发情期和妊娠早期孕酮对奶牛繁殖的影响及调控方法

doi:10.11843/j.issn.0366-6964.2024.10.001

摘要/Abstract

摘要：

奶牛发情期和妊娠早期体内孕酮水平不足是导致其繁殖效率低的重要因素之一。较高的孕酮水平能够提高卵母细胞质量、调节激素分泌、调控子宫内环境以及促进胚胎发育，从而提升奶牛的繁殖效率。因此，发情期和妊娠早期孕酮水平与奶牛繁殖效率之间的关系受到广泛了关注。本文总结了孕酮对奶牛发情期及妊娠早期不同阶段的影响，并探讨了在这些关键时期提高孕酮水平的方法，以期为奶牛养殖产业提供生产指导，助力奶牛繁育工作提质增效。

关键词: 奶牛, 孕酮, 发情期, 妊娠早期, 繁殖效率

Abstract:

Insufficient progesterone levels during estrus and early pregnancy in dairy cows is one of significant factors contributing to low reproductive efficiency. Elevated progesterone levels have been shown to enhance oocyte quality, regulate hormone secretion, control the uterine environment, and promote embryonic development, thereby improving reproductive efficiency in dairy cows. Consequently, the relationship between progesterone levels during estrus and early pregnancy and reproductive efficiency in dairy cows has attracted significant attention. This paper summarizes the effects of progesterone on various stages of estrus and early pregnancy in dairy cows and explores methods to enhance progesterone levels during these critical periods. The objective is to provide production guidance for dairy farming industry and to improve the quality and efficiency of dairy cow breeding.

Key words: dairy cow, progesterone, estrus, early pregnancy, reproductive efficiency

中图分类号:

孙国瀚, 郑浩, 杨卓, 沈文娟, 陶金忠. 发情期和妊娠早期孕酮对奶牛繁殖的影响及调控方法[J]. 畜牧兽医学报, 2024, 55(10): 4241-4249.

Guohan SUN, Hao ZHENG, Zhuo YANG, Wenjuan SHEN, Jinzhong TAO. Effects and Regulation Methods of Progesterone on Reproduction in Dairy Cows During Estrus and Early Pregnancy[J]. Acta Veterinaria et Zootechnica Sinica, 2024, 55(10): 4241-4249.

