The association between persistent maternal hypotension and small for gestational age neonates

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Neonatal Health

Background:

• Maternal hypotension's association with poor fetal growth is understudied.
• Hypotension may indicate reduced uteroplacental blood flow, impacting fetal development.

Purpose of the Study:

• To investigate the association between persistent maternal hypotension and the risk of small for gestational age (SGA) neonates.
• To determine if transient maternal hypotension is also associated with an increased risk of SGA neonates.

Main Methods:

• Secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort.
• Inclusion of nulliparous women with singleton pregnancies delivering at ≥24 weeks' gestation.
• Definition of persistent hypotension (low BP at 3 visits) and transient hypotension (low BP at 1 visit), analyzed using univariable and multivariable logistic regression.

Main Results:

• 2.3% of participants (164/7233) had persistent hypotension.
• Persistent hypotension was significantly associated with higher rates of SGA neonates (21.3% vs 11.6%, P<.001).
• Adjusted analysis confirmed persistent hypotension increased SGA risk (aOR, 1.65; 95% CI, 1.11-2.44); transient hypotension was not associated with SGA.

Conclusions:

• Persistent maternal hypotension is a significant risk factor for small for gestational age neonates in low-risk nulliparous women.
• Transient hypotension did not demonstrate a significant association with SGA in this cohort.