The incidence of ovarian remnant syndrome is difficult to determine. The available data are limited to case reports or to retrospective case series. The best available data are from a study describing the frequency and outcome of laparoscopy in women with chronic pelvic pain and/or a pelvic mass who were found to have ovarian remnants. In 119 women who underwent hysterectomy and oophorectomy by laparoscopy, ovarian remnants were known in 5 and were found during surgery in 21 patients (18%).[2] However, this was a small study and the participants were only symptomatic women. Therefore, it is not known whether the data can be extrapolated to include all women who have undergone oophorectomy.

Treatment for ovarian remnant (ORS) is generally indicated for women with suspected ORS who have symptoms (such as pain); have a pelvic mass; or need or desire complete removal of to decrease the risk of ovarian (for example, BRCA ). The mainstay of treatment is surgery to remove the residual ovarian tissue. Women with ORS with a pelvic mass should have appropriate evaluation for malignancy (cancer). Hormonal therapy to suppress ovarian function is an alternative treatment for those who refuse surgery, or those who are not candidates for surgery. Medications may be used to treat ORS and include GnRH agonists, danazol, or progesterone.

Pain associated with ovarian cysts may be treated in several ways:

- Pain relievers such as acetaminophen, nonsteroidal anti-inflammatory drugs, or opioids.

- While hormonal birth control prevents the development of new cysts in those who frequently get them, it is not useful for the treatment of current cysts.

Although most cases of ovarian cysts involve monitoring, some cases require surgery. This may involve removing the cyst, or one or both ovaries. Technique is typically laparoscopic, unless the cyst is particularly large, or if pre-operative imaging suggests malignancy or complex anatomy. In certain situations, the cyst is entirely removed, while with cysts with low recurrence risk, younger patients, or which are in anatomically eloquent areas of the pelvis, they can be drained. Features that may indicate the need for surgery include:

- Persistent complex ovarian cysts

- Persistent cysts that are causing symptoms

- Complex ovarian cysts larger than 5 cm

- Simple ovarian cysts larger 10 cm or larger than 5 cm in postmenopausal patients

- Women who are menopausal or perimenopausal

Surgical treatment of ovarian torsion includes laparoscopy to uncoil the torsed ovary and possibly oophoropexy to fixate the ovary which is likely to twist again. In severe cases, where blood flow is cut off to the ovary for an extended period of time, necrosis of the ovary can occur. In these cases the ovary must be surgically removed.

A prospective study of ovarian sex cord–stromal tumours in children and adolescents began enrolling participants in 2005.

Between 5 and 10 percent of women with POF may become pregnant. Currently no fertility treatment has officially been found to effectively increase fertility in women with POF, and the use of donor eggs with in-vitro fertilization (IVF) and adoption are popular as a means of achieving parenthood for women with POF. Some women with POF choose to live child-free. (See impaired ovarian reserve for a summary of recent randomized clinical trials and treatment methods.)

Currently New York fertility researchers are investigating the use of a mild hormone called dehydroepiandrosterone (DHEA) in women with POF to increase spontaneous pregnancy rates. Published results from studies conducted on DHEA have indicated that DHEA may increase spontaneously conceived pregnancies, decrease spontaneous miscarriage rates and improve IVF success rates in women with POF.

Additionally, over the last five years a Greek research team has successfully implemented the use of dehydroepiandrosterone (DHEA) for the fertility treatment of women suffering with POF.The majority of the patients were referred for donor eggs or surrogacy, however after a few months of DHEA administration, some succeeded in getting pregnant through IVF, IUI, IUTPI or natural conception. Many babies have been born after treatment with DHEA.

Ovarian tissue cryopreservation can be performed on prepubertal girls at risk for premature ovarian failure, and this procedure is as feasible and safe as comparable operative procedures in children.

