Hormonal monitoring of early pregnancy by a direct radioimmunoassay of steroid glucuronides in first morning urine

A time-resolved fluorescence microsphere-lateral flow immunochromatographic strip for quantitative detection of Pregnanediol-3-glucuronide in urine samples

Introduction: Pregnanediol-3-glucuronide (PdG), as the main metabolite of progesterone in urine, plays a significant role in the prediction of ovulation, threatened abortion, and menstrual cycle maintenance. Methods: To achieve a rapid and sensitive assay, we have designed a competitive model-based time-resolved fluorescence microsphere-lateral flow immunochromatography (TRFM-LFIA) strip. Results: The optimized TRFM-LFIA strip exhibited a wonderful response to PdG over the range of 30-2,000 ng/mL, the corresponding limit of detection (LOD) was calculated as low as 8.39 ng/mL. More importantly, the TRFM-LFIA strip was innovatively used for the quantitative detection of PdG in urine sample, and excellent recovery results were also obtained, ranging from 97.39% to 112.64%. Discussion: The TRFMLFIA strip possessed robust sensitivity and selectivity in the determination of PdG, indicating the great potential of being powerful tools in the biomedical and diagnosis region.

Unpredicted ovulations and conceptions during early pregnancy: an explanatory mechanism of human superfetation

In this bioessay, a literature review on human superfetation was performed in order to find epidemiological variables associated with this phenomenon. Thereafter, an explanatory mechanism of superfetation compatible with the endocrinological, histological and physiological changes undergone by women during early pregnancy is proposed. Superfetation can be defined as the ovulation, fertilisation and implantation of a second or additional embryo(s) during pregnancy. The literature review evidences a small discordance in gestational age between dizygotic twins in humans (range: 2–4 weeks; mean ± s.e.m.: 3.3 ± 0.3 weeks). This difference is compatible with a luteal out-of-phase (LOOP; i.e. atypical increase in E2 levels in the mid-luteal phase)-like event occurring between 1 and 3 weeks after the ovulation that allowed the first pregnancy to take place. The LOOP-like event may allow passive sperm transport from the vaginal fornix to the Fallopian tube ipsilateral to the ovulatory ovary and trigger a LH peak and ovulation. Furthermore, during very early pregnancy, the decidual reaction is not yet completed and at least one proximal Fallopian ostium may be opened, allowing the passage of the spermatozoa ascending to the fertilisation site and the extra embryo(s) descending to the implantation site(s).

A prospective study of early pregnancy loss in humans

OBJECTIVE

To test two hypotheses: In spontaneous conceptions, early pregnancy loss (EPL) is associated with [1] inadequate luteal (ovarian) P, and/or [2] elevated follicular (adrenal) P.

DESIGN

A population-based prospective study.

SETTING

Thirty rural Bolivian communities.

PATIENT(S)

Women volunteers (n = 191), 19-40 years old, in stable sexual unions and not using contraception.

INTERVENTION(S)

Collection of serial saliva samples throughout sequential ovarian cycles and urine samples during late luteal phases. Collections continued throughout pregnancy for each detected conception.

MAIN OUTCOME MEASURE(S)

Occurrence of spontaneous conceptions and subsequent outcomes. Salivary concentrations of P. Test for elevated urinary human chorionic gonadotropin (hCG).

RESULT(S)

Luteal (through implantation) P levels were similar in pregnancies lost within 5 weeks after conception (EPL; n = 8) and those pregnancies that were maintained longer (sustained conceptions, SC; n = 32). Follicular P was significantly higher in EPL than in SC.

CONCLUSION(S)

[1] Elevated follicular P was associated with EPL in natural conceptions in healthy women. [2] Early pregnancy loss exhibits absolute luteal P levels comparable to SC, but lower luteal/follicular P ratios.

Direct determination of estriol 3- and 16-glucuronides in pregnancy urine by column-switching liquid chromatography with electrospray tandem mass spectrometry

Using column-switching liquid chromatography/tandem mass spectrometry (LC-MS/MS), we developed an improved analytical method of urinary estriol glucuronides. This new method is derived predominantly from maternal and fetal precursors in pregnancy. We used in the following procedure: first, we filtered urine samples with a membrane filter. Next, we directly injected the 50 microL aliquot of urine samples onto a pre-column. Then, after activating the column-switching valve, we backflushed the loaded samples onto the C(18) analytical column. Urine samples can be assayed within 20 min without any sample preparation steps. We monitored separated estriol glucuronides by negative electrospray ionization (ESI) and selected-reaction monitoring (SRM). The calibration range of estriol-3-glucuronide (E3-3G) and estriol-16-glucuronide (E3-16G) was 0.1-20 microg/mL and the linearity of the method was 0.9984 for E3-3G and 0.9987 for E3-16G. The limits of detection at a signal-to-noise (S/N) ratio of 3 were 10 ng/mL (E3-3G) and 5 ng/mL (E3-16G). The analytical recovery was over 85% and, in general, inter-day and intra-day variability for precision and accuracy were less than 10%. When applied to a pregnancy urine sample to biomedical monitoring of the function of the maternal/fetal unit, the proposed method allowed rapid and sensitive screening for the detection of E3-3G and E3-16G.

