Developmental exposure to bisphenol A leads to cardiometabolic dysfunction in adult mouse offspring.

Bisphenol A (BPA) is a chemical compound that has adverse health outcomes in adults when exposed during the perinatal period. However, its effect on cardiovascular function remains to be elucidated. In this study, we examined the effects of daily administration of BPA to pregnant mice from gestational days 11 to 19 on cardiometabolic outcomes in the adult offspring. Prenatal BPA exposure resulted in altered growth trajectory and organ size, increase adiposity and impaired glucose homeostasis in male and female offspring. In addition, these BPA offspring exhibited raised systolic blood pressure, and in the males this was accompanied by impaired vascular tone. The aortas in females, but not in males, from the BPA group also showed reduced estrogen receptor gene expression. These results indicate that prenatal exposure to BPA increased susceptibility of the offspring to developing cardiovascular and metabolic dysfunction later in life.

Effect of a low-protein diet during pregnancy on expression of genes involved in cardiac hypertrophy in fetal and adult mouse offspring.

Gene markers for cardiomyocyte growth, proliferation and remodeling were examined in mouse fetuses and adult male offspring exposed to maternal low-protein (LP) diet during pregnancy. Whole heart volume, measured by magnetic resonance imaging, was smaller in day 15 LP fetuses v. those from chow-fed dams (C), whereas heart volume was greater in adult LP v. C offspring. These LP offspring were hypertensive and had larger cardiomyocytes v. C animals. The mRNA levels of cyclin G1, a marker for cell growth, were lower in LP fetal hearts v. C hearts, but similar in the left ventricle of adult LP and C offspring. Opposite trends were found in brain natriuretic peptide levels (a marker of cardiac hypertrophy). Thus, maternal LP during pregnancy results in smaller fetal hearts and is accompanied by changes in expression of genes involved in cardiomyocyte growth, which are associated with cardiac hypertrophy and hypertension in adulthood.

Progesterone inhibits insulin-like growth factor binding protein-1 (IGFBP-1) production by explants of the Fallopian tube.

The Fallopian tube provides the environment for early embryo growth, a process which is influenced by insulin-like growth factors (IGFs) in the tubal fluid. Whether the bioavailability of tubal IGFs is modulated by locally produced IGF-binding protein (IGFBP-1) is not clear. An explant culture system from human Fallopian tube mucosa was, therefore, developed enabling the potential for IGFBP-1 production by this tissue to be examined directly. Initial characterization of the system established that the explants maintained responsiveness to steroids. Thus, oviduct-specific glycoprotein production, a major product of the oviduct in vivo, continued to be made via an estrogen-sensitive pathway in the culture. The presence of mRNA for IGFBP-1 was established within the explants by the use of quantitative RT-PCR and IGFBP-1 protein was measured by enzyme-linked immunosorbent assay. Although insulin and estradiol had no consistent effect on IGFBP-1, addition of progesterone had a significant inhibitory effect on IGFBP-1 production, both at the mRNA and protein levels. A dose-range of progesterone revealed an incremental inhibitory effect of progesterone on IGFBP-1 output (maximal effect, 25-50 nmol/l), consistent with physiological inhibition of this process during the luteal phase. We suggest that progesterone might, therefore, play a role in controlling the bioavailability of IGFs to the embryo during early development within the Fallopian tube.

Glycine rectifies vascular dysfunction induced by dietary protein imbalance during pregnancy.

