to engage
-Polyhydroamniosis
-Poor formation of lower uterine segment
-Hydrocephalus
-Placenta Praevia
-Pelvic Tumors
-High Pelvic Inclination
-Functional -when no cause can be detected


15. Different methods to confirm FHS.

Simply by Auscultation
By USG Examination
By Fetoscope ( like Stethoscope )
By Doppler USG

16. Non-stress test
Non-stress testing (NST) simply involves monitoring a developing baby's heart rate over time. The monitor has two belts that go around the mother's waist-one registers any contractions she may have, the other tracks the fetal heart rate. These are graphed on paper or on a computer screen. Often, you can see the graph as it is being made. Usually, the NST is not uncomfortable, although it may get tiresome to stay in one position for 20 minutes or so (in fact, it's not unusual for these tests to run as long as an hour).

Reactive vs. nonreactive tests
The usual baseline fetal heart rate is between 120 and 160 beats per minute. Once the monitor is in place, your practitioner will look for certain measurements to see how the baby is faring, including if his heart rate rises when he moves. An NST is considered reassuring if there are accelerations of the fetal heart rate of at least 15 beats per minute over the baseline, lasting at least 15 seconds, occurring within a 20-minute time block. This is called a reactive NST. If these accelerations don't occur, the test is said to be nonreactive.

Although a reactive NST is a good sign, a nonreactive NST does not mean the baby is in trouble. If you are not reassured by the results of the NST, or if the fetal heart rate slows down alarmingly, more testing is usually done. This might include a more prolonged NST, a contraction stress test, or a biophysical profile.





17. Antepartum fetal surveillance

Antepartum (“before delivery”) tests in the third trimester look for signs of fetal distress or wellbeing in high-risk pregnancies.

1.Fetal movement assessment
2.Contraction stress test
3.Nonstress test
4.Biophysical profile consisting of nonstress test and four observations made by real-time ultrasonography:
5.Fetal breathing movements
6.Fetal movement
7.Fetal tone
8.Determination of the amniotic fluid volume
9.Modified biophysical profile
10.Umbilical artery Doppler velocimetry (in pregnancies complicated by intrauterine growth restriction only)


18. Ant. fontanelle from Post. fontanelle.




19. Asynclitism & Mouling

ASYNCLITISM : Asynclitism is diagnosed when the suture lines of the fetal skull are not felt to be aligned exactly halfway between the symphysis pubis and the sacrum. If the baby's head is tilted up toward the pubic bone, it is called anterior asynclitism, more common in Multiparae.
If tilted toward the mother's sacrum, it is a posterior asynclitism,More common in Primigravida due to good utrerine tone and tight abdominal wall.

MOULDING : Newborn head moulding is an abnormal head shape that results from pressure on the head during childbirth.
IMPORTANCE : Compared with an adult's, a newborn's head is large in proportion to the rest of the body, usually about 1/4 of the body surface area. The bones of the skull are soft and pliable with gaps between the plates of bone. These gaps close as the bones grow and the brain reaches its full size.
During a head-first delivery, pressure on the head caused by the narrow birth canal (vagina) may mold the head into an oblong shape. Depending on the amount and duration of pressure, the skull bones may even overlap.



20. Caput succedaneum and Cephal Hematoma.


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Tell me If you are not satisfied with any of answers..I will try to make that answers more better If I can....

Dude.. 19th question.. u hv just made a mistake of "If the baby's head is tilted up toward the pubic bone, it is called anterior asynclitism" - It is called posterior asynclitism.. and vice versa..

for the 7th question.. Additional point is that..

False labour pain usually relieves on taking laxative or on enema.. It is not progressive..

the answer of gastational age isn't right there is adifference between gastational age and enspected date of delivery EDD