图/表 8

表 1

表 2

表 3

表 4

表 5

表 6

表 7

表 8

参考文献 67

1	中华人民共和国农业农村部. 关于印发《"十四五"奶业竞争力提升行动方案》的通知[EB/OL]. (2022-02-16). https://www.moa.gov.cn/nybgb/2022/202204/202206/t20220607_6401741.htm.
	Ministry of Agriculture and Rural Affairs of the People's Republic of China. "14th five-year plan" dairy industry competitiveness improvement action plan[EB/OL]. (2022-02-16). https://www.moa.gov.cn/nybgb/2022/202204/202206/t20220607_6401741.htm. (in Chinese)
2	中华人民共和国农业农村部, 发展改革委, 科技部, 等. 关于进一步促进奶业振兴的若干意见[EB/OL]. (2018-12-24). https://www.moa.gov.cn/ztzl/xczx/zccs_24715/201812/t20181228_6165785.htm.
	Ministry of Agriculture and Rural Affairs of the People's Republic of China, National Development and Reform Commission, Ministry of Science and Technology of the People's Republic of China, et al. Several opinions on further promoting the revitalization of the dairy industry[EB/OL]. (2018-12-24). https://www.moa.gov.cn/ztzl/xczx/zccs_24715/201812/t20181228_6165785.htm. (in Chinese)
3	中华人民共和国农业农村部, 国家发展改革委, 财政部, 等. 关于印发《全国现代设施农业建设规划(2023—2030年)》的通知[EB/OL]. (2023-06-09). https://www.gov.cn/zhengce/zhengceku/202306/content_6887551.htm.
	Ministry of Agriculture and Rural Affairs of the People's Republic of China, National Development and Reform Commission, Ministry of Finance of the People's Republic of China, et al. Notice on issuing the national modern facility agriculture construction plan (2023-2030)[EB/OL]. (2023-06-09). https://www.gov.cn/zhengce/zhengceku/202306/content_6887551.htm. (in Chinese)
4	SPECKHART S L , OLIVER M A , EALY A D . Developmental hurdles that can compromise pregnancy during the first month of gestation in cattle[J]. Animals (Basel), 2023, 13 (11): 1760.
5	REKAWIECKI R , KOWALIK M K , KOTWICA J . The expression of progesterone receptor coregulators mRNA and protein in corpus luteum and endometrium of cows during the estrous cycle[J]. Anim Reprod Sci, 2017, 183, 102- 109. doi: 10.1016/j.anireprosci.2017.05.011
6	SILVA L O E , VALENZA A , ALVES R L O R , et al. Progesterone release profile and follicular development in Holstein cows receiving intravaginal progesterone devices[J]. Theriogenology, 2021, 172, 207- 215. doi: 10.1016/j.theriogenology.2021.07.001
7	MELO D B , COELHO W M Jr , MARQUES T C , et al. Effect of 200 μg of gonadorelin hydrochloride at the first GnRH of a CIDR Synch program on ovulation rate and pregnancies per AI in Holstein heifers[J]. J Dairy Sci, 2024,
8	SIMŌES L M S , LIMA E A , CARVALHO L R , et al. Exposure to progesterone before an ovulation synchronization protocol increases the follicular diameter and fertility of multiparous suckled Bos taurus cows[J]. Theriogenology, 2024, 218, 239- 243. doi: 10.1016/j.theriogenology.2024.01.031
9	费国庆, 宁致远, 赵泽芳, 等. 妊娠期奶牛黄体细胞的分离鉴定及培养特性[J]. 畜牧兽医学报, 2024, 55 (5): 2214- 2225.
	FEI G Q , NING Z Y , ZHAO Z F , et al. Isolation, identification of luteal cells from cows during pregnancy and investigation of their culture characteristics[J]. Acta Veterinaria et Zootechnica Sinica, 2024, 55 (5): 2214- 2225.
10	GAUDE I , KEMPF A , STRVVE K D , et al. Estrus signs in Holstein Friesian dairy cows and their reliability for ovulation detection in the context of visual estrus detection[J]. Livest Sci, 2021, 245, 104449. doi: 10.1016/j.livsci.2021.104449
11	BORCHARDT S , TIPPENHAUER C M , PLENIO J L , et al. Association of estrous expression detected by an automated activity monitoring system within 40 days in milk and reproductive performance of lactating Holstein cows[J]. J Dairy Sci, 2021, 104 (8): 9195- 9204. doi: 10.3168/jds.2020-19705
