A 29-Year-Old Woman, Gravida 0 Para 0, Comes to the Office

A 29-year-old woman, gravida 0 para 0, comes to the office for preconceptual counseling.  The patient has been taking oral contraceptives for the past 6 years and would like to become pregnant within the next 6 months.  She has no chronic medical conditions or previous surgeries.  Her menses occur every 28 days and last for 4 days.  Her menstrual flow is light and accompanied by mild cramping.  The patient's Pap tests, the last of which was 2 years ago, have been normal.  In addition to oral contraceptive pills, she takes a multivitamin daily and uses acetaminophen occasionally.  She has no known drug allergies and is up to date on all vaccinations.  The patient drinks socially once a week but does not use cigarettes or illicit drugs.  She is an aerobics instructor and teaches for 90 minutes 5 days a week.  On days the patient does not teach, she exercises with light weights.  In addition, she frequently goes scuba diving on weekends.  Blood pressure is 100/60 mm Hg and pulse is 62/min.  BMI is 22 kg/m².  Pelvic examination reveals a retroverted, normal-size uterus with no adnexal masses or tenderness, a closed cervix, and no vaginal discharge or bleeding.  In addition to recommending prenatal vitamins, which of the following is the best advice for this patient?

A) Aerobic exercise should be avoided until after delivery
B) Exercise should be decreased to 45 minutes daily
C) Scuba diving should be avoided until after delivery
D) The current exercise regimen and activities can be continued
E) Weightlifting should be avoided until 6 weeks postpartum