On Dec. 30, 1972 and Aug. 28, 1975 Linda Schreiber of Greenwich, Conn. and Susie Kellett of Chicago, Ill. experienced respectively the birth and subsequent survival of quadruplets, in both cases born seven weeks prematurely. That makes them two of only 76 mothers in the U.S. with a complete set of quads. Though both mothers had taken fertility drugs, their chances of conceiving quads were only one in about 700,000. After the shock, and an avalanche of publicity, they settled into the reality and burdens of raising their "instant families."

Today Linda Schreiber, 33, is as well-known in Greenwich as a marathon runner as she is for her children. She grew up in New London, Conn. and attended Brown University and Columbia. She married her attorney husband, James, 35, in 1966. Because of her difficulty in conceiving, she took Clomid and in 1970 delivered one daughter, Samantha. Two and a half years later she tried again with Pergonal and gave birth to Danielle, Elisabeth, Zachary and Amanda at New York Hospital.

Susie Kellett, 33, grew up in a suburb of Chicago and attended Denver University and Washington State University. She married and moved to Sun Valley, Idaho, where, after three years of futile effort and fertility testing, she took Clomid and had Lucas, Gwen, Abby and Tyler at the University of Washington Hospital in Seattle. Now in the process of a divorce, she lives with her parents outside Chicago and is a reporter for PEOPLE.

Recently Linda and Susie closed the door on children, laundry and toys in Linda's home and shared their feelings about the experience that changed their lives. (Kellett's questions and comments are in bold-faced type.)

Linda, how did you feel when you found you were going to have your four?

At first we had discussed the possibility of twins. One day Samantha, my 2½-year-old, was in her high chair, and all of a sudden she piped up, "Four babies." She clapped her hand over her face, wrinkled up her nose and made a ghastly expression. I said, "Yes, Samantha, my sentiments exactly." We all thought it was a big joke. Then the quads were diagnosed in the middle of my fourth month. My gut reaction was wow, this is exciting! On the other hand, there was this nagging little reminder saying caution, it could be a disaster.

How did you find out you had quads?

I was tested with ultrasound, and there it was on the screen, the little blips of the heads where the skeletal mass reflects the sound waves. First they confirmed two babies. Then, as I was getting off the table, they said wait a minute and picked up two more.

How did your husband react?

Jim was waiting in the car, glowering at his wristwatch. "What the hell took you so long?" he asked. I just turned to Samantha in the back seat and said, "Well, Samantha, tell Daddy how many babies." When he finally looked up from his fuming, he said, "No!" And I said, "Oh, yes!" It was just incredible!

What was your reaction?

It was scary. We decided we had to look at it as an adventure. It would be too depressing if we kept dwelling on the potential for disaster. Every time we verged on that, Jim would say something like, "Can you imagine four potties all in a row?" What about you?

I think I knew within three weeks after I conceived. I was starting to get a little paunchy and I felt odd. My husband, Dick, and I then went off to spend five weeks backpacking in Yucatán. If my kids ever wanted to leave me, that was the time. It was 105° everyday. At the end of four months, I had an ultrasound test also, and they found two babies, but hinted there might be three. That night the doctor called and said, "Mrs. Kellett, you're not having three babies, you're having four"—and he hung up. I burst into tears and thought, "Oh, no, this can't be happening to me!"

The most oppressive thing to me, Susie, was that nobody could say I'd end up with even one healthy baby.

There are simply no guarantees at all. I knew there were cracks in my marriage by this time, and I panicked about being 30 and having so many children to take care of. I had this idyllic sports-oriented life in Sun Valley, and I seriously considered abortion. But I couldn't do it, not after everything I'd done for three years to get pregnant.

The whole trick is to carry them as close to term as you can. The longer they stay inside you, the better their chances. But I felt like I was going to explode. I used to sleep sitting up with pillows. I couldn't lie down.

I was so big I don't think I saw my feet after the third month. I could have been walking on my knees. How was your delivery?

Fast, very fast. They came in a mere 16 minutes!

When I was wheeled into the delivery room, there were 50 people waiting for me, including four obstetricians, three anesthesiologists, a neonatology team for each baby and every med student who could get in the door. It was like Wide World of Sports/ They were all born in 17 minutes, and the last one got me a standing ovation. But when I saw my children 24 hours later, I was totally taken aback. They were so tiny, ranging from 3 lbs. to 3 lbs. 13 oz.

When they're your babies and they're that small, it is awesome. Their lifelines plug into you and the responsibility is overwhelming.

The first year I kept a very rigid schedule. I had a live-in girl, each day included making 24 bottles of formula, and we had to change 1,200 diapers a month. I just took the phone off the hook and slept when the children slept.

