ملخص المشاركة:
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Several
million babies have been born worldwide since IVF and assisted-reproductive
technologies (ART) became available. However, reports link IVF techniques
with adverse short- and long-term health outcomes.1, 2, 3 Using a mouse
model, we investigated the effect of IVF on the total cell number in
blastocyst stage embryos and the postnatal health of offspring.
Methods:
Experimental groups; (NM) C57/BL6 non-superovulated females naturally mated
with CBA males. (IVC) Two-cell stage embryos collected from C57/BL6
superovulated females mated with CBA males and transferred to MF1 pseudo
pregnant recipients. (IVF) Conducted on isolated C57/BL6 oocytes from superovulated
females using CBA sperm following an IVF protocol;4 embryos at two-cell stage
transferred as above. Blastocyst trophectoderm (TE) and inner cell mass (ICM)
cell numbers from NM and IVF embryos were determined by differential
staining.5 Offspring were analysed for body weight, systolic blood pressure
(SBP).
Results and
discussion: NM blastocysts (41 embryos from 12 mothers) had significantly
more TE and ICM cells
(P<0.05)
compared with IVF (25 embryos; 12 mothers). Male (26–40; 27 mothers) and female
(21–38; 27 mothers) offspring from IVC and IVF embryos were heavier than NM
offspring from week 6 and 5 (P<0.05); respectively; no differences between
IVC and IVF weights were present. IVF and IVC induced increased SBP in male
(weeks 9 and 15) and female (week 15) offspring vs NM (P<0.05). We
conclude IVF causes reduction in blastocyst cell numbers but superovulation
and embryo transfer are sufficient to alter offspring growth and SBP. Further
offspring growth, SBP and glucose tolerance analyses are underway.
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ملخص المشاركة:
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Since the
advent of IVF (in vitro fertilisation), several million babies have been born
worldwide. However, reports link in vitro techniques with adverse short and
long-term health outcomes. Using a mouse model, we investigated the effect of
IVF and duration of culture on blastocyst development and cell number and the
postnatal health of offspring.
Experimental
groups (8-13 litters each): NM (natural mating, non-superovulated);
IV-ET-2Cell (2-cell embryos derived in vivo from superovulated mothers (SOM)
and immediately transferred (ET) to recipients; IV-ET-BL (blastocysts derived
in vivo from SOM and immediate ET); IVF-ET-2cell (2-cell embryos generated by
IVF from SOM, short culture and ET); IVF-ET-BL (blastocysts generated by IVF
from SOM, long culture and ET). IVF blastocysts after prolonged culture
developed slower and comprised reduced trophectoderm and ICM cell numbers compared
with in vivo generated blastocysts (P<0.05; n= 50-87 per treatment).
IV-ET-2Cell (n= 57), IV-ET-BL (n=47), IVF-ET-2Cell (n= 75) and IVF-ET-BL (n=
42) groups compared with NM controls (n=80), showed increased body weight,
increased SBP, impaired GTT and abnormal organ:body weight ratios in both
genders (P<0.05), independent of litter size. At weeks 15, 21, SBP for
IVF-ET-BL males was increased compared to IV-ET-BL and IVFET-2Cell males.
However, glucose concentration 2 hours after glucose injection and AUC (area
under curve) in male IVF-ET-BL was reduced compared with IVF-ET-2Cell males.
Serum insulin for IVF-ET-BL males was significantly reduced compared with
IVF-ET-2Cell, but serum glucose and G:I ratio did not show any significant
differences. No differences were evident between the four treatments groups
for females. We conclude that reproductive treatments affect the development
and potential of preimplantation embryos, influencing postnatal development
and physiology compared with undisturbed reproduction. In particular,
duration of embryo culture, with normalised SO, IVF and ET, may affect male
offspring cardiometabolic health and organ allometry but female health is
less sensitive.
