Risk factors
Risk factors for premature birth or stillbirth due to cervical weakness include:
diagnosis of cervical weakness in a previous pregnancy
previous preterm premature rupture of membranes
history of conization (cervical biopsy)
diethylstilbestrol exposure, which can cause anatomical defects, and
uterine anomaliesRepeated procedures (such as mechanical dilation, especially during late pregnancy) appear to create a risk. Additionally, any significant trauma to the cervix can weaken the tissues involved. Diagnosis
Diagnosis of cervical weakness can be challenging and is based on a history of painless cervical dilation usually after the first trimester without contractions or labor and in the absence of other clear pathology. In addition to history, some providers use assessment of cervical length in second trimester to identify cervical shortening using ultrasound. However, short cervical length has actually been shown to be a marker of preterm birth rather than cervical weakness. Other diagnostic tests that have been suggested which have not been validated include hysterosalpingography and radiographic imaging of balloon traction on the cervix, assessment of the patulous cervix with Hegar or Pratt dilators, the use of a balloon elastance test, and use of graduated cervical dilators to calculate a cervical resistance index.Normally, the cervix should be at least 30 mm in length. Cervical weakness is variably defined. However, a common definition is a cervical length of less than 25 mm at or before 24 weeks of gestational age.
Black palm is a common name for several species of plants in the family Arecaceae, including:

Astrocaryum standleyanum, native to Central and South America
Borassus flabellifer
Normanbya normanbyi (Queensland black palm)