1. SON 2122 Obstetrical Sonography Part II Chapter 18- Ultrasound evaluation of the cervix HHHOLDORF

2. Ultrasound of the Cervix

3. Outline  Patient History  Cervical Anatomy and Histology  Functionality  Normal cervical Length/measurements  Normal cervical Position  The Lower Uterine Segment  Cervical Incompetence/insufficient cervix  Investigating the cervix  Insufficient Cervix (again)  Cervical funneling  The Hourglass sign  Cervical Cerclage  Pre—term labor  PROM  Placental Previa  Definitions

4. Prior to beginning the ultrasound examination, it is helpful for the sonographer to obtain a brief patient history. Information should include:  the first day of the last menstrual period (LNMP or LMP)  Results of any pregnancy tests  The presence of any clinical problems (pain, fever, bleeding, etc.)  Any pertinent medical history  the clinical estimation of the duration of the pregnancy

5.  The cervix (from Latin "neck") is the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall. Approximately half its length is visible with appropriate medical equipment; the remainder lies above the vagina beyond view. It is occasionally called "cervix uteri", or "neck of the uterus".  The portion projecting into the vagina is referred to as the ectocervix. On average, the ectocervix is 3 cm long and 2.5 cm wide. It has a convex, elliptical surface and is divided into anterior and posterior lips.

6. Cervical diagram

7. External os  The ectocervix's opening is called the external os. The size and shape of the external os and the ectocervix varies widely with age, hormonal state, and whether the woman has had a vaginal birth. In women who have not had a vaginal birth the external os appears as a small, circular opening. In women who have had a vaginal birth, the ectocervix appears bulkier and the external os appears wider, more slit-like and gaping.

8. Endocervical canal  The passageway between the external os and the uterine cavity is referred to as the endocervical canal. It varies widely in length and width, along with the cervix overall. Flattened anterior to posterior, the endocervical canal measures 7 to 8 mm at its widest in reproductive- aged women.

9. Internal os  The endocervical canal terminates at the internal os which is the opening of the cervix inside the uterine cavity

10. The internal and external os

11. Histology  The epithelium of the cervix is varied. The ectocervix (more distal, by the vagina) is composed of stratified Squamous epithelium The endocervix (more proximal, within the uterus) is composed of simple columnar epithelium.  The area adjacent to the border of the endocervix and ectocervix is known as the 'transformation zone. The Transformation zone undergoes metaplasia numerous times during normal life. When the endocervix is exposed to the harsh acidic environment of the vagina it undergoes metaplasia to Squamous epithelium which is better suited to the vaginal environment. Similarly when the ectocervix enters the less harsh uterine area it undergoes metaplasia to become columnar epithelium.  Times in life when this metaplasia of the transformation zone occurs: - puberty; when the endocervix everts (moves out) of the uterus - with the changes of the cervix associated with the normal menstrual cycle - post-menopause; the uterus shrinks moving the transformation zone upwards  All these changes are normal and the occurrence is said to be physiological.  However all this metaplasia does increase the risk of cancer in this area - the transformation zone is the most common area for cervical cancer to occur.  At certain times of life, the columnar epithelium is replaced by metaplastic Squamous epithelium, and is then known as the transformation zone.  Nabothian cysts are often found in the cervix.

12.  The Pap test (AKA Pap smear, cervical smear, or smear test) is a method of cervical screening used to detect potentially pre-cancerous and cancerous processes in the cervix.  A Pap smear is performed by opening the vaginal canal with a speculum, then collecting cells at the outer opening of the cervix at the transformation zone (where the outer squamous cervical cells meet the inner glandular endocervical cells).  The collected cells are examined under a microscope to look for abnormalities.

13. Cervical position  After menstruation and directly under the influence of estrogen, the cervix undergoes a series of changes in position and texture. During most of the menstrual cycle, the cervix remains firm, like the tip of the nose, and is positioned low and closed.  However, as a woman approaches ovulation, the cervix becomes softer, and rises and opens in response to the high levels of estrogen present at ovulation. These changes, accompanied by the production of fertile types of cervical mucus, support the survival and movement of sperm.