Protein restriction in rat pregnancy programmes the development of elevated systolic blood pressure and vascular dysfunction in the offspring. A recent study has shown that hypertension is reversed by maternal glycine supplementation. Whether this protective effect is exerted directly on the embryo and fetus, or indirectly via effects on the mother, is unknown although we have previously shown abnormalities in the maternal vasculature. We tested the hypothesis that dietary glycine repletion would reverse endothelial dysfunction in protein-restricted pregnant rat dams using wire myography. Impaired acetylcholine- (P < 0.01) and isoprenaline-induced (P < 0.05) vasodilatation in isolated mesenteric arteries (MA) from protein-restricted pregnant dams was accompanied by reduced vascular nitric oxide (NO) release (P < 0.05). Dietary glycine supplementation reversed vascular dysfunction in MA (P < 0.05) and improved NO release thus potentially protecting the maternal circulation. The impaired NO release in the MA of low protein diet dams was not accompanied by reduced eNOS mRNA expression, suggesting that eNOS activity was altered. Protein restriction did not alter the vascular function of a conduit artery, the thoracic aorta. These results provide evidence that adequate provision of glycine, a conditionally essential amino acid in pregnancy, may play a role in the vascular adaptations to pregnancy, protecting the fetus from abnormal programming of the cardiovascular system.

Progesterone up-regulates WT1 mRNA and protein, and alters the relative expression of WT1 transcripts in cultured endometrial stromal cells.

OBJECTIVE: To determine the change in expression of the Wilms tumor suppressor gene product, WT1, by progesterone alone in endometrial stromal cell culture and to study its relationship with prolactin, a marker of decidualization. In addition, to examine the change in ratio of WT1 isoforms with and without exon 5 message. METHODS: Endometrial biopsies were taken from eight patients who had hysterectomy. Stromal cells were isolated and cultured in the presence of progesterone alone (12 days) or progesterone and 8-bromo-cyclic adenosine monophosphate (cAMP) (6 days). RNA was extracted from cells, and reverse transcription, real-time polymerase chain reaction (PCR), and conventional PCR were done to analyze WT1 mRNA expression. Immunocytochemistry was performed on equivalent cells to study WT1 protein expression. Decidualization was identified by increased prolactin concentrations in the media and immunocytochemical markers IGFBP-1 and collagen IV. RESULTS: Reverse transcription and real-time PCR revealed a significant increase in WT1 mRNA with increasing progesterone concentrations when decidualization was occurring (n = 6, P =.002). Increasing progesterone concentrations also increased the proportion of the WT1 transcript containing a 17-amino-acid insert (+ exon 5 expression); changes in WT1 exon 5 expression have been shown to be involved in control of proliferation and differentiation. Significant correlations between WT1 message and prolactin existed at physiologic progesterone concentrations (6.25, 12.5, 25, and 50 nM; P <.05) until prolactin concentrations reached a plateau at 100 nM. At concentrations of progesterone alone (> 25 nM) and progesterone with 8-bromo-cAMP, WT1 protein was localized to the nuclei of many of the decidualized stromal cells. CONCLUSION: The changing expression of WT1 isoforms in endometrial stromal cells caused by progesterone may be important for differentiation into the decidualized phenotype.

Vascular endothelial growth factor and placental growth factor release in cultured trophoblast cells under different oxygen tensions.

The oxygen status of the placenta during pregnancy is unclear although it has been hypothesised that in pre-eclampsia large regions of the placenta are hypoxic. Circulating levels of vascular endothelial growth factor (VEGF) are increased in women with pre-eclampsia, while circulating placental growth factor (PlGF) levels are decreased. We hypothesise that secreted levels of VEGF are increased in cultures of trophoblast cells under lowered oxygen conditions while secreted levels of PlGFare alternatively regulated. Primary isolates of first trimester and term cytotrophoblasts cells were cultured in 20 and 5% oxygen for 24h. There was a significant increase in the levels of VEGF secreted fromfirst trimester and term cytotrophoblast cells cultured under lowered oxygen conditions compared to the controls while there was a significant decrease in the secreted levels of PIGF in the same cell populations (as measured by ELISA). In first trimester and term trophoblast cells the presence of VEGF (121, 165 and 189) and PlGF (132 and 152) mRNA were demonstrated in both groups by reverse transcription-polymerase chain reaction (RT-PCR). These altered levels of secreted VEGF andPIGF may be released as compensatory molecules in the pathogenesis of diseases such as pre-eclampsia and intrauterine growth restriction.

