Animal Reproduction/Theriogenology https://www.youtube.com/channel/UCHzZhYqMy10vsVRZdddEkUg

1. Maternal Recognition of
Pregnancy
THER 608
Prof. Dr. Nasim Ahmad
Chap. 13

2. Recognition of Pregnancy
Conceptus Secretions
• Proteins
• Steroids
INF-t
HCG
Estradiol

3. MATERNAL RECOGNITION OF
PREGNANCY
The critical series of events by which the
conceptus initially signals its presence to
the dam and enables pregnancy to
continue is referred as Maternal
Recognition of Pregnancy
How?
1. Antiluteolytic Factor = Prevent effects of PGF
or PGF release
2. Luteotropic Factor = Enhance survival of CL or
support CL (hCG)

6. Maternalrecognitionmust
occurpriortoluteolysis

7. Species Pregnancy
Recognition
Factor
Critical Period
for Recognition
(days after ov.)
Time of
Attachment
(days after ov.)
Cow bIFN-t(bTP-1) 15-16 18-22
Mare 3 Proteins/
Estrogens
12-14 36-38
Woman hCG 7-12 9-12
Pregnancy recognition factors, critical
days of pregnancy recognition and time
conceptus attachment in mammals

8. IFN-t from
the
conceptus
prevents
luteolysis in
the cow and
ewe

9. Transuterine migration of the
equine conceptus
Fixation on day 15-
16, can occur in
either horn!

10. Recognition of Pregnancy in Bovine and
Ovine
Conceptus Secretions
• Interferons
•oIFN-t
•bIFN-t
Mechanism
• Antiluteolytic
• Inhibit oxytocin receptor
synthesis
• Inhibit PGF2a synthesis
Critical Days
• Bovine - 16 to 17
• Ovine - 12 to 13

11. Recognition of Pregnancy in the
Mare
PGF2a
PGF2a
Conceptus Secretion
• ?
Critical Days
10 to 14
Mechanism
• antiluteolytic

12. Recognition of Pregnancy in the Human
HCG
Conceptus Secretes
• HCG
Mechanism
• luteotrophic
Critical Days
•8 to 12

13. Dog and Cat
• CL does not regress if not pregnant
– no uterine effect
• Psuedopregnancy
– CL last similar length as in pregnancy
•Thank you