Yes, a phone call at the wrong time could throw me totally off schedule. If there was no schedule, my husband and I would never have had any time together. I had to run a tighter ship than most mothers, and I still do. I feel that in some ways it is unfair to the children because it doesn't allow them much free rein.

A lot of people were curious whether my workload was phenomenally more than someone with one or two children. I got to the point where if I was going to make one meal, I might as well make four. You get so good at it.

We sound like automatons, don't we? Well, you sure do become efficient.

When people see you with your children, Linda, do they know they're quads?

Many times I am asked if my quads are a nursery school group—especially at the supermarket when I check out with two dozen 64-oz. jars of apple juice. When we moved them into umbrella strollers all clipped together, it was a showstopper! There's a sense of pride in being able to manage alone. After four years I didn't have any more live-in help. But common sense tells you that you really have to have assistance, because the quality of mothering goes down when you are torn umpteen different ways. There are times when you have no alternative but to burst into tears.

The hospital bills were astronomical! A lot of people think we were helped financially. We were given baby food by Gerber, and I had help from formula companies. That was all.

The thing that really would have helped was disposable diapers. I did get a discount on diaper service. To save money, I still buy at end-of-the-season sales. In fact, when my kids were five weeks old, I bought snowsuits at half price. My husband said that's ridiculous, but they would have cost me $120 the next winter!

I cannot walk out of a grocery store at under $60 a whack, and sometimes that doesn't even include meat. But, Linda, we shouldn't sound as if quads were just lots of work and no fun.

Not at all. Being quads, the first one helps teach the others. Toilet training, for instance, was a major milestone in easing the workload.

I wonder if things might not be easier for them in other ways. Compared to single children, my four seem to have greater patience. And I think they'll be more independent and resourceful. I kept wondering, will I ever have enough love to go around? Then I learned you always have as much as is necessary. I make sure we have a great big hugging session to start off the day. When I come home from work, I hear these little voices saying, "Mommy's home, Mommy's home." It makes it all worthwhile!

Obviously, they need individual holding and cuddling and loving, but it gets more specific as they become more verbal. I find discipline is very hard. What will dissolve one in tears won't even begin to deter another one. We do try to individualize. One weekend my husband, Jim, flew in at 7 a.m. from California. I figured he'd be a little tired, but I had to work at the school fair. Within an hour Jim had managed to take each of the kids individually on rides. I really have to give him credit.

If I miss anything at all about not having a husband, it's emotional support. I have to rely on myself for pats on the back. I can't turn the children over to someone and say, "I've had it," even for 15 or 20 minutes.

That's the hardest. It all falls on you.

How's your older daughter, Samantha?

She's quite lively and perfectly okay—in large measure because of the attention Jim gave her. If he felt at all excluded from the scene with the babies, he put his energy into her.

How do you feel about fertility drugs? That's a question I really dread.

The question that irritates me even more is: "Oh, did you want to have a multiple birth?" Obviously doctors don't prescribe the drug unless they've exhausted all other alternatives. It irks me that people assume you would play havoc with your own life and your babies' lives. I say pointblank: "We wanted a baby, one!" But you and I are fortunate. Those for whom a fertility drug doesn't work have nothing.

How soon after you had your quads did you start running?

They were at the hoary age of 18 months. One day it started to pour, and I was very antsy. I had to get out of the house, and my husband suggested I run in the rain. So I put on my old tennis shoes, jeans, and off I went. I guess I did about two and a half miles. I felt terrific! After two or three weeks I was running every day.

Is running connected in other ways to the quads?

Yes, in both you prove your potential is much greater than you could ever have anticipated. Dr. George Sheehan, when he describes his efforts to cope mentally with the pain of running a marathon, says he found help in a very unlikely source, Dr. Grantly Dick Read's book Childbirth without Fear. Dr. Sheehan says nothing else in normal human experience compares. After my first marathon, I said it was the closest thing to giving birth. There just wasn't a baby at the end of it.

How long did it take you to get to marathon shape?

Two and a half years. I had no serious thought of building up my mileage. It was just the only 20 minutes I could have any privacy from morning till night.

I know. When mine were asleep I would play racquetball or cross-country ski for miles and miles. I'd come back and have my mind in sync again.

Getting into marathons was also a way of asserting myself. People often asked, half-teasing, was I running away from home every morning. I said, "Sure, but I always turn around and come back." I had been so stuck with the tag "mother of quads" that I wanted the right to be me.

Are your children aware you're a marathon runner?

I get a lot of good feedback from them. They respect my right to run. I think it's good for them to know that Mommy can do this other thing too.

What do you answer when people ask you, would you do it again?

My children are healthy. Why Monday-morning quarterback when you've won the football game?