Pelvic head asymmetry

The article was written by Dr. Dang Pham Quang Thai – Obstetrician and Gynecologist, Obstetrics and Gynecology Department – Share99 Times City International Health Hub.

Pelvic head asymmetry is the case where the fetus and the mother's pelvis are disproportionate to the placenta due to the enlarged pregnancy or due to abnormal mother's pelvis (narrow pelvis, distorted pelvis). Making the fetus not reach the mother's pelvis so it is not possible to give birth vaginally.

1. What is pelvic head asymmetry?

Difficult calving due to abnormal pelvic causes with a rate of almost 5%. Previously, difficult calving due to the cause of the pelvis was of particular interest to doctors, meticulous examination to cause premature labor,avoiding the risk of pelvic and fetal asymmetry if waiting for the fetus to be full months.

Today thanks to the advances of science in general and medicine in particular, including the contribution of nutrition, pediatrics, end of end of the world … difficult calving due to the increasingly decreasing pelvic causes. Thanks to the good work of assisted reproduction, including planned childbirth, good pregnancy management examination, continuous progress of resuscitation anesthesia, especially the technique of cesarean section through the lower uterus at the beginning of the twentieth century, the cesarean section is widely applied, the crown test is completed, so the calving is difficult due to the cause of the pelvis being diagnosed early and handled promptly and is no longer the cause.

The pelvis is divided into two parts: the large pelvis (also known as the great frame)and the small pelvis (or subframe).

Pelvic head asymmetry

Pelvic head asymmetry makes it difficult to give birth

To measure the diameters of the great frame people use obstetric compa (also known as compa Baudelocque). The great frame consists of 3 notable horizontal diameters:

  • Upper pot bimp diameter: 22.5cm.
  • Pot crested diameter: 25.5cm.
  • Femoral bipolar diameter: 27.5cm and has a front diameter of 17.5cm or Baudelocque diameter.

But the great frame has little important role in obstetrics and gynecology, but if the frame is too small, it will also entail a narrow frame that makes it difficult to lay.

The framing is pictured as a tubular shape consisting of three waists: the upper waist, the middle waist and the lower waist

There are many ways of dividing narrow types of pelvis. Among them are:

  • Symmetrical narrow pelvis: Fully symmetrical and balanced narrow pelvis, flat pelvis, horizontal narrow pelvis, flat and narrow pelvis.
  • Asymmetrically narrowpelvis: including pelvises with uneven narrow diameters, deformed pelvises common in people with deformities or injuries such as: dislocation of the hip,hip tuberculosis or scoliosis … Abnormal pelvises after bone orthopedics.

Symmetrically narrow pelvis

Symmetrically narrow pelvis

2. How to handle when there is asymmetry of the pot head

If pregnancy and pelvis asymmetry is suspected and if the crown is the crown " crowntest" it will be reasonable to proceed. To avoid possible complications for the mother and for pregnancy. Pelvises with suspected abnormalities should be monitored for calving at the site of surgery and should be meticulously examined during pregnancy management.

Today, premature labor in narrow pelvises is no longer used, as cesarean section surgery is complete with clear indicators and avoids the burden on pediatrics, having to care for premature babies for whom their future of development is an outcturning for each ethnic group.

It is a test of whether the fetus is reached, when the fetus is a clearly specialized crown and the physician suspects fetal asymmetry and the mother's pelvis.

2.1. The indicators of the test of the crown

The pelvis is limited to normal fetuses: the test is conducted in pelvises with a protruding diameter – defenders from 8.5 to 10.5cm. The pregnancy is crowned, the pregnancy is of normal weight and has had real labor.

Suspected pregnancy and pelvic asymmetry: this specify already includes the pelvic index limited above. The pelvis here can be normal that the pregnancy is large or even spacious but the pregnancy is too large, the physician suspects there is a disproportionate pregnancy and pelvis. But always keep in mind that the test is carried out only when there is real labor and the fetus must be the crown.

2.2. Conditions for testing the crown

The pregnancy must be crowned, which is a prerequisite for the forensic test. You have to work where you can have a pregnancy surgery. The crown test can be successful but can also fail, especially when conducting there may be accidents, risks such as: vegetable cord sassing, rupture of the uterus or pregnancy failure… If it takes time to transfer the maternity, there will be an accident for the mother and for the pregnancy. And if more cautious, it is advisable to do the test when the facility has good qualifications and means of resuscitation.