People with strong genetic risk for ovarian cancer may consider the surgical removal of their ovaries as a preventative measure. This is often done after completion of childbearing years. This reduces the chances of developing both breast cancer (by around 50%) and ovarian cancer (by about 96%) in people at high risk. Women with "BRCA" gene mutations usually also have their Fallopian tubes removed at the same time (salpingo-oophorectomy), since they also have an increased risk of Fallopian tube cancer. However, these statistics may overestimate the risk reduction because of how they have been studied.

People with a significant family history for ovarian cancer are often referred to a genetic counselor to see if they if testing for BRCA mutations would be beneficial. The use of oral contraceptives, the absence of 'periods' during the menstrual cycle, and tubal ligation reduce the risk.

There may an association of developing ovarian cancer and ovarian stimulation during infertility treatments. Endometriosis has been linked to ovarian cancers. Human papillomavirus infection, smoking, and talc have not been identified as increasing the risk for developing ovarian cancer.

Ovarian pregnancies are dangerous and prone to internal bleeding. Thus, when suspected, intervention is called for.

Traditionally, an explorative laparotomy was performed, and once the ovarian pregnancy was identified, an oophorectomy or salpingo-oophorectomy was performed, including the removal of the pregnancy. Today, the surgery can often be performed via laparoscopy. The extent of surgery varies according to the amount of tissue destruction that has

occurred. Patients with an ovarian pregnancy have a good prognosis for future fertility and therefore conservative surgical management is advocated. Further, in attempts to preserve ovarian tissue, surgery may involve just the removal of the pregnancy with only a part of the ovary. This can be accomplished by an ovarian wedge resection.

Ovarian pregnancies have been successfully treated with methotrexate since it was introduced in the management of ectopic pregnancy in 1988.

An ovarian pregnancy can develop together with a normal intrauterine pregnancy; such a heterotopic pregnancy will call for expert management as not to endanger the intrauterine pregnancy.

Sporadic OHSS is very rare, and may have a genetic component. Clomifene citrate therapy can occasionally lead to OHSS, but the vast majority of cases develop after use of gonadotropin therapy (with administration of FSH), such as Pergonal, and administration of hCG to induce final oocyte maturation and/or trigger oocyte release, often in conjunction with IVF. The frequency varies and depends on a woman's risk factors, management, and methods of surveillance. About 5% of treated women may encounter moderate to severe OHSS. Risk factors include young age, the development of many ovarian follicles under stimulation, extreme elevated serum estradiol concentrations, the use of hCG for final oocyte maturation and/or release, the continued use of hCG for luteal support, and the occurrence of a pregnancy (resulting in hCG production).

Mortality is low, but several fatal cases have been reported.

The fertility drug clomiphene citrate (Clomid, Serophene), used to induce ovulation, increases the risk of a corpus luteum cyst developing after ovulation. These cysts don't prevent or threaten a resulting pregnancy. Women on birth control pills usually do not form these cysts; in fact, preventing these cysts is one way birth control pills work.

In contrast, the progesterone-only pill can cause increased frequency of these cysts.

Physicians can reduce the risk of OHSS by monitoring of FSH therapy to use this medication judiciously, and by withholding hCG medication.

Cabergoline confers a significant reduction in the risk of OHSS in high risk women according to a Cochrane review of randomized studies, but the included trials did not report the live birth rates or multiple pregnancy rates. Cabergoline, as well as other dopamine agonists, might reduce the severity of OHSS by interfering with the VEGF system. A systematic review and meta-analysis concluded that prophylactic treatment with cabergoline reduces the incidence, but not the severity of OHSS, without compromising pregnancy outcomes.

The risk of OHSS is smaller when using GnRH antagonist protocol instead of GnRH agonist protocol for suppression of ovulation during ovarian hyperstimulation. The underlying mechanism is that, with the GnRH antagonist protocol, initial follicular recruitment and selection is undertaken by endogenous endocrine factors prior to starting the exogenous hyperstimulation, resulting in a smaller number of growing follicles when compared with the standard long GnRH agonist protocol.

