Subsequent pregnancy following labor of a very-low-birth-weight infant.

During a period of 5 years (1978-1982), 55 mothers with an average age of 27.5 +/- 5.4 years, delivered 59 infants, weighing less than 1500 g. These infants had a mean birth weight of 1160.5 +/- 263 g and a mean gestational age of 28.7 +/- 2.25 weeks (range 25-32 weeks). Subsequently 47 (79.6%) survived and 12 (20.4%) died. There was a statistical difference of both mean gestational age and of mean gestational weight between survivors or infants with neonatal death. Twenty two of 29 mothers who subsequently became pregnant, gave birth to liveborn infants, who subsequently survived (four pregnancies terminated in induced abortion). Mean gestational age was 37 +/- 3 weeks (range 32-41 weeks) (P less than 0.001) and a mean birth weight was 2753.2 +/- 570 g (range 1620-3600 g) (P less than 0.001. All the 22 infants subsequently born weighed more than 1501 g, 7 (31.8%) infants weighed 1501-2500 g and 15 (68.2%) more than 2500 g. Similar data were obtained from a control group of 615 mothers (chosen at random) who delivered a normal infant at term, 202 subsequently became pregnant and 176 gave birth to a normal infant at term. Mean gestational age was 39.54 +/- 1.24 weeks (P less than 0.001) and mean birth weight was 3299.3 +/- 412 g (P less than 0.001). (In the control group 10 pregnancies terminated in induced abortions). The above data could be used in advising for future pregnancy outcome in regard to women with premature births.