– Those born in the year of the monkey are said to be crafty, clever and charming. That's spurred some couples in China to delay parenthood until the less-auspicious year of the sheep ends — a balm for companies offering fertility products and obstetric services.

The change in the Chinese zodiac from sheep to monkey, which happens on Feb. 8, has helped boost maternity bookings by as much as 30 percent at Harmonicare Medical Holdings Ltd.'s 72-bed hospital in Beijing, the company said. German drugmaker Merck KGaA said sales of fertility-related medications increased in China late last year as couples sought to build the ranks of little monkeys.

Harmonicare, China's largest private obstetrics and gynecology hospital group, is renovating wards in its Beijing and Wuhan centers, adding beds and hiring medical staff on expectation of a busier year. It expects the advent of the country's two-child policy will add to a monkey-baby drive.

"The number of obstetric deliveries will surely see substantial growth in the 2016 year of the monkey," said Chen Wei, vice president of the Beijing-based company. "In Chinese tradition, sheep-year babies are seen as less auspicious than those born in other years, so many families delayed their reproductive plans."

While the year of the monkey isn't considered the most desirable among the 12 zodiac signs, it's sandwiched between the years of the sheep — sometimes referred to as a goat — and the chicken, which can be seen by some as less favorable. The most auspicious year is that of the dragon, a symbol of China's emperors and synonymous with power and wealth. The last dragon year, in 2012, sparked a 1.9 percent jump in births in China.

Birth years don't always have a corresponding effect on fertility. In the past monkey year, in 2004, the number of births in China decreased by 0.37 percent in the wake of a deadly SARS epidemic.

Superstition persists in China. The impact on births though is difficult to predict, said Joy Huang, the Shanghai-based research manager at Euromonitor International. "For example, we expected fewer babies to be born in the goat year, whereas we found out that the birthrate wasn't severely impacted," she said.

Still, many couples in China waited until last May to fall pregnant, Marcus Kuhnert, chief financial officer of Darmstadt, Germany-based Merck, told analysts Nov. 12. "And since then indeed we saw a strong takeup of the business."

Deliveries may be bolstered by the commencement on Jan. 1 of the two-child policy, a relaxation of previous population curbs. The change will result in 3 million to 6 million more babies each year starting in 2017, Credit Suisse Group AG estimated in October. Suppliers of baby milk formula, diapers and certain medications will directly benefit.