A Cochrane review found administration of hydroxyethyl starch decreases the incidence of severe OHSS. There was insufficient evidence to support routine cryopreservation and insufficient evidence for the relative merits of intravenous albumin versus cryopreservation. Also, "coasting", which is ovarian hyperstimulation without induction of final maturation, does not significantly decrease the risk of OHSS.

Ovarian cancer is related to the amount of time spent ovulating. Thus not having children is a risk factor for ovarian cancer, likely because ovulation is suppressed via pregnancy. During ovulation, cells are constantly stimulated to divide while ovulatory cycles continue. Therefore, people who have not borne children are at twice the risk of ovarian cancer than those who have. A longer period of ovulation caused by early first menstruation and late menopause is also a risk factor. Both obesity and hormone replacement therapy also raise the risk.

The risk of developing ovarian cancer is less for women who have fewer menstrual cycles, no menstrual cycles, breast feeding, take oral contraceptives, have multiple pregnancies, and have a pregnancy at an early age. The risk of developing ovarian cancer is reduced in women who have had tubal ligation (colloquially known as having one's "tubes tied"), both ovaries removed, or hysterectomy (an operation in which the uterus, and sometimes the cervix, is removed). Age is also a risk factor.

Ovarian torsion (OT) is the rotation of the ovary at its to such a degree as to occlude the ovarian artery and/or vein.

Ovarian diseases can be classified as endocrine disorders or as a disorders of the reproductive system.

If the egg fails to release from the follicle in the ovary an ovarian cyst may form. Small ovarian cysts are common in healthy women. Some women have more follicles than usual (polycystic ovary syndrome), which inhibits the follicles to grow normally and this will cause cycle irregularities.

Other conditions include:

- Ovarian cancer

- Luteoma

- Hypogonadism

- Hyperthecosis

Most people develop symptoms of estrogen deficiency, including vasomotor flushes and vaginal dryness, both of which respond to hormone replacement therapy. There are several contraindications of estrogen supplement, including smokers over 35 years of age, uncontrolled hypertension, uncontrolled diabetes mellitus, or history of thromboemboli events.

Women younger than 40 year with primary ovarian insufficiency benefit from physiologic replacement of hormones. Most authorities recommend that this hormone replacement continue until age 50 years, the normal age of menopause. The leading hormone replacement regimen recommended involves the administration of estradiol daily by either skin patch or vaginal ring. This approach reduces the risk of pulmonary embolism and deep venous thrombosis by avoiding the first pass effect on the liver that is induced by oral estrogen therapy. To avoid the development of endometrial cancer young women taking estradiol replacement need also to take a progestin in a regular cyclic fashion. The most evidence supports the use of medroxyprogesterone acetate per day for days one through 12 of each calendar month. This will induce regular and predictable menstrual cycles. It is important that women taking this regimen keep a menstrual calendar. If the next expected menses is late it is important to get a pregnancy test. It this is positive, the woman should stop taking the hormone replacement. Approximately 5 to 10% of women with confirmed primary ovarian insufficiency conceive a pregnancy after the diagnosis without medical intervention.

The transdermal estradiol patch is commonly recommended due to several advantages. It provides the replacement by steady infusion rather than by bolus when taking daily pills. It also avoids the first-pass effect in the liver.

Ovarian pregnancies are rare: the vast majority of ectopic pregnancies occur in the fallopian tube; only about 0.15-3% of ectopics occur in the ovary. The incidence has been reported to be about 1:3,000 to 1:7,000 deliveries.

Potential methods in unexplained infertility include oral ovarian stimulation agents (such as clomifene citrate, anastrozole or letrozole) as well as intrauterine insemination (IUI), intracervical insemination (ICI) and in vitro fertilization (IVF).

In women who have not had previous treatment, ovarian stimulation combined with IUI achieves approximately the same live birth rate as IVF. On the other hand, in women who have had previous unsuccessful treatment, IVF achieves a live birth rate approximately 2-3 times greater than ovarian stimulation combined with IUI.

