Is there an association between previous multiple pregnancy terminations and adverse neonatal outcomes?

Association Between Multiple Pregnancy Terminations and Neonatal Outcomes

Multiple pregnancy terminations are associated with increased risk of adverse neonatal outcomes, including preterm delivery, cervical incompetence, placental abnormalities, and postpartum hemorrhage in subsequent pregnancies.

Impact of Previous Pregnancy Terminations on Subsequent Pregnancies

Preterm Birth Risk

• Each previous pregnancy loss is associated with a significant increased risk of preterm delivery: 14% increased risk at <37 weeks, 37% at <34 weeks, 45% at <32 weeks, and 77% at <28 weeks of gestation 1
• Women with a history of surgical pregnancy termination have an 11% increased risk of preterm delivery in subsequent pregnancies (adjusted OR 1.11,95% CI 1.02-1.20) 2
• The risk of preterm birth after second trimester loss is particularly high, with a pooled odds ratio of 4.52 (95% CI: 3.03-6.74) 3

Cervical Complications

• Previous surgical termination of pregnancy is associated with a 4.6-fold increased risk of cervical incompetence requiring cerclage treatment in subsequent pregnancies (adjusted OR 4.6,95% CI 2.9-7.2) 2
• The number needed to harm for cervical incompetence after surgical termination is approximately 1000 2

Placental Abnormalities

• Women with previous pregnancy terminations have a 42% increased risk of placental implantation or retention problems (adjusted OR 1.42,95% CI 1.29-1.55) 2
• These placental issues include placenta previa, placental abruption, and retained placenta, with a number needed to harm of 111 2

Hemorrhagic Complications

• Previous pregnancy termination is associated with a 16% increased risk of postpartum hemorrhage in subsequent pregnancies (adjusted OR 1.16,95% CI 1.08-1.25) 2
• The number needed to harm for postpartum hemorrhage is approximately 111 2

Dose-Response Relationship

• The risk of adverse neonatal outcomes increases in a dose-dependent manner with the number of previous pregnancy losses 1
• Women with multiple previous pregnancy losses have significantly higher rates of:
  • Hypertensive disorders of pregnancy 1
  • Diabetes mellitus (both pregestational and gestational) 1
  • Unplanned cesarean delivery 1
  • Perinatal death 1
  • Neonatal intensive care unit admissions 1
  • Neonatal hypoglycemia 1

Clinical Implications and Management

Risk Assessment

• Comprehensive obstetric history should include detailed information about previous pregnancy terminations, including number, gestational age, and method (surgical vs. medical) 4
• Gravidity and parity assessment should specifically document the number of previous pregnancy losses 4
• Previous adverse pregnancy outcomes should be carefully documented as they represent significant risk factors for subsequent pregnancies 4

Monitoring Recommendations

• Women with history of multiple pregnancy terminations should receive closer monitoring during subsequent pregnancies due to increased risk of complications 1
• Consider serial cervical length measurements to detect early signs of cervical incompetence 1
• Maintain high vigilance for signs of preterm labor, placental abnormalities, and other potential complications 1

Method of Termination Considerations

• Medical termination might be considered preferable to surgical methods when there is a choice between both, as surgical methods appear to have stronger associations with subsequent adverse outcomes 2
• The vast majority (90-95%) of pregnancy terminations in studies showing adverse outcomes were performed by surgical methods 2

Perspective on Risk

• While the relative risks are significantly increased, the absolute risks for individual adverse outcomes remain relatively small 2
• For any adverse outcome listed (preterm delivery, cervical incompetence, placental problems, or postpartum hemorrhage), the number needed to harm is approximately 63 2

Additional Considerations

• Multiple gestations themselves carry inherent increased risks of maternal morbidity and mortality compared to singleton pregnancies 5
• Women with multiple gestations have approximately twice the risk of maternal death compared to singleton pregnancies 5
• Multiple gestations are associated with increased risks of eclampsia (RR 3.0), preeclampsia (RR 2.2), and postpartum hemorrhage (RR 2.0) 5

By understanding these associations, clinicians can provide appropriate counseling and implement targeted monitoring strategies for women with histories of multiple pregnancy terminations to improve neonatal outcomes in subsequent pregnancies.