Does transient hyperprolactinemia during ovarian hyperstimulation interfere with conception or pregnancy outcome?

The significance of transiently increased serum prolactin (PRL) levels on pregnancy rates in in vitro fertilization (IVF) is unknown. The aim of this study was to evaluate PRL levels in IVF patients who conceived and in matched controls who did not. Thirty-seven IVF cycles resulting in pregnancy and 74 nonpregnant cycles were compared. Prolactin was measured before ovarian stimulation with clomiphene citrate, and human menopausal gonadotropin and estradiol (E2) and PRL were measured 8 hours after human chorionic gonadotropin (hCG) administration at midcycle. Before ovarian stimulation, serum PRL levels were not different in the pregnant and nonpregnant women (11.1 +/- 0.6 [mean +/- standard error] micrograms/l and 10.1 +/- 0.4 micrograms/l, respectively). After hCG, PRL levels were significantly higher in the pregnant women than in the nonpregnant women (20.8 +/- 1.6 and 16.0 +/- 0.9 micrograms/l, respectively; P less than 0.005) and more pregnant than nonpregnant women had elevated PRL levels (49% versus 28%, respectively; P less than 0.05). There was no correlation between PRL and E2 in either group. The abortion rate was not different between the women with elevated PRL (22.2%) and the normoprolactinemic women (31.6%). These results do not support treatment of transient hyperprolactinemia with dopamine agonists in IVF patients.     

The efficacy of bromocriptine in patients with ovulatory dysfunction and normoprolactinemic galactorrhea

The response to bromocriptine therapy of 12 infertile women with ovulatory dysfunction and euprolactinemic galactorrhea was studied. Four of the subjects had anovulation, four had oligo-ovulation, and four had delayed ovulation. Serum PRL levels in all 12 subjects were less than 20 ng/ml. Normal ovulation occurred at least once in all of the patients on bromocriptine therapy and in 38 of 41 (92%) of the cycles. Seven patients (58%) conceived promptly with bromocriptine therapy, and all subjects had cessation of galactorrhea within 1 month of the onset of therapy. The seven pregnancies included five normal term vaginal deliveries, one premature vaginal delivery, and one tubal pregnancy. The results of this study should be considered preliminary but suggest that the presence of euprolactinemic galactorrhea in patients with ovulatory dysfunction may still represent a covert disorder of PRL physiologic factors. The prompt correction of these ovulation disturbances gives supporting evidence for this hypothesis and suggests that a short trial of bromocriptine therapy may be warranted after minimal blood sampling. The differential outcome between our group of patients produces further evidence that variable mechanisms may be operative.     

Prolactin modulates peripheral androgen metabolism

Although hyperprolactinemia may be associated with hyperandrogenism, if hirsutism develops, it is usually a mild form. This study was designed to investigate whether prolactin (PRL) modulates 5 alpha-reductase activity (5 alpha-RA), because 5 alpha-RA is known to be a major factor influencing the manifestation of androgenicity. Compared with normal women, euprolactinemic hirsute and both hyperprolactinemic hirsute and nonhirsute women had elevated levels of unbound testosterone (uT). Serum 3 alpha-androstanediol glucuronide (3 alpha-diol-G) was elevated only in patients who were hirsute, and serum 3 alpha-diol-G/uT ratios were elevated in euprolactinemic hirsute patients and normal in hyperprolactinemic hirsute patients. Genital skin 5 alpha-RA in vitro was elevated only in euprolactinemic hirsute women. The previously recognized positive correlation between 5 alpha-RA and the severity of hirsutism was dissociated with hyperprolactinemia. Human PRL incubated in vitro with normal genital skin also inhibited 5 alpha-RA. These data suggest that PRL modulates 5 alpha-RA and peripheral androgen metabolism and that other factors may also be involved in the evolution of hirsutism in hyperprolactinemia.     

Evaluation of dopaminergic activity of the hypothalamus in patients with polycystic ovarian syndrome]

To evaluate the hypothalamic dopaminergic activity in patients with polycystic ovary syndrome (PCOS), we studied the PRL, TSH, LH and FSH responses to i.m. administration of sulpiride in five euthyroid women affected by PCOS and in five normal women. The mean basal PRL and TSH plasma levels resulted significantly higher (p less than 0.01) in PCOS subjects with respect to normal subjects. The incremental area under PRL and TSH profiles, after sulpiride administration, were significantly lower (p less than 0.05) in PCOS patients than in the control group; no significant variation of LH and FSH plasma levels resulted. Our data suggest a decrease dopaminergic activity in PCOS.     

