Jennifer is forty-two years old and pregnant with her first child. Knowing that her age puts her baby at increased risk for chromosomal abnormalities, she decides to undergo a prenatal screening procedure that will identify any abnormalities. Which of the following procedures will best help Jennifer to do this?

A glucose test is primarily used to screen for gestational diabetes, not for identifying chromosomal abnormalities. This test measures blood sugar levels and does not provide any genetic or chromosomal information about the fetus.

A biophysical profile assesses the well-being of the fetus through ultrasound and monitoring of fetal heart rate. While it provides information about the baby's health, it does not evaluate chromosomal abnormalities or genetic conditions.

Preimplantation genetic diagnosis (PGD) is performed during in vitro fertilization (IVF) before implantation of embryos. It is not applicable in Jennifer's situation since she is already pregnant, and it does not serve as a prenatal screening method during gestation.

Fetoscopy is a minimally invasive procedure that allows visualization of the fetus and can be used to obtain tissue samples. However, it is primarily used for diagnosing certain conditions rather than specifically identifying chromosomal abnormalities, making it less suitable for Jennifer's needs.