12	GARCIA-ISPIERTO I , LÓPEZ-HELGUERA I , SERRANO-PÉREZ B , et al. Progesterone supplementation during the time of pregnancy recognition after artificial insemination improves conception rates in high-producing dairy cows[J]. Theriogenology, 2016, 85 (7): 1343- 1347. doi: 10.1016/j.theriogenology.2015.12.021
13	LÓPEZ-GATIUS F , HUNTER R H F . Preventing twin pregnancies in dairy cattle, turning the odds into reality[J]. Livest Sci, 2019, 229, 1- 3. doi: 10.1016/j.livsci.2019.09.004
14	BRUINJÉ T C , MORRISON E I , RIBEIRO E S , et al. Associations of postpartum health with progesterone after insemination and endocrine signaling during early pregnancy in dairy cows[J]. J Dairy Sci, 2024, 107 (5): 3168- 3184. doi: 10.3168/jds.2023-24068
15	CONSENTINI C E C , CARNEIRO T O , NERI H , et al. Improved fertility following a gonadotropin-releasing hormone treatment on day 2 of an estradiol and progesterone-based timed-artificial insemination protocol in lactating dairy cows[J]. JDS Commun, 2022, 3 (3): 212- 216. doi: 10.3168/jdsc.2022-0212
16	PEREIRA M H C , WILTBANK M C , GUIDA T G , et al. Evaluation of presynchronization and addition of GnRH at the beginning of an estradiol/progesterone protocol on circulating progesterone and fertility of lactating dairy cows[J]. Theriogenology, 2020, 147, 124- 134. doi: 10.1016/j.theriogenology.2019.11.025
17	TSCHOPP J C , BÓ G A . Success of artificial insemination based on expression of estrus and the addition of GnRH to an estradiol/progesterone-based protocol on pregnancy rates in lactating dairy cows[J]. Anim Reprod Sci, 2022, 238, 106954. doi: 10.1016/j.anireprosci.2022.106954
18	CARVALHO P D , FUENZALIDA M J , RICCI A , et al. Modifications to Ovsynch improve fertility during resynchronization: evaluation of presynchronization with gonadotropin-releasing hormone 6 d before initiation of Ovsynch and addition of a second prostaglandin F_2α treatment[J]. J Dairy Sci, 2015, 98 (12): 8741- 8752. doi: 10.3168/jds.2015-9719
19	AZEVEDO C , MAIA I , CANADA N , et al. Comparison of fertility, regular returns-to-estrus, and calving interval between Ovsynch and CO-synch+CIDR protocols in dairy cows[J]. Theriogenology, 2014, 82 (6): 910- 914. doi: 10.1016/j.theriogenology.2014.07.006
20	CLAYPOOL C K , SPENCER J A , ZOCA S M , et al. Short communication: reproduction outcomes in dairy heifers following a 14-d progesterone insert presynchronization protocol[J]. J Dairy Sci, 2019, 102 (12): 11730- 11735. doi: 10.3168/jds.2019-17000
21	ABDALLA H , MAKAU D N , SALEM S E . Treatment of cows that fail to respond to pre-synchronization treatments with a CIDR-Ovsynch regimen improves the overall pregnancy percentage after a double Ovsynch treatment regimen[J]. Anim Reprod Sci, 2020, 216, 106356. doi: 10.1016/j.anireprosci.2020.106356
22	BISINOTTO R S , CASTRO L O , PANSANI M B , et al. Progesterone supplementation to lactating dairy cows without a corpus luteum at initiation of the Ovsynch protocol[J]. J Dairy Sci, 2015, 98 (4): 2515- 2528. doi: 10.3168/jds.2014-9058
23	EL-TARABANY M S . The efficiency of new CIDR and once-used CIDR to synchronize ovulation in primiparous and multiparous Holstein cows[J]. Anim Reprod Sci, 2016, 173, 29- 34. doi: 10.1016/j.anireprosci.2016.08.006
24	BERG D K , LEDGARD A , DONNISON M , et al. The first week following insemination is the period of major pregnancy failure in pasture-grazed dairy cows[J]. J Dairy Sci, 2022, 105 (11): 9253- 9270. doi: 10.3168/jds.2021-21773
25	FORDE N , LONERGAN P . Interferon-tau and fertility in ruminants[J]. Reproduction, 2017, 154 (5): F33- F43. doi: 10.1530/REP-17-0432
26	WILTBANK M C , BAEZ G M , GARCIA-GUERRA A , et al. Pivotal periods for pregnancy loss during the first trimester of gestation in lactating dairy cows[J]. Theriogenology, 2016, 86 (1): 239- 253. doi: 10.1016/j.theriogenology.2016.04.037