Acute effects of bromocriptine on gonadotropin secretion in polycystic ovary syndrome

Thirty-two women presenting with polycystic ovary syndrome (PCO) were studied on 3 consecutive days. On day 1, plasma androstenedione, testosterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEA-S), 17-hydroxyprogesterone (17-OHP), estrone (E1), estradiol, serum prolactin (PRL), and PRL response to thyrotropin-releasing hormone were determined. On day 2 the patients were given two placebos at 1-hour intervals; then serum PRL, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) and the LH and FSH responses to LH-releasing hormone (LH-RH) were determined. On day 3 the patients were given two 2.5-mg tablets of bromocriptine (BRCR) at 12-hour intervals; then serum PRL, LH, and FSH and the LH and FSH responses to LH-RH were again determined. After BRCR, mean values of basal serum PRL (P less than 0.001), LH (P less than 0.05), and FSH (P less than 0.001) and the FSH response to LH-RH (P less than 0.01) fell with respect to the values determined on day 2. Our group of patients was heterogeneous regarding the effects of BRCR upon the LH response to LH-RH. Of 32 women undergoing the trial, 17 did not respond to BRCR (change of the LH response to LH-RH less than 33% with respect to day 2). They were called "nonresponders." Among the 15 who responded to BRCR, 10 decreased their LH response greater than or equal to 33% ("decreasers") and 5 increased their LH response greater than or equal to 33% ("increasers"). Decreasers had mean values of serum PRL, plasma E1, DHEA-S, and 17-OHP higher than nonresponders (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Superovulation-induced transient hyperprolactinemia in human in vitro fertilization and embryo transfer

To examine the effects of transient hyperprolactinemia on in vitro fertilization and embryo transfer, 61 cycles in 50 euprolactinemic ovulatory women with irreparable tubal diseases were stimulated with clomiphene (CC) alone or CC and human menopausal gonadotropin followed by human chorionic gonadotropin (hCG). Serum prolactin (PRL) increased after hCG administration with peak values of 45.4 +/- 4.2 ng/ml on the day of laparoscopic oocyte aspiration. The highest serum estradiol (E2) concentration was found on the day before PRL peak and serum progesterone (P) began to increase after hCG injection concomitant with the PRL rise. The group having 50 ng/ml or more of PRL (34 cycles) had significantly higher levels of E2 during preovulatory and early luteal phase compared to those of the group having less than 50 ng/ml of PRL (27 cycles) but there was no significant difference between the P levels in the two groups. In the higher PRL group 72 (62.1%) of 116 collected oocytes were fertilized and 6 (20.0%) conceived. In the lower PRL group 45 oocytes (58.4%) of 77 were fertilized and 3 (12.5%) became pregnant. These data suggest that elevated serum PRL concentrations may have no effect on fertilization of oocytes in vitro or embryonic development.     

Serum prolactin levels in patients with fibrocystic breast disease

In 193 patients suffering from fibrocystic breast disease, basal serum prolactin concentrations were determined and compared to serum prolactin levels in 193 healthy women. In 45 additional patients and 23 healthy control subjects, a thyrotropin-releasing hormone (TRH) stimulation test was performed. The response to TRH in seven healthy female volunteers and in one patient with fibrocystic breast disease, was correlated with the mean serum prolactin levels over 24 hours. Serum prolactin levels were above normal in 45.6% of the patients and in 21.2% of the control subjects. Mean values of the two groups were significantly different (P less than .001). The maximum prolactin response to TRH stimulation was significantly higher in the study patients than in the control subjects (P less than .001). The TRH-stimulated prolactin response correlated positively with the mean 24-hour level (P less than .01, r = 0.8705). These results indicate that a high proportion of patients with fibrocystic breast disease exhibit increased daily prolactin secretion.     