14. Functionality  During menstruation the cervix stretches open slightly to allow the endometrium to be shed. This stretching is believed to be part of the cramping pain that many women experience. Evidence for this is given by the fact that some women's cramps subside or disappear after their first vaginal birth because the cervical opening has widened.  During childbirth, contractions of the uterus will dilate the cervix up to 10 cm in diameter to allow the fetus to pass through.

15. Normal cervical length (30mm or 3cm)  CL in the first trimester has no clinical value  CL normally decreases slightly between 20 and 32 weeks and more considerably after 32 weeks.  between 22 and 30 weeks, CL follows a normal bell-shaped curve:  5 th percentile @ 20mm  10 th percentile @ 25 mm  50 th percentile @ 35 mm  90 th percentile @ 45 mm  The median CL is 40 mm before 22 weeks, 35 mm at 22 to 32 weeks, and 30 mm after 32 weeks. CL is not affected much by maternal age, race, gravidity or parity.  Cervical shortening is indicated if CL is less than 25 mm (2.5 cm) between 22 and 30 weeks.

16.  CL (cervical length) is measured from internal to external os.  -Evaluated for shortening (effacement) and Funneling.  -Measurements of the cervix can be preformed after 15 weeks gestational age, when the cervix normally becomes distinct from the LUS.

18. Lower Uterine Segment  Lower uterine segment(LUS) – does not have a definite sonographic identity prior to or during the different stages of labor and delivery. Can be considered the portion of the uterine body closet to the inner os of the cervix.  LUS and the internal os are evaluated with Color Doppler for the possibility of vasa previa (blood vessels in that region which could cause hemorrhaging with vaginal delivery).

19. Lower Uterine Segment

20.  The LUS-lower uterine segment – does not have a definite sonographic identity prior to or during the different stages of labor and delivery. Can be considered the portion of the uterine body closet to the inner os of the cervix.  Techniques to evaluate the cervix include TAS, TPS, and EVS. (Trans-abdominal, Trans-Perineal- and Endo-vaginal sonography.  CL (cervical length) is measured from internal to external os.  Evaluated for shortening (effacement) and Funneling.  LUS and the internal os are evaluated with Color Doppler for the possibility of vasa previa (blood vessels in that region which could cause hemorrhaging with vaginal delivery.

21. Cervical Incompetence/Insufficiency Cervical incompetence is a condition in which a pregnant woman's cervix begins to dilate (widen) and efface (thin) before her pregnancy has reached term. Cervical incompetence is a cause of miscarriage and preterm birth in the second and third trimesters.  In a woman with cervical incompetence, dilation and effacement of the cervix occur without pain or uterine contractions. Instead of happening in response to uterine contractions, as in normal pregnancy, these events occur because of weakness of the cervix, which opens under the growing pressure of the uterus as pregnancy progresses. If the changes are not halted, rupture of the membranes and birth of a premature baby can result. It is thought to cause as many as 20—25% of miscarriages in the second trimester. Risk Factors  Risk factors for premature birth or stillbirth due to cervical incompetence include:  diagnosis of cervical incompetence in a previous pregnancy,  previous preterm premature rupture of membranes,  history of cervical biopsy  *DES exposure, which can cause anatomical defects, and  uterine anomalies. Treatment  Cervical incompetence is not generally treated except when it appears to threaten a pregnancy. Cervical incompetence can be treated using cervical Cerclage, a surgical technique that reinforces the cervical muscle by placing sutures above the opening of the cervix to narrow the cervical canal.

22. DES (Diethylstilbestrol) exposure  Diethylstilbestrol (DES) is a synthetic form of the female hormone estrogen. It was prescribed to pregnant women between 1940 and 1971 to prevent miscarriage, premature labor, and related complications of pregnancy. The use of DES declined after studies in the 1950s showed that it was not effective in preventing these problems.  DES is linked to a rare cancer called clear cell adenocarcinoma (CCA) in a very small number of daughters of women who used DES during pregnancy.  This cancer of the vagina and cervix usually occurs in DES-exposed daughters in their late teens or early 20s.