Rescue of the corpus luteum in human pregnancy

Rescue of the corpus luteum from its programmed senescence maintains progesterone production required for pregnancy. In primates, chorionic gonadotropin produced by the developing conceptus acts as the primary luteotrophic signal. The purpose of this research was to assess corpus luteum rescue by examining changes in daily urinary progesterone metabolite levels during the first week after implantation. We determined the variability in progesterone metabolite profiles and evaluated its relationship to early pregnancy loss in 120 naturally conceived human pregnancies, including 43 early pregnancy losses. In other primates, an abrupt increase in the progesterone metabolite occurs at the time of implantation. This pattern occurred in an estimated 45% of the pregnancies in the present study. In the remaining pregnancies, there was a delayed rise (18%), neither a rise or decline (22%), or a decline (15%) during the week after implantation. The estimated rate of early pregnancy loss increased across these categories (from 5% loss with an abrupt rise at implantation to 100% loss with progesterone metabolite decline). Low urinary hCG levels in early pregnancy were significant determinants of a decline in postimplantation progesterone metabolite. However, preimplantation steroid metabolite levels were not significant, suggesting no inherent problem with the corpus luteum. Examination of individual progesterone metabolite profiles in relation to hCG profiles also indicated that few losses were caused by corpus luteum failure. Delineating the functional importance of an abrupt progesterone rise at the time of implantation may provide new strategies for promoting successful implantation in assisted reproduction.

Effect of hydration on random levels of urinary pregnanediol glucuronide

To determine the effect hydration has upon the relationship between serum progesterone and its urinary metabolite pregnanediol-3 alpha-glucuronide (PDG) we measured spot samples from patients (n = 207) presenting in the 1st trimester of pregnancy. Serum and urine specimens were obtained simultaneously and measured for progesterone and PDG by radioimmunoassay (RIA). Urine specific gravity was also measured at the time of sample collection. Results demonstrated that in samples where the urine specific gravity was greater than or equal to 1.015 there was a strong positive correlation between serum progesterone and PDG (r greater than 0.60, p less than 0.001). However, when urine samples were below a specific gravity of 1.015, serum and urinary steroid values correlated poorly or not at all. We conclude that the measurement of specific gravity should be routinely performed when determining random values of urinary PDG, since only samples in which the urine is adequately concentrated accurately reflect corresponding serum progesterone concentrations.

Rapid measurement of urinary pregnanediol glucuronide to diagnose ectopic pregnancy

We investigated the ability of a single, random, urinary pregnanediol-3 alpha-glucuronide level to differentiate early intrauterine from ectopic pregnancy. Thirty-four patients with intrauterine gestations were compared with 60 patients with ectopic pregnancies. Urinary pregnanediol-3 alpha-glucuronide was measured by radioimmunoassay and enzyme immunoassay. Compared with intrauterine gestations, results demonstrate that urinary pregnanediol-3 alpha-glucuronide is significantly depressed in ectopic pregnancies: 24.5 +/- 2.2 versus 4.8 +/- 0.7 micrograms/ml (p = 0.0001). Urinary pregnanediol-3 alpha-glucuronide levels obtained by conventional radioimmunoassay correlated closely with values measured in minutes with enzyme immunoassay (r = 0.95, p = 0.0001), and with serum progesterone (r = 0.74, p = 0.0001). Urinary pregnanediol-3 alpha-glucuronide measured by enzyme immunoassay exhibited predictive values for detecting ectopic gestations comparable with random serum progesterone or serum beta-human chorionic gonadotropin values. We conclude that ectopic gestations demonstrate a reduced level of urinary pregnanediol-3 alpha-glucuronide (55/60 cases) detectable with a rapid enzyme immunoassay, which makes this assay a practical screening test in early pregnancy.

Urinary estrone glucuronide, pregnanediol glucuronide and human chorionic gonadotrophin in threatened abortion

Estimations of urinary estrone glucuronide, pregnanediol glucuronide and human chorionic gonadotrophin were carried out by ELISA to see their potential in predicting an abnormal outcome in cases with vaginal bleeding in early pregnancy. Reference values were set up with samples from women without bleeding in present or past pregnancies and with normal ultrasonic findings. None of the parameters were found to be sensitive enough to predict an abnormal outcome. However, predictability of an abnormal value was found to be 95% for estrone-3-glucuronide (E1G), 93% for pregnanediol glucuronide (PdG) and 87% for human chorionic gonadotrophin (hCG).

Hormone excretion during early pregnancy following spontaneous and clomiphene citrate-induced ovulation

Endocrine changes during early pregnancy have been studied in 12 patients between days 35 and 91 from the last menstrual period. Ovulation had occurred spontaneously in five patients and was induced with clomiphene citrate (CC) in the remaining seven women. All the patients collected daily samples of early morning urine throughout the period of study; on each sample, human chorionic gonadotropin (hCG), pregnanediol-3-alpha-glucuronide (PGDG) and estrone-3-glucuronide (E1G) were measured by chemiluminescence immunoassay. No significant difference was observed between the two groups of patients with respect to the concentrations of hCG and PGDG. The excretion of E1G, however, was significantly higher in patients treated with CC. These data suggest that the induction of ovulation with CC may affect estrogen production in early pregnancy.