When there is a rupture in the fetal membranes, the woman notices a painless sudden leakage of fluid from her vagina, which is usually excess and watery. However, when the amount of amniotic fluid in the sac is minimal, the leaking fluid may only wet her underwear, and you may be unsure whether to make the diagnosis of PROM from the woman's complaint.

The mother may be worried, but not be sure whether the leakage is normal or abnormal. A little bit of excess vaginal discharge is normal near to full term, and this may be confused with the leakage of amniotic fluid. So you need to refer any woman complaining of excess vaginal discharge for further evaluation at a higher level health facility, in case the woman is showing signs of PROM.

Clinical features of PROM

The woman complains of leakage of fluid from her vagina (minimal or excess).
She says she noticed a decrease in the size of her abdomen after leakage of fluid.
You observe watery fluid coming out through the vagina, or the woman's under clothing is soaked with watery fluid.
When you measure the distance between the pubic symphysis and the fundal height, you find the baby is small for gestational age. (Note that being 'small for gestational age' can also be due to scanty amount of amniotic fluid with intact membranes, intrauterine growth restriction and wrong date for the stated gestational age.)
In PROM, the amniotic fluid remaining in the sac will be minimal, so you may be able to feel (palpate) the fetal parts easily through the mother's abdomen.
Although not specific, the woman may have an offensive smell due to vaginal discharge, and she may have a fever; these signs indicate an already established infection, which may be the cause of PROM.
You can give her a dry vaginal pad or Goth and check after some hours whether it is wet or still dry. Note that being dry doesn't necessarily rule out PROM.