* Sees 2018 EPS growth of 2-5 pct, below some forecasts
* Group expects to benefit from U.S tax reform
* Q4 hurt by Dengvaxia provision
* Shares fell as much as 3 pct (Adds share price, context)
PARIS, Feb 7 (Reuters) - Sanofi forecast on Wednesday a return to profit growth this year, but its shares fell as analysts had hoped for a bigger boost from recent deals and a revamped drugs pipeline.
France's largest drugmaker also said net profit in the fourth quarter of 2017 was hit by an impairment of 87 million euros ($107 million) related to Dengvaxia, its dengue vaccine at the centre of a health scare in the Philippines.
The company predicted earnings per share (EPS) growth of 2-5 percent at constant exchange rates this year, after a 0.4 percent drop in 2017.
The guidance fell short of some analysts' hopes, and Sanofi shares dropped as much as 3.2 percent to a 20-month low of 65.36 euros.
"FY 18 EPS guidance at mid-point, including the impact of acquisitions, is 3 percent below consensus at December rates, but we estimate 4 percent below at current exchange rates," analysts at investment bank Jefferies wrote in a note.
The group should also benefit from a cut in U.S. corporate tax, with Sanofi predicting its tax rate would be around 22 percent in 2018, down from 23.5 percent last year.
Finance chief Jerome Contamine declined during a press conference to give guidance excluding acquisitions.
Sanofi struck two big takeover deals last month, agreeing to buy U.S haemophilia specialist Bioverativ for $11.6 billion and Belgium's Ablynx, which is developing a prized experimental drug for a rare blood disorder, for 3.9 billion euros ($4.8 billion).
The transactions marked a return to successful deal-making for Sanofi after failures to land major takeovers since 2011, when it bought U.S biotech company Genzyme for around $20 billion, although some investors have questioned the costs.
The deals will complement Sanofi's rare diseases business, while its diabetes sales continue to suffer from generic competition, especially in the United States, the world's largest health market.
In the fourth quarter, sales at the group's diabetes and cardiovascular unit were down nearly 20 percent.
Sanofi announced in November that Dengvaxia - the world's first dengue vaccine - might increase the risk of severe disease in people who had never been exposed to the virus.
A Philippine government agency on Monday filed a lawsuit against Sanofi, seeking compensation for the parents of a 10-year-old girl the agency said had died as a result of receiving Dengvaxia.
"The Dengvaxia question of course is very worrisome to us. But we have not seen any reaction similar to the one in the Philippines in other countries," Sanofi Chief Executive Olivier Brandicourt told journalists.
"We are worried with this insistence of trying to link some deaths of children with the vaccine, something we have absolutely no evidence of," he said.
Dengvaxia has been approved in almost 20 countries. It is currently under review by European health regulators.
Sanofi's fourth-quarter business net income fell 10.8 percent at constant exchange rates to 1.33 billion euros. Total sales rose 4.1 percent to 8.7 billion euros.
Analysts polled by Reuters in partnership with Inquiry Financial had on average been expecting business net profit of 1.46 billion euros and net sales of 8.7 billion.
($1 = 0.8069 euros) (Editing by Sudip Kar-Gupta and Mark Potter)