Karleen Oberton
Chief Financial Officer at Hologic
Thank you, Essex, and good afternoon, everyone. In my comments today, I will start by walking through the rest of our non-GAAP income statement, then touch on several key financial metrics and finish with our guidance for fiscal Q2 and the full-year. Before, let me begin by saying we are pleased to grow non-GAAP earnings per share by 5% this quarter when revenue only grew 1%. Although we clearly want revenue to grow faster and we believe it will, this demonstrates the substantial operating leverage we can generate and gives us confidence that we can grow earnings at a double-digit rate over-time.
So how did we do that in the first-quarter? To start, non-GAAP gross margin of 61.6% increased 80 basis-points. However, this margin expansion was primarily the result of favorable product mix and operating efficiencies., moving down the P&L, first-quarter operating expenses of $329 million increased approximately 0.5%. As a reminder, Q1 usually represents our highest-level of operating expense for the year due to several large commercial initiatives. Despite this, the year-over-year increase was driven by the addition of Endomagnetics. Excluding Endomag, operating expenses would have decreased 2.3%. First-quarter operating margin finished at 29.4%, representing an increase of 90 basis-points., this operating margin expansion came primarily from drop-through of our higher gross margin and good expense control.
As Steve said, leveraging the P&L to drive modest margin expansion from already best-in-class levels and strong EPS growth remains a key focus. Below operating income, other income net was a loss in our fiscal first-quarter by slightly more than $4 million. This result was better-than-expected due to the benefit of our foreign-exchange hedging programs., as a reminder, this hedging program seeks to minimize the negative or positive bottom-line impact of currency fluctuations. Finally, our tax-rate in Q1 was 19.5% as expected. Altogether, net margin for the quarter was 23.4%, approximately flat to the prior year and very strong relative to our diagnostics and med-tech peers.
Because we have tremendous confidence in our long-term future, we continue to bet on ourselves and use our balance sheet to enhance shareholder value. In the first-quarter, we repurchased 6.8 million shares for a total of $517 million, including the completion of the $250 million ASR announced on our Q4 earnings call. As a result, we brought our weighted-average diluted share count down to 232 million, a decrease of 8 million shares compared to the prior year. All of this led to non-GAAP earnings per share of $1.03, which we were pleased to deliver at the high-end of our guidance range. With strong operating cash-flow of $189 million in the first-quarter and $2 billion in cash and investments on our balance sheet at the end-of-the quarter, we are well-positioned to continue to execute our capital deployment strategy to drive both top and bottom-line growth. Now let's move on to our updated non-GAAP financial guidance for the full-fiscal year and for the second-quarter.
Before we, I'd like to start by acknowledging the dramatic shift in the geopolitical and macro-environment since we first provided guidance in early November. As everyone knows, we are seeing an immediate impact from the new administration in the US, both in terms of policy changes and a strengthening US dollar. Entering the new calendar year, we also have greater visibility on our end-market landscape for 2025. Combining these pieces together, we are using this opportunity to reset our financial expectations for the year. For the full-year, we are lowering our revenue guidance range by $100 million to $4.05 billion to $4.10 billion, but we are maintaining our non-GAAP EPS guidance of $4.25 to $4.35.
Our Diagnostics and surgical businesses are performing well, and we are adding roughly $25 million of Gynasonics revenue to our reported results. However, these positive developments are being offset by three factors. First, like everyone else, we have experienced a significant strengthening of the US dollar since early November. We now expect FX to represent a headwind of $30 million for the full-year. This represents a swing of more than $60 million from our original expectations, which we are baking into our reduced guidance today.
The second, we are expecting lower sales of our breast health capital equipment for the year. As Essex detailed, we didn't have a clear picture of the gantry market, which led to two aggressive forecast for 2025. Especially considering that our next-generation gantry is still a ways off. And third, two potential policy changes in the new US administration are introducing uncertainty in our business. First, the freeze on foreign aid has affected our main partner for HIV testing in developing countries., the President's emergency Plan for AIDS relief or PETFAR.
Although PETFAR has been granted an exemption based on the lifesaving work they do, activities on-the-ground have still been disruptive. This disruption could affect our revenue by as much as $30 million for the balance of our fiscal year. Second, contract manufacturers in Mexico make our skeletal and gynasonics products. So we could be subject to tariffs that lower our gross margins as we import them into the United States., although these are relatively small pieces of our businesses that -- and the tariffs could have -- and the tariffs have been delayed for now, we believe it is appropriate to risk-adjust our forecast for the potential impact.
Despite these headwinds, we are maintaining our full-year EPS guidance of $4.25 to $4.35. The strong financial discipline and capabilities we've established as an organization are enabling us to mitigate the bottom-line impact of these issues. For the second-quarter, we are expecting total revenues in the range of $995 million to $1.005 billion, including a $10 million FX headwind quarter and non-GAAP EPS in the range of $1 to $1.03. Thank you. Now let me provide some additional details that underpin our guidance. In terms of quarterly pacing, we expect our revenue growth rate to improve in the 3rd-quarter and further in Q4. So we should exit the year above our long-term mid-single-digit target -- target on a quarterly basis. In terms of the divisions, we expect Diagnostics to grow mid-single digits for the year, excluding the impact of declining COVID-19 sales.
First, we continue to forecast that growth will be driven by strength in our molecular women's health assays and lab testing. For COVID revenue, we expect assay sales to be about $9 million in the second-quarter and approximately $35 million for the full-year. COVID-related items are expected to be about $25 million in the second-quarter and approximately at $100 million for the year. Finally, in diagnostics, we expect blood screening revenue of about $5 million in Q2 and about $20 million for the full-year.
As you know, both COVID-related sales and blood screen revenue are backed out of our organic growth calculations. Within Breast Health, as mentioned, we are lowering our expectations for the full-year based on softer capital equipment sales. First, we now expect this business to decline in the low-single digits for the full-year, including endomagnetics. We. We do, however, expect revenue growth to build-in the second-half with good year-over-year growth in Q4 as we exit our fiscal year.
Thank you lastly, in Surgical, we expect high single-digit growth for the year with the inclusion of Gynasonics in our results for the third 3/4. In our core surgical business, we expect growth to be powered by international with contributions in the US from MyoSure Influence to moving to the rest of the P&L, we expect gross margin in the low-60s for the full-year. We anticipate gross margins to step-up in the second-half with higher sales with the elimination of redundant manufacturing facilities in breast Health and direct sales and endomagnetics. For operating margin, we're expecting to be in the low-30s for the full-year with steady margin expansion as we move through the year. Below operating income, we estimate other income net to be an expense of $10 million to $15 million in Q2 and an expense between $40 million and $45 million for the full-fiscal year., our effective tax-rate of approximately 19.5% for the full-year remains unchanged from our prior guidance.
To reflect the share repurchase activity we completed in Q1, diluted shares outstanding are expected to be approximately $230 million for the full-year. To conclude, our financial discipline and strength have us in a position to meet our EPS commitments even in a year where we're seeing pressures on the top-line., we believe these pressures are largely transitory in nature and we expect top-line growth to be healthy as we exit the year., we feel great about the long-term outlook for each of our divisions, driven by our ability to retain and grow our market-leading positions, while continuing to add new growth drivers through internal innovation and business development.
With that, we ask the operator to open the call for questions.