Physiology of ovarian function

The ovarian function including follicular maturation, ovulation and corpus luteum formation is regulated by a complex control system composed of hypothalamus, pituitary and the ovary itself. These organs communicate via positive and negative feedback loops and can be considered as a functional entity. Special neurons in the hypothalamus produce gonadotropin-releasing hormone (GnRH) being delivered to the anterior pituitary lobe by the pituitary portal vessels. GnRH binds to specific receptors inducing synthesis and release of the gonadotropins FSH and LH into the circulation. After binding to their specific receptors at the ovary FSH and LH induce follicular maturation, ovulation and corpus luteum formation. The ovary responds to gonadotropin stimulation in dual fashion: secretion of sexsteroids and the liberation of a fertilizable oocyte. In addition the ovary is also able to secrete peptide-hormones such as inhibin and activin. Sexsteroids and inhibin modulate the pulsatile secretion of GnRH and gonadotropins. Cooperation of theca- and granulosa cells at the ovarian level and the corpus luteum formation are described and the significance of growth factors and cytocines is emphasized. The effects of estradiol and progesterone are highlighted by the morphological response of the endometrium. The ovary is actively involved in maintaining cyclicity, as reflected by the processes of follicular growth, follicle rupture and formation of the corpus luteum with the dramatic morphological changes involved.     

超声对卵巢子宫内膜异位囊肿的鉴别诊断

目的:探讨卵巢子宫内膜异位囊肿与卵巢其它囊性肿物的超声鉴别诊断.方法:对比分析279个术前超声或术后病理诊断为卵巢子宫内膜异位囊肿的卵巢囊性肿物的声像图表现与病理结果.结果:卵巢子宫内膜异位囊肿超声诊断与病理诊断的符合率为94.3%.结论:超声对卵巢子宫内膜异位囊肿诊断率高,但仍需与其它囊性肿物相鉴别,部分病例有与卵巢黄体囊肿出血、卵巢脓肿、囊性畸胎瘤、粘液性囊腺瘤、卵巢子宫内膜异位囊肿合并感染相似的声像图表现.     

Sonographic comparison of the tubal ring of ectopic pregnancy with the corpus luteum.

OBJECTIVE: Pregnant patients without a sonographically visible intrauterine pregnancy and with a thick-walled cystic adnexal structure present a dilemma. This study compared the utility of various sonographic features in differentiating between the tubal ring of ectopic pregnancy and the corpus luteum. METHODS: Retrospective review of first-trimester transvaginal sonograms revealed a cystic adnexal structure in 79 women. Each structure was evaluated for 6 specific sonographic characteristics: echogenicity of its wall compared with that of the ovary and endometrium, wall thickness in 2 planes, color Doppler flow distribution and percentage of wall circumference, and internal texture. RESULTS: Forty-one (52%) of the 79 women had ectopic pregnancies, and 38 (48%) had corpora lutea. Eleven (32%) of 35 ectopic walls were more echogenic than the endometrium, compared with none of the corpora lutea. A cyst wall less echogenic than the endometrium was more likely in corpora lutea (84% versus 31%; P < .0001). More than twice as many ectopic rinds were more echogenic than ovarian tissue compared with corpora lutea (76% versus 34%; P < .0001). The only predictive internal texture feature was a clear pattern, which was more common in the corpora lutea (P < .01, Fisher exact test). There was no significant difference in mural flow distribution or extent between the 2 groups. CONCLUSIONS: Ancillary sonographic signs to distinguish between an ectopic pregnancy and a corpus luteum include decreased wall echogenicity compared with the endometrium and an anechoic texture, which suggests a corpus luteum.     

