330. SEASONAL EFFECTS ON OVARIAN DYNAMICS AND OOCYTE DEVELOPMENTAL COMPETENCE IN SOWS EXPERIENCING EARLY-PREGNANCY LOSS

2010 ◽  
Vol 22 (9) ◽  
pp. 130
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen
Keyword(s):  
Early Pregnancy ◽  
Pregnancy Loss ◽  
Oocyte Quality ◽  
Late Spring ◽  
Seasonal Effects ◽  
Early Pregnancy Loss ◽  
Developmental Potential ◽  
Generalised Linear Mixed Model ◽  
Seasonal Infertility ◽  
Ovarian Dynamics

Seasonal infertility in the domestic sow has a considerable economic impact on the pig industry. Reduced oocyte quality and increased wean-to-service interval (WSI) have been observed during the seasonal infertility period (1, 2). The aim of this study was to determine the relationship between season, WSI, ovarian dynamics and oocyte quality in sows experiencing early-pregnancy loss. Sows that experienced early-pregnancy loss were grouped according to their previous WSI (≤ 6 or > 6 d) and the presence (CL) or absence (NCL) of corpora lutea on their ovaries at the time of slaughter. Groups were WSI≤6d/CL, WSI≤6d/NCL, WSI>6d/CL and WSI>6d/NCL. Cumulus–oocyte complexes were recovered from antral follicles (3–8 mm) and subjected to parthenogenetic activation following in vitro maturation in summer (n = 742) and late-spring (n = 594). Data were analysed using a generalised linear mixed-model in GenStat release 10. The mean number of CL/sow was greater (11.57 ± 3.30) in late-spring compared to summer (9.26 ± 0.99; P < 0.05). There were no effects of WSI on oocyte developmental potential. A greater proportion of oocytes developed to the blastocyst stage in summer (55.94 ± 5.17%) compared to late-spring (31.18 ± 6.38%; P < 0.05). Blastocysts derived from oocytes collected in summer had a greater number of cells (46.60 ± 1.17) than blastocysts derived from oocytes collected in spring (43.2 ± 0.95; P < 0.05). Blastocysts derived from oocytes of CL ovaries had more cells (47.08 ± 1.13) than those derived from oocytes of NCL ovaries (42.91 ± 0.75; P < 0.05). It appears that sows experiencing early-pregnancy loss have inherently poor oocyte quality. The greater developmental potential of oocytes in summer suggests a proportion of sows culled for early-pregnancy loss in summer have good oocyte quality, but fail to conceive and/or initiate pregnancy due to other summer-autumn related factors, such as heat stress. (1) Bertoldo et al., Reproduction, Fertility and Development, in press.(2) Bertoldo et al., 2009. Theriogenolgy, 72: 393–400.

129. REDUCED OOCYTE DEVELOPMENTAL COMPETENCE DURING THE PERIOD OF SEASONAL INFERTILITY IN PIGS

2009 ◽  
Vol 21 (9) ◽  
pp. 48
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen
Keyword(s):  
Linear Mixed Model ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Seasonal Effects ◽  
Cumulus Expansion ◽  
Developmental Potential ◽  
Parthenogenetic Activation ◽  
Oocyte Developmental Competence ◽  
Generalised Linear Mixed Model ◽  
Seasonal Infertility

Reduced farrowing rate due to early pregnancy loss is a manifestation of seasonal infertility in pigs. It has been hypothesised that the early disruption of pregnancy is due to poor oocyte developmental competence. The aim of this study was to determine if there are seasonal differences in oocyte developmental competence. Ovaries were collected from sows slaughtered 4 days after weaning. Cumulus-oocyte complexes (COCs) recovered from small (3–4mm) and large (5–8mm) antral follicles were morphologically graded and subjected to parthenogenetic activation following in vitro maturation (IVM) during the winter (n = 1419) and summer (n = 2803). Cumulus expansion was assessed subsequent to IVM. Data were analysed using a generalised linear mixed model in GenStat release 10. There was an effect of season on oocyte grade, with a larger proportion of oocytes collected in summer being graded suitable for IVM, compared with winter oocytes (P<0.05). A larger proportion of COCs had expanded cumulus during the winter than in the summer, which suggested that the preovulatory LH surge had already occurred. There was a season x follicle size interaction affecting cumulus expansion (P<0.05). There were no seasonal effects on the proportion of oocytes reaching metaphase II or cleaving after parthenogenetic activation. However, the proportion of oocytes from large follicles that developed to the blastocyst stage was higher in winter than in summer (55% vs 23%; P<0.05). There was no effect of season on the proportion of oocytes developing to the blastocyst stage from small follicles. However, during summer there was a reduction in the cell number of blastocysts derived from small follicles (P<0.05). Our results suggest that porcine oocytes are less able to reach their full developmental potential during the period of seasonal infertility, and that the associated pregnancy losses are due to reduced oocyte developmental competence.

Obesity is a risk factor for early pregnancy loss after IVF or ICSI

2000 ◽  
Vol 79 (1) ◽  
pp. 43-48 ◽  
Author(s):  
PÉTER FEDORCSÁK ◽  
RITSA STORENG ◽  
PER OLAV DALE ◽  
TOM TANBO ◽  
THOMAS ÅBYHOLM
Keyword(s):  
Risk Factor ◽  
Early Pregnancy ◽  
Pregnancy Loss ◽  
Early Pregnancy Loss

The effect of mifepristone pretreatment on bleeding and pain during medical management of early pregnancy loss

Contraception ◽  
2021 ◽  
Author(s):  
Andrea H. Roe ◽  
Arden McAllister ◽  
Anne N. Flynn ◽  
Brandon Martin ◽  
Eva Jiang ◽  
...  
Keyword(s):  
Early Pregnancy ◽  
Medical Management ◽  
Pregnancy Loss ◽  
Early Pregnancy Loss

scholarly journals Early pregnancy loss: DoPer- and polyfluoroalkyl substances matter?

2021 ◽  
Vol 157 ◽  
pp. 106837
Author(s):  
Bin Wang ◽  
Jianjie Fu ◽  
Ke Gao ◽  
Qian Liu ◽  
Lili Zhuang ◽  
...  
Keyword(s):  
Early Pregnancy ◽  
Pregnancy Loss ◽  
Early Pregnancy Loss ◽  
Polyfluoroalkyl Substances
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