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The effect of a folic acid supplment on birth weight and placental weight in women delivering in the early summer in Denmark was investigated. Thirty-six women with normal pregnancy and expected delivery in the first half of June were selected consecutively. They were paired two and two, and allotted to two groups, one of which was supplied daily with 5 mg folic acid, and the second with tablets without folic acid, from the 23rd week of pregnancy. A significant correlation was found between erythrocyte folic acid and birth weight. The infants in the folic acid group were 12.7 per cent heavier than those in the control group (p less than 0.01). A similar difference was found with regard to placental weight and the number of placental cells.

A study has been made of a prospectively selected material of circumvallate placentae; the latter being defined as an elevated edge of more than 50% of the circumference. The material consists of 447 placentae from liveborn singleton infants, where 287 were from exemplary pregnancies, and 160 from births with a gestational age (GA) of less than 266 days and/or a birth weight of less than 2 750 g. The material was prospectively randomized. It was divided into clinical groups according to the GA and under-weight. Nineteen circumvallate placentae were found. Among these were more multigravidae and more with pre-gestational menstrual irregularity than expected. The number of antepartum haemorrhages was as expected. There were more premature infants, premature under-weight infants and under- weight infants than expected. Nine of the 20 premature under-weight infants in the material had circumvallate placenta. In relation to a previously published basic material, it was found that the birth weight, and placental content of RNA and DNA were significantly reduced. It is concluded that placentae with more than 50% circumvallation are associated with prematurity and under-weight, as well as a placenta with fewer cells than normal. The genesis of the anomaly is discussed.

Some disorders of the umbilical cord-Single umbilical artery, oedema of the cord, battledore insertion and velamentous insertion-have been examined in a prospectively randomized material. The material consists of 447 placentae from liveborn, singleton infants, where 287 were from exemplary pregnancies, and 160 from births with a gestational age of less than 266 days and/or a birth weight of less than 2750 g. The placentae were examined macroscopically and microscopically, and the total amount of protein, RNA, and DNA were determined in a randomized sample. Single umbilical artery was found to coincide with circumvallate placenta, suggesting a common fault in the placentation. Oedema of the umbilical cord was found to have no significance for the infant, but their placentae were significantly heavier, without signs of generalized oedema. The birth weight and placental weight were slightly and equally reduced in battledore insertion of the cord. The RNA/DNA ratio was increased, indicating tissue stress. This anomaly contrasted to the placentae, in which the cords were inserted velamentously. These had significantly reduced birth weights, and the weights of the placentae were slightly reduced. The incidences of complications during labour and congenital anomalies were increased.

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