术中超声在畸胎瘤手术时对侧卵巢探查中的价值探讨

目的探讨术中超声在单侧卵巢畸胎瘤手术中评价对侧卵巢的价值。方法对41例（平均年龄30岁）术前经影像学检查提示一例卵巢畸胎瘤的患者,术中行对侧卵巢超声检查,超声医师与手术医师共同对图像进行观察和分析。结果生育期正常卵巢内见卵泡,卵泡间组织呈均匀中高回声：血体形成时无回声内见点状回声,黄体形成时呈中高回声、低回声或呈网隔状结构出现高回声团高度怀疑小型畸胎瘤。本组资料38例患者对侧卵巢未显示明显畸胎瘤声像图改变,其中2例经术中剖视证实,36例未行术中剖视,2例显示液性为主混合回声区者剖视证实为黄体。结论术中超声探头频率高,探测卵巢不受位置及周围脏器的影响,可弥补术前超声的不足,进一步确定有无小病灶,从而指导手术进行剖视,减少不必要的手术创伤。     

经阴道彩色多普勒超声对盆腔积液的诊断与分析

目的 对256例盆腔积液进行回顾性分析，总结各种疾病引起盆腔积液的图像特点及毗邻关系。方法 采用经阴道超声与彩色多普勒对盆腔积液的形成及原因作探讨分析，对所显示病灶进行血流动力学观察。结果 256例中超声诊断宫外孕71例，黄体破裂12例，正常排卵33例，结核性包裹性积液9例，卵巢肿瘤22例，盆腔炎性肿块109例。最后确诊宫外孕66例，黄体破裂16例，正常排卵36例，结核性包裹性积液8例，卵巢肿瘤24例，盆腔炎性肿块106例。结论 经阴道超声不仅可提高盆腔器官与病灶显示的清晰度，提高盆腔积液的病因诊断，而且还可较敏感的显示病灶内部血流，有助于血流动力学的测定，判定病灶良、恶性，弥补经腹部超声诊断的不足，为临床提供更为可靠的信息。     

经阴道彩色多普勒超声对输卵管妊娠中妊娠黄体的临床研究

目的探讨妊娠黄体在超声诊断输卵管妊娠(TP)中的临床意义。方法临床拟诊宫外孕患者50例,于术前行经阴道超声(TVS)检查。在确定TP包块的同时,对妊娠黄体进行观察,CDFI显示双侧子宫动脉输卵管支血流,检测收缩期最大流速(PSV)、舒张末期流速(EDV)、平均流速(TAmax)、搏动指数(PI)及阻力指数(RI),并进行统计学处理。结果在确诊为TP的40例中,超声诊断符合38例。妊娠黄体的声像图表现可分为:薄壁囊肿型、薄壁囊肿内部光点型、厚壁囊肿型、实质低回声型四种类型。超声显示妊娠黄体38例(95.0%),黄体与TP同侧33例(86.8%);与TP非同侧5例(13.2%)。黄体与TP同侧时,患侧输卵管动脉血流EDV、TAmax明显高于健侧,PI、RI则明显低于健侧(P<0.05),PSV双侧无统计学差异(P>0.05);黄体与TP非同侧时,双侧血流参数均无统计学意义(P>0.05)。结论妊娠黄体在超声诊断早期TP时具有重要的定位作用。     

Investigation of the human corpus luteum by ultrasonography: a proposed scheme for clinical investigation.

The corpus luteum was investigated in 18 women undergoing hysterectomy. Preoperative ultrasonography with measurements was performed before the corpus luteum was extirpated, weighed, inspected and the diameters were measured. The concentrations of progesterone and estradiol were also determined in peripheral serum. The ultrasound pictures show that the corpus luteum has a slightly cloudy central part, which can vary from hypoechoic to hyperechoic. The peripheral part (corpus luteum 'wall') has a stronger echo and the maximal and minimal thicknesses can be measured. The results showed correlations between ultrasound measurements and anatomical measurements for wall thickness, outer diameter, inner diameter and wall area of the corpus luteum (n = 12, p < 0.02-0.0001). Moreover, all mid-luteal corpora lutea with a hypoechoic central part (five of 13 women) on ultrasound scan had a cystic central structure. Based on these findings, we suggest that an ultrasound investigation of the corpus luteum in the mid-luteal phase should use the following criteria to classify it into four types. Type a: hypoechoic central part with wall of < 3 mm; type b: hyperechoic central part with wall of < 3 mm; type c: hypoechoic central part with wall of >or= 3 mm; and type d: hyperechoic central part with wall of >or= 3 mm. The finding of a hypoechoic central region with a thin wall (< 3 mm) may indicate corpus luteal insufficiency, since significantly lower serum progesterone levels were found in women with this type of corpus luteum.     

Comparison of tubal ring and corpus luteum echogenicities: a useful differentiating characteristic.

