The purpose of this study is to detect if adding resistance to maternal blood flow from the arm will help increase the blood flow through the uterine arteries to the placenta and the baby.

In the setting of uteroplacental insufficiency, there is little that can be done to increase blood flow through the uterus and placenta. Historically, women with growth restricted fetuses or oligohydramnios have been placed on bed rest. Unfortunately, this treatment modality has met with only limited success. Cardiologists have long recognized the simple act of making a fist or otherwise occluding blood flow through a limb dramatically increases a person's peripheral vascular resistance. If maternal peripheral resistance can be increased, perhaps the increased differential between the maternal peripheral vascular resistance and that of the uteroplacental unit will increase flow through the uterus and placenta.

Inclusion Criteria:

• Pregnant women greater than or equal to 18 years old
• Able to speak and read English
• Have a singleton pregnancy greater than or equal to 18 weeks gestation

Exclusion Criteria:

• Multiple gestation
• Less than 18 weeks gestation
• Uterine anomalies
• Fetal anomalies
• Preeclampsia
• Hypertension
• Inability to have BP cuff on left arm

Pregnant women greater than or equal to 18 weeks gestation and 18 years old eligible for an ultrasound without fetal or uterine anomalies