Referral to Maternal-Fetal Medicine for Advanced Maternal Age
Patients should be referred to Maternal-Fetal Medicine (MFM) specialists at age 35 years or older at the time of delivery for singleton pregnancies, and at age 33 years or older for twin pregnancies. 1
Definition and Rationale for Referral
Advanced Maternal Age (AMA) is defined as:
- Age ≥35 years at the time of delivery for singleton pregnancies
- Age ≥33 years at the time of delivery for twin pregnancies
The primary reason for MFM referral at these age thresholds is to discuss testing options for identifying age-related chromosomal anomalies 1. Women of advanced maternal age have increased risks of:
- Chromosomal abnormalities (particularly trisomies)
- Spontaneous miscarriage
- Preterm labor
- Gestational diabetes mellitus
- Pre-eclampsia
- Stillbirth
- Cesarean delivery 2, 3
Risk Assessment and Management
Genetic Counseling and Testing
- MFM specialists provide counseling regarding available screening and diagnostic testing options
- Options typically include:
- Non-invasive prenatal testing (NIPT)
- First trimester combined screening
- Quad screening
- Amniocentesis
- Chorionic villus sampling (CVS)
Monitoring for Pregnancy Complications
MFM specialists will typically implement enhanced surveillance for:
- Fetal growth restriction (FGR)
- Pre-eclampsia
- Gestational diabetes
- Placental dysfunction
Special Considerations for Multiple Gestations
For twin pregnancies, the threshold for MFM referral is lower (age ≥33) due to:
- Higher baseline risk of complications
- More complex management requirements
- Increased risk of chromosomal abnormalities 1
Common Pitfalls to Avoid
Delayed referral: Waiting until complications develop before referring to MFM can miss opportunities for early intervention and planning.
Overlooking twin pregnancies: Remember that the age threshold for MFM referral is lower (33 years) for twin gestations 1.
Focusing only on genetic risks: While chromosomal abnormalities are a primary concern, AMA also increases risks of other pregnancy complications that benefit from MFM oversight.
Assuming all AMA patients need invasive testing: Modern non-invasive screening options may be appropriate for many patients, and MFM specialists can help guide this decision-making process.
Conclusion
The evidence clearly establishes age 35 for singleton pregnancies and age 33 for twin pregnancies as the thresholds for MFM referral for advanced maternal age 1. This referral enables appropriate counseling about genetic testing options and enhanced monitoring for potential pregnancy complications associated with advanced maternal age.