The purpose of this report is to compare the echogenicity of the tubal ring of an ectopic pregnancy and the corpus luteum with that of the ovary for improved detection of early ectopic pregnancy. In patients with ectopic pregnancy diagnosed at sonography on the basis of the presence of an adnexal tubal ring, echogenicity of the ring was compared with the echogenicity of the ovarian parenchyma. Twenty-six patients with tubal rings containing either a yolk sac or cardiac activity were included. Twenty-three (88%) of the 26 tubal rings had echogenicity equal to or greater than that of ovarian parenchyma. In 13 patients with ectopic pregnancy diagnosed on the basis of an empty tubal ring, 10 rings (77%) were more echogenic than the ovary. In 45 control patients with intrauterine pregnancy, the corpus luteum was more echogenic than the ovary in only 3 (7%). The tubal ring of an ectopic pregnancy is usually more echogenic than ovarian parenchyma, and the corpus luteum is usually equal to or less echogenic than the ovary. Echogenicity of an adnexal mass may help distinguish the tubal ring of an ectopic pregnancy from a corpus luteum.     

The aging ovary

Aging of the human ovary is a continuous process that begins intra utero with the demise of the first crop of oocytes. The process continues throughout life with the relentless attrition of the oocyte's capital through three fundamental events: follicle degeneration or atresia, corpus luteum formation, and transformation of varying cell populations from atretic and luteal complexes into stromal cells. The ultimate consequence of ovarian aging is the modulation of this organ from a follicle-rich, cyclic secretor of estrogen and progesterone to a stroma-rich, noncyclic, low secretor of androgen. Other structural features of the "aged" ovary, such as obliterative arteriolar sclerosis and surface epithelium cysts, indicate that obvious involution is admixed with persisting ovarian activity. It appears, then, that even after the reproductive period has ended, the human ovary is still a viable organ. The contribution of this organ to the overall well-being of the postmenopausal woman remains to be defined.     

Blood flow velocity in the uterine and ovarian arteries during the normal menstrual cycle.

Twelve healthy women with regular menstrual cycles were examined with a combination of two-dimensional real-time ultrasound and color and spectral Doppler techniques on cycle days 4 and 8 and daily from cycle day 12 until follicular rupture, then days + 1, +2, +5, +7 and +12 after follicular rupture. The uterine and subendometrial arteries, arteries in the ovarian stroma and hilum, in the wall of the largest follicle of each ovary, and in the wall of the corpus luteum were examined. The pulsatility index and the time-averaged maximum velocity were calculated. In the uterine arteries the pulsatility index was highest on day + 2, after which it decreased successively to its lowest value, whereas the time-averaged maximum velocity reached its highest value on day + 12. Similar changes were observed in the subendometrial arteries. In the non-dominant ovary, neither the pulsatility index nor the time-averaged maximum velocity manifested any consistent changes during the cycle. In the dominant ovary, the time-averaged maximum velocity increased and the pulsatility index decreased after follicular rupture, being significantly higher and lower, respectively, in the luteal than in the follicular phase. These changes were seen in the ovarian hilum, stroma and follicular wall, but were most obvious in the wall of the dominant follicle and of the corpus luteum. We conclude that the blood circulation in the uterus and in the dominant ovary changes considerably during the menstrual cycle, whereas that in the non-dominant ovary shows no unequivocal changes.     

Heterotopic pregnancy following intrauterine insemination: successful management with salpingectomy and continuation of intrauterine pregnancy

We report the first case of a heterotopic pregnancy (HP) following ovulation induction and intrauterine insemination (IUI) with resultant normal intrauterine pregnancy after salpingectomy. A 41-year-old para 0 +0 that presented with primary infertility due to azoospermia and polycystic ovaries after laparoscopic evaluation. She had induction of ovulation with Clomiphene citrate, gonadotropin stimulation (hCG), and intrauterine insemination using donor sperm. The resulting pregnancy was later diagnosed as heterotopic pregnancy following rupture of the tubal component at 8 weeks' gestation after an initial misdiagnosis as corpus luteum cyst of pregnancy. She had an emergency laparotomy and left salpingectomy, and the intrauterine pregnancy has continued subsequently to 25 weeks of gestation as at 01/04/2011.This report demonstrates that HP may occur after ovulation induction and IUI. The ectopic component could be misdiagnosed as corpus luteum cyst. It is recommended that pregnancies following this procedure be followed up with serial trans-vaginal ultrasound in the first trimester. Presence of corpus luteum cyst of pregnancy in early ultrasound should be an index of suspicious of a possible heterotopic pregnancy. Early diagnosis and prompt intervention is essential to salvage the intrauterine pregnancy and avoid maternal morbidity and mortality.     