27	TALUKDER A K , MAREY M A , SHIRASUNA K , et al. Roadmap to pregnancy in the first 7 days post-insemination in the cow: immune crosstalk in the corpus luteum, oviduct, and uterus[J]. Theriogenology, 2020, 150, 313- 320. doi: 10.1016/j.theriogenology.2020.01.071
28	HANSEN P J . Perspective: can early embryonic losses be reduced in lactating dairy cows?[J]. J Dairy Sci, 2023, 106 (10): 6593- 6596. doi: 10.3168/jds.2023-23445
29	COLAZO M G , BEHROUZI A , AMBROSE D J , et al. Diameter of the ovulatory follicle at timed artificial insemination as a predictor of pregnancy status in lactating dairy cows subjected to GnRH-based protocols[J]. Theriogenology, 2015, 84 (3): 377- 383. doi: 10.1016/j.theriogenology.2015.03.034
30	BURNETT T A , MADUREIRA A M L , BAUER J W , et al. Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression[J]. J Dairy Sci, 2022, 105 (2): 1743- 1753. doi: 10.3168/jds.2021-20156
31	GOBIKRUSHANTH M , MAPLETOFT R J , COLAZO M G . Estrous activity and pregnancy outcomes in Holstein heifers subjected to a progesterone based 5-d CO-Synch protocol with or without administration of initial GnRH[J]. Theriogenology, 2023, 202, 36- 41. doi: 10.1016/j.theriogenology.2023.02.024
32	DEWEY S T , MENDONÇA L G D , LOPES G , et al. Resynchronization strategies to improve fertility in lactating dairy cows utilizing a presynchronization injection of GnRH or supplemental progesterone: I.Pregnancy rates and ovarian responses[J]. J Dairy Sci, 2010, 93 (9): 4086- 4095. doi: 10.3168/jds.2010-3233
33	GARCIA-ISPIERTO I , DE RENSIS F , CASAS X , et al. Inducing ovulation with hCG in a five-day progesterone-based fixed-time AI protocol improves the fertility of anestrous dairy cows under heat stress conditions[J]. Theriogenology, 2019, 124, 65- 68. doi: 10.1016/j.theriogenology.2018.10.015
34	SÁNCHEZ J M , RANDI F , PASSARO C , et al. Effect of human chorionic gonadotrophin administration 2 days after insemination on progesterone concentration and pregnancy per artificial insemination in lactating dairy cows[J]. J Dairy Sci, 2018, 101 (7): 6556- 6567. doi: 10.3168/jds.2017-14058
35	EL AZZI M S , VALDES-ARCINIEGA T , ANTA-GALVAN E , et al. Effects of human chorionic gonadotropin on the last day of a 5-day CIDR Synch protocol and 5 days later on circulating progesterone concentrations and luteal area in Holstein heifers[J]. JDS Commun, 2022, 3 (5): 368- 372. doi: 10.3168/jdsc.2022-0220
36	ALNIMER M A , SHAMOUN A I . Treatment with hCG 4 or 6 days after TAI to improve pregnancy outcomes in repeat-breeding dairy cows[J]. Anim Reprod Sci, 2015, 157, 63- 70. doi: 10.1016/j.anireprosci.2015.03.016
37	VASCONCELOS J L M , SÁFILHO O G , JUSTOLIN P L T , et al. Effects of postbreeding gonadotropin treatments on conception rates of lactating dairy cows subjected to timed artificial insemination or embryo transfer in a tropical environment[J]. J Dairy Sci, 2011, 94 (1): 223- 234. doi: 10.3168/jds.2010-3462
38	FORDE N , CARTER F , FAIR T , et al. Progesterone-regulated changes in endometrial gene expression contribute to advanced conceptus development in cattle[J]. Biol Reprod, 2009, 81 (4): 784- 794. doi: 10.1095/biolreprod.108.074336
39	FERGUSON C E , KESLER D J , GODKE R A . Improving pregnancy rates in problem breeder cattle by administration of 15 mg of progesterone on days 3-5 post-mating[J]. J Appl Anim Res, 2012, 40 (3): 173- 178. doi: 10.1080/09712119.2011.645038
