If the gestational age as calculated from an early ultrasound is contradictory to the one calculated directly from the last menstrual period, it is still the one from the early ultrasound that is used for the rest of the pregnancy. In case of in vitro fertilization, calculating days since oocyte retrieval or co-incubation and adding 14 days.Gestational age can also be estimated by calculating days from ovulation if it was estimated from related signs or ovulation tests, and adding 14 days by convention.A more complete listing of methods is given in following table:
As a general rule, the official gestational age should be based on the actual beginning of the last menstrual period, unless any of the above methods gives an estimated date that differs more than the variability for the method, in which case the difference cannot probably be explained by that variability alone.
In anagen effluvium, histopathologic evaluation of a punch biopsy of the scalp will exhibit a normal anagen-to-telogen ratio, which is less than 15% telogen hair follicles. If greater than 15% of the hair follicles are in the telogen phase, this more supports a diagnosis of telogen effluvium. Treatment
The management of anagen effluvium should be aimed at limiting the amount of time the patient has alopecia. To date, several agents have been studied; unfortunately, no treatment appears to be effective in preventing or stopping the hair loss. Although the results have not been impressive in stopping or preventing hair loss, it has been postulated that topical minoxidil is effective in reducing the period of baldness by an average of fifty days. Several studies have described limiting drug delivery to the scalp by using a scalp tourniquet during chemotherapy. If scalp or brain metastases are a possibility, this method should not be used to allow penetration of the chemotherapeutic agent. Another method that has shown success is inducing scalp hypothermia (by keeping ice over the scalp) to a scalp temperature of fewer than 24° Celsius during chemotherapy with daunorubicin, doxorubicin, paclitaxel, vincristine, vinblastine, mechlorethamine, actinomycin D, and epirubicin.As pharmacologic agents successful in treating and preventing anagen effluvium have not been found, patient education and aesthetic advice on managing hair loss are fundamental to managing androgen effluvium.