  • There must have beenreal labor: Only tested for the crown when the uterus opened > 4cm in humans and > 5cm in humans compared.
  • There must be close and careful monitoring:It is best to do and monitor regularly by a certain person on Continuous Monitoring. Especially when prostaglandin or oxytocin is used. All fluctuations on the part of the mother and the fetus must be meticulously documented and analyzed.

Determination of the middle longitudinal joint and vaginal examinations

Determination of the middle longitudinal joint and vaginal examinations

2.3. How to conduct the test of the crown

  • Amniotic puncture

It's the first impact of the test. Immediately after that it is necessary to assess the amount of amniotic fluid, the color of the amniotic fluid, the progress of the fetus, the fetal condition through the fetal heart and the contraction of the uterus and possible complications. After amniotic puncture: vegetable cord sa,sa chi … After the amniotic fluid is thoroughly checked, so, the type to decide whether to continue the forensic test or have to have a cesareansection if the throne, that is not favorable (frontal, forehead …).

  • Monitoring of uterus contractions

Uterus contractions are the main motivation of labor, so monitoring of uterus contractions is necessary and important. It is best to constantly monitor on monitoring one will evaluate the whole trio: intensity, amplite and frequency. The activity of the uterus must be consistent with the stage of labor and in harmony with the opening of the cervical .

  • Monitor mother's condition

The mother's health directly affects the fetus through vegetable and fetal veins, so it is necessary to always closely monitor the mother's condition through mental and physical health: pulse, temperature, blood pressure … The test of the crown is successful or not, there is no small part of the cooperation of the maternity with the physician.

  • Fetal status monitoring

Best track on Continuous Monitoring. The condition of the fetus is shown by how the fetal heart rate changes: normal pathology or the appearance of a contraction of the uterus. The crown must be stopped immediately when there is apparent pregnancy failure.

It is also possible to monitor the condition of the pregnancy by classical methods if there is no monitoring such as listening to the fetal heart with a wooden tube, tracking the coins in the amniotic fluid, the sensation of movement of the mother's fetus … But in general these methods are either less accurate or un objective.

Monitor the mound

Monitor fetal status through monitoring
  • Monitoring and evaluatiy the progress of the pregnancy

The purpose of the test is to test whether the pregnancy is down, shortlisted and booked, that is, whether to give birth under the lower line, so monitoring the birth of the fetus is essential and it is necessary to conduct regular external examinations or vaginal visits to avoid cervical edema that makes it difficult to open the cervical neck and infection upstream because we have now poked the amniotic head.

  • Cervical Open Tracking

If the test is successful, the cervical will open harmoniously over time, the pregnancy will pass and the calving is carried out through the lower line. Many times the test fails only because the cervical cause is not open (which clinical physicians are accustomed to calling the cervical does not progress); today in advanced countries thanks to modern means of monitoring, adequate medicines are very rarely failed when testing for the cause of not opening the cervical.

  • Duration of french experiments

Usually the doctors agreed to take the timeline of 06 hours. Because after 06 hours of amniotic puncture, the test continues to be prolonged doctors worry that there will be potential infections or pregnancy failure. But here the time is also understood and applied flexible depending on the general situation: if you have 06 hours of french testing but have to wait another 30 minutes or 1 hour, the birth will end with a lower sugar without any great risk for the mother and for the fetus, it is still possible to continue the experiment. However, there are also cases where only 01 to 2 hours later, the physician has assessed whether to continue or stop the test.

There are even cases where the amniotic fluid has been completed with pregnancy failure or vegetable cord prolife order, it must be stopped immediately to test the crown to prescribe a cesarean section.

Pregnancy examination

Pregnant mother should go to the pregnancy check-up according to the doctor's appointment

Share99 International Health Hub is one of the hospitals that not only ensures professional quality with a team of leading doctors, modern technology equipment system but also stands out for comprehensive and professional medical examination, consultation and treatment services; civilized, polite, safe and sterilized medical examination and treatment space.

For direct advice, please click hotline number or register online HERE. In addition, you can register for remote consultation HERE


  • Pregnancy failure and pregnancy failure during labor: Tell-how signs
  • Procedures for performing newborn resuscitation
  • How does pregnancy failure work?

About: John Smith

b1ffdb54307529964874ff53a5c5de33?s=90&r=gI am the author of I had been working in Vinmec International General Hospital for over 10 years. I dedicate my passion on every post in this site.


Leave a Comment