Transient hyperprolactinemia during cycle stimulation: influence on the endocrine response and fertilization rate of human oocytes and effects of bromocriptine treatment

The effect of transient hyperprolactinemia and its treatment during cycle stimulation on the endocrine response and fertilization rate of human oocytes was studied. Fifty stimulated cycles were included in the study and divided into three groups: group I consisted of 18 cycles with serum prolactin (PRL) levels less than or equal to 25 ng/ml; group II contained 15 cycles, where patients developed PRL levels greater than 25 ng/ml; group III consisted of 17 cycles, where patients, who already developed hyperprolactinemia in a previous cycle, were treated by 3.75 mg bromocriptine daily. The serum estradiol (E2), progesterone (P) and PRL levels 1, 2, and 3 days before and at oocyte retrieval were evaluated. The E2 decrease at oocyte retrieval was significantly steeper in groups I and III. Follicular luteinization was more effective in groups I and III. The fertilization rate in groups I and III was significantly higher than in group II. High serum PRL levels seem to interfere in follicular and oocyte development. The treatment of transient hyperprolactinemia improved the patients' endocrine response and the fertilization rate of oocytes.     

腹腔镜电凝打孔治疗多囊卵巢综合征的远期疗效分析

目的 :观察腹腔镜电凝打孔治疗多囊卵巢综合征 (PCOS)的远期疗效。方法 :于 1997年 7月～ 2 0 0 3年 9月对克罗米酚促排卵治疗无效的PCOS患者 5 0例 ,行腹腔镜电凝打孔术 ,观察手术前后FSH、LH、T、E2 、PRL、LH/FSH的变化。并对比手术前后卵巢体积及形态的变化。术后根据基础体温测定 (BBT)及B超监测排卵并随访受孕情况。结果 :随访时间 3～ 73月 ,其中 6 0月以上 15例。术后LH、T、LH/FSH较术前明显降低 (P <0 .0 1) ,卵巢体积由术前平均 11cm3变为术后平均 8.4cm3,月经情况明显改善 ,该方法治疗PCOS自然恢复排卵率 94 % ,术后 5年累积受孕率 76 % ,无并发症发生。结论 :腹腔镜治疗PCOS简单易行、创伤小、恢复快 ,远期疗效好 ,为难治的PCOS患者提供了新的治疗途径     

The incidence of transient hyperprolactinemia in gonadotropin-stimulated cycles for in vitro fertilization and its effect on pregnancy outcome

The incidence of transient hyperprolactinemia and its impact on in vitro fertilization (IVF) were determined in 151 euprolactinemic women with tubal infertility undergoing an identical gonadotropin stimulation for IVF. Prolactin (PRL) levels were measured on the morning of cycle day 3, days of human chorionic gonadotropin (hCG) administration, and peak estradiol (E2), and in the midluteal phase. Women were divided into high (H: peak E2 greater than 1,000 pg/mL, n = 51), intermediate (I:peak E2: 500 to 800 pg/mL, n = 50), or low (L:peak E2 less than 400 pg/mL, n = 50) E2 response groups. There was no difference in the incidence of hyperprolactinemia on cycle day 3 between the response groups (H:16%, I: 12%, and L:8%). However, high responders had a higher incidence of hyperprolactinemia than intermediate or low responders on all other study days. The incidence of hyperprolactinemia was greater than baseline (cycle day 3) only in the high responders on the day of peak E2. Serum prolactin was strongly correlated with peak E2 (r = 0.41). There were no differences in the number of preovulatory oocytes retrieved or fertilized or the pregnancy rates between hyperprolactinemic and euprolactinemic patients in each response group or when all hyperprolactinemic and euprolactinemic patients, regardless of E2 response, were compared. Transient hyperprolactinemia during gonadotropin stimulation for IVF occurs and correlates with E2 response but has no impact on IVF outcome.     

Macroprolactinemia in women presenting with hyperandrogenic symptoms: Implications for the management of polycystic ovary syndrome

Eight of 109 consecutive hyperandrogenic patients had increased serum PRL levels; macroprolactinemia was diagnosed in 4 patients by measuring PRL levels after precipitation of serum with polyethylene glycol, and after detecting macroprolactinemia, these 4 patients were diagnosed with polycystic ovary syndrome (PCOS). Therefore, macroprolactinemia must be ruled out in women presenting with hyperandrogenic symptoms and increased serum PRL concentrations to avoid misdiagnosis (hyperprolactinemia is an exclusion criterion for the diagnosis of PCOS), unnecessary diagnostic tests, and inappropriate use of dopaminergic agonists.     

