Birthweights in sickle cell trait pregnancies.

Area of Science:

• Obstetrics and Gynecology
• Hematology
• Perinatal Medicine

Background:

• Conflicting evidence exists regarding the impact of sickle cell trait (SCT) on birthweight.
• Previous studies lacked gestational age specificity and did not adequately control for maternal and infant factors.

Purpose of the Study:

• To determine the contemporary mean birthweight and mean customized birthweight centile in SCT pregnancies.
• To analyze the risk of small-for-gestational-age (SGA) and large-for-gestational-age (LGA) infants in pregnancies with SCT.

Main Methods:

• A large retrospective cohort study was conducted in a London hospital.
• Singleton pregnancies (24-42 weeks gestation) between 2000-2005 with maternal BMI 18.0-35.0 kg/m² were analyzed.
• Birthweight and customized birthweight centiles were compared between SCT pregnancies and controls (no hemoglobinopathy), with statistical analysis performed using Stata.

Main Results:

• The study analyzed 505 SCT pregnancies and 16,320 controls.
• SCT pregnancies had a slightly lower mean birthweight (3223 g vs. 3280 g), but mean birthweight centiles were similar (49.0% vs. 47.5%).
• Logistic regression indicated that risks of LGA were associated with maternal age, ethnicity, and infant sex, not SCT status.

Conclusions:

• Sickle cell trait (SCT) is not identified as a risk factor for SGA or LGA infants.
• Customized birthweight centiles provide a more accurate assessment than unadjusted birthweight.
• Further research may explore other genetic or environmental factors influencing birthweight in SCT pregnancies.