40	BISINOTTO R S , RIBEIRO E S , MARTINS L T , et al. Effect of interval between induction of ovulation and artificial insemination (AI) and supplemental progesterone for resynchronization on fertility of dairy cows subjected to a 5-d timed AI program[J]. J Dairy Sci, 2010, 93 (12): 5798- 5808. doi: 10.3168/jds.2010-3516
41	HANLON D W , DAVIDSON P J , HITTMANN A R , et al. Supplementing previously treated anestrous dairy cows with progesterone does not increase first-service conception rate[J]. Theriogenology, 2005, 63 (1): 239- 245. doi: 10.1016/j.theriogenology.2004.04.008
42	MONTEIRO P L J , RIBEIRO E S , MACIEL R P , et al. Effects of supplemental progesterone after artificial insemination on expression of interferon-stimulated genes and fertility in dairy cows[J]. J Dairy Sci, 2014, 97 (8): 4907- 4921. doi: 10.3168/jds.2013-7802
43	FRIEDMAN E , ROTH Z , VOET H , et al. Progesterone supplementation postinsemination improves fertility of cooled dairy cows during the summer[J]. J Dairy Sci, 2012, 95 (6): 3092- 3099. doi: 10.3168/jds.2011-5017
44	MANN G E , FRAY M D , LAMMING G E . Effects of time of progesterone supplementation on embryo development and interferon-τ production in the cow[J]. Vet J, 2006, 171 (3): 500- 503. doi: 10.1016/j.tvjl.2004.12.005
45	BRUINJÉ T C , MORRISON E I , RIBEIRO E S , et al. Associations of postpartum health with progesterone after insemination and endocrine signaling during early pregnancy in dairy cows[J]. J Dairy Sci, 2024, 107 (5): 3168- 3184. doi: 10.3168/jds.2023-24068
46	WILTBANK M C , MEIDAN R , OCHOA J , et al. Maintenance or regression of the corpus luteum during multiple decisive periods of bovine pregnancy[J]. Anim Reprod, 2016, 13 (3): 217- 233. doi: 10.21451/1984-3143-AR865
47	KAYA S , KAÇAR C , POLAT B , et al. Association of luteal blood flow with follicular size, serum estrogen and progesterone concentrations, and the inducibility of luteolysis by PGF_2α in dairy cows[J]. Theriogenology, 2017, 87, 167- 172. doi: 10.1016/j.theriogenology.2016.08.022
48	FRANCO M , THOMPSON P M , BRAD A M , et al. Effectiveness of administration of gonadotropin-releasing hormone at days 11, 14 or 15 after anticipated ovulation for increasing fertility of lactating dairy cows and non-lactating heifers[J]. Theriogenology, 2006, 66 (4): 945- 954. doi: 10.1016/j.theriogenology.2005.12.014
49	LÓPEZ-GATIUS F , SANTOLARIA P , MARTINO A , et al. The effects of GnRH treatment at the time of AI and 12 days later on reproductive performance of high producing dairy cows during the warm season in northeastern Spain[J]. Theriogenology, 2006, 65 (4): 820- 830. doi: 10.1016/j.theriogenology.2005.07.002
50	BRUNO R G S , MORAES J G N , HERNÁNDEZ-RIVERA J A H , et al. Effect of an Ovsynch56 protocol initiated at different intervals after insemination with or without a presynchronizing injection of gonadotropin-releasing hormone on fertility in lactating dairy cows[J]. J Dairy Sci, 2014, 97 (1): 185- 194. doi: 10.3168/jds.2013-6827
51	CHEBEL R C , SCANAVEZ A A , SILVA P R B , et al. Evaluation of presynchronized resynchronization protocols for lactating dairy cows[J]. J Dairy Sci, 2013, 96 (2): 1009- 1020. doi: 10.3168/jds.2012-5892
52	BILBY T R , BRUNO R G S , LAGER K J , et al. Supplemental progesterone and timing of resynchronization on pregnancy outcomes in lactating dairy cows[J]. J Dairy Sci, 2013, 96 (11): 7032- 7042. doi: 10.3168/jds.2013-6960
53	ALNIMER M A , LUBBADEH W F . Effect of progesterone (P₄) intravaginal device (CIDR) to reduce embryonic loss and to synchronize return to oestrus of previously timed inseminated lactating dairy cows[J]. Anim Reprod Sci, 2008, 107 (1/2): 36- 47.
54	MADOZ L V , RABAGLINO M B , MIGLIORISI A L , et al. Association between progesterone concentration and endometrial gene expression in dairy cows[J]. Domest Anim Endocrinol, 2021, 74, 106481. doi: 10.1016/j.domaniend.2020.106481