Gonadotropin secretion before and during acute and chronic dopamine-receptor blockade in insulin-dependent diabetic patients with amenorrhea

The dopaminergic influence on luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin (PRL) was studied in 12 diabetic patients with amenorrhea (DMAM) and in 10 normal menstruating diabetic patients (DM). DMAM patients had a reduction in LH pulsatility (P less than 0.05) and basal LH levels (P less than 0.02), compared with DM patients, whereas they had an LH and FSH response to intravenous metoclopramide (MTC) at 30, 45, and 60 minutes and at 30 minutes, respectively (P less than 0.05). Basal (P less than 0.05) and MTC-stimulated (P less than 0.05) PRL levels were lower in DMAM than in DM patients. Serum PRL and FSH increased significantly (P less than 0.02) in six DMAM patients during 10 weeks of oral MTC administration, whereas no significant (P greater than 0.05) alterations occurred in serum LH and estradiol levels. These data point toward increased dopaminergic activity in DMAM patients.     

A prospective,double-blind,randomized, placebo-controlled clinical trial of bromocriptine in clomiphene-resistant patients with polycystic ovary syndrome and normal prolactin level

OBJECTIVE: To evaluate the effects of administration of bromocriptine combined with clomiphene citrate (CC) in CC-resistant patients with polycystic ovary syndrome (PCOS) and normal prolactin (PRL) level. DESIGN: Prospective double-blind, placebo-controlled, randomized. SETTING: Referral university hospitals. PATIENTS: One hundred women with PCOS and normal PRL who failed to ovulate with a routine protocol of CC. INTERVENTIONS: Treatment group received 150 mg of CC from day 5 to 9 and 7.5 mg bromocriptine continuously, with hCG 10,000 units on day 16 or 17. Control group received the same protocol of CC combined with placebo. MAIN OUTCOME MEASURES: Follicular development, hormonal changes, ovulation rate, pregnancy rate. RESULTS: Follicular development (follicular size greater than 15 mm) was observed in 12 (25.5%) and 8 (15.1%) women in the treatment and placebo group, respectively (p = 0.29). The serum prolactin level was within normal limits in all patients before treatment. After 3 and 6 months of treatment with bromocriptine, there was a significant decrease in serum level of prolactin (p = 0.000001). No significant differences were seen in ovulation, pregnancy rate, or serum levels of FSH, LH, DHEAS, and progesterone between treatment and placebo groups after treatment. CONCLUSIONS: The only significant effect of long-term bromocriptine therapy in CC-resistant women with PCOS was to lower the serum PRL concentration. It is also concluded that 10%-15% of patients with PCOS experienced occasional ovulatory cycles and pregnancy whether or not they were on treatment.     

Polycystic ovaries in patients with hypogonadotropic hypogonadism: similarity of ovarian response to gonadotropin stimulation in patients with polycystic ovarian syndrome.

OBJECTIVE: To characterize the ovarian response in patients with isolated hypogonadotropic hypogonadism with ultrasound (US) findings of polycystic ovaries (PCO). DESIGN: Twenty-seven treatment cycles in patients with hypogonadotropic hypogonadism and US findings of normal ovaries were compared with 31 cycles in patients with hypogonadotropic hypogonadism and US-diagnosed PCO. Forty-one cycles in the hypogonadotropic hypogonadism and US-diagnosed PCO were compared with 59 cycles of patients with polycystic ovarian syndrome (PCOS) to examine pattern of response after ovulation induction. SETTING: Specialist Reproductive Endocrine Unit. PATIENTS, PARTICIPANTS: Twenty hypogonadotropic patients in whom 10 had US findings of PCO and 13 patients with PCOS. MAIN OUTCOME MEASURE: Serum estradiol (E2) concentration, number of leading follicles on US, cancellation, and pregnancy rate. RESULTS: Hypogonadotropic patients with US-diagnosed PCO had higher baseline ovarian volume (P less than 0.02) compared with patients with hypogonadotropic hypogonadism with normal ovaries. After ovarian stimulation, a higher mean serum E2 concentration (P less than 0.001), endometrial thickness (P less than 0.001), and increased number of leading follicles (P less than 0.0001) were found in hypogonadotropic patients with US-diagnosed PCO, compared with hypogonadotropic patients with US findings of normal ovaries. Patients with PCOS had a higher serum E2 concentration (P less than 0.008), although they were treated for fewer days (P less than 0.0001) and with fewer ampules of gonadotropin (P less than 0.001) compared with patients with hypogonadotropic hypogonadism with US-diagnosed PCO. CONCLUSIONS: We have characterized a group of hypogonadotropic patients with US findings of PCO, in which the ovarian response to ovulation induction was similar to patients with PCOS. The results have practical and theoretical implications for the etiology and treatment of patients with PCO.     