Investigation of women with endometrial carcinoma using serum vascular endothelial growth factor (VEGF) measurement.

This study assessed whether serum VEGF measurement in women presenting with endometrial cancer could predict advanced stage disease. Preoperative sera from 37 women undergoing laparotomy for suspected endometrial cancer were assayed for VEGF, CA125 and platelet count. Significant positive correlation was shown between VEGF and platelet levels (P = 0.003, r = 0.477). However, no correlation was demonstrated between VEGF and stage overall, and no significant difference was shown between those with early (stage 1A/1B, n = 20) compared to those with advanced (stage >1B, n = 13) or disseminated (stage >2, n = 7) disease. Serum VEGF measurement was not beneficial in the preoperative assessment of stage in patients with endometrial carcinoma. Strong correlation with platelet levels suggests that this is one of the sources of VEGF measured.

The effects of vascular endothelial growth factor on endothelial cells: a potential role in preeclampsia.

OBJECTIVES: Preeclampsia is primarily a disorder of the maternal endothelium. An as yet unidentified circulating factor causes widespread alteration in endothelial function, and levels of vascular endothelial growth factor are elevated in preeclampsia. We hypothesized that vascular endothelial growth factor is involved in the alteration of endothelial function and set out to find further evidence for this contention. STUDY DESIGN: Bovine microvascular endothelial cells (B-88) were cultured in vitro. These cultured cells were then stimulated with vascular endothelial growth factor and with plasma from women with preeclampsia in the presence and absence of anti-vascular endothelial growth factor antibody. Prostacyclin, nitric oxide, and lactate dehydrogenase levels were measured. RESULTS: Vascular endothelial growth factor induced a significant concentration-dependent increase in prostacyclin production but not nitric oxide production. Cells stimulated with plasma from women with preeclampsia showed increases in production of both prostacyclin and nitric oxide. Vascular endothelial growth factor concentration in plasma was correlated with prostacyclin production by stimulated cells. The increase in prostacyclin production that usually followed the addition of plasma did not occur when anti-vascular endothelial growth factor antibody was present. CONCLUSIONS: Vascular endothelial growth factor has the ability to alter endothelial cell function in a manner analogous to that of plasma from women with preeclampsia.

Morphology and functional characteristics of human ovarian microvascular endothelium.

Corpus luteum formation is characterized by a period of extensive vascularization, as capillaries in the thecal layer of the collapsed follicle following ovulation invade the previously avascular granulosa layer. In order to study these processes in vitro we have developed an endothelial cell preparation from the specific microvasculature of the ovarian follicle. Follicular aspirates, obtained at oocyte collection for in-vitro fertilization (IVF), were filtered to obtain fragments of follicle wall. These were set in Matrigel and then cultured allowing the growth of capillary-like structures through the matrix. Upon emergence from the Matrigel the growing cells formed monolayers with the characteristic cobble-stone morphology of endothelial cells. Immunocytochemistry demonstrated the presence of a range of endothelial-specific markers including von Willebrand factor (vWF), Ulex europeus agglutinin (UEA)-1, CD31 and E-selectin, as well as VCAM-1, which is normally associated with stimulated endothelial cells. RT-PCR analysis showed the expression of two receptors for vascular endothelial growth factor (flt-1 and KDR), and the endothelial nitric oxide synthase, adding further evidence of their identity as human ovarian microvascular endothelial cells (HOMEC). Thus, the novel preparative procedure described now allows the generation of HOMEC cultures from readily available material resulting from IVF procedures.

Relationship between maternal serum vascular endothelial growth factor concentration in early pregnancy and fetal and placental growth.

