A second dose of kisspeptin-54 improves oocyte maturation in women at high risk of ovarian hyperstimulation syndrome: a Phase 2 randomized controlled trial

Abstract

Study question: Can increasing the duration of LH-exposure with a second dose of kisspeptin-54 improve oocyte maturation in women at high risk of ovarian hyperstimulation syndrome (OHSS)?

Summary answer: A second dose of kisspeptin-54 at 10 h following the first improves oocyte yield in women at high risk of OHSS.

What is known already: Kisspeptin acts at the hypothalamus to stimulate the release of an endogenous pool of GnRH from the hypothalamus. We have previously reported that a single dose of kisspeptin-54 results in an LH-surge of ~12-14 h duration, which safely triggers oocyte maturation in women at high risk of OHSS.

Study design, size, duration: Phase-2 randomized placebo-controlled trial of 62 women at high risk of OHSS recruited between August 2015 and May 2016. Following controlled ovarian stimulation, all patients (n = 62) received a subcutaneous injection of kisspeptin-54 (9.6 nmol/kg) 36 h prior to oocyte retrieval. Patients were randomized 1:1 to receive either a second dose of kisspeptin-54 (D; Double, n = 31), or saline (S; Single, n = 31) 10 h thereafter. Patients, embryologists, and IVF clinicians remained blinded to the dosing allocation.

Participants/materials, setting, methods: Study participants: Sixty-two women aged 18-34 years at high risk of OHSS (antral follicle count ≥23 or anti-Mullerian hormone level ≥40 pmol/L). Setting: Single centre study carried out at Hammersmith Hospital IVF unit, London, UK. Primary outcome: Proportion of patients achieving an oocyte yield (percentage of mature oocytes retrieved from follicles ≥14 mm on morning of first kisspeptin-54 trigger administration) of at least 60%. Secondary outcomes: Reproductive hormone levels, implantation rate and OHSS occurrence.

Main results and the role of chance: A second dose of kisspeptin-54 at 10 h following the first induced further LH-secretion at 4 h after administration. A higher proportion of patients achieved an oocyte yield ≥60% following a second dose of kisspeptin-54 (Single: 14/31, 45%, Double: 21/31, 71%; absolute difference +26%, CI 2-50%, P = 0.042). Patients receiving two doses of kisspeptin-54 had a variable LH-response following the second kisspeptin dose, which appeared to be dependent on the LH-response following the first kisspeptin injection. Patients who had a lower LH-rise following the first dose of kisspeptin had a more substantial 'rescue' LH-response following the second dose of kisspeptin. The variable LH-response following the second dose of kisspeptin resulted in a greater proportion of patients achieving an oocyte yield ≥60%, but without also increasing the frequency of ovarian over-response and moderate OHSS (Single: 1/31, 3.2%, Double: 0/31, 0%).

Limitations, reasons for caution: Further studies are warranted to directly compare kisspeptin-54 to more established triggers of oocyte maturation.

Wider implications of the findings: Triggering final oocyte maturation with kisspeptin is a novel therapeutic option to enable the use of fresh embryo transfer even in the woman at high risk of OHSS.

Study funding/competing interest(s): The study was designed, conducted, analysed and reported entirely by the authors. The Medical Research Council (MRC), Wellcome Trust & National Institute of Health Research (NIHR) provided research funding to carry out the studies. There are no competing interests to declare.

Trial registration number: Clinicaltrial.gov identifier NCT01667406.

Trial registration date: 8 August 2012.

Date of first patient's enrolment: 10 August 2015.

Keywords: ICSI outcome; IVF; OHSS; kisspeptin; oocyte maturation; trigger injection.

© The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.

Figures

Figure 1

Patient flow diagram showing the number of patients assessed for eligibility, study enrolment and kisspeptin-54 dosing group allocation. Seventy-six patients were screened for participation in the study, of whom 62 women at high risk of ovarian hyperstimulation syndrome (OHSS) were randomized 1:1 to receive either one (Single, n = 31) or two (Double, n = 31) doses of kisspeptin-54 to trigger oocyte maturation.

Figure 2

In vitro fertilization study protocol using kisspeptin-54 to trigger oocyte maturation. The timeline shows the day of menstrual cycle for a typical patient. On Day 2 or 3 of the menstrual cycle, daily subcutaneous recombinant FSH (Gonal F 112.5 IU) was commenced. Daily GnRH antagonist injections (Cetrotide 0.25 mg) were commenced after 5 days of recombinant FSH injections. If serum LH was undetectable (n = 62) received a subcutaneous injection of kisspeptin-54 (9.6 nmol/kg) 36 h prior to oocyte retrieval to trigger oocyte maturation (between 20 :30 and 23:00 h). Injections of GnRH-antagonist and FSH were stopped 24 h and 12 h prior to the first kisspeptin-54 injection, respectively. We have previously shown that this protocol and dose of kisspeptin-54 safely and effectively triggers oocyte maturation in women at high risk of ovarian hyperstimulation syndrome (OHSS) undergoing IVF treatment (Abbara et al., 2015). All patients then received a second injection 10 h after the first injection, but were randomized 1:1 to receive either a second dose of kisspeptin-54 (D; Double, n = 31), or saline (S; Single, n = 31) to determine if a second dose of kisspeptin-54 could increase the duration of LH-exposure and optimize oocyte yield compared to a single dose of kisspeptin-54. Serum reproductive hormones (LH, FSH, estradiol and progesterone) were measured immediately prior to as well as 4 and 10 h after the first kisspeptin-54 injection. Serum reproductive hormones were also measured immediately prior to as well as 4 and 10 h after the second injection (of kisspeptin-54 or saline). Transvaginal ultrasound-directed oocyte retrieval (TVOR) was carried out 36 h following the first kisspeptin-54 injection, and ICSI was performed using fresh sperm from the male partner. If a high quality blastocyst was available, elective single embryo transfer (eSET) was carried out 5 days following oocyte retrieval. Progesterone 100 mg daily intramuscular injections (Gestone, Nordic Pharma, UK) and estradiol valerate 2 mg orally three times daily (Progynova, Bayer, Germany) was commenced from the evening of TVOR until 12 weeks gestation. All women recruited to the study were regarded as being at high risk of OHSS and were routinely screened for the development of early OHSS (assessed on day of embryo transfer 3–5 days after TVOR) and late OHSS (assessed 11 days after embryo transfer). Biochemical pregnancy (serum βHCG > 10 iU/L) was assessed 11 days following embryo transfer and clinical pregnancy was assessed by ultrasonography at 6 weeks gestation.

Figure 3

Reproductive hormonal response following kisspeptin-54 trigger administration. All patients received 9.6 nmol/kg of kisspeptin-54 subcutaneously 36 h prior to oocyte retrieval to trigger oocyte maturation. Patients were then randomized to receive a second injection 10 h later of either saline (Single shown in red) or kisspeptin-54 9.6 nmol/kg (Double shown in blue). Serum LH in iU/L ( A), serum FSH in iU/L (B), serum estradiol in pmol/L ( C) and serum progesterone in nmol/L (D) is presented by kisspeptin-54 dosing group (single or double).