The GDPNow model forecast for first-quarter growth was 0.1 percent as of Friday, unchanged from April 16. The metric from the Federal Reserve Bank of Atlanta combines various economic data points for a rolling estimate of growth.
The advance read of U.S. gross domestic product comes at 8:30 a.m. on Wednesday, between two housing market reports. Weekly mortgage applications come at 7 a.m. and pending home sales at 10 a.m.
Last week, existing home sales hit an 18-month high, while new home sales missed expectations.
The U.S. 10-year Treasury yield rallied on Tuesday and will be watched as it attempted to break past 2 percent in late trade.
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More worrisome for the health of U.S. businesses, the majority of corporate reports have beat lowered earnings per share estimates but fewer than half have topped sales expectations.
"We still have concerns," said Tim Dreiling, senior portfolio manager for The Private Client Reserve of U.S. Bank. "Equity markets continue to grind higher on much lower earnings across the board."
Analysts and companies blame the strong dollar for the misses, with traders looking through the currency headwinds to keep equities near their highs.
The U.S. dollar weakened slightly on Tuesday, as the euro crept towards $1.10. The greenback is still up more than 12 percent for the last six months.
"FX is weighing a lot more on the earnings in the current quarter than it ever was, " said Lindsey Bell, senior analyst at S&P Capital IQ.
That impact will likely worsen. Analysts estimate a decline of 3.6 percent for the second quarter, down from a 2.6 percent two weeks ago, Bell said. Outlook on third-quarter earnings also fell to negative 0.2 percent from a 1.1 percent gain.
"I think it's the continued strength of the strong U.S. dollar. People are being cautious," she said. "We're going to have to see the second-quarter data improve."
To be sure, Wall Street is still optimistic in the long term.
"While it has been a little disappointing that growth has yet to pick up in April, I fully expect the U.S. economy to pick up in the second, third and fourth quarters of 2015," said Eric Stein, co-director of global income at Eaton Vance Management. He expects cold weather, West Coast port strikes and adjustment to the stronger U.S. dollar to weigh on first-quarter growth.
S&P Capital's Bell said expectations hold for 3.8 percent growth in the fourth quarter, "which is pretty aggressive." But then "literally all the growth for 2015 is reliant on the fourth quarter," she said.
Federal Reserve policymakers have also emphasized their belief that growth will likely pick up in the coming months, and analysts are watching for updated view on the impact of the strong dollar and the timing of an interest rate hike.
U.S. stocks closed mixed on Tuesday as investors eyed earnings and remained on edge ahead of the Fed statement release.
Merck gained more than 5 percent to lead the Dow Jones industrial average higher, up 72 points at 18,110. The S&P 500 closed up about 6 points at 2,115, with consumer discretionary the only lagging sector. The Nasdaq closed lower, down 5 points at 5,055, as Apple ended more than 1.5 percent lower despite a strong earnings report Monday. The stock was also the worst-performing blue chip.
Companies reporting on Wednesday include MasterCard and Time Warner before the bell, and Marriott and Murphy Oil after the bell.
Crude will also be in focus, with weekly inventories expected at 10:30 a.m. on Wednesday.
"Oil is still being supported at $57 by the situation in Yemen," said John Kilduff, partner at Again Capital. If there's another large supply build, we'll see a similar "downward thrust on the inventory input, then climb on Yemen."
Tensions between the country and Saudi Arabia have increased prospects of tighter supply.
Crude settled up 7 cents at $57.06 a barrel on Tuesday, paring gains from news of the seizure of a Western cargo ship off the coast of Iran.
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The nation is in the middle of negotiations with the United States and other major countries on a nuclear deal that could lift sanctions on Iranian oil and increase supply.
Correction: Deutsche Bank was inaccurately listed as reporting earnings on Wednesday morning.