Summary
Definition
History and exam
Key diagnostic factors
- history of preterm labor, cervical trauma, or induced abortion
- multifetal pregnancy and presence of maternal infection
- uterine contractions
- preterm premature rupture of membranes (PPROM)
- advanced cervical dilation
- cervical length <2 cm
Other diagnostic factors
- increased maternal or fetal heart rate
- nonspecific lower abdominal or back pain
- fever
- vaginal bleeding
Risk factors
- previous preterm labor
- previous cervical trauma
- previous induced abortion
- maternal infections
- multifetal pregnancies
- short cervical length
- positive fetal fibronectin test
- preterm premature rupture of membranes (PPROM)
- fetal abnormalities
- smoking
- body mass index (BMI) <19 kg/m^2
- social factors and ethnicity
- polyhydramnios
- domestic violence
- poor dental hygiene
- late-stage caesarean section
Diagnostic investigations
1st investigations to order
- nonstress cardiotocogram
- tocography
- transvaginal ultrasound of the cervix
- cervico-vaginal swab for fetal fibronectin
- CBC
- CRP
- urine dipstick
- urine microscopy, culture, and sensitivity
- high vaginal/rectal culture
Investigations to consider
- microscopy of vaginal fluid
- Kleihauer blood test
- urine toxicology screen
- insulin-like growth factor binding protein-1 (IGFBP-1) test
- placental alpha microglobulin-1 (PAMG-1)
Treatment algorithm
threatened preterm labor (TPTL)
preterm premature rupture of membranes (PPROM)
high risk of imminent delivery without PPROM
Contributors
Authors
Andrew H. Shennan, MD, FRCOG
Professor of Obstetrics
King's College London
London
UK
Disclosures
AHS has received a grant from Hologic to evaluate fetal fibronectin. AHS is an author of several references cited in this topic.
Joanna C. Girling, MA, MRCP, FRCOG
Consultant in Obstetrics and Gynaecology
West Middlesex University Hospital
London
UK
Disclosures
JCG declares that she has no competing interests.
Peer reviewers
Jo Trinder, MD
Consultant Obstetrician and Gynaecologist
St Michael's Maternity Wing
Bristol Royal Infirmary
Bristol
UK
Disclosures
JT has accepted honoraria for speaking to groups of midwives and doctors about miscarriage management.
Kirsty Dundas, MBChB, DCH, FRCOG
Consultant Obstetrician and Gynaecologist
Royal Infirmary of Edinburgh
Honorary Senior Lecturer
University of Edinburgh
Edinburgh
UK
Disclosures
KD declares that she has no competing interests.
Deidre Lyell, MD
Assistant Professor of Maternal-Fetal Medicine
Stanford University
Stanford
CA
Disclosures
DL declares that she has no competing interests.
Differentials
- Placental abruption
- Urinary tract infection (UTI)
- Ovarian cyst
More DifferentialsGuidelines
- Prediction and prevention of spontaneous preterm birth
- Practice bulletin no. 217: prelabor rupture of membranes
More GuidelinesPatient leaflets
Preeclampsia
Premature labor
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