THE CYCLIC CHANGES IN THE MAMMARY GLAND UNDER NORMAL AND PATHOLOGICAL CONDITIONS : I. THE CHANGES IN THE NON-PREGNANT GUINEA PIG.

1. A definite cycle exists in the mammary gland of the non-pregnant guinea pig which corresponds to the cycle in the ovary and uterus. This cycle can be presented through a curve in which the ordinates represent the degree of activity of the gland in a series of animals, and the abscissæ the time since ovulation (period of sexual cycle). The curve passes through a first maximum at the time of heat and ovulation and gradually falls. The minimum is reached on the 6th day and continues until the 15th day after ovulation. Next begins the period when a new ovulation is imminent and the number of the proliferating glands again increases. We see. then that during the normal cycle the presence of well preserved, functioning corpora lutea does not lead to proliferation, neither do mature follicles have such an effect. On the other hand, the absence or degeneration of the corpora lutea is required to insure the proliferation of the mammary gland in the first period of the sexual cycle. If the sexual period is experimentally prolonged, we find in some instances proliferation, while in others it is absent. As far as we can determine at the present time, two factors seem to favor proliferation of the mammary gland under these conditions: (1) the presence of well preserved corpora lutea, particularly if they are associated with well preserved experimentally produced deciduornata, and (2) the imminence of a new period of heat. The connection between good corpora lutea and good deciduornata and the presence of proliferating mammary glands at this stage of the sexual cycle is, however, not absolute. There are cases in which a proliferating gland is associated with some degeneration of the corpus luteum. Or on the other hand a well preserved corpus luteum is associated with a non-proliferating gland. In some of the latter cases the simultaneous presence of a necrotic deciduorna may perhaps explain the lack of proliferation in the mammary gland. However, in the majority of cases we found the presence of good corpora lutea and good deciduomata associated with a proliferating mammary gland. Whether a living corpus luteum as such is able to produce proliferation of the gland is as yet doubtful. 2. Extirpation of the ovaries prevents not only the proliferation of the mammary gland associated with the first stage of the sexual cycle, the condition of heat and ovulation no longer taking place in castrated animals, but in all probability also inhibits the proliferation of the mammary gland which occurs under certain conditions towards the end of the sexual cycle, or in instances of experimentally prolonged sexual cycle in which well preserved corpora lutea and deciduornata are present. 3. In animals in which the ovaries were hypotypical, the mammary glands were in an inactive condition. The presence of hypotypical ovaries has the same influence on the mammary gland as castration. In the majority, but not in all of these cases well preserved corpora lutea were absent. 4. Complete extirpation of the corpora lutea seems directly or indirectly to prevent the secondary proliferation of the mammary gland, which occurs during the latter part of the sexual cycle or during an experimentally prolonged cycle, in cases in which the extirpation is not followed at once by a new ovulation. This conclusion we consider, however, merely as suggested, not yet as definitely established through our results. On the other hand, the primary proliferation of the mammary gland, during the first stage of the sexual cycle, as well as ovulation and the objective signs of heat, is accelerated through complete extirpation of the corpora lutea. Thus the effect of extirpation of the corpora lutea differs from the effect of castration, in that after the latter neither a new heat nor the primary proliferation of the mammary gland occurs. As one of the authors has pointed out previously, the absence of functioning corpora lutea and the presence of either well developed ovarian follicles or of mature follicles are necessary for the occurrence of heat and ovulation. The same conditions are prerequisites for the primary proliferation of the mammary gland. 5. In cases in which the whole or almost the whole uterus had been extirpated, the corpora lutea were well preserved and the mammary gland was proliferating.     

Corpus luteum blood flow in normal and abnormal early pregnancy: evaluation with transvaginal color and pulsed Doppler sonography.

