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Query: UMLS:C0728731 (prematurity)
 7,134 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The article compares seasonal variation in conception in Baroda and Manipal, both at sea level on the west coast of India. The maximum seasonal difference in mean monthly temperature is 3.5 degrees C in Manipal, and 11.3 degrees C in Baroda. Both are industrialized towns, Manipal serving the surrounding taluk of Udupi. Clinical records were obtained from local hospitals; it must be remembered that birth registration in India is compulsory. The number of births in each month were aggregated for the period under review and adjusted to standard month of 30 days, from which an annual mean was calculated. A similar procedure was used to find mean annual temperature. A few relationships are apparent: 1) conception correlates inversely with temperature at both places, 2) abortions and stillbirths are higher in the hottest weather at both places, 3) in Baroda, but not in Udupi, the maximum prematurity rate occurs 5 months after the hottest weather. The links between weather and variations in human reproduction are not clear. Although patterns are not consistent, the conception rate appears to be low at times of maximum temperature. A number of biological and social factors, such as a rise in testicular temperature, can lead to oligospermia. Maternal body temperature can affect the life of spermatozoa, and climate influences the frequency of coitus. Implications from these variations must be taken into consideration in designing new family planning services.
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PMID:Seasonality of birth in India. 72 46

Zinc is a very important element in the reproductive cycle of species. In humans, it is necessary for the formation and maturation of spermatozoa, for ovulation, and for fertilization. During pregnancy, zinc deficiency causes a number of anomalies: spontaneous abortion, pregnancy-related toxemia, extended pregnancy or prematurity, malformations, and retarded growth. Delivery is adversely affected by deficiency. These different effects of zinc can be explained by its multiple action on the metabolism of androgen hormones, estrogen and progesterone, together with the prostaglandins. Nuclear receptors for steroids are all zinc finger proteins. Zinc supplementation has already proven beneficial in male sterility and in reducing complications during pregnancy. However, it would be worth conducting larger-scale trials to confirm these beneficial effects.
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PMID:The role of zinc in reproduction. Hormonal mechanisms. 137 78

The correlations with maturity of gametes and fertilizability was studied. Specimens of semen were treated by several methods for induction of capacitation and acrosome reaction (AR). Follicular oocytes were recovered with endoscopic aspiration procedures, and divided to two groups: 1, maturing in vivo (preovulatory) and 2, immature. Immature oocytes were divided further into two subgroups: 1, germinal vesicle breakdown (GVBD) and 2, first polar body formation (FPB), after maturation culture. The sperms treated with the centrifuge-trypsinization-layering method showed a higher incidence of in-vitro fertilization (69.2%) and cleavage (51.3%) of human preovulatory eggs compared with other capacitation inducing methods. It was found that human spermatozoa that have undergone the acrosome reaction prior to zona attachment are capable of fertilizing eggs under the in vitro conditions. On the estimation of fertilizability with reference to egg maturity, 52.5% (21/40) of IMIV-GVBD and 64.7% (22/34) of IMIV-FPB eggs were fertilized. However, only 12.5% (5/40) of IMIV-GVBD and 11.8% (4/34) of IMIV-FPB eggs cleaved. These results showed that IMIV eggs had fair fertilizability, but no developmental capacity after the first cleavage. This may due to prematurity of the cytoplasm in IMIV eggs.
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PMID:[Methodological study for human in-vitro fertilization related to maturity of gametes]. 403 25

The obstetric data of 904 consecutive pregnancies obtained after intracytoplasmic sperm injection (ICSI) using ejaculated spermatozoa (group I), epididymal spermatozoa (group II), testicular spermatozoa (group III) and after the replacement of frozen-thawed embryos (group IV) are described. In all, there were 785 pregnancies in group I, 37 pregnancies in group II, 30 pregnancies in group III and 52 pregnancies in group IV. A total of 24 pregnancies (2.5%) have so far been lost to follow-up. The incidence of pregnancy loss, i.e. subclinical pregnancies, clinical abortions and ectopic pregnancies were highest in group IV (61.4%). Early pregnancy loss in groups I, II and III were 21.9, 37.8 and 33.3% respectively. Prenatal diagnosis was performed in 64.4% of the clinical pregnancies: amniocentesis in 48.2% and chorionic villus sampling in 16.2%. The karyotypes were normal in 97.6% of the prenatal diagnoses and there were 1.2% de novo and 1.2% inherited chromosome aberrations. Pregnancy complications such as prematurity and low birthweight were related to pregnancy multiplicity. Perinatal mortality occurred in 15 babies (17.1 per thousand), including nine intrauterine fetal deaths after 25 weeks of gestation and six cases of mortality during the first 7 days after birth. There is no evidence that the technique of ICSI using sperm cells of different origins yielded a higher obstetric risk.
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PMID:Obstetric outcome of 904 pregnancies after intracytoplasmic sperm injection. 914 15

The need to assess the health of children born after assisted reproductive technologies (ART) using frozen donor spermatozoa has been a major concern for the last decade. Most available published studies are confusing (since they are retrospective) and refer to small numbers of cases or involve a bias. Two prospective and large population-based studies have been published, one in France and the other in Australia. The general characteristics of children born after ART using frozen spermatozoa was unchanged in comparison with the general population (weight, prematurity, stillbirths, sex ratio). However, the rate of multiple pregnancy was increased, first in artificial insemination with donor semen (AID), where the use of hormonal treatment may be too heavily prescribed, and second in IVF with donor semen (IVF/D) where both the ovulation induction treatments and embryo transfer policy increase the rate of multiple pregnancies. As far as birth defects or chromosomal abnormalities are concerned, no difference has been observed from the general population. Finally, the use of frozen spermatozoa does not seem to affect the health of children conceived by AID or IVF/D. The psychosocial development of such infants is not as well known because of the confidentiality in many countries concerning sperm donation. However, the available information on the psychosocial development of these children up to the age of 8-10 years appears to be reassuring. Larger and longer studies are needed to answer such questions, particularly with regard to adulthood.
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PMID:Follow-up studies of children born after frozen sperm donation. 1121 72