In this week’s parashah, Pharaoh orders the midwives named Shifra and Puah to kill any new born Jewish boy. However, the midwives feared G‑d and did not obey. When challenged by Pharaoh, they told him that the Jewish women were skilled in the art of giving birth, and would give birth before the midwives even got to them.
So who were these heroines who were willing to risk their lives only to never be mentioned in the Torah again?
Rashi tells us that Shifra was Yocheved and Puah was Miriam. The name “Shifra,” translates as “improvement,” a reference to the way that Yocheved would “improve” the new-borns by cleaning them and straightening their limbs. “Puah” means “cooing,” a reference to how Miriam would “coo” to the babies.
So just how many midwives were there? Let’s take a step back. Sixty-six Jewish males descended to Egypt, along with many women. The commentaries tell us that at that point in history all Jewish mothers were having sextuplets. So that would mean that there was a population boom among the Jewish nation at that time. Their numbers were increasing so dramatically that Pharaoh feared they’d soon be strong enough to wage war against his country!
So how did two midwives single-handedly deliver every baby from every mother?
Most commentaries offer a simple answer: There were in fact many midwives, up to 500 of them. Shifra and Puah were merely the ones in charge of all other midwives, hence they were the ones Pharaoh addressed.
Yet from Rashi it seems that Shifra and Puah were the only midwives in Egypt – which would be impossible! What is even more mind-boggling is the possibility that the midwives weren’t necessary at all. As the midwives tell Pharaoh: “The Hebrew women are not like the Egyptians, they know how to deliver. They can give birth before a midwife even gets to them.” We know that this wasn’t merely an excuse the midwives gave to throw off Pharaoh, because Pharaoh could have easily verified their assertion.
The Lubavitcher Rebbe answers that Yocheved and Miriam still had roles as midwives, as they were available in case of any complications during a birth. Even though they were only two people, their reputation as wellborn and righteous individuals (who would be granted Divine assistance if necessary) was enough to reassure the entire population of birthing women.
 For a more in depth scope on the topic see Sefer HaMa’amarim 5709, Kuntres 64.