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It is now well accepted that a woman can conceive from an act of intercourse for a maximum of only about 7 days of her menstrual cycle. The reliability of natural family planning depends on identifying this window of fertility without ambiguity. Several symptomatic markers, cervical mucus and basal body temperature, have been used extensively and with considerable success in most women but failures occur. Ovarian and pituitary hormone production show characteristic patterns during the cycle. Urinary estrogen and pregnanediol measurements yield reliable information concerning the beginning, peak, and end of the fertile period, provided that the assays are accurate and performed on timed specimens of urine. We have developed such enzyme immunoassays for urinary estrogen and pregnanediol glucuronides that can be performed at home. In the early versions of the assays, enzyme reaction rates were measured by eye, but more recently, a simple photoelectronic rate meter has been used. The final problem to be solved is not technologic but whether women are sufficiently motivated to expend the same time and effort each day for 10 days a month, with less cost, on fertility awareness as they spend on making a cup of tea.

Derivatives of estrone were prepared and linked to bovine serum albumin or its methyl-esterified form to produce immunogens which were effective in raising antisera to estrone sulfate. The most effective was estrone-3-methylphosphonothioate, electrostatically complexed with methylated bovine serum albumin. The ionically combined hapten functioned as an antigenic determinant as do covalently bound haptens when administered to sheep in emulsions with Freund's complete adjuvant. Estrone-3-phosphate covalently or electrostatically linked to bovine serum albumin also produced antisera reactive to estrone sulfate. Estrone sulfate itself, after electrostatically complexing to methylated bovine serum albumin and administration with Freund's complete adjuvant to sheep, was ineffective in producing antisera. The sera which had workable titres to estrone sulfate showed considerable cross-reaction with free estrone but was otherwise highly specific with little or no reaction with other steroid sulfates, glucosiduronates or other free steroids. Radioimmunoassay curves using [6,7-3H]-estrone sulfate were highly sensitive and were effective in the range of 5-250 pg estrone sulfate.

A study of the lipid composition of ram testicular and ejaculated spermatozoa was made in an attempt to resolve conflicting results in the literature. Testicular spermatozoa were found to contain more than double the amount of phospholipid present in ejaculated spermatozoa. Most phohpholipid components, including choline plasmalogen, decrease substantially in concentration during migration of the spermatozoa through the male reproductive tract. Phosphatidylserine, ethanolamine phosphoglycerides and cardiolipin components accounted for the greatest relative decreases in concentration, the former decreasing by approximately nine tenths. Of the phospholipid-bound fatty acids the most pronounced change occurs in palmitic during migration of spermatozoa through the reproductive tract. There is a net loss of approx. 500 mug of palmitic acid for every 10-9 spermatozoa. The loss of arachidonic acid was particularly interesting, and prompted a study of the prostaglandin content of testicular and epididymal fluids, since arachidonic acid can act as a precursor of prostaglandin. The concentration of prostaglandin F2alpha found in the testicular and epididymal fluid is considerably in excess of that found in venous plasma of the ram.

Premature parturition was induced in five pregnant goats infused intravenously with 4.65-8.4 mg estradiol-17beta but not in one treated with 5.85 mg estradiol-17alpha. A single intramuscular injection of 12 mg estradiol benzoate (8.8 mg estradiol-17beta equivalents) was also effective. These doses were estimated to provide plasma concentrations of estradiol-17beta in the physiological range for animals at sponteneous parturition. Circulating plasma concentrations of progesterone decreased and lactogenesis occurred before all instances of induced parturition but no such changes resulted from infusion of estradiol-17alpha. Placental delivery was normal in all animals but neonates of more than 10 days prematurity were non-viable.

The effect of exogenous progesterone or megestrol acetate (MGA) on cervical extensibility and on the concentrations of prostaglandin (PG) F in utero-ovarian plasma and progesterone, estrone sulphate and unconjugated estradiol-17 beta concentrations in jugular plasma was studied over Days 238-242 in pregnant cows given intrafetal infusions of dexamethasone to induce premature delivery. All 11 cows used in the study were given continuous intrafetal infusions of dexamethasone at a rate of 3.3 mg/day to induce premature labor. Progesterone was infused continuously at a rate of 400 mg/day for 10 day into the jugular vein of 3 of 11 cows while another 3 were given MGA at a rate of 20 mg/day. In the cows given dexamethasone alone premature parturition was induced in 2.5-4.5 days and all calves were born alive and well. However, in the progestogen-treated cows, dexamethasone failed to induce premature delivery. The cervix of these cows remained firm and unyielding during the time of the progesterone infusion. Following the withdrawal of exogenous progestogens the cervix became soft and compliant and the cows delivered within 0.5-1.5 days, but only 2 of the 6 calves were alive at birth. Hormone changes in the cows given intrafetal infusions of dexamethasone included a marked rise in utero-ovarian PGF and a concomitant decline in jugular progesterone concentrations. Plasma concentrations of estrone sulphate and estradiol-17 beta showed a small increase before delivery. An increase in utero-ovarian PGF concentrations was also observed in all of the progestogen-treated cows, although there was considerable individual variation in the timing of the PGF surge. The plasma concentrations of estrone sulphate and unconjugated estradiol-17 beta levels in the progestogen-treated cows showed the same general trend, with the levels increasing within 1-2 days of starting the dexamethasone infusion and then falling before delivery.(ABSTRACT TRUNCATED AT 250 WORDS)