Pain experience during oocyte aspiration: comparison between a newly designed reduced needle and a standard needle

This prospective, randomised, multi-centre study was performed at four different clinics in Sweden. Oocyte retrieval was performed under local anaesthesia according to each clinic’s local procedures either with a Sense needle (RN) with 0.9 mm tip or a Standard needle (SN) with 1.4 mm tip. In total, 257 patients were randomised.

The primary end-point was the overall pain experience registered by the patient on a visual analogue scale (VAS). To further prove the benefits of the thin tip, the degree of vaginal bleeding was registered as one of the secondary end-points.

Significantly less bleeding and pain

The overall pain during the oocyte retrieval procedure was significantly lower in the Sense group than in the Standard needle group. This was also true when adjusting for baseline characteristics such as number of follicles, number of previous oocyte pick-up, body mass index and age, by a multiple linear regression analysis.

Significantly more patients had less than expected vaginal bleeding in the Sense group when compared with the Standard needle group.


Percent of patients with less bleeding than normal

Percentage of patients with less bleeding than normal_new 20190618 (002).png

Level of overall pain experience

Level of overall pain experience_new 20190618 (002).png

Uncompromised performance

No differences were found between the two needles with regard to additional i.v. analgesia, aspiration time, oocyte recovery, fertilisation, cleavage rate, number of good quality embryos, number of embryos for freezing and pregnancy rate.


Oocyte recovery and fertilisation rate

Oocyte recovery and fertilisation rate_Sense_3C.png

Aspiration timeAspiration time_Sense_3C_new 20190618 (002).png

Oocyte safetyOocyte safety_new 20190618 (002).png


Oocyte retrieval performed with Sense resulted in significantly less overall pain and less vaginal bleeding, without prolonging the retrieval procedure or influence the oocyte recovery rate, when compared with a Standard needle.


REF: Wikland M et al. A randomized controlled study comparing pain experience between a newly designed needle with a thin tip and a standard needle for oocyte aspiration. Hum Reprod. 2011 Jun;26(6):1377-83

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