One hundred and thirteen (66.5%) women in this study had a normal intrauterine pregnancy with ages ranging 6 to 12 weeks of gestation. Fifty-seven (33.5%) patients were admitted to the hospital owing to clinically suspected abnormal early pregnancy. Dilatation and curettage were done on all women and tissue sample sent to the pathologist for a final diagnostic. Diagnosis of ectopic pregnancy was made on laparoscopy. Both ovaries were examined carefully by color Doppler in sonography in all patients. Color flow was used as a guide for pulsed Doppler exploration. Corpus luteum blood flow was defined as random, usually semilunar in appearance, dispersed vessels with very low impedance to blood flow. The resistive index and pulsatility index were calculated. Overall detection rate of corpus luteum blood flow in normal pregnancies was higher for the left ovary (62.6%) than for the right ovary (37.4%) (P < 0.01). The mean resistive and pulsatility indices from corpus luteum blood flow were not influenced by gestational age in normal pregnancy. The overall mean value for for resistive index was 0.452 +/- 0.04 and for pulsatility index 0.636 +/- 0.09. The overall detection rate of corpus luteum in abnormal pregnancies also was higher for the left ovary (56.7%) than for the right ovary (43.4%) (P < 0.01). The mean resistive indices from corpus luteum blood flow in patients with missed abortion was higher than in women with normal pregnancy (P < 0.01). Both resistive and pulsatility indices were higher in patients with incomplete or threatened abortion in comparison with normal pregnancy (P < 0.01). No statistically significant difference was seen in the case of anembryonic, molar, or ectopic pregnancy.     

卵巢黄体囊肿破裂75 例临床分析

目的：探讨卵巢黄体囊肿破裂的临床特征和治疗方案。方法：对75例卵巢黄体囊肿破裂临床资料进行回顾性分析。结果：75例均发生于卵巢功能旺盛时期,均以突发性下腹痛为主要症状,5l例以右下腹痛为主,43例伴阴道流血,后穹隆穿刺或腹腔穿刺均抽出不凝血液。入院诊断为黄体囊肿破裂65例,腹痛原因待查10例。73例经手术病理证实为黄体囊肿破裂;2例经临床分析诊断为卵巢黄体囊肿破裂,保守治疗而愈。结论：卵巢黄体囊肿破裂既可发生于月经黄体,又发生于妊娠黄体,以右侧卵巢多见,临床应注意与阑尾炎、异位妊娠破裂及卵巢肿瘤蒂扭转鉴别。     

Is the corpus luteum normal after ovulation induction?

Repeated ultrasound examinations and blood samplings for determination of estradiol (E), progesterone (P), and luteinizing hormone (LH) were carried out in 15 normal and 11 clomiphene citrate (CC)/human menopausal gonadotropin (hMG) stimulated cycles. Human chorionic gonadotropin (hCG) was administered in the stimulated cycles on the day of the expected LH-peak as determined in each woman's normal cycle. Ovulation and normalcy of the luteal phase were confirmed by the hormonal values. Ultrasound examinations showed development of a single follicle in the normal group and development of 4.1 follicles on average, of 15 mm or more in diameter in the stimulated group (total of 45 follicles). Midluteal phase images at the site of the former follicle showed echogenic structures of echo-free structures with scattered echoes in 25 cases in the stimulated group and in 11 cases in the normal group. There was no sign of the former follicle in 1 and 3 cases, respectively, in the two groups. A significantly higher number of "persistent follicles" was seen in the stimulated group: 42% vs. 7%. It is discussed whether a compromised corpus luteum function occurs after stimulation despite a normal luteal phase.     

Sonographic and Doppler characteristics of the corpus luteum: can they predict pregnancy outcome?