益生菌补充对多囊卵巢综合征患者血糖和血脂的影响

目的:探讨益生菌补充对多囊卵巢综合征(PCOS)患者血糖和血脂的影响。方法:选取2015年3月—2016年1月于广州市番禺中心医院就诊的60例PCOS患者为研究对象,采用随机数字表法将其分为观察组和对照组,每组各30例。对照组给予常规二甲双胍药物治疗,观察组除给予常规治疗外,加用双歧杆菌三联活菌散。检测2组患者血清标本中空腹血糖(FBS)、总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-c)、低密度脂蛋白胆固醇(LDL-c)、极低密度脂蛋白胆固醇(VLDL-c)、空腹血清胰岛素(FSI)、黄体生成激素(LH)、卵泡刺激素(FSH)、泌乳素(PRL)、孕酮(P)、雌二醇(E_2)和睾酮(T)水平,并计算胰岛素抵抗指数(HOMA-IR)。结果:治疗后观察组患者血清FBS、FSI、HOMA-IR、TG和VLDL水平均显著低于对照组(P<0.05);观察组治疗后血清LH和T水平低于治疗前(P<0.05)。观察组体质量和体质量指数(BMI)较对照组有所下降(P<0.05)。结论:PCOS患者补充益生菌,其血糖、血脂和体质量指标有所改善,对PCOS及其合并症的发展有一定的缓解作用。     

Effects of pregnancy, delivery and lactation in hyperprolactinemia with prolactin producing pituitary adenoma

The effects of pregnancy, delivery and lactation on changes in serum prolactin (PRL) values were investigated in patients with hyperprolactinemia. Thirty-seven patients with hyperprolactinemia who wished to become pregnant were treated by transsphenoidal surgery, bromocriptine therapy, or a combination of the two. In 33 patients whose pre-pregnancy serum PRL concentration exceeded 30ng/ml, only in two did serum PRL return to the normal range below 30ng/ml after pregnancy, delivery and lactation. However, the serum PRL concentration was decreased in 28 patients. When classified according to the pre-pregnancy serum PRL concentrations, PRL less than or equal to 100 (Group A), 100 less than PRL less than or equal to 200 (Group B) and 200 less than PRL (Group C), patients with the greatest pre-pregnancy serum PRL concentration showed the greatest reduction. The ratios of post-pregnancy serum PRL to pre-pregnancy PRL in group A, B and C were 91.4 +/- 22.1%, 81.5 +/- 7.0% and 65.0 +/- 6.5% (Mean +/- SE), respectively. Group C with the highest pre-pregnancy serum PRL concentration consisted almost entirely of patients with macroadenoma. Thus, the reduction in serum PRL after pregnancy, delivery and lactation was considered to be the result of a decrease in the size of the adenoma due to adenoma enlargement over the sella turcica through the estrogen effects during pregnancy, and from impairment of pituitary circulation.     

Response of amenorrheic patients with normal serum prolactin to chlorpromazine during administration of human menopausal gonadotropin

To study the effects of graded amounts of estrogens on prolactin (PRL) secretion, PRL response to chlorpromazine (CPZ) during administration of human menopausal gonadotropin (hMG) was determined. A control CPZ test was done prior to initiation of hMG therapy and the test was repeated when endogenous estrogen secretion reached the physiologic range (350 to 400 pg. per milliliter) which stimulates luteinizing hormone surge in the normal ovulatory menstrual cycle. Six euprolactinemic women with secondary amenorrhea were studied. Studies showed that there was no significant change in the mean serum prolactin concentrations during control and repeat CPZ testing procedure (5.8 +/- 2 and 10.8 +/- 2 ng. per milliliter, p less than 0.1). The maximal response of PRL to CPZ was significantly higher during hMG-induced high estrogenic state than during control testing (69.9 and 32.3 ng. per milliliter, p less than 0.01). This findings suggests that endogenous estrogen may play a role in the regulation of serum prolactin concentration during the menstrual cycle.     