55	DOMINGUES R R , ANDRADE J P N , CUNHA T O , et al. Is pregnancy loss initiated by embryonic death or luteal regression?Profiles of pregnancy-associated glycoproteins during elevated progesterone and pregnancy loss[J]. JDS Commun, 2023, 4 (2): 149- 154. doi: 10.3168/jdsc.2022-0282
56	GIORDANO J O , WILTBANK M C , GUENTHER J N , et al. Effect of presynchronization with human chorionic gonadotropin or gonadotropin-releasing hormone 7 days before resynchronization of ovulation on fertility in lactating dairy cows[J]. J Dairy Sci, 2012, 95 (10): 5612- 5625. doi: 10.3168/jds.2011-5035
57	LÓPEZ-GATIUS F , SANTOLARIA P , YÁNIZ J L , et al. Progesterone supplementation during the early fetal period reduces pregnancy loss in high-yielding dairy cattle[J]. Theriogenology, 2004, 62 (8): 1529- 1535. doi: 10.1016/j.theriogenology.2004.02.005
58	LOPES G , GIORDANO J O , VALENZA A , et al. Effect of timing of initiation of resynchronization and presynchronization with gonadotropin-releasing hormone on fertility of resynchronized inseminations in lactating dairy cows[J]. J Dairy Sci, 2013, 96 (6): 3788- 3798. doi: 10.3168/jds.2012-6429
59	SOUZA A H , CUNHA A P , SILVA E P B , et al. Comparison of gonadorelin products in lactating dairy cows: efficacy based on induction of ovulation of an accessory follicle and circulating luteinizing hormone profiles[J]. Theriogenology, 2009, 72 (2): 271- 279. doi: 10.1016/j.theriogenology.2009.02.016
60	LÓPEZ-GATIUS F , GARCIA-ISPIERTO I . Treatment with an elevated dose of the GnRH analogue dephereline in the early luteal phase improves pregnancy rates in repeat-breeder dairy cows[J]. Theriogenology, 2020, 155, 12- 16. doi: 10.1016/j.theriogenology.2020.06.011
61	GARCIA-ISPIERTO I , LÓPEZ-GATIUS F . Inducing ovulation with the GnRH analogue dephereline in a five-day progesterone-based fixed-time AI protocol improves embryo survival in anestrous dairy cows[J]. Livest Sci, 2020, 239, 104087. doi: 10.1016/j.livsci.2020.104087
62	GARCIA-ISPIERTO I , DE RENSIS F , PÉREZ-SALAS J A , et al. The GnRH analogue dephereline given in a fixed-time AI protocol improves ovulation and embryo survival in dairy cows[J]. Res Vet Sci, 2019, 122, 170- 174. doi: 10.1016/j.rvsc.2018.11.020
63	WIJMA R , STANGAFERRO M L , MASELLO M , et al. Resynchronization of ovulation protocols for dairy cows including or not including gonadotropin-releasing hormone to induce a new follicular wave: effects on re-insemination pattern, ovarian responses, and pregnancy outcomes[J]. J Dairy Sci, 2017, 100 (9): 7613- 7625. doi: 10.3168/jds.2017-12550
64	靳青, 张相伦, 魏晨, 等. 氧化应激通过Fas/FasL信号通路调控奶牛子宫内膜细胞凋亡[J]. 畜牧兽医学报, 2022, 53 (6): 1819- 1828.
	JIN Q , ZHANG X L , WEI C , et al. Oxidative Stress-induced apoptosis in bovine endometrial cells is mediated through Fas/FasL signaling pathway[J]. Acta Veterinaria et Zootechnica Sinica, 2022, 53 (6): 1819- 1828.
65	BRUINJÉ T C , MORRISON E I , RIBEIRO E S , et al. Progesterone profiles in postpartum dairy cows with inflammatory disorders[J]. J Dairy Sci, 2024, doi: 10.3168/jds.2023-24604
66	MION B , MADUREIRA G , SPRICIGO J F W , et al. Effects of source of supplementary trace minerals in pre-and postpartum diets on reproductive biology and performance in dairy cows[J]. J Dairy Sci, 2023, 106 (7): 5074- 5095. doi: 10.3168/jds.2022-22784
67	CERNY K L , ANDERSON L , BURRIS W R , et al. Form of supplemental selenium fed to cycling cows affects systemic concentrations of progesterone but not those of estradiol[J]. Theriogenology, 2016, 85 (5): 800- 806. doi: 10.1016/j.theriogenology.2015.10.022