IUI and ICI has higher pregnancy rates when combined with ovarian stimulation in couples with unexplained infertility, for IUI being 13% unstimulated and 15% stimulated, and for ICI being 8% unstimulated and 15% stimulated. However, the rate of twin birth increases substantially with IUI or ICI combined with ovarian stimulation, for IUI being 6% unstimulated and 23% stimulated, and for ICI being 6% unstimulated and 23% stimulated.

According to NICE guidelines, oral ovarian stimulation agents should not be given to women with unexplained infertility. Rather, it is recommended that in vitro fertilization should be offered to women with unexplained infertility when they have not conceived after 2 years of regular unprotected sexual intercourse. IVF avails for embryo transfer of the appropriate number of embryos to give good chances of pregnancy with minimal risk of multiple birth.

A review of randomized studies came to the result that IVF in couples with a high chance of natural conception, as compared to IUI/ICI with or without ovarian stimulation, was "more" effective in three studies and "less" effective in two studies.

There is no evidence for an increased risk of ovarian hyperstimulation syndrome (OHSS) with IVF when compared with ovarian stimulation combined with IUI.

Not all women with PCOS have difficulty becoming pregnant. For those that do, anovulation or infrequent ovulation is a common cause. Other factors include changed levels of gonadotropins, hyperandrogenemia and hyperinsulinemia. Like women without PCOS, women with PCOS that are ovulating may be infertile due to other causes, such as tubal blockages due to a history of sexually transmitted diseases.

For overweight, anovulatory women with PCOS, weight loss and diet adjustments, especially to reduce the intake of simple carbohydrates, are associated with resumption of natural ovulation.

For those women that after weight loss still are anovulatory or for anovulatory lean women, then the ovulation-inducing medications clomiphene citrate and FSH are the principal treatments used to promote ovulation. Previously, the anti-diabetes medication metformin was recommended treatment for anovulation, but it appears less effective than clomiphene.

For women not responsive to clomiphene and diet and lifestyle modification, there are options available including assisted reproductive technology procedures such as controlled ovarian hyperstimulation with follicle-stimulating hormone (FSH) injections followed by in vitro fertilisation (IVF).

Though surgery is not commonly performed, the polycystic ovaries can be treated with a laparoscopic procedure called "ovarian drilling" (puncture of 4–10 small follicles with electrocautery, laser, or biopsy needles), which often results in either resumption of spontaneous ovulations or ovulations after adjuvant treatment with clomiphene or FSH. (Ovarian wedge resection is no longer used as much due to complications such as adhesions and the presence of frequently effective medications.) There are, however, concerns about the long-term effects of ovarian drilling on ovarian function.

Although no large studies showing the long term outcomes for women with hyperthecosis exist, a diagnosis of hyperthecosis may suggest an increased risk for metabolic complications of hyperlipidemia and type 2 diabetes . In postmenopausal women, hyperthecosis may also contribute to the pathogenesis of endometrial polyp, endometrial hyperplasia, and endometrioid adenocarcinoma due to the association of hyperestrinism (excess estrins in the body) and hyperthecosis. Treatment for hyperthecosis is based upon each case, but may range from pharmacological interventions to surgical.

Medications for PCOS include oral contraceptives and metformin. The oral contraceptives increase sex hormone binding globulin production, which increases binding of free testosterone. This reduces the symptoms of hirsutism caused by high testosterone and regulates return to normal menstrual periods. Metformin is a drug commonly used in type 2 diabetes to reduce insulin resistance, and is used off label (in the UK, US, AU and EU) to treat insulin resistance seen in PCOS. In many cases, metformin also supports ovarian function and return to normal ovulation. Spironolactone can be used for its antiandrogenic effects, and the topical cream eflornithine can be used to reduce facial hair. A newer insulin resistance drug class, the thiazolidinediones (glitazones), have shown equivalent efficacy to metformin, but metformin has a more favorable side effect profile. The United Kingdom's National Institute for Health and Clinical Excellence recommended in 2004 that women with PCOS and a body mass index above 25 be given metformin when other therapy has failed to produce results. Metformin may not be effective in every type of PCOS, and therefore there is some disagreement about whether it should be used as a general first line therapy. The use of statins in the management of underlying metabolic syndrome remains unclear.

