Strandell 1999.

Methods	Randomised controlled trial. Multicentre trial involving 9 Scandinavian IVF centres. Patients recruited prospectively; patient sampling not explained explicitly. Inclusion criteria: hydrosalpinges, laparoscopic acces ability, age<39 at time of randomisation. Exclusion criteria ‐ previous IVF; uterine fibroids.Concomitant male factor requiring ICSI accepted if centre had established successful ICSI programme with results equivalent to conventional IVF. 204 women were recruited and randomised. Number of exclusions not known. 5 patients of the intervention group did not undergo surgery; 6 patients in the intervention group and 6 patients in the non‐intervention group did not undergo IVF. 204 women were analysed. Follow‐up duration up to 1 IVF cycle (further follow‐up data anticipated).
Participants	Age <39 years (range 22‐38) Type of infertility: majority primary infertility (treatment group 73%, control group 63%) Duration of infertility not stated. Investigative work‐up not stated. Contributary causes to infertility: not stated. Previous fertility treatment: not stated; no previous IVF. Diagnosis of tubal pathology: by HSG or laparoscopy. 37(51%) had ultrasound visible hydrosalpinges compared to 42(57%). Characteristics and distribution of tubal pathology: Hydrosalpinges. Bilateral in 69(59%) and 36(41%); unilateral in 47(41%) and 52(59%). Characteristics of IVF treatment : IVF protocol: Long GnRh antagonist protocol, with either HMG of FSH. 1‐2 IVF ovarian stimulation cycles per woman. Mean oocytes retrieved at IVF (SD) ‐ 10.6 (5.9) in the salpingectomy group; 10.6 (6.1) in the non intervention group. Proportion undergoing ICSI, 13.1% in the salpingectomy group; in the non intervention group12.6%. Mean no. of fertilized and cleaved oocytes in treatment group 6.8 (4.8); 7.0 (4.9) in the non intervention group. Mean embryos transferred per cycles (SD) ‐ treatment group 2.0 (0.3); 2.0 (0.4)in the non intervention group.
Interventions	Laparoscopic bilateral or unilateral salpingectomy (or, if technical difficulties e.g. extensive adhesions, proximal ligation and distal fenestration recommended) VERSUS no surgery. Criteria for surgical treatment prior to IVF ‐ Uni‐ or bilateral hydrosalpinges (a distally occluded pathologically dilated tube or one which became pathologically dilated on patency testing by HSG/laparoscopy. Interval from surgical intervention to IVF ‐ minimum 2 months, IVF was performed in the control group directly after randomisation. Co‐interventions: none (deviations from protocol though) Data on surgeons: not stated.
Outcomes	PRIMARY OUTCOMES Ongoing pregnancy (pregnancy>20 weeks) or delivery rate in first cycle per woman, per started cycle, and per transfer cycle. Pregnancy rate ‐ per woman, per started cycle and per transfer cycle. Clinical pregnancy verified by gestational sac on ultrasound. SECONDARY OUTCOMES Ectopic pregnancy rate ‐ per implanted embryo's/ clinical pregnancy Miscarriage rate ‐ not defined, presumably as outcome of clinical pregnancy Implantation rate ‐ number of gestational sacs on ultrasound divided by the number of embryos transferred. Multiple pregnancy rate not stated
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	True randomisation ‐ sealed opaque envelopes in blocks of 10‐30.
Blinding? All outcomes. Participants, outcome assessors, clinicians, statisticians	High risk	No blinding.
Incomplete outcome data addressed? Intention to treat for primary outcome?	Low risk	'Intention to treat' analysis performed.
Free of selective reporting?	Low risk	No suggestions of selective reporting.
Detection adequate?	Low risk	Follow‐up duration up to 1 IVF cycle (further follow‐up data anticipated).
Source of funding stated?	Low risk	Study was funded by grants from the Goteborg Medical Society, the Hjalmar Svensson Foundation and the society 'ordensallskapet W:6'
Powercalculation performed?	High risk	Power calculation performed ‐ sample size 300 not adhered to due to decrease in recruitment rate.
Loss to Follow‐up explained?	Low risk	Withdrawal and loss to follow up explained.