23. Techniques to evaluate the cervix  include Trans abdominal Sonography, Trans Perineal Sonography and Endovaginal Sonography.  Focal uterine contractions, fibroids, and even Nabothian cysts can interfere with cervical interpretation.

24.  TA evaluation-  Full bladder. Pitfalls: Overdistended bladder can elongate the cervix. Interference from the presenting fetal part can interfere with adequate cervical visualization.  Large maternal body habitus can result in inferior image quality.  Trans-perineal / Trans Labial evaluation:  TAS transducer is placed on the anterior perineum between the labia minora and the vagina. The transducer may be covered with a glove or plastic wrap.  Empty or near empty bladder  TPS may be especially valuable in patients with ruptured membranes when EVS is contraindicated.  Pitfalls include rectal air and packed fecal matter  Difficult to technically master

26. Transvaginal approach of investigating the cervix

27.  Trans-perineal /Trans Labial evaluation:  TAS transducer is placed on the anterior perineum between the labia minora and the vagina. The transducer may be covered with a glove or plastic wrap.  Empty or near empty bladder  TPS may be especially valuable in patients with ruptured membranes when EVS is contraindicated.  Pitfalls include rectal air and packed fecal matter  Difficult to technically master

28. Transperineal/Translabial approach of evaluating the cervix

29.  Measurements of the cervix can be preformed after 15 weeks gestational age, when the cervix normally becomes distinct from the LUS.  It should be noted that even with all three techniques of cervical evaluation (TAS, TPS, and EVS), focal uterine contractions, fibroids, and even Nabothian cysts can interfere with cervical interpretation.  TA evaluation-  Full bladder. Pitfalls: Overdistended bladder can elongate the cervix. Interference from the presenting fetal part can interfere with adequate cervical visualization.  Large maternal body habitus can result in inferior image quality

30. Endovaginal Evaluation  Preferred technique for evaluation of the cervix and measurement of cervical length.  Rectal contents do not interfere.  The cervix may be adequately evaluated in the third trimester in 99% of patients.  bladder empty  Excessive pressure can artificially increase the CL.  Sagittal long axis view of the cervix should be obtained from the internal os to the external os.  ROT: cervix should occupy one-half to two-thirds of the image display area.  Three measurements should be taken  Abdominal pressure applied t the uterine fundus can sometimes be helpful to show the internal os more clearly and can sometimes elicit a funnel (cervical stress test).

31.  The LUS-lower uterine segment – does not have a definite sonographic identity prior to or during the different stages of labor and delivery. Can be considered the portion of the uterine body closet to the inner os of the cervix.  Techniques to evaluate the cervix include TAS, TPS, and EVS. (Trans-abdominal, Trans-Perineal- and Endo-vaginal sonography.  CL (cervical length) is measured from internal to external os.  Evaluated for shortening (effacement) and Funneling.  LUS and the internal os are evaluated with Color Doppler for the possibility of vasa previa (blood vessels in that region which could cause hemorrhaging with vaginal delivery.

32.  Endovaginal Evaluation  Preferred technique for evaluation of the cervix and measurement of cervical length.  Rectal contents do not interfere.  The cervix may be adequately evaluated in the third trimester in 99% of patients.  bladder empty  Excessive pressure can artificially increase the CL.  Sagittal long axis view of the cervix should be obtained from the internal os to the external os.  ROT: cervix should occupy one-half to two-thirds of the image display area.  Three measurements should be taken

33. ENDO VAG SCANNING CONT…  Abdominal pressure applied to the uterine fundus can sometimes be helpful to show the internal os more clearly and can sometimes elicit a funnel (cervical stress test).  Pitfalls:  Operator and interpreter dependent.  bladder must be empty  excessive probe pressure can mask funneling artificially elongate the cervix (false negative result)  If there is evidence of LUS contraction, wait for it to subside.