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ملخص المشاركة:
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Since the
advent of IVF (in vitro fertilisation) and assisted reproductive technologies
(ART), several million babies have been born worldwide. However, reports link
in vitro techniques with adverse short and long-term health outcomes. Using a
mouse model, we investigated the effect of IVF and culture on blastocyst development
and cell number and the postnatal health of offspring. Offspring were weighed
weekly, systolic blood pressure (SBP) taken at weeks 9, 15, 21 and LIFE
(average), glucose tolerance test (GTT) carried out prior to cull for organ
collection at week 27. Serum glucose and insulin concentration and G:I was
calculated, also serum and lung angiotensin converting enzyme (ACE) were
determine after collection of serum and lungs were freeze thawed following
culling, with random effects regression statistical analysis used to assess
independence of litter size and maternal origin. Experimental groups (8-13
litters each): NM (natural mating control, non-ART treatment,
non-superovulated); IV-ET-2Cell (2-cell embryos derived in vivo from
superovulated (SO) mothers and immediately transferred (ET) to
pseudo-pregnant recipients; IV-ET-BL (blastocysts derived in vivo from SO
mothers and immediate ET); IVF-ET-2cell (2-cell embryos generated by IVF from
SO mothers, short culture and ET); IVF-ET-BL (blastocysts generated by IVF
from SO mothers, long culture and ET). IVF blastocysts after prolonged
culture developed slower and comprised reduced trophectoderm and ICM cell
numbers compared with in vivo generated blastocysts (P<0.05; n= 50-87 per
treatment; differential nuclear labelling). IV-ET-2Cell (n= 57), IV-ET-BL (n=
47), IVF-ET-2Cell (n= 75) and IVF-ET-BL (n=
42) groups
compared with NM controls (n=80), showed increased body weight, increased
SBP, impaired GGT and abnormal organ:body weight ratios in both genders
(P<0.05), independent of litter size. At weeks 15, 21 and LIFE, SBP for
IVF-ET-BL males was increased compared to IV-ET-BL males (P= 0.003, 0.014 and
0.001, respectively). At weeks 15, 21 and LIFE, IVF-ET-BL males had increased
SBP compared to IVF-ET-2Cell males (P=0.032, 0.034 and 0.017, respectively).
In addition, offspring from IVF-ET-BL group have a significant increase in
serum and lung ACE activity compared with NM group (P= 0.034), (P= 0.019);
respectively. Offspring from IVF-ET-BL group also have a significant increase
in lung ACE activity compared with IVF-ET-BL group (P=0.042), but, serum ACE
activity tended to be higher than IV-ET-BL, this did not reach statistical
significance (ʈ =0.070). Selected correlations show that SBP at 21 weeks in
male from IVF-ET-BL were positively correlated with body weight at 9 weeks (ʈ
=0.051), at 15 weeks
(P=0.018)
and at 21 weeks (P=0.016). With R2 values of 0.046, 0.09 and 0.09
respectively. SBP at 21 weeks and LIFE was also positively correlated with
lung ACE activates (0.002) and (0.009); respectively.
However,
glucose concentration 2 hours after glucose injection and AUC (area under
curve) in male IVF-ET-BL was reduced compared with IVF-ET-2Cell males (P=
0.03, 0.003, respectively). A low G:I ratio indicates high amounts of glucose
present in relation to glucose. In male, IV-ET-2Cell, IVF-ET-2Cell and
IV-ET-BL offspring all demonstrate low G:I ratios in comparison to control
mice (P=0.005, P=0.001 and P=0.038; respectively).
Male
IVF-ET-BL heart:body weight ratio was increased and liver:body weight ratio
reduced compared with IVF-ET-2Cell males (P=0.019, 0.023, respectively).
Selected correlations demonstrate that there is relationships between weight
and AUC, in which weight is positively correlated with AUC measurements in
normal mating (P=0.001), IVET-2Cell (P=0.000), IVF-ET-2Cell (P=0.046),
IV-ET-Bl (P=0.013) and IVF-ET-Bl offspring (P=0.002). With R2
values of
0.2, 0.29, 0.13, 0.26 and 0.2 respectively.
No
differences were evident between the four treatments groups for females. Our
results suggest that reproductive treatments affect the development and
potential of preimplantation embryos, influencing postnatal development and physiology
compared with undisturbed reproduction. In particular, duration of embryo
culture, with normalised SO, IVF and ET, may affect male offspring
cardiometabolic health and organ allometry but female health is less
sensitive.
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