Background: The objective was to study fetal growth parameters in in vitro fertilization (IVF) pregnancies and to investigate the relationship between fetal growth and maternal blood pressure.
Methods: We examined 64 women, pregnant after in vitro fertilization, with repeated ultrasound examinations measuring biparietal diameter, femur length, abdominal diameter and fetal weight at 24, 30, and 36 weeks of gestation. We calculated deviations in percent from expected values in regards to biparietal diameter, femur length, abdominal diameter, and fetal weight. Blood pressure was measured every second week.
Results: Biparietal diameter in the study group was significantly smaller at 24 (-3.3%, 95%CI -4.4 to -2.2) and 30 (-1.4%; 95%CI -2.5% to -0.3) weeks. Femur length differed significantly on all three occasions, at 24 (-6.3%; 95%CI -7.7 to -5.1), 30 (-6.6%; 95%CI -8.0 to -5.3), and 36 (-3.9%; 95%CI; -5.0 to -2.8) weeks. Abdominal diameter demonstrated a significant deviation at 24 weeks (-1.6%; 95%CI -2.8 to -0.4). Fetal weight did not reach significant deviations at any gestational age. There was no correlation between deviation of the individual growth parameters or estimated fetal weight and elevated blood pressure.
Conclusion: The growth pattern of in vitro fertilization pregnancies does not seem to differ from spontaneously conceived pregnancies to any appreciable extent. In the present material, no relationship between fetal growth and maternal blood pressure could be observed. We could not show that an impaired fetal growth predates the development of hypertension.