34. Pitfalls of Endovaginal Evaluation  Operator and interpreter dependent.  bladder must be empty  excessive probe pressure can mask funneling artificially elongate the cervix (false negative result)  If there is evidence of LUS contraction, wait for it to subside.

35.  The median CL is 40 mm before 22 weeks, 35 mm at 22 to 32 weeks, and 30 mm after 32 weeks. CL is not affected much by maternal age, race, gravidity or parity.  Cervical shortening is indicated if CL is less than 25 mm between 22 and 30 weeks.  What all this means is that the magic number is 30 mm or 3 cm.  There are other cervical measurements from other studies, but forget them.

36. The Abnormal cervix

37. Incompetent cervix Next slide: Funneling of the cervix

39. Incompetent/Insufficient Cervix  AKA painless premature dilation of the cervix, it is the inability of the cervix to prevent the premature expulsion of the uterine contents. Incompetent cervix may be acquired or congenital, and is most frequently related to cervical trauma.  Surgical repair of cervical tears following previous vaginal deliveries may be one cause.  Habitual abortion in the 2 nd trimester may be the only clinical feature.

40.  An incompetent cervix is identified by the following sonographic criteria:  Cervical length < 3 cm before 34 weeks  Cervical dilation > 2 cm in the 2 nd trimester  bulging membranes (such as PROM)

41. Incompetent Cervix-Sonographic Findings:  Sonographic findings:  Cervical length <3cm before 34 weeks  Cervical dilation with a width >2 cm in 2 nd trimester- MOST RELIABLE  Firm diagnosis cannot always be made using Sonography  Diagnosis based on history and clinical findings  Bulging membranes  Bladder distention may cause false negative diagnosis

42. Cervical insufficiency/incompetent cervix  DEF: structural weakness of cervical tissue that causes or contributes to the loss of an otherwise healthy pregnancy.

43. FUNNELING  DEF: the sonographic observation of protrusion of the amniotic fluid and intact membranes into an open internal os.  Cervical effacement is shortening and thinning of the cervix; it is one of the first steps in the birthing process and precedes labor by four to eight weeks.  Three funneling shapes (Y, V, U) have been described based on the severity of funneling, however, the distinctions between the shapes are somewhat subjective.  In general, the risk of Preterm birth (PTB) increases with funnel shape (U-shaped funneling is more likely to be associated with PTB than V-shaped funneling.

45. “Hourglass Sign”  With dilation of the cervix, the amniotic-chorionic membrane herniates into the cervix and bulges. In the most severe cases, the membranes may bulge into the vagina with fetal parts or loops of umbilical cord, and delivery must take place.  The US appearance of bulging membranes in the cervix and vagina has been referred to as the HOURGLASS SIGN.

48. Bulging membranes  The cervix begins to thin out and widen without any contractions or labor.  The membranes surrounding the fetus bulge down into the opening of the cervix until they break, resulting in the loss of the baby or a very premature delivery.  The fetal membrane are membranes associated with the developing fetus. The two chorioamniotic membranes are the amnion and chorion, which make up the amniotic sac that surrounds and protects the fetus.

49. Cervical Cerclage  Refers to a variety of surgical procedures in which sutures, wires, or synthetic tape are used to reinforce the cervix.  Intended to mechanically increase the strength of the cervix to prevent the prolapsed of the fetal membranes into the vagina (bulging membranes), PTB, and fetal loss.  Note: It has been reported that a short cervix can be caused by factors other than structural weakness and can be treated successfully with medication.

50.  A cervical Cerclage is a suture that can be placed in the cervix to prevent dilation and effacement in patients who have a history of incompetent cervix

51. Cervical insufficiency/incompetent cervix  DEF: structural weakness of cervical tissue that causes or contributes to the loss of an otherwise healthy pregnancy. Cervical Cerclage  Refers to a variety of surgical procedures in which sutures, wires, or synthetic tape are used to reinforce the cervix.  Intended to mechanically increase the strength of the cervix to prevent the prolapsed of the fetal membranes into the vagina (bulging membranes), PTB, and fetal loss.  Note: It has been reported that a short cervix can be caused by factors other than structural weakness and can be treated successfully with medication.

