Birthing 101

How Kittens Get Here from There

- By Sara Thornton DVM

The excitement grows as the queen’s belly expands. You’re counting down the days. Normal pregnancy in cats averages 65 days. Larger litters tend to have slightly shorter gestations, while extremes can range from 54 to 74 days.

Meanwhile, the kittens are growing inside the uterus. As they increase in size, fetal cortisol—also known as “the stress hormone”— rises to a threshold which triggers a cascade of events, including a decrease in progesterone. The decrease in progesterone to a median of 3.18 ng/ml, leads to the stimulation of myometrial contractions, and prompts the beginning of labor.

The Stages of Labor

Stage one of labor is generally the longest stage. The cervix gradually dilates and contractions begin. At this time, the contractions are generally not visible to an observer. A queen in this stage of parturition may display panting, nesting behavior and restlessness. She may also be anorexic and/or nauseous. The first stage may be as short as a few hours or as long as a day.

Stage two begins when active contractions are noticeable. Once these contractions begin, the first kitten should be expected to arrive within four hours. but it is usually closer to one hour. Stage two and stage three—delivery of the placenta—occur at practically the same time since kittens and placenta are usually expelled at the same time or relatively close together.