Pregnancy US

What is the difference between focused and unfocused ultrasound?
What is the difference between FoCUS and POCUS?
Such ultrasound examinations performed by a doctor for assessment of disease condition, management, or guidance of treatment at bedside has been called point-of-care ultrasound (POCUS). Cardiac POCUS is divided into a focused cardiac ultrasound examination (FoCUS) and limited echocardiography
POCUS has been widely used in many disciplines as a rapid diagnostic tool, especially in emergency medicine. POCUS has been used to aid the diagnosis of multiple medical conditions ranging from acute appendicitis, airway compromise, abdominal aortic aneurysm, traumatic injury assessment

POCUS FAST
Focused Assessment with Sonography for Trauma (FAST) scan is a point-of-care ultrasound (POCUS) examination performed at the time of presentation of a trauma patient.Jul 3, 2023
What is the point of FoCUS ultrasound?
With focused ultrasound, an acoustic lens is used to concentrate multiple intersecting beams of ultrasound on a target deep in the body with extreme precision and accuracy. Depending on the design of the lens and the ultrasound parameters, the target can be as small as 1×1.5mm or as large as 10x16mm in diameter

Mean Sac Diameter (MSD) measurement is used to determine gestational age (GA) Before a Crown Rump length can be clearly measured.The average sac diameter is determined by measuring the length,width and height then dividing by 3 (L/W/H) .
Once a fetal Pole can be visualised the CRL measurement is the most accurate method for dating the pregnancy
HCG Levels for normal Pregnancy.NOTE : The quantitative maternal serum beta HCG peaks at approximately 10 weeks and then reduces

Gestational Sac

 The gestational sac (GS) is the earliest sonographic finding in pregnancy.
    ‘If the mother has a retroverted uterus or fibroids, the GS may be difficult to identify.
    The GS is an echogenic ring surrounding an anechoic centre.
    An ectopic pregnancy will appear the same but it will not be within the endometrial cavity.
    The GS is not identifiable until approximately 4 & 1/2 weeks with a transvaginal scan (sometimes not visible until even later, depending on the patient)
Gestational sac size should be determined by measuring the mean of three diameters. These differences rarely affect gestational age dating by more than a day or two.
The following image is using a transvaginal approach. The gestational sac can often be seen during week 4-5
The yolk sac (YS) will be visible before a clearly definable embryonic pole
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At 5 weeks, your baby is only about the size of a peppercorn. The only things you’re likely to see on an ultrasound are the yolk sac and the gestational sac. And even those may not be visible.
 GS diameter at the start is about 2 mm and increases in size to measure 5–6 mm at 5 weeks. The MGSD then increases by approximately one millimetre per day throughout the first trimester
Is it normal to NOT see yolk sac at 5 weeks?
If YS is not seen at 5 wks, it might indicate the pregnancy is not viable. But it also can mean that the estimated GA is wrong. Another US in a week or two is recommended to look again.
YS appears during the 5th week & provides embryo with1/ nutriens in addition to 2/ circulate gases between mother & fetus & 3/ produces cells that turn into important structures, such as the umbilical cord, blood cells and reproductive organss
YS size, appearance & location can provide important information about the health of pregnancy (PG)

• The yolk sac appears during the 5th week.
  
• It is the second structure to appear on US after the GS.
  
• It should be round with a hyperecoic rim an anechoic centre.
  
• It should NOT BE calcified, misshapen or >6mm from the inner to inner diameter.
  
• Yolk sacs larger than 6 mm are usually indicative of an abnormal pregnancy.
  
• Failure to identify a YS (with TVS US) when the GS has grown to 12 mm is also usually indicative of a failed PG.
  
• A misshapen YS is a higher predictor of a poor outcome than size of the yolk sac. 
  

 The yolk sac is one of the first structures a healthcare provider can see during prenatal ultrasound. It can help confirm pregnancy, along with other factors, such as a missed menstrual cycle and levels of certain hormones in the mother’s blood
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If you’re 5 weeks pregnant, you’re undergoing some major changes.
But you likely won’t notice any differences to your body on the outside. On the other hand, your body is already working to nurture a growing embryo, which is quickly developing important things like the brain, heart, spinal cord, and blood vessels.
It’s normal to want to get a glimpse of your baby as soon as you can. With that being said, if you haven’t had previous complications in pregnancy and you’re relatively healthy, it’s better to wait until at least 12 to 14 weeks into pregnancy to schedule your first US. This is because it’s too early to see the baby’s limbs and organs before this point.