Vascular endothelial growth factor (VEGF) has important effects on endothelial cells increasing cell proliferation, permeability and nitric oxide production; concentrations of VEGF in the maternal serum increase during the first 10 weeks of pregnancy. In this study, the relationship of maternal serum VEGF with maternal health during pregnancy and with fetal and placental size at mid-pregnancy and at term was investigated. Serum was obtained from 539 Caucasian women with singleton pregnancies between 8 and 20 weeks of pregnancy (mean 14 weeks). Total serum VEGF concentrations were measured by direct competitive radioimmunoassay. Fetal size and placental volume were measured by ultrasound between 16 and 20 weeks gestation. Birthweight, placental weight and anthropometric measurements of the baby were obtained after delivery. Serum VEGF concentrations were found to be higher in women with a lower weight before pregnancy (P = 0.01) and in those carrying a female fetus (P = 0.002). VEGF concentrations were positively correlated with placental volume (r = 0.17, P = 0.0001) but not with fetal size between 16 and 20 weeks gestation. Serum VEGF concentrations were positively correlated with both birthweight (r = 0.10, P = 0.02) and placental weight at delivery (r = 0.13, P = 0.003). The data presented support the view that VEGF may be one of the factors involved in mediating the maternal cardiovascular adaptation to pregnancy.

The relation between immunoglobulin G antibodies to Chlamydia trachomatis and poor ovarian response to gonadotropin stimulation before in vitro fertilization.

OBJECTIVE: To determine whether a relation exists between previous exposure to Chlamydia trachomatis and impaired ovarian response to gonadotropin stimulation. DESIGN: Controlled clinical study. SETTING: Two university IVF centers. PATIENT(S): Two hundred forty-two patients receiving IVF treatment and 81 control patients. Ninety-four patients with a poor response to IVF, defined by cycle cancellation in response to a daily stimulation dose of 300 IU of FSH, and 148 patients with a good response were matched for age. Twenty-eight pregnant controls and 53 controls of proven fertility also were included. INTERVENTION(S): Serum samples were obtained from patients and controls. Serum levels of immunoglobulin (Ig) G antibodies to C. trachomatis were determined by ELISA. MAIN OUTCOME MEASURE(S): The prevalence of serum IgG antibodies to C. trachomatis in critically defined poor responders was compared with that of age-matched good responders. RESULT(S): A significantly higher proportion of poor responders had serum IgG antibodies to C. trachomatis compared with good responders (44.7% and 30.4%, respectively). Patients undergoing IVF had a significantly higher prevalence of IgG antibodies to C. trachomatis (36%) than did either pregnant or nonpregnant controls (12%). CONCLUSION(S): A significantly higher prevalence of serum IgG antibodies to C. trachomatis was observed in critically defined poor responders, suggesting a possible detrimental effect of C. trachomatis on subsequent ovarian function.

A longitudinal study of maternal serum vascular endothelial growth factor in early pregnancy.

Using a competitive radioimmunoassay to measure total immunoreactive vascular endothelial growth factor (VEGF), we describe for the first time longitudinal changes in serum VEGF in early pregnancy. The measurements were obtained from 26 women following the transfer of cryopreserved embryos; 18 singleton and eight twin pregnancies were identified by ultrasound at 6 weeks gestation and subsequently delivered as live births. Subjects did not have corpora lutea and exogenous hormone support was provided for the first 70 days of pregnancy. Serum VEGF increased approximately 30 days after embryo transfer and thereafter continued to rise in both singleton and twin pregnancies over a period of 20-40 days after which concentrations remained elevated. The longitudinal profile of serum VEGF concentrations was characterized by a logistic curve for singleton and twin pregnancies; the profile of VEGF concentrations in the twin pregnancies was significantly higher than in the singleton pregnancies (P < 0.0001). Profiles of the longitudinal concentrations of serum human chorionic gonadotrophin (HCG), oestradiol and progesterone were created by polynomial regression for singleton and twin pregnancies. The VEGF profiles were positively correlated with the profiles of HCG (r = 0.44, P = 0.02) and oestradiol (r = 0.36, P = 0.07) but not progesterone (r = 0.16, P = 0.42). Serum VEGF concentrations in the singleton thawed embryo pregnancies were compared with gestation-matched normal singleton pregnancies with corpora lutea. Concentrations of VEGF were significantly (P = 0.004) greater in the pregnancies with corpora lutea although this difference became less marked with advancing gestation. In addition to its important role in angiogenesis, we speculate that VEGF is involved in mechanisms which control the maternal cardiovascular adaptation to pregnancy.

