Table 4.

The association between the type of COVID-19 vaccine and the impact on the menstrual cycle

Variable	Vaccine type
	First dose				Second dose
	AstraZeneca	Pfizer	Moderna	P-value	AstraZeneca	Pfizer	Moderna	P-value
Q1. After receiving the COVID-19 vaccine, your next period was
				0.12				0.09
Lighter than usual	149	423	2		47	284	3
Heavier than usual	86	246	6		50	223	2
The same as usual	392	1025	9		153	819	25
Q2. After receiving the COVID-19 vaccine, your next period was
				0.26				0.77
Earlier than usual	98	294	1		43	241	3
On-time	368	919	10		147	756	20
Later than usual	161	481	6		60	329	7
Q3. After receiving the COVID-19 vaccine, the cramps you experienced in your next period was
				0.32				0.61
Worse than usual	158	456	5		73	350	7
Less bad than usual	41	141	0		24	118	1
The same as usual	428	1097	12		153	858	22
Q4. After receiving the COVID-19 vaccine, premenstrual syndrome) PMS you experienced in your next period was
				0.06				0.89
Worse than usual	138	409	6		61	319	6
Less bad than usual	26	113	0		18	91	1
The same as usual	463	1172	11		171	916	23