Myoinositol is an insulin-like compound that is present in both plant and animal cells. Humans synthesize it naturally, but it is also obtained in our diet. It works through an intracellular signaling pathway to increase insulin sensitivity. Myoinositol has been used as an over-the-counter (OTC) supplement in the management of polycystic ovarian syndrome due to this effect. Myoinositol has also been shown to improve glycemic profiles in pregnant euglycemic women and well as improve insulin sensitivity in pregnant patients with gestational diabetes mellitus (GDM).

This is a double blind RCT offering myo-inositol or placebo to those who are eligible and enrolled.

Inclusion Criteria:

Singleton gestations

Women aged > 18 years and < 45 years

Recruited before 16 weeks gestation

Obese (pre-pregnancy BMI ≥ 30)

Receiving prenatal care at Tufts Medical Center

Planning to give birth at Tufts Medical Center

Can tolerate glucose tolerance test

Willing and able to wear CGM

Willing and able to sign informed consent

Exclusion Criteria:

Multiple gestation

Preexisting diabetes

Taking medications that impact body weight or metabolism (eg metformin)

Inability to tolerate glucose tolerance test

Adults unable to consent (cognitively impaired adults)

Wards of the state

Non-viable neonates

Neonates of uncertain viability