Why you might get a 5-week ultrasound

Some women may get an early ultrasound during their first trimester to estimate the age of the GS, which usually becomes visible in an US during the fifth week.
If you have a history of 1/ ectopic pregnancy or 2/ miscarriage, or 3/ if you’ve conceived via (IVF) in vitro fertilization, your doctor may also want you to have an early US. In addition, 4/ bleeding after a positive pregnancy test might warrant a look at your uterus.

What to expect during a 5-week ultrasound

If you’re 5 weeks pregnant, your US will be done via the vagina as opposed to transabdominal ultrasounds that are typically performed later on in pregnancy.
During a TVS US, a lubricated wand is inserted into your vagina and images translate back to a screen. It shouldn’t be painful, but it may be a little uncomfortable

What will you see?

Don’t be worried if you can’t see your baby! The embryo is only the size of a peppercorn right now — about 2 millimeters (mm). حبة الفلفل
At this stage, the only things you’ll likely see are the YS & GS.
It’s possible that the sonographer might be able to point out the embryo, which at this stage is likely a tiny white curled object.
Surrounding the embryo is the yolk sac, which will look like a small white circle. The YS nourishes the embryo and also helps produce blood cells during the early stages of pregnancy.
The YS is surrounded by a larger black area, known as the gestational sac (GS). The GS contains amniotic fluid and surrounds the embryo. You may see the gestational sac (GS) in an ultrasound (US)as early as 4 1/2 to 5 weeks.
The gestational sac increases in diameter by 1.13 mm per day and initially measures 2 to 3 mm in diameter, according to the National Center for Biotechnology InformationTrusted Source.
You may get to see the flicker of a little heartbeat, but again, don’t stress if the sonographer can’t see it yet. It’s more common to see the heartbeat at 6 weeks or even later.

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What is the function of a yolk sac?

The yolk sac has many essential jobs in fetal development before the placenta and organs develop. The yolk sac:

• Circulates gasses between the pregnant person and embryo.
  
• Delivers nutrients to the embryo.
  
• Develops the earliest form of blood cells.
  
• Makes cells that turn into the umbilical cord, gastrointestinal system, reproductive organs and more.
  
• Provides early immune function and metabolism.
  

• Where is the yolk sac located?

  The yolk sac is inside the GS, a large cavity of fluid inside the uterus that surrounds an embryo. The yolk sac attaches to the outside of the developing embryo. The yolk sac must be inside the gestational sac, and the gestational sac must be inside the uterus. Otherwise, this can indicate the pregnancy has failed or will fail.
  
• A healthy yolk sac is a round or pear-shaped pouch. It’s made of membranes (thin, skin-like material). An ultrasound may detect a fetal pole, the early form of an embryo, next to the yolk sac.
  
• The yolk sac begins to develop during the second week of gestation (pregnancy). A healthcare provider can see the yolk sac using transvaginal ultrasound starting at about week five. The yolk sac grows as pregnancy progresses from week five to week 10.
  
• After week 10, the yolk sac gradually gets smaller and disappears. The embryo absorbs it. By weeks 14 to 20, it may not be visible by ultrasound at all.
  
• In a typical early pregnancy, a yolk sac’s diameter is usually 3 to 5 millimeters from one inside rim to the other.
  If a yolk sac is larger than 6 millimeters, it might indicate a problem with the pregnancy. It might be an early sign of miscarriage.
  
• If a yolk sac is smaller than a healthcare provider expects, it might mean the gestational age (GA) was miscalculated. In other words, you may not be as far along as you thought. Your healthcare provider may recommend a follow-up ultrasound. They will recheck the yolk sac size and look for other signs that the pregnancy is healthy or not.
  
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What if there are two or more yolk sacs?

If an ultrasound detects more than one yolk sac, you may have multiple embryos, such as twins or triplets.

What other problems can affect the yolk sac?

A yolk sac also can be irregular. For example, it may be shaped abnormally, or it may be hardened (calcified) on areas along the outside or all over the sac.
An abnormal yolk sac might indicate a problem with the pregnancy, but it might not. Your healthcare provider will talk to you about any abnormal findings, what they mean for you and what other tests you might need.

What’s a yolk sac tumor?

A yolk sac tumor is a rare type of cancer, sometimes called a germ cell tumor. The cancer starts in the cells that line the yolk sac and forms a tumor sometime after birth.
This type of tumor often occurs in the ovaries or testes, but it can appear elsewhere in your body. The condition usually is diagnosed in children but can be diagnosed later in life. Germ cell tumors can produce substances (hormones) that can lead to certain changes in our bodies as we grow.
First-trimester ultrasound : 12 to 13 weeks

• Can detect :
  
•  Confirm that the fetus is alive.
  
• Provide accurate estimation of the due date.
  
• Detect multiple pregnancies (twins, triplets).
  