OBJECTIVE: To determine whether there is a relationship between gray scale or Doppler characteristics of the corpus luteum and first-trimester pregnancy outcome. METHODS: We conducted a prospective study of patients with spontaneous singleton pregnancies between 5 and 8 weeks' gestation. The corpus luteum size, sonographic appearance, resistive index, and peak systolic velocity were measured on transvaginal sonography. Maternal use of exogeneous progesterone was recorded. Only patients with known first-trimester outcome were included. RESULTS: There were 201 study patients. The corpus luteum could be visualized in 197 (98%) and had a mean +/- SD size of 1.9 +/- 0.6 cm, a mean resistive index of 0.50 +/- 0.08, and a peak systolic velocity of 20.5 +/- 11.2 cm/s. There were 151 first-trimester survivors (75.1 %) and 50 spontaneous losses (24.9%). In a comparison of the survivors and losses, there was no significant difference in mean corpus luteum size (1.9 versus 1.7 cm; P = .10, t test), mean resistive index (0.50 versus 0.50; P = .71, t test), peak systolic velocity (21 versus 19 cm/s; P = .29, t test), or sonographic appearance (P = .78, chi2 test). The lack of association between corpus luteum characteristics and outcome persisted when cases were stratified by progesterone use and the presence or absence of a heartbeat on the study sonogram. CONCLUSION: There is no apparent relationship between the characteristics of the corpus luteum and first-trimester pregnancy outcome.     

The corpus luteum

The primary function of the corpus luteum is secretion of progesterone for maintenance of pregnancy. The development and function of the corpus luteum from residual follicular granulosa and theca cells after ovulation is induced by the midcyclic peak of LH secretion followed by further pulsatile LH release. Due to this stimulation the follicular granulosa and theca cells are converted to large and small luteinized cells with high proliferation rate. During this process Vascular-Endothelial-Growth Factor (VEGF) plays a major role as a potent stimulator of neo-angiogenesis. Formation of new blood vessels is essential to ensure supply of LDL-Cholesterol as substrate for steroidogenesis. If pregnancy does not occurs, the corpus luteum must regress to initiate another cycle. Luteal regression seems to be initiated by PGF2 alpha which is secreted from the uterus. PGF2 alpha, reduces luteal blood flow and progesterone synthesis. Furthermore it is a potent inducer of apoptosis. If pregnancy occurs, sustained secretion of progesterone and other substances like estradiol and relaxin are required to provide an appropriate uterine environment for maintenance of pregnancy. In that case the corpus luteum is further stimulated by hCG secreted by the blastocyst and the trophoblast-cells until 8/9 weeks of gestational age, when synthesis and secretion of steroids is taken over by the placenta.     

Cysts in pregnancy discovered by sonography

The incidence of cysts in pregnancy was established with ultrasound. In 3,330 pregnant patients who underwent sonography, 38 adnexal cystic lesions (1.14%) were found. All but two cysts were discovered before 16 weeks. Follow-up showed that the majority of the cystic lesions resolved spontaneously; these were presumed to represent corpus luteum cysts. Five patients underwent surgery because of persistent cystic lesions; a mucinous cystadenoma, a benign cystic teratoma, a paraovarian cyst, an inclusion cyst, and a tuboovarian abscess were found. Septations and echogenic material were seen within the cystic teratoma and the tuboovarian abscess but the sonographic features of the other operated lesions were identical to those seen in the corpus luteum cysts.     

Blood flow velocity in the uterine and ovarian arteries during menstruation.

Eleven healthy women with regular menstrual cycles were examined with a combination of two-dimensional real-time ultrasound and color and spectral Doppler techniques on the 7th day after follicular rupture, and on the 1st, 2nd, 3rd and 4th days of menstrual bleeding. Both uterine arteries, arteries in the stroma and hila of both ovaries, in the wall of the largest follicle of the non-dominant ovary and in the wall of the corpus luteum were examined with the Doppler technique. The pulsatility index (PI) and the time-averaged maximum velocity were calculated. In the uterine arteries, the PI was highest on the first day of menstrual bleeding (median PI 3.2 for the dominant and 3.0 for the non-dominant uterine artery), after which it decreased to its lowest values on the second day (median PI 2.1 and 1.8, respectively) and third day (median PI 2.2 and 2.1, respectively). The time-averaged maximum velocity reached its highest value on the second and third days of menstruation. The corpus luteum was still visible on the first day of menstrual bleeding in all women, and on the second day in five. It was indistinguishable on the third and fourth days of menstruation in all women. In the dominant ovary, the time-averaged maximum velocity of flow in the arteries in the ovarian hilum decreased during menstrual bleeding and was lower during menstruation than in the preceding luteal phase. In the non-dominant ovary, neither the PI nor the time-averaged maximum velocity manifested any consistent changes during the period studied. We conclude that substantial changes in PI and time-averaged maximum velocity occur in the uterine arteries and in the arteries of the dominant ovary during menstruation.