Maternal obesity (OB) accounts for the majority of large‐for‐gestational‐age infants, and newborn percent fat (NB%fat) correlates strongest with childhood OB. In addition to maternal glucose, fasting triglycerides (TGs) may contribute, but postprandial triglycerides (PPTGs) are unstudied. It was hypothesized that fasting TGs and PPTGs are higher in women with OB compared with women with normal weight (NW) throughout pregnancy, correlate more strongly with NB%fat than glucose, and may relate to dietary chylomicron TGs.

Fasting TGs and PPTGs, free fatty acids, glucose, and insulin were prospectively measured 10 times over 4 hours after a controlled liquid breakfast early (14‐16 weeks) and later (26‐28 weeks) in pregnancy in 27 mothers with NW and 27 with OB. NB%fat was measured by dual x‐ray absorptometry.

Fasting TGs and PPTGs were already ≥ 30% higher in mothers with OB at 14 to 16 weeks (P < 0.001) versus mothers with NW. In mothers with OB, a simple 1‐hour (r = 0.71; P < 0.01) or 2‐hour (r = 0.69; P < 0.01) PPTG at 14 to 16 weeks correlated strongest with NB%fat. In mothers with NW, the increase in TGs from early to later pregnancy correlated strongest with NB%fat (r = 0.57; P < 0.01). Maternal glucose did not statistically add to prediction models.

These novel data suggest that 1‐ or 2‐hour PPTGs might be a new target for early intervention in pregnancies with OB to prevent excess newborn adiposity and attenuate child OB risk.