• Detect many abnormalities (but NOT as many as at the second trimester ultrasound)
  
• Detect problems within the mother's ovaries; uterus; or other pelvic structures.
  
• The reason why you don’t see anything during a 5-week ultrasound.
  This is common and has everything to do with your human chorionic gonadotropin (hCG) levels. HCG is the same hormone that confirms pregnancy from urine on a pregnancy test.
  Your hCG levels should be around 1,500 to 2,000 at 5 weeks pregnant, but it may be difficult to see anything until hCG exceeds 2,000.
  
• CAN US BE wrong in 1st trimester?
  
• Evidence suggests that ultrasounds more accurately predict your due date than using your last menstrual period—but only in the first trimester and early second trimester (until roughly 20 weeks). 3 Early ultrasound due dates have a margin of error of roughly 1.2 weeks.
  
• An ectopic pregnancy may be the reason why you don’t see anything during a 5-week ultrasound. This is less common than having the dates wrong and may be life threatening if not treated.
  An ectopic pregnancy happens when fertilized eggs implant and grow on the outside main cavity of the uterus. These pregnancies require treatment and may cause heavy bleeding inside the abdomen. Most ectopic pregnancies occur in a Fallopian tube.
  See your doctor if you notice any vaginal bleeding or pain in the pelvic area while pregnant.
  

  Miscarriage

  Falling hCG levels and the inability to find a gestational sac may also point to an early miscarriage. A miscarriage happens when a fertilized egg doesn’t form properly to form an embryo.
  Vaginal bleeding is a common sign of a miscarriage but isn’t a unique symptom for miscarriages — vaginal bleeding may mean something else in your pregnancy.
  In more rare cases, miscarriages may occur because of problems with your uterus or cervix. See your doctor if you have questions or concerns about miscarriage.
  
• Pregnancy symptoms are impacted by your hCG levels. Common symptoms during the fifth week of pregnancy include:
  
• metallic taste in your mouth
  
• tender breasts
  
• morning sickness
  
• mood swings
  
• unusual pregnancy cravings
  
• constipation
  
• expanded sense of smell
  
• increased urination
  
• white vaginal discharge
  
• light spotting
  
• abdominal cramps
  
• thicker and shinier hair
  
• bloating
  
• missed period
  
• https://www.healthline.com/health/pregnancy/5-week-ultrasound#early-pregnancy-symptoms
  
  
  

Abnormalities in maternal serum marker levels and fetal measurements obtained during the first trimester screening can be a marker not only for certain chromosomal disorders and anomalies in the fetus but also for specific pregnancy complications. In particular, low maternal serum pregnancy-associated plasma protein-A (PAPP-A), at 11–13 weeks of gestation, is associated with stillbirth, infant death, intrauterine growth restriction, preterm birth, and pre-eclampsia in chromosomally normal fetuses, while a raised nuchal translucency is associated with specific structural abnormalities and genetic syndromes. We have studied the serum Papp-A level in 560 pregnant patients (11–13 weeks gestation) registered at Bharati Hospital and Research Centre, Pune. All patients undergoing testing were followed till the delivery and their neonatal outcome was also taken into consideration.

Aims and Objectives

Our aim is to study the pregnancy outcome in relation to the variations of Papp-A level in the first trimester of pregnancy.

Materials and Methods

Every patient visiting the antenatal OPD was counseled for testing of First Trimester Screening to assess fetal well-being. Patients who were registered for delivery at our hospital were taken into the trial. Blood samples were taken at 11–13 weeks of pregnancy and sent to the PerkinElmer lab for analysis. Results were expressed in Multiple of Median and patients having MOM value less than 0.5 were carefully observed till the delivery, and a thorough neonatal examination was done by a pediatrician.
Though Papp-A level in the first trimester of pregnancy (11–13 weeks) is an important predictor of future obstetric outcome, it has poor positive predictive value. Patients having a Papp-A level less than 0.5 MOM have a high risk for preterm delivery, fetal growth restriction, and stillbirths along with increased incidence of hypertensive disorders of pregnancy. A low Papp-A level is a useful indicator of risk of preterm delivery and future chance of development of pregnancy-induced hypertension.
Keywords: Papp-A in pregnancy, Preterm delivery, Fetal growth restriction
A low PAPP-A is defined as a maternal serum PAPP-A value <0.4 MOM, with increased frequency of adverse obstetrical outcomes noted below this level
PAPP-A is a large glycoprotein produced by the placenta and decidua thought to have several functions, including prevention of recognition of the fetus by the maternal immune system, matrix mineralization, and angiogenesis. A low PAPP-A is therefore descriptive of poor early placentation resulting in complications such as fetal growth restriction, fetal demise, preterm birth, and pre-eclampsia in the third trimester.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3984652/