Midterm eGFR Predicts Pregnancy Outcomes: An Observational Study

Area of Science:

• Obstetrics and Gynecology
• Nephrology
• Reproductive Medicine

Background:

• Pregnancy involves significant hemodynamic adjustments crucial for gestation.
• The clinical implications of midterm renal hyperfiltration and its impact on maternal and fetal health require further investigation.
• This study examines midterm estimated glomerular filtration rate (eGFR) as a marker for hyperfiltration in pregnant women without chronic kidney disease (CKD).

Purpose of the Study:

• To assess midterm renal hyperfiltration during pregnancy using eGFR.
• To determine the association between midterm eGFR and adverse maternal and fetal outcomes.
• To identify the optimal eGFR range for favorable pregnancy outcomes.

Main Methods:

• Retrospective study including 1,045 pregnancies in women aged 18-50 years with available pregestational serum creatinine.
• Midterm renal hyperfiltration quantified as the highest eGFR using the creatinine clearance method.
• Statistical analysis to assess the association between eGFR levels and adverse pregnancy outcomes.

Main Results:

• 65% of pregnancies exhibited midterm eGFR between 120-150 mL/min per 1.73 m2; 4.3% had eGFR >150 mL/min per 1.73 m2.
• Increased risk of poor pregnancy outcomes observed for eGFR levels outside the 120-150 mL/min per 1.73 m2 range.
• Significantly higher odds ratios for adverse outcomes were noted for eGFR <90 mL/min per 1.73 m2 (OR=5.64) and eGFR ≥150 mL/min per 1.73 m2 (OR=1.97).

Conclusions:

• A distinct relationship exists between midterm eGFR and adverse pregnancy outcomes.
• Optimal pregnancy outcomes are associated with midterm eGFR levels between 120-150 mL/min per 1.73 m2.
• Suboptimal maternal hyperfiltration responses can significantly impact pregnancy outcomes, even without overt renal function decline.