Influence of hypoxia on vascular endothelial growth factor and chorionic gonadotrophin production in the trophoblast-derived cell lines: JEG, JAr and BeWo.

Growth of trophoblast tissue in early pregnancy is rapid and accomplished in an unusually hypoxic environment. Hypoxia has been reported to upregulate mRNA production of vascular endothelial growth factor (VEGF), and VEGF receptors have been found on trophoblast cells. These observations suggest that VEGF may have an important role in early placentation. This study examines the influence of hypoxia on both the production of the VEGF message and protein and on the production of human chorionic gonadotrophin (hCG) protein by the cell lines JEG, JAr and BeWo. Cells were grown under normoxic and hypoxic conditions for 72 h. The average oxygen tension in the culture media of the hypoxic cultures (6-7 kPa) was significantly less than in the normoxic cultures (19-21 kPa). RNA was extracted and message for VEGF(121), VEGF(165) and VEGF(189) found in all cell lines by reverse transcription and the polymerase chain reaction (RT-PCR). These messages were upregulated by hypoxia; findings confirmed by competitive PCR for VEGF and expression of the house keeping gene GAPDH. hCG and VEGF were measured by immunoassay. Hypoxia resulted in an increase in VEGF production (P<0.05) but had inconsistent effects on hCG production. In some experiments the absolute concentrations of hCG and VEGF in the culture media were noted to be significantly correlated (r>0.5, P<0.05). In addition to its role in angiogenesis, VEGF may have direct effects on trophoblast cells encouraging proliferation and invasion. These effects may be regulated in part through oxygen supply and hCG.

Variation in detection of VEGF in maternal serum by immunoassay and the possible influence of binding proteins.

Using radioimmunoassay (RIA) and a polyclonal antibody we have shown that maternal serum vascular endothelial growth factor (VEGF) is elevated during pregnancy. In contrast, a commercial VEGF ELISA utilizing a sandwich two-site immunoassay was unable to detect VEGF in 19 of the 20 maternal serum samples analysed. In addition, the recovery of exogenous VEGF added to the pregnancy samples was low or not recordable with the ELISA. Using RIA, 82-101% of the added VEGF was recovered. These differing results could be explained by the formation of VEGF-protein complexes that are detectable using RIA but undetectable with the ELISA. Our data imply that there is a substantial increase in circulating VEGF binding proteins during pregnancy. The increase in VEGF and its binding proteins during pregnancy may reflect important physiological events in the mother and feto-placental unit.

Serum relaxin and the major endometrial secretory proteins in in-vitro fertilization and down-regulated hormone-supported and natural cycle frozen embryo transfer.

Relaxin has been postulated to be a modulator of the expression of the endometrial secretory proteins, insulin-like growth factor binding protein (IGFBP-1) and placental protein 14 (PP14). This study evaluated the expression of relaxin in relation to concentrations of these secretory proteins along with oestradiol, progesterone and human chorionic gonadotrophin in groups of pregnant and non-pregnant patients who underwent differing assisted conception treatments. Serum samples were taken from 88 patients at 8 and 12 days after embryo transfer. At 12 days after embryo transfer, relaxin concentrations in the pregnant patients who had undergone in-vitro fertilization (IVF) or natural cycle frozen embryo transfer were significantly higher than those who did not conceive in these groups (mean concentrations 8334 versus 28 and 2608 versus 62 pg/ml respectively, P<0.001). However concentrations in the pregnant patients who had hormone support and transfer of frozen embryos were not significantly different from the patients who did not conceive after the same treatment. Although relaxin expression was associated with corpus luteum activity, it was not related to the number of corpora lutea in IVF patients. A wide range of relaxin concentrations was seen to be compatible with a healthy pregnancy. These serum relaxin concentrations were not found to be directly related to the serum concentrations of IGFBP-1, PP14 or the other factors assessed in this study.