参考文献 Reference	注射时间 Injection time	剂量/μg Dosage		妊娠率/% Pregnancy rate
参考文献 Reference	注射时间 Injection time	试验组 Experimental group	对照组 Control group	试验组 Experimental group	对照组 Control group
Tschopp和Bó^[17]	TAI前3~2 d	100	0	50.6^a	42.7^b
Consentini等^[15]	TAI前11 d	100	0	34.4^a	30.4^b
Carvalho等^[18]	TAI前16 d	100	0	40	37
Carvalho等^[18]	TAI前16 d	100	0	33	32

参考文献 Reference	插入时间 Insertion time	剂量/g Dosage		妊娠率/% Pregnancy rate
参考文献 Reference	插入时间 Insertion time	试验组 Experimental group	对照组 Control group	试验组 Experimental group	对照组 Control group
Azevedo等^[19]	TAI前9 d	1.38	0	40.3	33.3
Abdalla等^[21]	TAI前10 d	1.38	0	32.8^a	22.5^b
Bisinotto等^[22]	TAI前10 d	2.76	0	42.2^a	31.3^b
El-Tarabany^[23]	TAI前10 d	1.38	0	35.9^a	22.5^b

参考文献 Reference	注射时间 Injection time	剂量/μg Dosage		妊娠率/% Pregnancy rate
参考文献 Reference	注射时间 Injection time	试验组 Experimental group	对照组 Control group	试验组 Experimental group	对照组 Control group
Burnett等^[30]	TAI后0 d	100	0	41.3^a	35.7^b
Gobikrushanth等^[31]	TAI后0 d	100	0	61	54.5
Dewey等^[32]	TAI后7 d	100	0	30.7	19.7
Dewey等^[32]	TAI后7 d	100	0	35.2	27.5

参考文献 Reference	注射时间 Injection time	剂量/IU Dosage		妊娠率/% Pregnancy rate
参考文献 Reference	注射时间 Injection time	试验组 Experimental group	对照组 Control group	试验组 Experimental group	对照组 Control group
Alnimer和Shamoun^[36]	TAI后4 d	1 500	0	32.4^a	30.9^b
Alnimer和Shamoun^[36]	TAI后6 d	1 500	0	38.9^a	30.9^b
Vasconcelos等^[37]	TAI后7 d	2 500	0	32.4	30.1
Vasconcelos等^[37]	TAI后7 d	2 500	0	45.1	38.1

参考文献 Reference	插入时间 Insertion time	剂量/g Dosage		妊娠率/% Pregnancy rate
参考文献 Reference	插入时间 Insertion time	试验组 Experimental group	对照组 Control group	试验组 Experimental group	对照组 Control group
Bisinotto等^[40]	TAI后0~5 d	1.38	0	51.3^a	43.1^b
Hanlon等^[41]	TAI后4~11 d	1.56	0	36.7	35
Monteiro等^[42]	TAI后4~18 d	1.38	0	35.2	30.8
Friedman等^[43]	TAI后5±1~18 d	1.9	0	42	33