Prior OB/GYN history |
- Prior PTB (especially multiple PTBs or PTB at an early gestational age)
|
- Prior cervical surgery (eg, cone biopsy, LEEP)
|
|
|
Maternal demographics |
|
- Non-Hispanic Black race, Indigenous women
|
- Lower educational level (eg, <12 grades)
|
|
- Lower socioeconomic status
|
- Short interpregnancy interval (eg, <18 months)
|
- Other social factors (eg, poor access to medical care, physical abuse, acculturation)
|
Nutritional status/physical activity |
- BMI <18.5 kg/m2 or prepregnancy weight <50 kg (<120 lb)
|
|
- Long working hours (eg, >80 hours/week)
|
- Hard physical labor (eg, shift work, standing >8 hours)
|
Current maternal/pregnancy characteristics |
- Conception by assisted reproductive technology (eg, IVF)
|
|
- Fetal disorder (eg, chromosome anomaly, structural abnormality, growth restriction, death, etc)
|
- Vaginal bleeding (eg, 1st and 2nd trimester, placenta previa, abruption)
|
|
- Maternal medical conditions (eg, hypertension, diabetes, thyroid disease, asthma, etc)
|
- Maternal abdominal surgery during pregnancy
|
- Psychological issues (eg, stress, depression, unplanned pregnancy)
|
- Substance use:
- Smoking (eg, tobacco)
- Heavy alcohol consumption
- Cocaine
- Heroin
|
- Infection:
- Bacterial vaginosis
- Trichomoniasis
- Chlamydia
- Gonorrhea
- Syphilis
- Urinary tract (eg, asymptomatic bacteriuria, pyelonephritis)
- Severe viral infection
- Intrauterine infection
|
- Short cervical length between 14 and 28 weeks
|
- Positive fFN between 22 and 34 weeks
|
|