Endometrial progesterone receptor expression during the human menstrual cycle.

The human endometrium undergoes regular cyclical changes under the endocrine control of oestrogens and progesterone acting via specific nuclear receptors. The molecular and cellular events mediating these changes are not understood. The present study examined the changes in the endometrial progesterone receptor and its mRNA during the menstrual cycle. Forty-four endometrial samples obtained from women with normal menstrual cycles were divided into four categories: early proliferative (days 6-9), late proliferative (days 10-14), early secretory (days 15-21) and late secretory (days 22-28). The progesterone receptor protein was determined using a human progesterone receptor enzyme-linked immunoassay kit. Total RNA was extracted using RNAzol and the abundance of mRNA encoding the progesterone receptor was determined by reverse transcriptase-polymerase chain reaction and by northern blot analysis. The concentration of the progesterone receptor in the endometrium was highest during the late proliferative phase and was lowest in the late secretory phase. Significant differences were observed between the menstrual cycle phases (P < 0.003). No cyclical variation was observed in the concentration of mRNA encoding for the progesterone receptor in the endometrium when analysed by reverse transcriptase polymerase chain reaction or by northern analysis. There appears to be no association between the amounts of mRNA encoding the progesterone receptor and progesterone receptor protein during the menstrual cycle suggesting that the control of the expression of the progesterone receptor may not occur solely at the transcriptional level.

Angiogenesis and the placental environment.

Rapid growth and vascularization of the human placenta are characteristic of early pregnancy and are accomplished in an unusually hypoxic environment. Stimulation of placental growth through hypoxia-induced angiogenesis may therefore be of particular importance. We have previously found that several varieties of vascular endothelial growth factor (VEGF) mRNA, including VEGF165, are present in cultured placental fibroblasts. We hypothesized that hypoxia would increase the transcription and translation of VEGF by these cells and provide one mechanism linking placental development with its environment. Placental fibroblasts were grown in aerobic or anaerobic atmospheric conditions for 72 h. By 24 h the oxygen tension of the anaerobic culture media was significantly less than that of the aerobic cultures. RNA was extracted from the cells at 24, 48 and 72 h. Following reverse transcription polymerase chain reaction (RT-PCR) stronger signals for VEGF were always found in the anaerobic cultures and this was confirmed by competitive PCR. mRNA for VEGF165 was represented most strongly but the anaerobic cultures also showed clearly mRNA for VEGF121, VEGF189 and VEGF206. The VEGF protein was also measured in the aerobic and anaerobic culture medium. By 72 h the average concentration of VEGF was significantly higher (P = 0.01) in the anaerobic culture medium. VEGF production is one mechanism through which oxygen supply may influence placental development. Examples of this may include the compensatory placental hypertrophy associated with maternal anaemia and with reproduction at high altitude.

Variations in concentrations of the major endometrial secretory proteins (placental protein 14 and insulin-like growth factor binding protein-1) in assisted conception regimes.