52. Pre-Term Labor Defined as the onset of labor before 37 weeks.  Etiologies include:  Previous uterine surgery  Uterine anomalies  Maternal stress  Heavy cigarette smoking  Multiple gestations  Polyhydramnios  Ante partum bleeding, from previa, abruption

53. Preterm labor (PTL)  Defined as regular uterine contractions that cause progressive dilation of the cervix prior to a GA of 37 completed weeks. It is the second most common cause of Perinatal mortality next to congenital anomalies.

54. Spontaneous Preterm Birth (PTB)  before 37 weeks (AKA prematurity)  After 20 weeks gestational age, the CL shortens in prep for term labor.  A CL less than 25 mm at 24 weeks is the best of all the predictors of PTB evaluated in twins.  Most of the data collected and the questions on the boards will deal with Singletons and CL. Twins…not so much. Triplets… not so much. The data is not good enough to draw solid conclusions from.

55. Premature Rupture of Membranes PROM  Premature rupture of membranes is defined as the spontaneous rupture of the membranes prior to the onset of labor.  Clinical signs are the passage of a large amount of watery fluid from the vagina  Sonographic findings are Oligohydramnios with a normal fetal bladder

56. Homework  Show several different images of PROMs

57. Placenta previa  Placental Previa is an obstetric complication in which the placenta has attached to the uterine wall close to or covering the cervix. It can some times occur in the latter part of the first trimester, but usually during the second or third. It is a leading cause of antepartum hemorrhage (vaginal bleeding). It affects approximately 0.5% of all labors.

58. Pathophysiology  No specific cause of placenta previa has yet been found but it is hypothesized to be related to abnormal vascularization of the endometrium caused by scarring or atrophy from previous trauma, surgery, or infection.  In the last trimester of pregnancy the isthmus of the uterus unfolds and forms the lower segment. In a normal pregnancy the placenta does not overlie it, so there is no bleeding. If the placenta does overlie the lower segment, it may shear off and a small section may bleed.  Women with placenta previa often present with painless, bright red vaginal bleeding. This bleeding often starts mildly and may increase as the area of placental separation increases. Previa should be suspected if there is bleeding after 24 weeks of gestation. Abdominal examination usually finds the uterus non-tender and relaxed.  The proper timing of an examination in theatre is important. If the woman is not bleeding severely she can be managed non- operatively until the 36th week. By this time the baby's chance of survival is as good as at full term.

59. Placenta previa is classified according to the placement of the placenta:  Type I or low lying: The placenta encroaches the lower segment of the uterus but does not infringe on the cervical os.  Type II or marginal: The placenta touches, but does not cover, the top of the cervix.  Type III or partial: The placenta partially covers the top of the cervix.  Type IV or complete: The placenta completely covers the top of the cervix. This type of previa often will not bleed until labour starts. Placenta previa is itself a risk factor of placenta Accreta.

60. Placenta Previa

61. Know the following definitions:  Hydrocolopos: is literally “water in the vagina.” It is often used as a generic term for the collection of fluid in the vagina or uterine cavity.  Hematometra is literally “Blood in the uterus.”  Hydrometrocolopos is literally “Water in the uterus and vagina.”  Pyometrocolopos is literally “pus in the uterus and vagina.

62.  The most common cause of Hydrocolopos in the pediatric patient is an imperforate hymen.

63. The sonographic findings of Hydrocolopos include:  a hypoechoic distention of the endometrial cavity and or vagina  posterior acoustic enhancement  internal echoes may be present, representing debris or clot  Hydronephrosis may be present in cases of severe obstruction

64.  Spontaneous Preterm Birth (PTB)  before 37 weeks (AKA prematurity)  After 20 weeks gestational age, the CL shortens in prep for term labor.  A CL less than 25 mm at 24 weeks is the best of all the predictors of Preterm Birth evaluated in twins.  Most of the data collected and the questions on the boards will deal with Singletons and Cervical Length. Twins…not so much. Triplets… not so much. The data is not good enough to draw solid conclusions from.