It can be difficult to become pregnant with PCOS because it causes irregular ovulation. Medications to induce fertility when trying to conceive include the ovulation inducer clomiphene or pulsatile leuprolide. Metformin improves the efficacy of fertility treatment when used in combination with clomiphene. Metformin is thought to be safe to use during pregnancy (pregnancy category B in the US). A review in 2014 concluded that the use of metformin does not increase the risk of major birth defects in women treated with metformin during the first trimester.

An adnexal mass is a lump in tissue of the adnexa of uterus (structures closely related structurally and functionally to the uterus such as the ovaries, fallopian tubes, or any of the surrounding connective tissue). Adnexal masses can be benign or cancerous, and they can be categorized as simple or complex. One of the most important factors used to determine the clinical suspicion of malignancy of an adnexal mass is the sonographic appearance of the mass. Indications that the mass is at a higher risk of being malignant include: presence of loculations, nodules, papillary structures, septations, size greater than 10 cm.

Clomifene citrate (or clomid) is the medication which is most commonly used to treat anovulation. It is a selective estrogen-receptor modulator, affecting the hypothalamic–pituitary–gonadal axis to respond as if there was an estrogen deficit in the body, in effect increasing the production of gonadotrophins. It is relatively easy and convenient to use. Clomifene appears to inhibit estrogen receptors in hypothalamus, thereby inhibiting negative feedback of estrogen on gonadotrophin production. It may also result in direct stimulation of the hypothalamic-pituitary axis. It also has an effect on cervical mucus quality and uterine mucosa, which might affect sperm penetration and survival, hence its early administration during the menstrual cycle. Clomifene citrate is a very efficient ovulation inductor, and has a success rate of 67%. Nevertheless, it only has a 37% success rate in inducing pregnancy. This difference may be due to the anti-estrogenic effect which clomifene citrate has on the endometrium, cervical mucus, uterine blood flow, as well as the resulting decrease in the motility of the fallopian tubes and the maturation of the oocytes.

The standard dosage for first-time takers is 50 or 100 mg of clomifene per day for five consecutive days, starting early in the menstrual cycle, usually on the third to fifth day counting from the beginning of the menstrual period. In case of amenorrhea, a period can be induced by intake of an oral progestin for 10 days. In absence of success, the dosage can be increased in subsequent cycles with increments of 50 mg. However, at a dosage of 200 mg, further increments are unlikely to increase pregnancy chances.

Prognosis in unexplained infertility depends on many factors, but can roughly be estimated by e.g. the

Hunault model, which takes into account female age, duration of infertility/subfertility, infertility/subfertility being primary or secondary, percentage of motile sperm and being referred by a general practitioner or gynecologist.

The usual chemotherapy regimen has limited efficacy in tumours of this type, although Imatinib has shown some promise. There is no current role for radiotherapy.

The usual treatment is surgery. The surgery for females usually is a fertility-sparing unilateral salpingo-oophorectomy. For malignant tumours, the surgery may be radical and usually is followed by adjuvant chemotherapy, sometimes by radiation therapy. In all cases, initial treatment is followed by surveillance. Because in many cases Leydig cell tumour does not produce elevated tumour markers, the focus of surveillance is on repeated physical examination and imaging.

In males, a radical inguinal orchiectomy is typically performed. However, testes-sparing surgery can be used to maintain fertility in children and young adults. This approach involves an inguinal or scrotal incision and ultrasound guidance if the tumour is non-palpable. This can be done because the tumour is typically unifocal, not associated with precancerous lesions, and is unlikely to recur.

The prognosis is generally good as the tumour tends to grow slowly and usually is benign: 10% are malignant. For malignant tumours with undifferentiated histology, prognosis is poor.