We have previously shown that placental protein 14 (PP14) concentrations were depressed in two pregnancies that followed down-regulation of the anterior pituitary and exogenous hormone support prior to a frozen-thawed embryo transfer. We now report on a more comprehensive series of pregnancies following this form of treatment, in-vitro fertilization (IVF) and natural cycle frozen-thawed embryo transfer. Serum specimens were analysed for PP14 and insulin-like growth factor binding protein-1 12 days after embryo transfer and at 7 weeks gestation. At 12 days after embryo transfer, the mean serum PP14 concentrations in the IVF and natural cycle were significantly higher in those who conceived than those who did not (82 versus 23 and 107 versus 39 micrograms/l respectively, P < 0.001). Although the mean PP14 concentration in the hormone-supported pregnant patients was higher than in the non-pregnant patients, this had not reached statistical significance 12 days after embryo transfer (49 versus 31 micrograms/l). By 7 weeks gestation the PP14 concentrations in the hormone-supported pregnant patients were significantly higher than in the non-pregnant patients (152 versus 31 micrograms/l, P < 0.001). However, the PP14 concentrations for hormone-supported pregnant patients were significantly lower (P < 0.001) than those for pregnant IVF or natural cycle patients at 7 weeks gestation (152, 777 and 660 micrograms/l respectively). The PP14 concentrations in the pregnant patients, although lower than those in IVF and natural cycle pregnancies, were higher than those previously reported in ovarian failure and Turner's syndrome ovum donation cycles.(ABSTRACT TRUNCATED AT 250 WORDS)

The selection criteria on an IVF program can remove the association between maternal age and implantation.

BACKGROUND: 1190 consecutive in vitro fertilization (IVF) treatment cycles from the Southampton University/BUPA Chalybeate unit, spanning a four year period, were studied retrospectively in order to assess the relationship between maternal age and implantation. Our aim was to evaluate the hypothesis that the number of transferred embryos can be determined by age alone. METHOD: The cases were allocated to two age groups, Group 1 was composed of patients of less than or equal to 35 years of age and Group 2 of patients greater than 35 years of age. RESULTS: We found that the selection criteria used in our programme for abandoning treatment cycles led to significantly more older patients being excluded from oocyte collection (p < 0.001). The patients from both groups that progressed to oocyte collection and embryo transfer showed no significant difference in embryo implantation. The overall implantation rate (12.4%) and clinical pregnancy rate per embryo transfer (22.8%) were achieved by being able to transfer comparable numbers of embryos in both age groups and in spite of the younger age group having a significantly better quality of transferred embryos. CONCLUSION: Although advancing maternal age predisposes to a reduced chance of success from IVF treatment, maternal age alone was not a useful predictor of embryo implantation or endometrial receptivity in completed IVF treatment cycles.

The influence of ovarian follicular activity on late proliferative phase serum IGFBP-1 in down-regulated assisted conception cycles.

Serum insulin-like growth factor binding protein-1 (IGFBP-1) concentrations were measured at the end of the proliferative phase in infertility patients undergoing normal menstrual cycle frozen embryo transfer, exogenous hormone-supported frozen embryo transfer and in-vitro fertilization (IVF) treatment cycles. These patients were divided into five groups according to their ovarian follicular activity. The exogenous hormone-supported frozen embryo transfer group, who had no ovarian follicles, and the IVF groups (number of follicles ranging from 4-38) showed statistically higher serum IGFBP-1 concentrations when compared to the normal menstrual cycle group (P < or = 0.01). There was no significant difference in the serum IGFBP-1 concentrations between the exogenous hormone support frozen embryo transfer group and the poor or normal response IVF groups (number of follicles ranging from 4 to 16). An IVF group that displayed an excessive response to our standard human menopausal gonadotrophin stimulation (> 20 mature follicles or oestradiol > 10,000 pmol/l) showed a significantly higher serum IGFBP-1 concentration when compared with the other groups (P = 0.001). This subgroup was subsequently given a modified (follicle-stimulating hormone) stimulation regime which resulted in a significant reduction in serum IGFBP-1 concentrations (P < 0.05). There was no correlation between serum oestradiol and IGFBP-1 overall or within the patient groups. We conclude that serum IGFBP-1 concentrations in our down-regulated assisted conception cycles did not increase in line with ovarian follicular activity, unless an excessive response was displayed.