Professor Andrew Horne
Professor of Gynaecology and Reproductive
MRC Centre for Reproductive Health,
University of Edinburgh,
Professor Norah Spears
Norah Spears, D Phil
Professor of Reproductive Physiology,
Centre for Integrative Physiology,
University of Edinburgh,

ProAKAP4 is synthetized as a precursor polypeptide that must be converted into mature AKAP4 in living spermatozoa and is considered as a functional marker of spermatozoa. The gene is well-conserved in mammals although uncharacterized in Camelidae. In the present study, we investigate the expression metabolism of proAKAP4 and AKAP4 proteins and evaluate their seasonal dynamics relative to semen quality in dromedary camels. Semen parameters including volume and viscosity and characteristics of sperm including concentration, total production, total and progressive motility, vitality, acrosome integrity and morphological abnormalities were assessed in semen samples collected weekly from six camels during the rutting season, from November to April. Only total sperm production varied, peaking in January. Both the precursor proAKAP4 and AKAP4 proteins were investigated and shown to express biochemical properties similar to those described in other mammals. ProAKAP4 concentrations expressed in ng/10 million spermatozoa as assayed using a specific ELISA showed a strong positive correlation with ejaculate volume (P = 0.045), viscosity (P < 0.001) and sperm total motility (P = 0.049). Furthermore, their concentrations exhibited clear seasonal variations in camel semen. In conclusion, the assessment of proAKAP4 concentrations in camel sperm provides a novel parameter to assess sperm quality. Further studies should be performed to investigate proAKAP4 concentrations relative to fertility in Camelidae that may help to define the right time for mating and semen collection and increase the success of breeding programs.

Lay summary

Breeding related to the seasons/time of year in the camel has been reported in several studies. A better knowledge of semen quality during the breeding season would assist in determining the best period for mating in camels. However, conventional sperm parameters are held to be unsatisfactory because they cannot predict breeding potential. ProAKAP4 a sperm-specific protein has been described as a functional marker of sperm and a key fertility marker in several species but has not been described in camels. Motility or membrane integrity parameters of semen collected throughout the breeding season and also the presence of proAKAP4 protein were investigated. ProAKAP4 was identified for the first time in camels and their concentrations exhibited clear seasonal variations in camel semen showing strong correlations with ejaculate volume and total motility and viscosity. Further studies should be performed to investigate proAKAP4 concentrations relative to fertility in camels to define the right time for mating and increase the success of breeding programs.

Authors: Jenna Lowe and Erin Curry

Previous reports indicate that red pandas (Ailurus fulgens styani) may experience fetal loss during gestation; however, neither the rate nor timing of pregnancy failure has been described in this species. The objective of this study was to utilize ultrasound video and images collected between 2010 and 2020 at the Cincinnati Zoo and Botanical Garden to better characterize pregnancy loss and fetal development. Trans-abdominal ultrasound examinations were performed on six female red pandas over a 10-year period, resulting in 12 profiles. Pregnancy was diagnosed via ultrasound in 10 of 12 profiles, and 40.0% of pregnancies showed evidence of fetal loss prior to parturition. Pregnancy loss was classified into lost (2 of 10; 20.0%), in which no cubs were produced, or partial loss (2 of 10; 20.0%), in which two concepti were visualized via ultrasound, but only one cub was born. Fetal loss occurred between days 51 and 23 pre-partum. Fetal growth characteristics were documented, including skeletal ossification (occurring between days 32 and 27 pre-partum), crown-rump length, head length, cranial length, and fetal heart rate (173–206 b.p.m.). These findings provide novel insights into pregnancy loss, may serve as a reference for milestones of fetal development, and may be useful in diagnosing pregnancy and assessing pregnancy loss in red pandas.

Lay summary

For many wildlife species, there is no non-invasive method of determining pregnancy; therefore, the rate of pregnancy loss oftentimes is unknown. Many red pandas in human care that are paired for breeding are observed exhibiting normal mating behaviors; however, only a relatively low proportion of females produce cubs. We utilized animals conditioned for ultrasound examination to diagnose pregnancy and characterize the incidence and timing of pregnancy loss. In total, 12 potential pregnancies were monitored, beginning after breeding season and ending ~2 weeks prior to anticipated cubbing. Of these, ten were (83.3%) were diagnosed as pregnant, with 40% undergoing either full or partial pregnancy loss. Fetal growth characteristics, such as body length and head size, are described which may be useful for monitoring pregnancies and estimating fetal age. Results of this study provide novel data on pregnancy loss in red pandas. Insights into the rate and timing of reproductive failure may illuminate causes and contributing factors, ultimately allowing for improvements in husbandry which may result in greater reproductive success of individuals recommended for breeding.

