Estimated probability of small for gestational age, preterm delivery, complicated delivery, and preeclampsia, by gestational weight gain rate. Analysis of 104,070 singleton pregnancies in nulliparous Japanese women. The probability is shown for the average non-smoking woman of 160 cm, age 30 years, and mean BMI of each stratum. Complicated delivery includes any of the following: cesarean section, forceps or vacuum delivery, obstructed labor, post-partum hemorrhage. BMI, body mass index; SGA, small for gestational age.