What is the greatest risk for a 37-year-old primigravid woman at 12 weeks' gestation with a triplet gestation?

Greatest Risk for a 37-Year-Old Primigravid Woman with Triplet Gestation

The patient with a triplet gestation at 12 weeks is at greatest risk for preterm labor (option D).

Background and Risk Assessment

Triplet gestations carry significantly higher risks compared to singleton pregnancies, with preterm birth being the most common and serious complication. Multiple factors in this case contribute to this risk:

• Triplet gestation (primary risk factor)
• Advanced maternal age (37 years)
• Primigravid status
• IVF conception
• Long work hours (10-12 hours daily)

Evidence for Preterm Labor as Greatest Risk

The evidence strongly supports preterm labor as the predominant risk in triplet gestations:

• Multiple gestations have significantly higher rates of spontaneous preterm birth, with triplets having even greater risk than twins 1
• MC diamniotic twin pregnancies have a 53.1% incidence of spontaneous preterm birth compared with 44.9% for DC pregnancies - triplets would have even higher rates 1
• Preterm labor is the leading cause of perinatal morbidity and mortality in the United States 2

Risk Analysis of All Options

Preterm Labor (D)

• Highest risk for triplet gestations
• Studies show extremely high rates of preterm delivery in triplet pregnancies:
  • In a study of triplet pregnancies, even with cerclage, delivery occurred at a mean of 32.8±2.4 weeks 3
  • Without intervention, triplet pregnancies have a 95.5% prematurity rate 4

Abruptio Placentae (A)

• While placental abruption risk is increased in multiple gestations, it remains less common than preterm labor
• Placenta abruption has an adjusted odds ratio of 1.87-2.14 in multiple gestations 1, which is significant but substantially lower than preterm labor risk

Hepatitis B (B) and HIV Infection (C)

• No increased risk based on triplet gestation
• No evidence in the provided literature suggesting these infections are particularly associated with multiple gestations

Uterine Rupture (E)

• Rare in primigravid patients without prior uterine surgery
• No specific increased risk in triplet gestations without other risk factors
• Patient has no history of uterine surgery

Management Considerations

Given the high risk of preterm labor, management should focus on:

1. Regular cervical length monitoring:

   • Transvaginal ultrasound assessment of cervical length
   • Cervical length <1.5 cm is predictive of preterm labor in multiple gestations 1

2. Close fetal surveillance:

   • More frequent ultrasound examinations than singleton pregnancies
   • Assessment of growth, amniotic fluid, and Doppler studies

3. Consideration of antenatal corticosteroids:

   • Administration if preterm delivery appears imminent
   • SMFM suggests consideration for antenatal corticosteroids in multiple gestations 1

4. Avoidance of activity restriction:

   • Evidence does not support routine activity restriction for preventing preterm birth
   • Some studies suggest activity restriction may actually increase preterm birth risk 1

Conclusion

Among the options presented, preterm labor represents the most significant risk for this 37-year-old primigravid woman with triplet gestation at 12 weeks. Management should focus on close monitoring and appropriate interventions to optimize outcomes for both mother and fetuses.