Graphical Abstract


Studies evaluating pregnancy outcomes after assisted reproductive treatment (ART) in women with high-normal (2.5–4.5 mIU/L) thyroid-stimulating hormone (TSH) levels are conflicting, possibly due to different patient charactistics and subfertility indications. The aim of this study was to examine the hypothesis that high-normal compared to low-normal TSH levels are associated with adverse implications for pregnancy outcomes in conventional in vitro fertilization (IVF)-treated women. Therefore, we analyzed retrospectively the characteristics and pregnancy outcomes of 949 subfertile women with TSH 0.3–4.5 mIU/L, treated with conventional IVF between January 2008 and March 2012. Demographic and baseline characteristics were compared between groups of patients based on TSH quartiles, using one-way Anova, Kruskal–Wallis ANOVA and chi-square test. Women with high-normal quartile TSH were significantly more likely to be primary subfertile (P = 0.01), with a higher prevalence of unexplained subfertility and with 15% fewer live births after IVF compared to lower TSH quartiles (P = 0.02). In secondary subfertile women with high-normal TSH, male factor subfertility prevailed (P = 0.01), with more live births (P = 0.01). When analyzing primary and secondary subfertile women as one group, these differences failed to be observed, showing no differences in cumulative pregnancy outcomes of IVF between TSH quartiles (I: 0.3–1.21 mIU/L; II: 1.22–1.68 mIU/L; III: 1.69–2.31 mIU/L; IV: 2.32–4.5 mIU/L). In conclusion, primary subfertile women predominate in the high-normal TSH quartile, associated with significantly fewer live births in a subgroup of primary unexplained subfertile women (9%; n  = 87/949), while in secondary subfertile women, dominated by male factor subfertility, high-normal TSH is associated with more live births.

Lay summary

Thyroid hormones are required for all cell processes in the body. An underactive thyroid gland, in which insufficient thyroid hormones are produced and thyroid-stimulating hormone (TSH) rises, is associated with a lower chance of pregnancy. It is not yet clear above which TSH level, 4.5 or also 2.5 mIU/L, this lower probability occurs. Therefore, in 949 couples treated with conventional IVF, we examined whether high-normal TSH levels (TSH: 2.5–4.5 mIU/L) compared to low normal TSH levels (0.3–2.5 mIU/L) affect the live birth rate. We found that women who were trying to become pregnant for the first time, especially without any other cause, that is unexplained subfertility, were more likely to have higher TSH levels. These women had a much lower chance of having a baby compared to women with low-normal TSH levels.


Read the following articles chosen by the Editors


The impact of Covid-19 on infertility services and future directions

Authors: I Robertson, A J Kermack, and Y Cheong
Volume 1: Issue 1, Pages: C3–C7


Undernutrition reduces kisspeptin and neurokinin B expression in castrated male sheep

Authors: Christina M Merkley et al.
Volume 1: Issue 1, Pages: 21–33


Effects of lifestyle factors on fertility: practical recommendations for modification

Authors: Mathias Abiodun Emokpae and Somieye Imaobong Brown
Volume 2: Issue 1, Pages: R13–R26


Pelvic pain correlates with peritoneal macrophage abundance not endometriosis

Authors: Douglas A Gibson et al.
Volume 2: Issue 1, Pages: 47–57


One day is better than four days of ejaculatory abstinence for sperm function

Authors: Fatima Kazue Okada, Rhayza Roberta Andretta, and Deborah Montagnini Spaine
Volume 1: Issue 1, Pages: 1–10


Factors affecting reproductive traits in male snow leopards (Unciauncia)

Authors: Jason R Herrick et al.
Volume 1: Issue 1, Pages: 35–49


Study design flaws and statistical challenges in evaluating fertility treatments

Authors: Jack Wilkinson and Katie Stocking
Volume 2: Issue 2, Pages: C9–C21

Follow @Reprod_Fertility Twitter advert


Reproduction and Fertility article publication charge waived advert


Reproduction and Fertility sign up for alerts advert