65.  Preterm labor (PTL)  Defined as regular uterine contractions that cause progressive dilation of the cervix prior to a GA of 37 completed weeks. It is the second most common cause of Perinatal mortality next to congenital anomalies.

66. Benign Cervical/Gynecological conditions  warts  fibroids  nabothian cysts  Gartner duct cysts  leiomyosarcomas  adenomyosis  endometrial polyps  endometrial hyperplasia  ovarian cysts  epithelial tumors  germ cell tumors  endometriosis.

67. Malignant cervical/Gynecological conditions  Endometrial carcinoma  Cervical Cancer

68. Cervical cancer  The cervix may be affected by cervical cancer, a particular form of cancer which is detectable by cytological study of epithelial cells removed from the cervix in a process known as the pap smear. Evidence now shows that those with exposure to HPV (human papilloma virus) are at increased risk for cervical cancer. These viruses are related to the viruses that causes warts. The incidence of new cases of cervical cancer in the United States was observed to be 7 per 100,000 women in 2004.

69. Cervical Cancer

70. Think Tank The Cervix

71. Question one  The portion of the cervix that projects into the vagina is referred to as the what?

72. Question two  The ectocervix's opening is called the what?

73. Question three  The passageway between the external os and the uterine cavity is referred to as the what?

74. Question four  Number three terminates at the _________which is the opening of the cervix inside the uterine cavity

75. Question five  _____________ cysts are often found in the cervix.

76. Question six  Some women's cramps subside or disappear after their first vaginal birth because the cervical opening has widened.  True or False

77. Question seven  During childbirth, contractions of the uterus will dilate the cervix up to ____cm in diameter to allow the fetus to pass through.

78. Question eight  CL in the first trimester has a significant clinical value  True or false

79. Question Nine  CL normally decreases slightly between 20 and 32 weeks and more considerably after 32 weeks.  True for false

80. Question 10  The median CL is 40 mm before 22 weeks, 35 mm at 22 to 32 weeks, and 30 mm after 32 weeks. CL is not affected much by maternal age, race, gravidity or parity.  ___________mm

81. Question 11 CL is affected by which of the following:  A. maternal age  B. Race  C. Gravidity  D. Parity  E. None of the above

82. Question 12  Cervical shortening is indicated if CL is less than ______ between 22 and 30 weeks.

83. Question 13  CL (cervical length) is measured from where to where?

84. Question 14  This area does not have a definite sonographic identity prior to or during the different stages of labor and delivery. Can be considered the portion of the uterine body closet to the inner os of the cervix.

85. Question 15  List the three Techniques used to evaluate the cervix

86. Question 16  A condition in which a pregnant woman's cervix begins to dilate (widen) and efface (thin) before her pregnancy has reached term.

87. Question 17 List at least two Risk Factors of number 16

88. Question 18  Measurements of the cervix can be preformed after ___ weeks gestational age.

89. Question 19  Habitual abortion in the 2 nd trimester may be the only clinical feature of this.

90. Question 20  What is being identified by the following sonographic criteria?  length < 3 cm before 34 weeks  dilation > 2 cm in the 2 nd trimester  bulging membranes (such as PROM)

91. Question 21  The sonographic observation of protrusion of the amniotic fluid and intact membranes into an open internal os.  Cervical effacement is shortening and thinning of the cervix; it is one of the first steps in the birthing process and precedes labor by four to eight weeks.  The above is describing what cervical condition?

92. Question 22  Three shapes (Y, V, U) have been described based on the severity of What?

93. Question 23  The US appearance of bulging membranes in the cervix and vagina has been referred to as the _________SIGN.

94. Question 24  Refers to a variety of surgical procedures in which sutures, wires, or synthetic tape are used to reinforce the cervix.

95. Question 25  Pre-Term labor is defined as the onset of labor before a.25 weeks b.30 weeks c.35 weeks d.37 weeks

96. Question 26 Define:  Hydrocolopos:

97. Question 27 Define:  Hematometra

98. Question 28 Define:  Hydrometrocolopos