Serum prolactin levels during sleep and in metoclopramide stimulation in normoprolactinemic anovulation and ovulation induction with bromocriptine

Diurnal and nocturnal serum prolactin (PRL) levels were determined in 37 normoprolactinemic anovulatory (nPRL-Anov) patients and 6 normal cycling women each in the early follicular phase (EFP) and the luteal phase (LP). PRL responsiveness to metoclopramide (MCP) was assessed. The nPRL-Anov patients received 5mg/day bromocriptine (CB-154) for 2 months and ovulation was investigated. To the CB-154 non-responders was added 150mg/day clomiphene (CL) for 5 days. The nPRL-Anov patients were classified into 3 groups; i.e. I: those who ovulated with CB-154 (n = 14), II: those who ovulated with CB-154 + CL (n = 6), and III: those who failed to ovulate (n = 10). Nocturnal serum PRL levels in I (42.0 +/- 26.2ng/ml; M +/- SD) were significantly higher than those in EFP, II and III (p less than 0.05). Eleven (78.6%) of I had nocturnal PRL levels higher than 25ng/ml. The peak PRL values at MCP provocation were significantly higher in I (213.3 +/- 89.1ng/ml) than in EFP, II and III (p less than 0.01). Thirteen (92.9%) of I had peak PRL values more than 150ng/ml. The peak PRL values and nocturnal PRL levels correlated. There were some exhibiting nocturnal or latent hyperprolactinemia, who responded effectively to CB-154, among nPRL-Anov patients. A MCP provocation test could be used in prediction of the efficacy of CB-154 treatment when applied to nPRL-Anov patients.     

Dopamine might not be involved in the pathogenesis of polycystic ovary syndrome

The possible alteration in dopamine (DA) metabolism as an etiological factor was investigated in 31 normoprolactinemic patients with typical polycystic ovary syndrome (PCOS) in comparison with 14 normal women (early follicular phase). Subjects were submitted to intravenous infusion of 4 micrograms/kg DA per minute over a period of 3 hours and blood samples were collected every 30 minutes over a period of 5 hours. Two days later subjects were submitted to intravenous infusion of 10 mg metoclopramide (MCP) as a bolus and blood samples were collected every 15 minutes over a period of 2 hours. Dopamine infusion caused a similar maximum decrease (MD) in LH levels in both the PCOS and control groups (50.9% and 47.5%, respectively). No changes in plasma LH levels were observed in either group after MCP infusion. Dopamine caused a 50.2% and 60.4% MD in prolactin (PRL) in the PCOS and control groups, respectively, the difference being statistically non-significant. Metoclopramide increased PRL levels by 1261.0% and 1832.0% in the PCOS and control groups, respectively (not significant). In a double-blind study, the PCOS patients were treated with 5 mg/day bromocriptine (n = 16) or placebo (n = 15) over a period of 3 months and evaluated in clinical and laboratory terms during and after treatment. Seven patients in each group had monthly menstrual periods, but only 1 in each group had an ovulatory cycle (progesterone greater than 5 ng/ml). During treatment, median plasma PRL levels were significantly decreased only in bromocriptine-treated patients (10.8 vs 7.3 ng/ml). The present results lead us to question whether dopamine is indeed involved in the pathogenesis of normoprolactinemic PCOS and whether bromocriptine treatment is of benefit in this type of patients.     

Prolactin response after gonadotropin-releasing hormone in the polycystic ovary syndrome

The administration of gonadotropin-releasing hormone (GnRH) has been shown to stimulate prolactin (PRL) release under certain conditions. The authors compared PRL responses after GnRH in normoprolactinemic patients with the polycystic ovary syndrome (PCO) with those of normal ovulatory women in the follicular phase. Seven of 15 patients had a significant increase in PRL after GnRH, whereas none of the control subjects had a positive response. After 1 week of oral L-dopa, the responders no longer exhibited this positive response. Baseline PRL levels in responding patients with PCO were similar to levels in control subjects, whereas nonresponding patients with PCO had higher PRL levels. Baseline follicle-stimulating hormone (FSH)/luteinizing hormone (LH) ratios were higher in patients with a positive response. The positive PRL response after GnRH was not correlated with baseline serum LH, the LH/FSH ratio, delta maximum LH responses, serum testosterone (T), unbound T, or baseline PRL. The positive response correlated positively with serum levels of unbound estradiol (P less than 0.05) and serum unbound estradiol/unbound T ratios (P less than 0.01). These data suggest that under certain conditions a subgroup of patients with PCO may demonstrate a positive PRL response after GnRH. Dopamine, gonadotropins, and estrogen may play a role in this interaction.